text:
- Published on Monday, 10 September 2012 09:16
- Written by Ed Holtgraver
Sub-arctic climates experience temperatures from 100° F (38° C) in the summer to –60° F (–51° C) in the winter (Figure 1). While there is nothing spectacular about the high end of the range, the low end impacts the functionality of pneumatic actuators.
WHAT CAN HAPPEN
There is never a good time for an actuator to fail, but a failure when the temperature is at 60 below or when a blizzard limits capacity for transporting repair parts could be especially troublesome. Careful selection of valve actuation is critical.
When considering safety integrity, one assesses what might cause failure in a product. To illustrate, let's begin with an off-the-shelf pneumatic actuator intended for normal service and then consider what may fail if applied at –60° F (–51° C). Our basic parameters are as follows:
- The actuator housing is steel.
- The drive shaft is a precipitation-hardened stainless steel.
- The seals are buna.
- The shaft bushings are Nylon 6.
With these parameters in mind, at –60° F (–51° C):
The steel housing has become brittle. It is not necessarily weaker, but a sudden impact or an imperfection that would have no effect on the metal when ductile, could result in a sudden fracture at these sub-zero temperatures because the temperature is below the brittle transition temperature of steel. The question "will it fail at –60° F?" cannot be answered without knowing if there will be sudden impact loading, but possibility of failure has increased there.
A normally ductile metal will yield before fracture while a brittle metal will fracture without yield (Figure 2).
The precipitation-hardened shaft material has also become brittle and may fracture given an impact load. If, for example, the driven valve resists opening and then breaks free, the resulting sudden impact may cause the actuator shaft to fail.
The shaft material will have contracted at a rate of 9.4 by 10–6 per inch of diameter per degree F, while the Nylon 6 bushings will contract at a rate of 44.2 x 10–6 per inch per degree F. If the original gap between the bushing bore and the shaft surface was.002 inches and if the shaft diameter was 3 inches, then 130° F (54° C) temperature change from 70° F (21° C) to –60° F (–51° C) would contract the shaft diameter to 2.996 inches and the 3.002 inches diameter bushing bore to 2.985 inches, causing binding and failure.
The buna seals have turned to stone. Their normal resiliency, which allows flowing into and sealing leak paths, is gone. The seals cannot flex and leakage will occur at all seal points resulting again in actuator failure.
Failure of the example standard actuator is a certainty in this case. While there is nothing in the above example that is not obvious to every designer and user, the solution to avoid failure is to apply what we know.
For example, metals that have a brittle transition temperature that falls within the range of possible application temperatures should not be used unless absolutely no impact loads can occur. Examples of suitable metals are 300 series stainless steel and aluminum—neither has brittle transition temperature. Because of its greater strength, stainless steel may be the best choice for larger actuators.
Figures 3 and 4 show a simplistic representative impact test performed on a notched steel bar. One end was locked in a vice, and a hammer blow served to provide an impact. At room temperature, the hammer blow bent the specimen, but there was no fracture.
Figures 5 and 6 show an identical specimen that was brought to a temperature of –60° F. (An interesting side note is that the air cans used to clean a keyboard, when turned over, emit a liquid that has a measured temperature of –60° F, which proved convenient for testing.)
If at all possible, where there is close fit between moving parts, select materials having the same coefficients of thermal expansion/contraction (Figure 7).
Select seal materials that retain adequate resiliency at the lowest temperatures to be encountered. Additionally, eliminate every possible seal via basic design. A seal that is removed by design cannot fail. Figure 8 shows a simple drop test where a bar is dropped against an O-ring at both room temperature and at –60° F. Basic buna, ethylene propylene diene monomer (EPDM), Viton and silicone O-rings were tested. All except Viton showed excellent "bounce" at room temperature but only silicone retained resiliency and bounce at –60° F. Suppliers show low-temperature options for each of these elastomers, but in-house testing is recommended.
Designers and users who read this may respond: "We've used essentially standard actuators and all we did was select a seal material that remained resilient at the low temperatures." This article is not stating such a combination will fail, only that it may fail—the steel plates of the Titanic may not have fractured if it had not hit the iceberg, and not all World War II Liberty ships cracked in half. But by considering the above suggestions, the supplier can greatly reduce the risk of failure.
Users, as well as designers, have responsibilities regarding pneumatic actuators under extreme cold conditions.
First, and most obvious, users should shelter the actuator from weather extremes where possible. Second, users must assure a dry air supply, at least 15° F (–9° C) below the lowest temperature that may be experienced since ice plays havoc with air flow and mechanical motion. Finally, users should assess the recommended actuator and whether all possible precautions have been incorporated by the supplier.
Clearly, pneumatic actuators can perform their intended functions despite having to operate in extreme temperatures. However, they need to be designed and manufactured properly, and users need to take responsibility to keep them functioning correctly.


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Spring in the Netherlands is synonymous with the blooming of tulips, hyacinths, and daffodils.
The Keukenhof Gardens, located in Lisse, is the world's largest flower garden, and a must-visit destination for nature lovers. The park is only open for two months each year, and Keukenhof garden tickets are highly sought-after. For an unforgettable experience, why not take a helicopter tour of the gardens? In this article, we'll explore everything you need to know about visiting Keukenhof Gardens and taking a helicopter tour.
The Keukenhof Gardens were originally established in 1949 by the then-mayor of Lisse, who wanted to create a space where flower growers from all over the Netherlands could showcase their products. Today, the park is still owned by the same flower growers, and it has become a world-renowned destination for nature enthusiasts.
The Keukenhof Gardens cover an area of 32 hectares and feature over 7 million flower bulbs, including tulips, daffodils, and hyacinths. The park is divided into different sections, each with its own unique theme. Visitors can stroll through the English landscape garden, the Japanese country garden, or the historical garden, among others.
Some of the highlights of the Keukenhof Gardens include the flower shows, which take place throughout the season. These shows feature different varieties of flowers and are a great way to learn more about the history and cultivation of tulips. Another must-see is the Willem-Alexander Pavilion, which showcases a variety of orchids and other tropical plants.
Keukenhof Garden Tickets
Types of Tickets
There are several types of Keukenhof garden tickets available, depending on your needs. The most popular option is the regular entrance ticket, which gives you access to the park and all of its attractions. There are also combination tickets available, which include access to other attractions in the area, such as the Amsterdam Canal Cruise or the Rijksmuseum.
How to Purchase
Keukenhof garden tickets can be purchased online or at the entrance to the park. It's recommended to purchase your tickets in advance, as the park can get very crowded during peak season. When purchasing online, you can choose to receive your tickets via email or mobile phone, which allows for contactless entry to the park.
Helicopter Tours of Keukenhof Gardens
For an unforgettable experience, why not take a helicopter tour of the Keukenhof Gardens? Helicopter tours are available from several different companies, and they provide a unique perspective on the park's layout and the surrounding tulip fields. The tours typically last around 20 minutes and include commentary from the pilot.
What to Expect
During a helicopter tour of the Keukenhof Gardens, you'll see the park's many different sections from above, including the stunning flower displays and the surrounding tulip fields. You'll also get a sense of the park's scale and layout, which can be difficult to appreciate from the ground. The helicopter tours typically operate during the park's opening hours, so you can combine a tour with a visit to the park itself.
The cost of a helicopter tour of the Keukenhof Gardens varies depending on the company you choose and the length of the tour. Prices typically range from €100 to €200 per person. While it may seem expensive, the experience is truly one-of-a-kind and well worth the investment for many visitors.
Tips for Visiting Keukenhof Gardens
Best Time to Visit
The Keukenhof Gardens are open from late March to mid-May each year, with peak bloom typically occurring in mid-April. If you want to see the flowers at their most vibrant, plan your visit for this time period. However, keep in mind that the park can get very crowded during peak season, so be prepared for long lines and large crowds.
What to Wear
The weather in the Netherlands can be unpredictable, even in the springtime. Be sure to dress in layers and wear comfortable shoes for walking around the park. It's also a good idea to bring sunscreen and a hat, as there may be limited shade in some areas.
Getting to Keukenhof
The Keukenhof Gardens are located in Lisse, about an hour's drive from Amsterdam. There are also several public transportation options available, including buses and trains. If you're driving, be sure to arrive early in the day to secure a parking spot, as the lots can fill up quickly.
Visiting the Keukenhof Gardens is a truly magical experience, and taking a helicopter tour of the park is the perfect way to see it from a different perspective. With a little bit of planning and preparation, you can make the most of your visit and take in the beauty of spring in the Netherlands.
This content is part of the HWM Partnership.
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The Competitive Landscape template gives you guidance in how to segment competitors based on competing factors. The idea here is that we identify competing factors that are important for customers to distinguish offerings from different market players and also have a significant impact on their buying decision. We group them into those factors that are important for customers to recognize differences between competitors (competing factors) and those factors that are absolutely mandatory to be compliant to (hygiene factors). While competing factors later will be used for the positioning in the matrix, the hygiene factors are "exclusive".
Running the competitive landscape exercise early in the process is a great way to find the right positioning for you and your new market offering and helps you to define a business model supporting this positioning. Running for a price-differentiated "red-ocean" strategy for example would mean that your company either gains competitive advantage from more efficient processes, cheaper resource acquisition or better deals with required delivery partners, compared to your competition. A technology leadership driven "blue ocean" strategy on the other side might mean that your business model needs to speak about which key resources and/or which key processes support this leadership position compared to your competition.
Coming up with such competing factors sounds easy, right? But experience has shown that spending more time on identifying less obvious factors is worth it because it enables you to create multiple "dimensions" of the positioning. You can then pick differentiating elements that help you to sustainably distinguish your offering from the competition. The general procedure is as follows:
 1. Think about your (primary) target group and recall their "job(s) to get done".
 2. Collect a bunch of actual or potential competitors. Remember to think broad at this stage and also include non-industry sector competitors.
 3. Group them in the "Market Players" section based on how well their offering fits your primary target group's "job(s) to get done".
 4. Brainstorm competing factors. Sort out hygiene factors into the lower section of the template.
 5. Now, you are ready for a number of rounds of positioning: Put two random competing factors on the two axes (x, y), e.g. price and brand value, and place the competitors on the matrix accordingly.
 6. Position your own company within that matrix in relation to the other competitors.
 7. Review the matrix according to the following criteria: Is your position within the red-ocean sector? If yes, what can you do to move it to one of the blue-ocean sectors? Also, what are your "defense" measures to survive the red-ocean competitive situation?
Click here...
Usage Scenarios
 - Analyzing and visualizing the positioning of competitors based on selected factors
 - Analyzing competitive situation (blue ocean / red ocean) and deriving required activities to address customers right
 - Identifying hygiene factors that relate to the own product / service specification
 - Identifying strength and weaknesses of competitors and linking it back to the business model
Instruction for Coaches
 1. Get out of the building and do not rely too much on existing competitor intelligence to gain deeper insights from the real world. Consider DIY activities to research certain competitor positions when it comes to their products or services.
 2. Make sure that while doing the positioning in the team that everyone is on the same page about the meaning of the competing factor as results and interpretation can dramatically change for even simple factors. E.g. price (high/low) might be an easy one but it makes a huge difference if you talk about your unit price being 140€ or your competitiveness according to price-levels of others. The first one is an absolut measure you use to position on one axis of the matrix whilst the other one is relational measure comparing your position in relation to the other players. You should be aware that the later approach does hold a lot of room for (mis)-interpretation and (mis)-judgment and consequently wrong measures reflected back to your business model.
Competitive Landscape
Key Elements
Market Players
Which market players are offering the products and services that serve the same customers' job(s) we are focusing on?
Consider every market player that focuses on the same customer's "job(s) to get done" even if their solution might be entirely different to yours. Identify solutions that achieve the same result for the customer or probably just "feel" the same but using entirely different technology, resources, processes, etc.
For existing companies, remember to identify soon-to-be competitors that could join in if current suppliers or customers extend their offering (forward/backward integration).
Competing FactorsWhich factors will help us to describe the differences between us and other market players to excite customers?
Examples for competing factors are:
 - Price
 - Core Value
 - Unfair Advantage
 - Service Quality
 - Brand Perception
 - Global Reach
Hygiene FactorsWhich factors might instantly dissatisfy customers if we or other market players would not comply to them?
Classical hygiene factors could be things like:
 - Compliance/non-compliance to policies & regulations
 - Support for certain payment methods that are required for e.g. B2B customers
 - Technical norms and standards
 - etc.
How can we position market players as our competition based on competing factors?
The process of positioning will be repeated several times and it might take a while to build up different perspectives on the competitive landscape around you. Play around with different labels of your axes and see what clusters you get.
Positioning market players on a competitive landscape requires a deep understanding of how other market players create value, and how customers make their buying decisions. Guesswork is OK at the start, but it should be replaced quickly by quantitative and qualitative insights.
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While essential in many industries, welding generates fumes that pose significant health risks. During welding, various toxic gases and fine metal particles are released, which can be hazardous when inhaled. Over the years, multiple methods have been used to manage and control these fumes, with downdraft tables being one. However, are they the best solution for welding fumes? The natural behavior of welding fumes suggests otherwise.
This article seeks to discuss the inefficiencies of downdraft tables for capturing welding fumes and offers an exploration of three alternative methods that can provide a more effective solution.
The Problem with Downdraft Tables for Welding Fumes
Downdraft tables, a popular fume extraction system, operate on a straightforward principle. They draw fumes or dust downward, away from the worker's breathing zone, and capture them in a filter system within the table. However, this approach presents significant inefficiencies when it comes to welding fumes.
The fundamental problem lies in the natural behavior of welding fumes. When metal is heated during welding, the generated fumes rise upwards due to the heat, following the natural law of convection. The higher the welding power, the faster they move. This upward movement is counter to the downdraft table's function, which seeks to pull these fumes downward.
Extracting these rising fumes from the bottom can be a Herculean task. It is inefficient and can sometimes prove impossible, particularly in the case of significant volumes of fumes. Instead of helping, the downdraft system often ends up fighting against the natural flow of the fumes, leading to an unnecessary waste of energy and resources.
The airflow required to make a downdraft table work to extract welding fume is much higher than the alternative solutions we will introduce later. A job that a fume extraction gun can do with 100 cfm would require over ten times the airflow with a downdraft table.
Moreover, it's essential to understand that downdraft tables are ideally suited for specific scenarios, but welding isn't one of them. They excel at capturing dust from processes such as grinding or cutting, where the particulate matter tends to settle downward. In such instances, downdraft tables efficiently capture and remove these particulates, preventing them from spreading throughout the workspace.
However, for welding fumes, the downdraft approach is like trying to fit a square peg into a round hole. It's not the best fit, and as we will discuss next, there are alternatives that better align with the natural behavior of welding fumes, providing a more efficient and safer solution.
If you have any questions about welding fume, do not hesitate to contact us. We will be happy to give you some insight, and we can even visit you for free in the US and Canada.
Henlex Inc.
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_EMAIL_
Three Alternative Methods for Capturing Welding Fumes
Understanding the limitations of downdraft tables for welding fumes extraction opens the door to exploring better-suited alternatives. Here, we introduce three methods that consider the natural upward movement of welding fumes, thus proving more effective.
Backdraft or Sidedraft Table
Backdraft or side-draft tables offer a slight but important shift in the fume extraction approach. Unlike downdraft tables, they pull the fumes horizontally (side-draft) or backward (backdraft) rather than downwards. While they still face challenges due to the rising nature of welding fumes, their design is slightly more compatible with welding processes. This could be a better choice if a table-based solution is required, although it's still not the most effective method.
Fume Extraction Arm
A substantial improvement over table-based solutions, the fume extraction arm captures fumes from above directly in their natural movement path. These arms can be adjusted to sit above the welding operation, capturing and extracting the fumes as they rise. This results in more efficient fume control and improved worker protection, making fume extraction arms a significantly better solution than both downdraft and side-draft tables.
Fume Extraction MIG Guns
Arguably the most effective solution for MIG welding is using fume extraction MIG guns. MIG welding, being the most widely used process in the industry, generates a substantial amount of fumes. Fume extraction MIG guns are designed with built-in extraction capabilities, capturing fumes right at the source, which ensures maximum fume extraction and improves visibility for the welder, contributing to more precise work.
Each of these alternatives offers a different approach to handling welding fumes, with varying degrees of effectiveness. The choice depends on several factors, such as the welding process, workspace constraints, and specific safety requirements.
The Limitations of Fume Extraction Hoods
While discussing alternatives, it's essential to consider the limitations of another popular choice in the industry – fume extraction hoods. These systems work similarly to kitchen exhaust hoods, drawing in fumes from the welding process and directing them away from the workspace. They can be highly effective in specific scenarios, particularly in robotic welding.
However, when it comes to manual welding, fume extraction hoods fall short of providing adequate protection to the welder. The main issue is the position of the welder relative to the weld pool and the extraction hood. In manual welding, the welder's head often lies between the weld pool and the hood, meaning that the hazardous fumes must pass the welder's breathing zone before being extracted.
Thus, fume extraction hoods may seem like an ideal solution due to their high extraction rate and suitability for robotic welding, but their effectiveness is significantly compromised during manual welding. It's crucial to remember that the goal is not just to extract fumes but to ensure that they don't reach the welder's breathing zone in the first place.
The Best Fume Extractor for Each Process
ProcessMIG gunArmNozzleHoodTable
MIG / GMAWBestYesYesNoNo
TIG / GTAWNoBestYesNoNo
Fluxed-Cored / FCAWBestYesYesNoNo
Stick / SMAWNoBestYesNoNo
Robotic WeldingYesYes*NoBestNo
Aluminum WeldingBest**YesYesNoNo
Grinding***NoNoNoNoYes
Plasma Cutting****NoNoNoNoYes
* For a robot that welds in a small area (like a welding lathe),you can use a flexible arm.
** When MIG welding aluminum, a fume extraction MIG gun will be the most efficient. Otherwise, a flexible arm is to favor.
*** On-tool extraction is possible for grinders and would be the most efficient solution in most cases.
**** It is possible to extract at the source with a Teflon extraction nozzle for a CNC plasma table.
Conclusion
Welding fumes pose a significant health risk, and effective control is necessary in any welding environment. Although adequate for specific tasks, downdraft tables are not ideal for welding fumes due to their contradictory nature with the fumes' upward movement. Alternatives like backdraft or side-draft tables, fume extraction arms, and fume extraction MIG guns offer more suitable solutions, each with unique advantages and considerations.
While fume extraction hoods can be effective in specific scenarios, they do not provide the best protection for manual welding, further emphasizing the need for efficient source-capture methods. Ultimately, the safety and health of welders should be paramount when choosing an extraction method. We can create safer, healthier welding environments by considering the natural behavior of welding fumes and using an appropriate extraction system.
We have two great resources to help you in your effort to manage welding fume. The first is an 8-step method to solve this problem, and the second introduces effective strategies to minimize welding fume.
Any Questions?
Feel free to contact us. We will help you protect your workers and comply with welding fumes standards anywhere in the US and Canada.
_PHONE_
_EMAIL_


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Chapter 4. Authorization
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4.1. Overview
This topic contains authorization tasks for application developers and their capabilities, as dictated by the cluster administrator.
4.2. Checking If Users Can Create Pods
Using the scc-review and scc-subject-review options, you can see if an individual user, or a user under a specific service account, can create or update a pod.
Using the scc-review option, you can check if a service account can create or update a pod. The command outputs the security context constraints that admit the resource.
For example, to check if a user with the system:serviceaccount:projectname:default service account can a create a pod:
$ oc policy scc-review -z system:serviceaccount:projectname:default -f my_resource.yaml
You can also use the scc-subject-review option to check whether a specific user can create or update a pod:
$ oc policy scc-subject-review -u <username> -f my_resource.yaml
To check if a user belonging to a specific group can create a pod in a specific file:
$ oc policy scc-subject-review -u <username> -g <groupname> -f my_resource.yaml
4.3. Determining What You Can Do as an Authenticated User
From within your OpenShift Container Platform project, you can determine what verbs you can perform against all namespace-scoped resources (including third-party resources).
The can-i command option tests scopes in terms of the user and role.
$ oc policy can-i --list --loglevel=8
The output helps you to determine what API request to make to gather the information.
To receive information back in a user-readable format, run:
$ oc policy can-i --list
The output provides a full list.
To determine if you can perform specific verbs, run:
$ oc policy can-i <verb> <resource>
User scopes can provide more information about a given scope. For example:
$ oc policy can-i <verb> <resource> --scopes=user:info
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A study was conducted for theoretical investigation of stability of doubly charged negative ions of elemental clusters, such as C2-8. The study demonstrated that the C2-8 system was stable with respect to electron detachments in agreement with the experimental observation. The investigations showed the final total energies and the first and second vertical electron affinities of C8. Both second electron affinities were positive, indicating that the C2-8 anion should be stable and long lived.
ASJC Scopus subject areas
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Retrieving Earth's phase curve
Presentation #1119 in the session "Open Engagement Session B".
Published onMar 17, 2021
Retrieving Earth's phase curve
The EPOXI extended mission phase for the Deep Impact spacecraft observed the Earth in 2008 and 2009 as an analog for a habitable terrestrial exoplanet. The EPOXI data ranges over visible and near-infrared wavelengths and consits of five observations. They are at five different phase angles and three are equatorial observations and two polar (one North and one South) over a 24 hour period. This data is used to create the phase curve and it is compared to a Lambertian scattering disk as can be seen in Figure 1.
The model lines are made using Equation 1 where Ag is the geometric albedo, pi F is the incoming flux and the final term is the Lambert phase function [Madhusudhan and Burrows, 2012].
The geometric albedo to create the lines is 0.2 [Mallama, 2009]. This value is greatly smaller than the classic value for geometric albedo of 0.4341, showing that there is research to be done. Besides this, it can be seen that the difference between model and empirical data is dependent on wavelength. Furthermore, the polar observations have clearly a higher signal than the model for all wavelengths. Since the geometric albedo is the only variable, one can solve for the required geometric albedo to match the model with the data. These values can be seen in Table 1.
From these values, it can be seen that the shorter wavelengths require higher values than longer wavelengths. Furthermore, it shows that the polar observations are distinct from the equatorial ones and it shows that results can be misleading if only equatorial observations would be used. Additionally, it can be seen that despite the different phase angle, the equatorial observations have a similar geometric albedo for each wavelength. The same can be said for the polar observations, even though they are opposite poles. In general, all these numbers are much lower than the geometric albedo of 0.434. Now the values for geometric albedo from EarthObs1 are used to plot the model lines, the result can be seen in Figure 2. This figure visualises what is said before, that the equatorial observations are similar but the polar observations are clearly different.
The analysis still needs to be extended to the infrared region but the visible already shows potential for research. The same potential is expected from the infrared, due to the high signal-to-noise ratio compared to what would be available for a real exoplanet observation. The next step of the research will also involve adapting and improving an exoplanet model made by Dr. D. M. Stam (TU Delft) as the goal is to be able to predict the signal for a certain phase angle.
 - Nikku Madhusudhan and Adam Burrows. ANALYTIC MODELS FOR ALBEDOS, PHASECURVES, AND POLARIZATION OF REFLECTED LIGHT FROM EXOPLANETS. The Astrophysical Journal, 747(1):25, feb 2012. doi: 10.1088/0004-637x/747/1/25. URL
 - Anthony Mallama. Characterization of terrestrial exoplanets based on the phase curvesand albedos of mercury, venus and mars. Icarus, 204(1):11–14, 2009. ISSN 0019-1035.doi: URL
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Behind every number: A portrait of Canada
Catalogue number: Catalogue number: 11-629-x
Issue number: _PHONE_
Release date: June 26, 2017
Behind every number: A portrait of Canada - Transcript
Description of visuals
(The Statistics Canada symbol and Canada wordmark appear on screen with the title: "Behind every number: A portrait of Canada")
All across Canada, every day, things are changing.
(Landscapes of Canada appear such as a field, a lake, a city, and icy mountain terrains.)
Our population is increasing faster than it has in almost fifty years.
(A woman holds a baby in her arms. Numbers increase from 1971: 21,568,000 to 2016: 35,151,728)
Some of us were born here, and so were our parents and grandparents. We have strong connections to our land and history.
(Indigenous person walks alongside a lake, on-screen text appears: 600+ First Nations bands in Canada)
And some of us chose to come here from other places, to find work, to chase a dream, to build a better life.
(People in an airport, on-screen text appears: 1 in 5 people in Canada was born elsewhere and a man opens up a garage door.)
Canadians now live and work in cities and urban areas.
(Fast-forward shot of people walking on a busy intersection in a city and the following text appears: 7 of 10 Canadians live in cities.)
We work hard so that at the end of the day, we can play hard too.
(An office building is shown and the following text appears: Median total income of couples: $78,870; then, we see a couple kiss.)
Go watch the game and cheer for the home team.
(Outdoor hockey game is taking place, and the following text appears: 77% of Canadians believe that hockey is an important national symbol.)
See a play, or a movie, or take the kids to a concert.
(Mother, father and daughter watch a movie at the theatre.)
Many of us also live in rural settings.
(Top view of a farm with the following text: over 6.3 million Canadians live in rural areas.)
Some of us work on farms, growing food for tables at home and around the world.
(Combine harvester on a farm, and the following text appears with a pie chart animation: Cropland makes up 54.6% of total farmland.)
And we're doing it without increasing how much water we use.
(Sprinkler appears on-screen, and the following text appears: 1.7 billion cubic metres of water used to irrigate crops.)
That's good news for our most precious natural resources, and our environment.
(Rapids and landscapes of mountains appear on-screen.)
But we don't just grow things in Canada.We make things here, too.
(Man in a factory holds a ring, and the following text appears: Sales of transportation equipment: $113 billion.)
Like cars, and parts for airplanes, and metals to build products here and abroad.
(A man inspecting part of an airplane with the following text appears: Aerospace production: $19.9 billion.)
But what binds us together is our shared values. Canadians know that access to healthcare is the greatest gift of all.
(Older man opening the door to his home to a nurse, with the following text appearing: over 25 million have family physician.)
And ours is a country where education matters.
(Classroom appears; circles appear above desks that read: Diploma; the text on-screen reads: 9 in 10 Canadians aged 25 to 64 have completed high school.)
Where children have the opportunity to learn and grow.
(Little girl is writing on a piece of paper.)
Where higher learning and research are valued and taken seriously.
(An open book appears with the following text: 2 out of 3 Canadians aged 25 to 64 have completed postsecondary education.)
How do we know all of this? Because behind every number, there's a person, a family, a relationship. Together, we write Canada's story.
(Various scenes of cities, landscapes, families, and the little girl as she writes on the floor.)
(Canada 150 logo appears.)
(Canada wordmark appears.)
Date modified:


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I would like to know how to point this to the selected element (event source) inside.on() method without defining an anonymous event handling function.
For example, in the code bellow, the context for my selected element is document, i.e. $(this) is interpreted as document
$('.nav-item').click(MyFrameworkUtils.navigationBinding($(this), 'arg1', 'arg2'))
However, if wrapped in an anonymous event handler, $(this) is interpreted (desirably) as the selected element.
 var source = $(this);
 MyFrameworkUtils.navigationBinding(source, 'arg1', 'arg2');
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up vote 4 down vote accepted
You could use this syntax:
$('.nav-item').click({arg1:'arg1', arg2:'arg2'}, MyFrameworkUtils.navigationBinding)
and the function would look like this:
function navigationBinding(event) {
 var source = $(this);
 var arg1 = event.data.arg1;
 var arg2 = event.data.arg2;
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Thank you. Very pretty. – Lim H. Jan 24 '13 at 11:28
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In your first example, you're passing the result of MyFrameworkUtils.navigationBinding($(this), 'arg1', 'arg2') into your click method. The context of this is therefore the context is the outer scope, which is the document in your case.
With the second example however the scope is the inner function, and as with most events triggered by the DOM, this is the triggering element.
Additionally [possibly unrelated], when calling functions you can define this by using the apply or call methods, as described quite nicely in What is the difference between call and apply?
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Thanksssss. It makes a lot of sense.. well, Javascript sense. And thanks for suggesting the apply and call functions. – Lim H. Jan 24 '13 at 11:26
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text: The moon is a marvel. It pulls the tides and its phases help us track the passage of time. So let's knit a cowl inspired by the moon. We can pretend each stitch is a tiny handcrafted crater. We'll knit in the round, so the path of our stitches honors the moon's orbit. This cowl is double-sided (half black and half white) so that when you wear it, you can reverse it just the right amount to match the current phase of the moon.

source: openbmb/Ultra-FineWeb


Quality Control for the Identify QIAseq DNA Variants workflow
The Ready-to-Use QIAseq DNA Workflows for variant analysis have been configured by default to address general needs, provided that the data quality fulfills minimal standards of coverage, proper library preparation, and appropriate reads/UMI structure. We do recommend running the workflow from the panel guide a first time using the default configuration, and then inspect the QC reports: the UMI Groups Report and the Create UMI Report.
The following subsections describe how to perform proper quality controls and why they are important. For example, the relationship between the number of reads per UMI and the original coverage is not straightforward: if the original molecule has been amplified many times, the resulting, seemingly deep, coverage will not add much information. So when the quality criteria are not fulfilled, we cannot guarantee the validity of the variant calls. After reviewing the quality controls described in this section, you can adjust workflows parameters and re-run the workflow in order to address specific experimental conditions. Parameters can be modified by opening a copy of the workflow and configuring workflow elements individually, as described at _URL_
All figures in these subsections are based on three different samples. The sample pictured to the left in each figure is a sample with few reads per UMI, the sample shown in the middle is an example of an ideal good quality sample and the one pictured to the right in each figure represents a sample with too many reads per UMI. All three samples are real samples and therefore also have different numbers of input reads which also needs to be taken into account when performing the quality control of the samples.
Proportion of reads per UMI group
According to the QIAseq Targeted DNA panel Handbook and protocol, and depending on the input DNA for the library preparation, the ideal value for Average reads per group should be 2 to 4, with 4 being the best value for the highest DNA input (i.e., 40ng). This value can be found in the Summary table of the "UMI Groups report" (see red highlight in figure 6.7).
Image umigroupreport
Figure 6.7: Summary section of the UMI group report.
Average reads per group values smaller than 2 will make it impossible to create a consensus read, and therefore difficult to improve the Q scores and achieve higher precision (the advantage of using UMIs in the first place). In this case, Average quality should be adjusted for the Identify candidates variants (Low average quality variants).
Similarly, if the value is more than 6 to 8, it indicates that not enough DNA input in the library preparation resulted in an excessive PCR amplification of the same fragments. This in turn leads to decreased efficiency of the library and a lower UMI coverage as a result of creating consensus across many reads per group. As the filtering of the variants depends on the counts (number of times a variant is observed at a UMI read), the Count filters might need further adjustments (available for Illumina workflows when configuring the Identify Candidate Variants tools for Low, Medium and High counts).
Reads by group size, 25th, 50th and 75th percentile shows the distribution of reads by group size. Examples from the figure where the 50th percentile is 5 meaning that half the reads will be in UMI groups containing up to 5 reads. If the 75th percentile is 73 it mean that 75 percent of all reads are in UMI groups containing up to 73 reads. The histogram shows the distribution of all reads by groups.
Proportion of singletons
The proportion of singletons indicates how many UMI barcodes are shared across different reads. If the number is too high, this corresponds to a very low number of reads per UMI on average. This value can be found in the Summary table (see red highlight in figure 6.7) and assessed with the Read by group size plot (figure 6.8) of the "UMI groups report". When the proportion of singletons is too high, you can modify the Average quality and Count filters as described above.
Image umigroupplot
Figure 6.8: Distribution of reads by group size also showing the proportion of singletons as seen in the UMI Groups report
Median Q scores
The median Q score is correlated to the generation of a good consensus among reads with the same UMIs. When there are not enough "big UMI" reads (i.e., reads created out of consensus of 2 or more reads carrying the same UMI barcode), the Q scores will be similar to the original Q scores calculated for the raw sequencing. In this case, you cannot benefit of stringent filtering based on average Q scores that are expected to improve by the creation of UMI reads.
The improvements of the Q score values can be inspected in the report called "Create UMI Report" Summary table (figure 6.9). When there is no difference in Q score between reads and UMI reads, adjust the Average quality parameter as described above.
Image umicreatereport
Figure 6.9: Summary section of the Create UMI report highlighting average and median Q scores
Composition of the barcodes used in the library prep.
The base composition of the barcodes used for UMI tagging is not dependent on the user (the barcodes are random) and can also be independent of the quality of the library preparation (input, reads per UMIs etc), but it will affect the quality of the consensus creation.
If the barcodes are not unique (i.e., their base composition is in percentage of the total barcodes very small), there is a risk that the UMI consensus step will group barcodes together that are meant to tag different fragments, and therefore reducing the quality of the consensus. This can be inspected in the plot "Nucleotide percentages of the unique molecular barcode symbols" of the report "Create UMI report" (figure 6.10). For good quality, we expect the distribution to be skewed to the left as much as possible.
Image umicreateplot
Figure 6.10: Item no. 18 from the Create UMI report showing the nucleotide composition of the barcode.
Coverage and accuracy when using UMIs
Appropriate coverage is important to achieve the best results when using UMIs, particularly when you wish to call variants with an allele-fraction lower than 5%. In our analyses, we observe that a UMI-coverage of at least 2000X is recommended to achieve the best results.
We analyzed only variants with variant allele-fraction (VAF) of 1%, thus measuring the performance of the workflow only on variants considered more difficult to detect. In these scenarios, UMIs are expected to reduce significantly the number of false-positives, and therefore show the highest impact on precision. The plots in figure 6.11 illustrate the relationship between sensitivity and coverage, precision and overage, and accuracy and coverage, with sensitivity, precision and accuracy defined as:
Sensitivity = $ TP / (TP + FN)$
Precision = $ TP / (TP + FP)$
Accuracy calculated at F1 = 2 * ((Precision * Sensitivity) / (Precision + Sensitivity))
and TP: True Positives, FN: False Negatives, FP: False Positives.
A/ For sensitivity, the total number of reads are known to be an important factor, influencing the number of variants called, and hence sensitivity. Comparing our results at 2000X UMI-coverage with the results at the same level of raw coverage, the sensitivity of UMI analysis is 90.13%, while a traditional pipeline achieves 77.28%. However, comparing the results on the same subsampled data, the effect of UMI on low VAF loci is more evident only at higher levels of coverage, because the creation of consensus reads reduces the total number of reads, although increasing their quality. The sensitivity analysis (A) also highlights an important message: when sequencing at very high coverage, hard filters may not be appropriate in all situations, as they tend to over-filter, reducing sensitivity. In these cases, adaptive filters may be necessary.
B/ The precision results show the clear advantage of UMI in reducing common errors, and hence the number of falsepositive variants. Our results show that precision in detecting variants is higher for the UMI-aware analysis even at the lower coverage levels: 69.79% for UMI versus 63.77% without UMI. While at higher coverage levels, UMI-aware workflow reaches 95.22% in the present analysis, versus 78.48% of the non-UMI workflow. The results of this analysis on VAF 1% variants show that overall the precision of a UMI-aware workflow is higher than the analysis ignoring UMI information, at all coverage levels, and accuracy shows its best performance at higher levels, where sensitivity is >90%.
C/ In the following figure, we observed an accuracy of 92% for UMI-aware at this coverage, compared to 78.4% achieved by the non-UMI workflow.
Image vafexperiment
Figure 6.11: Sensitivity, Precision and Accuracy of calling variant allele-fraction of 1% at different raw and UMI coverage values.


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Physics LibreTexts
2.10: Dimensionless forms of Planck's equation
 - Page ID
 8020
 - [ "article:topic", "authorname:tatumj" ]
 The Planck functions (of wavelength or frequency and temperature) can be collapsed on to dimensionless functions of a single variable if we express the exitance in units of the maximum exitance, and the wavelength or frequency in units of the wavelength or frequency at which the maximum occurs. Equations 2.7.1-4 and 16-20 will be needed to achieve this, and the reader might enjoy doing it as a challenge. (I said "might".) The results are
 \[M_\lambda = \frac{b_1}{\lambda^5 \left( e^{x_1 / \lambda}-1\right)} \tag{2.10.1}\]
 \[N_\lambda = \frac{b_2}{\lambda^4 \left( e^{x_2 / \lambda}-1\right)} \tag{2.10.2}\]
 \[M_\nu = \frac{b_3 \nu^3}{e^{x_3 \nu} -1}\tag{2.10.3}\]
 \[N_\nu = \frac{b_4 \nu^2}{e^{x_4 \nu} - 1} \tag{2.10.4}\]
 where \[b_n = e^{x_n} -1 \quad (n=1,2,3,4) \tag{2.10.5} \]
 The numerical values of \(x_n\) are given in equations 2.7.8-11, and the values of \(b_n\) are
 \[b_1 = 142.32492 \tag{2.10.6}\]
 \[b_2 = 49.435253 \tag{2.10.7}\]
 \[b_3 = 15.801016 \tag{2.10.8}\]
 \[b_4 = 3._PHONE_ \tag{2.10.9}\]
 The numbers \(x_n \ y_n, \ b_n\) are independent of the values of any physical constants such as \(h\), \(c\) or \(k\), and will not change as our knowledge of these values improves. These functions, which are independent of temperature, are drawn in figures II.1,2,3,4 shown at the end of this chapter.

 Example
 Here is an example to show the use of the dimensionless functions to calculate the blackbody radiance quickly. What is the radiance per unit wavelength of a \(5000 \ \text{K}\) black body at \(400 \ \text{nm}\)? You may prefer to calculate this directly from equation 2.6.1, but let's try it using the dimensionless form. From equation 2.7.1 we find that the wavelength at which maximum exitance per unit wavelength occurs is \(579.56 \ \text{nm}\), and therefore our dimensionless wavelength to be inserted into equation 2.10.1 is 0.6902. This gives a radiance per unit wavelength interval (in units of the maximum) of 0.6832. But equation 2.7.16 gives the maximum radiance per unit wavelength interval as \(4.0178 \times 10^{13} \ \text{W m}^{-2} \text{m}^{-1}\) and therefore the radiance at \(400 \ \text{nm}\) is \(2.745 \times 10^{13} \ \text{W m}^{-2} \text{m}^{-1}\).
 I don't think there is much point in integrating the dimensionless functions 2.10.1-4 over all wavelengths and frequencies, but, for the record:
 \[ \int_0^\infty M_\lambda d \lambda = \frac{\pi^4 x_1}{15 y_1} = 1.52080 \tag{2.10.10}\]
 \[ \int_0^\infty N_\lambda d \lambda = \frac{2 \zeta (3) x_2}{y_2} = 1.97199 \tag{2.10.11}\]
 \[ \int_0^\infty M_\nu d\nu = \frac{\pi^4}{15x_3 y_3} =1.61924 \tag{2.10.12}\]
 \[ \int_0^\infty N_\nu d\nu = \frac{2 \zeta (3)}{x_4 y_4} = 2.32946 \tag{2.10.13}\]
 Figure II.1. Blackbody exitance per unit wavelength interval. The equation is equation 2.10.1, with constants given by equations 2.10.6 and 2.7.8. The maximum value is given by equations 2.7.16 and 2.7.27. It occurs at a wavelength given by equations 2.7.1 and 2.7.12.

 Figure II.2. Blackbody photon exitance per unit wavelength interval. The equation is equation 2.10.2 with constants given by equations 2.10.7 and 2.7.9. The maximum value is given by equations 2.7.17 and 2.7.28. It occurs at a wavelength given by equations 2.7.2 and 2.7.13.

 Figure II.3. Blackbody radiance per unit frequency interval. The equation is equation 2.10.3 with constants given by equations 2.10.8 and 2.7.10. The maximum value is given by equations 2.7.18 and 2.7.29. It occurs at a frequency given by equations 2.7.3 and 2.7.14.

 Figure II.4. Blackbody photon radiance per unit frequency interval. The equation is equation 2.10.4 with constants given by equations 2.10.9 and 2.7.11. The maximum value is given by equations 2.7.19 and 2.7 30. It occurs at a frequency given by equations 2.7.4 and 2.7.15.


Retire.Js - Scanner Detecting The Use Of JavaScript Libraries With Known Vulnerabilities
What you require you must also retire
There is a plethora of JavaScript libraries for use on the Web and in Node.JS apps out there. This greatly simplifies development,but we need to stay up-to-date on security fixes. "Using Components with Known Vulnerabilities" is now a part of the OWASP Top 10 list of security risks and insecure libraries can pose a huge risk to your Web app. The goal of Retire.js is to help you detect the use of JS-library versions with known vulnerabilities.
Retire.js can be used in many ways:
 1. As command line scanner
 2. As a grunt plugin
 3. As a gulp task
 4. As a Chrome extension
 5. As a Firefox extension
 6. As a Burp and OWASP Zap plugin
Command line scanner
Scan a web app or node app for use of vulnerable JavaScript libraries and/or Node.JS modules. In the source code folder of the application folder run:
$ npm install -g retire
$ retire
Grunt plugin
A Grunt task for running Retire.js as part of your application's build routine, or some other automated workflow.
Gulp task
An example of a Gulp task which can be used in your gulpfile to watch and scan your project files automatically. You can modify the watch patterns and (optional) Retire.js options as you like.
var gulp = require('gulp');
var spawn = require('child_process').spawn;
var gutil = require('gulp-util');
gulp.task('retire:watch', ['retire'], function (done) {
 // Watch all javascript files and package.json
 gulp.watch(['js/**/*.js', 'package.json'], ['retire']);
});
gulp.task('retire', function() {
 // Spawn Retire.js as a child process
 // You can optionally add option parameters to the second argument (array)
 var child = spawn('retire', [], {cwd: process.cwd()});

 child.stdout.setEncoding('utf8');
 child.stdout.on('data', function (data) {
 gutil.log(data);
 });
 child.stderr.setEncoding('utf8');
 child.stderr.on('data', function (data) {
 gutil.log(gutil.colors.red(data));
 gutil.beep();
 });
});
Chrome and firefox extensions
Scans visited sites for references to insecure libraries, and puts warnings in the developer console. An icon on the address bar displays will also indicate if vulnerable libraries were loaded.
Burp and OWASP ZAP plugin
@h3xstream has adapted Retire.js as a plugin for the penetration testing tools Burp and OWASP ZAP. An alternative OWASP ZAP plugin exists at _URL_
Retire.Js - Scanner Detecting The Use Of JavaScript Libraries With Known Vulnerabilities Retire.Js - Scanner Detecting The Use Of JavaScript Libraries With Known Vulnerabilities Reviewed by Zion3R on 5:38 PM Rating: 5


text:
What is the purpose of DNA Fragment Analysis?
Explanation: The correct answer is B) To determine the size of DNA fragments. DNA Fragment Analysis is a technique used to determine the size of DNA fragments. It involves separating the DNA fragments based on their size using gel electrophoresis or capillary electrophoresis. By comparing the migration pattern of the unknown DNA fragments with known size standards, the size of the DNA fragments can be determined.
What is the principle behind DNA Fragment Analysis using gel electrophoresis?
Explanation: The correct answer is A) Separation based on size and charge. DNA Fragment Analysis using gel electrophoresis relies on the principle of separating DNA fragments based on their size and charge. In this technique, DNA fragments are loaded into wells of an agarose gel and subjected to an electric field. The negatively charged DNA fragments migrate through the gel matrix towards the positively charged electrode, with smaller fragments moving faster and traveling farther than larger fragments. The separation is based on the differential mobility of the DNA fragments, which is influenced by their size and charge.
What is the main advantage of DNA Fragment Analysis using capillary electrophoresis over gel electrophoresis?
Explanation: The correct answer is A) Higher resolution. DNA Fragment Analysis using capillary electrophoresis offers a higher resolution compared to gel electrophoresis. In capillary electrophoresis, DNA fragments are separated in a narrow capillary filled with a polymer matrix, and the separation is based on size and charge. The capillary format allows for better resolution of DNA fragments, particularly for fragments that are close in size. Capillary electrophoresis also offers higher sensitivity, faster run times, and automated data collection, making it a preferred method for DNA Fragment Analysis in many applications.
Which fluorescent dye is commonly used to label DNA fragments for DNA Fragment Analysis?
Explanation: The correct answer is B) SYBR Green. SYBR Green is a commonly used fluorescent dye for labeling DNA fragments in DNA Fragment Analysis. SYBR Green binds to double-stranded DNA and becomes fluorescent upon binding, allowing for the visualization and detection of DNA fragments during gel electrophoresis or capillary electrophoresis. The fluorescence emitted by the SYBR Green-labeled DNA fragments can be detected and quantified using appropriate imaging systems or instruments.
What can be inferred if multiple DNA fragments of the same size are observed in DNA Fragment Analysis?
Explanation: The correct answer is D) Heterozygosity. If multiple DNA fragments of the same size are observed in DNA Fragment Analysis, it suggests the presence of heterozygosity. Heterozygosity refers to the presence of different alleles or DNA sequences at a particular locus in a diploid organism. The presence of multiple fragments of the same size indicates that the DNA sample contains different alleles or variants of the target region, which can be informative for genetic studies or diagnostic purposes.


text:
Although adult arsonists can cause a devastating loss in property and
lives, very little is known about them.
However, the 2001-2002 National Epidemiologic Survey on Alcohol and Related
Conditions, a nationally representative sample of some 43,000 Americans aged
18 or older, gave some scientists an unprecedented opportunity to learn more
about adult arsonists because one of the many questions asked of those
surveyed was the following: "In your entire life, did you ever start a
fire on purpose to destroy someone else's property or just to see it
Out of the approximately 43,000 survey respondents, some 400 individuals
answered yes to this question, the scientists reported online July 10 in
Comprehensive Psychiatry. Thus, extrapolating from this finding, it
looks as if arsonists constitute 1 percent of the U.S. population.
Moreover, by comparing survey responses from the individuals who reported
having intentionally started fires with those from the individuals who had
not, the scientists were able to glean some valuable insights into adult
"I expect the study findings will be of interest not only to the
psychiatric community, but also to insurance-company personnel, municipal
firefighters, and other entities affected by the serious costs associated with
arson," Vaughn noted. For instance, their findings might help the police
better profile arsonists. Also, "Given the substantial personal and
social costs related to arson, prevention and treatment interventions
targeting fire setters potentially could save lives and property,"
Vaughn and his colleagues wrote.
The study was funded by the National Institutes of Health.
An abstract of "Prevalence and Correlates of Fire Setting in
the United States: Results From the National Epidemiological Survey on Alcohol
and Related Conditions" can be accessed at
under "Browse by Title," "C," and then"
Comprehensive Psychiatry Articles in Press." ▪

source: HuggingFaceFW/fineweb-edu


text:
KINGSTON – The Cataraqui Region Conservation Authority (CRCA) has issued a Flood Watch today.
The storm event that occurred October 28th through 30th dropped more than 100 mm of rain in some parts of the CRCA region, including over 50 mm in 12 hours. The resulting impacts (e.g. roadway flooding) and increase to urban creek levels peaked and began receding on October 30th.
Significant increases to creek and lake levels have occurred across the region. Fast-moving water and higher than normal levels remain, and some lake levels continue to rise.
The Surface Water Monitoring Centre of the Ministry of Natural Resources and Forestry issued a Provincial Flood Watch at 11 am today for Southeastern Ontario.
'Water levels and stream flows in eastern Ontario' … 'are elevated from heavy rainfall last weekend. The saturated conditions have reduced the capacity of soils to store additional rainfall. Forecast cumulative rainfall of 50 to 60 mm by Saturday morning has the potential to further elevate water levels, resulting in localized flooding'
Specific to the CRCA region, flooding of low-lying areas associated with the following may occur:
Gananoque System: Brockville:
Upper Beverley Lake Buells/Butlers Creek and the Detention Basin
Lower Beverley Lake Lyn Creek
Singleton Lake Kingston:
Graham Lake Collins Creek
Water managers continue to conduct operations to minimize the effects of the increased water levels and pass flows down through the systems. CRCA staff is urging residents to stay away from deep, fast flowing watercourses, as well as any dams and outflow channels.
Widespread flooding is NOT expected as a result of the coming rainfall, however localized flooding of low-lying areas adjacent to creeks is a possibility.
CRCA staff will continue to monitor conditions, forecasts, and update statements as needed.
This Flood Watch will remain in effect until Friday, November 10, 2017.
For up to date flooding information, please visit the CRCA's flood forecasting and information page at _URL_


text:
World Agroforestry Centre Considers Climate Adaptation in Chinese Mountain Communities
29 April 2013: In the context of increased rainfall variability and recurrent drought in mountain regions of China, the World Agroforestry Centre (ICRAF) has published a study, titled 'Coping with Climate-induced Water Stress Through Time and Space in the Mountains of Southwest China,' on strategies to increase resilience to water shortages.
ICRAF scientists documented a range of coping strategies, including erosion control, village water management rules, changes in cropping patterns, and new irrigation methods. The study highlights that political trends in China are promoting decentralized and market-driven solutions.
The authors note that not all coping strategies will be sustainable in the long-term, and stress the need to link short-term strategies with long-term ecological and socioeconomic adaptations. They promote afforestation both for restoration of natural forest and for incorporating trees into farmlands.
ICRAF is a member of the Consultative Group on International Agricultural Research [Publication: Coping with Climate-induced Water Stress Through Time and Space in the Mountains of Southwest China] [ICRAF Press Release]


text:
WebMD Medical News
Laura J. Martin, MD
Dec. 12, 2011 -- Against heavy odds, the world's tiniest and the fourth-smallest surviving infants have had normal childhood development, a new study shows, although the girls' heights and weights still lag behind other kids the same age.
Little information is available to doctors and parents on how extremely low-birth-weight babies develop and grow as toddlers, school-age children, or into young adulthood. So a report like this offers a rare glimpse at the long-term health and growth of two of the world's teeniest premature babies as they get older.
Rumaisa Rahman, a girl who holds the Guinness Book of World Records title of "World's Smallest Surviving Baby," is at her five-year follow-up doctor's visit.
Born at just 26 weeks after her mother had severe preeclampsia, a serious condition involving high blood pressure and other abnormalities during pregnancy, Rumaisa was a twin. She weighed 9.2 ounces. She was roughly 9 inches long. Rumaisa spent 142 days in the hospital's neonatal intensive care unit.
Madeline Mann is now a 22-year-old college senior. She was born at nearly 27 weeks into the pregnancy, also to a mother who had preeclampsia. She weighed roughly 9.9 ounces and was also about 9 inches long. Madeline was hospitalized for 122 days as a newborn before going home.
Her case is the first 20-year follow-up for one of the world's smallest surviving infants reported in the medical literature.
Few babies born at birth weights of less than 14 ounces survive, so cases such as these are very rare. But the numbers of these "micro-preemies" who survive are on the rise.
The research appears in the Dec. 12 issue of Pediatrics.
Both girls, who were born at the same Illinois hospital, showed normal language skills and hit normal milestones for walking and toilet training. Rumaisa's movement skills -- writing, grasping for toys, and getting dressed -- are mildly delayed, while Madeline's are described as normal.
Both girls remain small for their age for weight and height. Rumaisa is in first grade with an individualized education plan.
At 20, Madeline stood 4 feet, 7 inches and weighed about 65 pounds. Her growth has been consistently far below other girls her age.
"We tell parents of babies born this small not to expect their children to be super tall," says researcher Jonathan Muraskas, MD.
Even so, he credits three main reasons for the girls' relatively normal development. The first, says Muraskas, is that number of weeks of the pregnancy is much more important than birth weight for a child's growth and brain development.
A second is that female preemies do better than males. "But we don't know why," says Muraskas, a professor of neonatal and perinatal medicine at Loyola University Medical Center in Maywood, Ill.
And a third reason is that both mothers were given steroids before birth. These medications help the baby's lungs and brains mature faster and lower the risk of bleeding in the brain.
Muraskas points out that the two girls' outcomes are not typical. Many micro-preemies either do not survive or grow up with disabilities from conditions such as cerebral palsy, mental retardation, and blindness.
While the researchers caution against considering their results as an expected outcome, it's important for parents of these babies to recognize that there's some hope.
"Good outcomes are possible even for the smallest babies," says Edward Bell, MD, a neonatologist at the University of Iowa Children's Hospital in Iowa City. He also says that for these tiny infants, the number of weeks spent inside the mother's uterus affects their chances of survival more than their birth weight.
In 2000, Bell started a Tiniest Babies Registry when he realized he didn't have good answers for parents' questions about these babies who were born very premature.
Although information remains scarce, the registry has more than 100 babies who have survived weighing less than 14 ounces at birth.
"Most of them are doing pretty well," Bell tells WebMD.
But this case report is not the norm, says Leslie Kerzner, MD, a neonatologist at MassGeneral Hospital for Children in Boston. "[Rumaisa and Madeline] are two remarkable, isolated cases of survival of very low-birth-weight babies."
It's much more common for babies of this size to not survive or to have medical problems. "While these two girls may be the lucky ones, so many more suffer from hearing loss, vision, and movement problems, and [mental] delays," Kerzner tells WebMD.
She says we still don't know the long-term effects of the preemies' long hospital stays. Nor do we know how much the babies' discomfort and pain from their early-in-life medical care affects them later on.
Also, Kerzner says the report was not clear about how much special education or tutoring the girls need in school.
SOURCES:Muraskas, J. Pediatrics, published online Dec. 12, 2011.Jonathan Muraskas, MD, professor of pediatrics and neonatal/perinatal medicine, Loyola University Medical Center, Maywood, Ill.Edward F. Bell, MD, neonatologist, University of Iowa Children's Hospital, Iowa City.Leslie Kerzner, MD, neonatologist, MassGeneral Hospital for Children, Boston.
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The Health News section does not provide medical advice, diagnosis or treatment. See additional information.


text:
Math Standards and Coherence Maps
The Utah State Board of Education (USBE) adopted the K-12 Utah Core Standards for Mathematics in January 2016. The Core Standards are the mathematical content that should be taught in each grade level. The Utah Core Guides provide a description of the Core Standards, including concepts and skills to master, critical background knowledge and academic vocabulary. The coherence maps show how the Core Standards build on each other and indicate necessary prerequisites for each individual standard. They can be helpful as you plan scaffolding for math instruction and assist in identifying required background knowledge during RtI.


Work Accident Claims
What are the Accidents at Work that Occur in Waste Management?
In the UK the Waste Management sector is one of the most dangerous sectors for employees to work in. This is not only because of the immediate dangers present but because unlike other hazardous occupations within other industries, this sector has many additional problems associated with it which are not apparent until long past the time at which the problem started. In layman's terms illnesses associated with the waste management industry can take a lengthy time to surface due to the exposure of hazardous waste.
What are the Types of Accidents that occur in Waste Management?
The types of accidents that occur in the waste management sector can be widespread and diverse. The most common injuries that occur are strains, sprains as well as wounds and dislocations. However, the area of damage can be anywhere on the body, including the head, spine, etc.
Although, most of these injuries listed above are superficial and can be fixed with little or minor treatment, the amount of concussions and internal injury and illnesses are actually far higher than many other sectors. The cause of these injuries/illnesses can be highly varied and range from poisoning, effects of sound and pressure as well as shocks and various other causes.
How Severe can Accidents in the Waste Management Sector be?
The severity of the accidents occurring in the waste management sector is also much higher than in the other industries. However, most of the injuries are not permanent. NACE data shows that temporary absences account for a majority of these accidents (95.4%) followed by permanent incapacity to continue working (4.4%), while fatal accidents account for around0.3% of the total figures. While most of these accidents occur in the age group of 35-54, it is seen that most of them occur to the relatively lower age group as compared to the more experienced elder groups.
Have you suffered from an Accident at work?
If you work in a waste or recycle workplace and if you work in a waste or recycle workplace and you have suffered from an accident you will want to find out how to make a compensation claim and look for some accidents at work compensation examples to see what you could claim. Its very important as you could have life time lasting injuries and you might need medical health care the compensation can cover medical expenses as it can be expensive.
What are the Causes of Accidents at Work in Waste Management?
Waste management is more than just refuse collection. It involves recycling and corrective measures as well. As such, since the scope of work activities are quite diverse, the kind of accident relates to the field of work. For example, the dominant form of accidents faced by refuse collectors (~70%) is related to transport. By comparison, the other sectors have different forms of predominant accidents. However, the most common form of accident observed in relation to the waste management industry is with handling.
Handling is a loose term encompassing accidents like lifting, moving, cutting etc. This is about 45% of all accidents reported. Other major accidents include slips and trips (26%) and getting struck by falling objects (10%).
Statistics on Workplace Accidents that happen in Waste Management Employment
Waste management injury and illness incident statistics illustrates that the waste management industry has a much higher rate of affecting the worker's well-being than any other industry. In fact, while the average for all sectors stands at 24.2% for work affecting the health of an average worker, it is 36.9% in the waste management sector (NACE data). Not only that, the physical risk factors are also significantly higher regarding the waste management industry. For example, while the risk of working in low temperature is at 25.2% across all sectors, for the waste management industry, it is nearly double that figure at 50.2%, while the risk of handling infectious materials is at 30.1% within the waste management industry against the usual figure of 11.3%. Also visit the HSE waste management statistics page.
What are the main causes of Illness and Injury in Waste Management?
The most common form of sickness observed in the waste management workers was related to musculoskeletal disorders. This is connected to the particular risks associated with the waste management sector, including heavy muscle usage due to pulling, pushing and heavy lifting. Other factors which contribute to it are the temperature along with work hours and the repetitive nature of the work, among other things.


Amazing Care Assist – Health Care Intellytics LLC
Our mobile app AmazingCareAssist would like to receive data related to the following fields from Apple HealthKit:
steps, distance, calories, calories.active, calories.basal, activity, height, weight, heart rate,blood glucose, temperature, insulin, nutrition.sodium,blood pressure, body temperature, resp rate, fat percentage, gender, nutrition, oxygen saturation .
The above data collected by the mobile app AmazingCareAssist will be sent to the AmazingCareAssist server and stored as associated data of the patient. The Doctors of the Amazing Care Clinic through the browser-based dashboard (_URL_) will have access to the above data corresponding to the patient. The above data fields and values are displayed in a graphical form in the dashboard so that the Doctor can see the progression of symptoms related to the patient condition. Based on the above data, the Doctor will decide the next set of medical actions. Essentially, in Amazing Care Clinic practice, the above data field values will influence the treatment options related to that patient. As mentioned elsewhere, the access to the above data fields and values is restricted to need-to-know basis. Only the authorized Doctors will have access to the above data fields and values.


Reasonable adjustment and use of agricultural machinery can save fuel
Industry news
2018/09/29 17:13
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Agriculturalmachineryrationallyadjustfueleconomy: 1Adjustthevalveclearance.Theintakeandexhaustvalvesareadjustedbeforeandafterthetopendoftheexhauststroke,andthevalveclearanceisensuredtoensurenormalva
Agricultural machinery rationally adjust fuel economy:
 1 Adjust the valve clearance. The intake and exhaust valves are adjusted before and after the top end of the exhaust stroke.and the valve clearance is ensured to ensure normal valve distribution.
2 Adjust the oil supply advance angle. The adjustment of the optimal fuel supply advance angle of the diesel engine should be properly adjusted according to the change of the environment. The oil supply advance angle assembly directly affects the power and fuel consumption of the diesel engine. For example, the fuel supply advance angle of the SI95 oil machine should generally be controlled at 16°-20°.
3 Adjust the fuel injection pressure of the injector. The fuel injection pressure of the 195 diesel engine injector is (120 ± 5) kg / c. According to tests, when the injection pressure is lower than 100 kg/cm2, the fuel consumption increases. In order to maintain the normal injection pressure of the injector, the operator should periodically test the injector.
Reasonable use of fuel for fuel:
 1 Regularly maintain the air filter, diesel filter, and oil filter.
2 Replace the lubricant on schedule.
3 Refueling as required.
4 Parallel multiple farm implements under possible conditions to maximize the working width of the implement.
5 Choose the appropriate pull-out and throttle operation, and try to use high-speed small throttle operation when light load.


text:
The Cultural and Historic Preservation Department and the Cultural and Historic Preservation Committee strive to promote and preserve traditional teachings, cultural awareness, and historical accuracy of the Penobscot people. The department and committee work to address the cultural needs of the Penobscot people in the areas of, but not limited to:
Language - revitalize, sustain, and encourage the use of the Penobscot language by providing contiuning education opportunities.
History - research, document, and present Penobscot history that depicts an accurate picture of the Penobscot.
Education - provide educational opportunities for Penobscots to develop a strong foundation of cultural awareness, and preserve traditional knowledge for future generations.
Museum - provide a place that supports the material culture of the tribe.
Archaeology - support the archaeologcial efforts of the tribe in protecting an documenting sites of cultural significance to the Penobscot people.
Outreach - provide accurate Penobscot history from a Wabanaki perspective through educational resource development to classrooms, schools, and other interested organizations.


Can you tell a difference between a male and a female penguin?
The only way I can tell who is who is because the male is spanking the ass of the female penguin. On the other hand, the female is curiously preoccupied with "her" genitals which leads me to believe that it might be a male after all.
Chances are you can't. And neither can I?
How come both male and female penguins look pretty much identical?
Any time there is a species that shares equally in rearing of the offspring, both male and female look identical.
Whenever that's not the case, species tend to develop differences in the way they look because the division of labor (rearing of the offspring) is NOT equally distributed.
Example: Male peacock has developed rich and colorful plumage in order to attract the female peacock.
This configuration offers no survival benefit to this peacock. It only ensures the survival of his genes.
Human males must show their own rich plumage in order to attract a human female the same way peacocks do.
We do this in many ordinary and expected as well as extraordinary and unexpected (unconscious) ways.
Here is an example
 - Like female flies, human females will determine the suitability of the male based on his dance moves.
This makes perfect sense since in order to dance one must be in pretty good shape and posses the gift of coordination (both desirable traits) and is therefore suitable for procreation
Dancing in this context is basically short-hand for perceived fitness level which can also be demonstrated in other ways (through sports, wars, and other forms of competition).
Another example.
 - In most independent studies, bottled water neither tastes better nor is better for you, and yet, it's more expensive than gasoline and we spend billions of dollars every year on it. Why?
Dig the high-status trifecta. Erect posture, suit and tie and bottled water.
For the same reason we buy Starbucks and not Dunkin Donuts.
And for the same reason we own Macbook and not PC.
For the same reason we buy fancy cars.
It's a signaling method which demonstrates the male's ability to provide.
All of these are simply signaling methods to the human female that we are better suited for procreation than the next guy.
And why does the male have to demonstrate its suitability? Why isn't it the other way around?
Because we are not penguins.
I can't believe I managed to find two humans dressed as penguins and in a pretty much the same configuration as the first picture of male and female penguin.
Male sperm is little more than the propeller and the seed.
Female egg provides all the building material for the new life and once impregnated, the female is disproportionately responsible for the seed for the next several years at least.
Meanwhile, the male is free to impregnate as many other females as he can get his hands on.
This is why females must be picky. The time and commitment is NOT evenly distributed.
When the situation is reversed (as is with some fish) the males are the picky ones.
We all think of ourselves as individuals. But are we?
How many of us are aware of the evolutionary factors that affect our choice of partners?
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- Molter-Linnemann Architekten BDA
If we need to lift large amounts of water of the ground in order to pressurize a water distribution system, we might as well use and complement the structure for other purposes, such as generating and storing energy. First, we propose to split the water reservoir into two separate reservoirs placed above eachother. We can use the higher water reservoir to store potential energy, creating a system for storing solar energy. We cover the construction as much as possible with high efficiency solar photovoltaic cells. Solar energy is used to pump water up into the lower tank. If there is a energy surplus water is pumped into the higher tank. Flowing back into the lower reservoir this water can drive turbines, extracting the energy again. When sufficient solar energy is available, the water is pumped into the high reservoir again. The top reservoir also doubles as a sun cover to keep the main water storage reservoir cool (preventing the development of microbes). The middle volume holds the technical spaces. The filter systems are integrated in the carrying construction.


Sports FAQ
Home / Athletics
Why do cigarette tax the heaviest
11 listening2010-01-30 10:01:46 +0000 #1
zian19992010-01-30 10:08:07 +0000 #2
for several aspects of the considerations
first, because cigarettes are a huge profit industries, from tobacco taxes, health care and environmental protection can be put up. We should know that smoking not only harmful to health, but also pollute the environment.
Second, can effectively control the smoking population
our country's 2008 data show that China has 350 million smokers, accounting for over 15 years of age 36% of the population. Every year one million people die of tobacco-related diseases, this figure highest in the world. This is the air pollution caused by the death of three times the cause of AIDS deaths of 30 times. Per pack of cigarettes increased by 1 million the number of smokers will be reduced by 13.7 million to save 3.4 million lives, government revenue will increase by 64.9 billion yuan.
In fact, China's tobacco tax fairly low. The international level in about five Liucheng to Qi Cheng.
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Unordered map
Aaron Denney wnoise at
Fri Aug 1 07:13:34 EDT 2008
On 2008-08-01, Johannes Waldmann wrote:
> Aaron Denney wrote:
>> If you're going to make users write an
>> equality function, making them write an ordering adds little effort, and
>> a reasonable amount of gain. Usually.
> Then why is there a distinction between e.g.
You would have to ask the Java designers.
> The practical problem with Haskell's type class mechanism
> is that all instances (of Eq, Ord) are global,
This is a feature, not a bug. It helps ensure that manipulations
on maps will always use compatible functions. If, instead,
you constructed maps by passing in a comparison function, what
happens when you merge two maps? Which function gets used? Normally
you would be able to re-use the structure of each map in combining them.
But if the functions they used are different, than they have to be
resorted according to the kept function. Or, you have an obscure,
difficult to track down bug, rather than an error at compile time.
> so if one library (Data.Map) requires them,
> then you're stuck with these instances for all of your program.
> Of course the same thing holds for Java's "implements Comparable<>"
> but they have local types. Well, Haskell has newtype,
> but that's (module-)global.
They don't have local types. They have inner classes, and objects get
Newtypes do work. The newtype deriving extension works even better.
If something has multiple ways of comparing, then the context in which
they are used should be tagged differently. Haskell types are cheap,
both in the compiler, and when typing, because it's nowhere near as
verbose as Java.
Aaron Denney
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text:
Machine learning is increasingly integrated into chemistry research by guiding experimental procedures, correlating structure and function, interpreting large experimental datasets, to distill scientific insights that might be challenging with traditional methods. Such applications, however, largely focus on gaining insights via big data and/or big computation, while neglecting the valuable chemical prior knowledge dwelling in chemists' minds. In this paper, we introduce an Electrochemistry-Informed Neural Network (ECINN) by explicitly embedding electrochemistry priors including the Butler-Volmer (BV), Nernst and diffusion equations on the backbone of neural networks for multi-task discovery of electrochemistry parameters. We applied the ECINN to voltammetry experiments of and redox couples to discover electrode kinetics and mass transport parameters. Notably, ECINN seamlessly integrated mass transport with BV to analyze the entire voltammogram to infer transfer coefficients directly, so offering a new approach to Tafel analysis by outdating various mass transport correction methods. In addition, ECINN can help discover the nature of electron transfer and is shown to refute incorrect physics if imposed. This work encourages chemists to embed their domain knowledge into machine learning models to start a new paradigm of chemistry-informed machine learning for better accountability, interpretability, and generalization.
Keywords: Cyclic Voltammetr; Electrochemistry; Multi-Task Discovery; Physics-Informed Neural Networks; Tafel Analysis.
© 2024 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.


text:
If you want to move or copy the entire table, be sure to select the entire table first. Note that the entire table is selected only if the table end-of-row marks are included in the selection, as shown above. (You can be assured that the end-of-row marks are included in your selection when you select the table by using the option on the Table menu described earlier in this lesson.)
A table can be copied or moved just like text.
First, you select the table (or part of the table) that you want to copy or move. Then, on the Edit menu, you click Copy (to copy) or Cut (to move), and then Paste, just as you would for document text (or press CTRL+C, CTRL+X, and CTRL+V, respectively).
Caution When resting the pointer over a table, you may see the Table Move Handle at the upper-left corner of the table. When you click and drag this icon to move a table, it enables text to wrap around your table. While this is a fun feature, it turns your table into a floating graphic object — which can make the table and the document more complex to manage. Instead, keep your table easy to manage by using the Cut and Paste method above for moving your table.


Serving Texans since 1934 | LCRA Serving Texans since 1934 | LCRA
Serving Texans since 1934
Downtown Austin before the Highland Lakes dams
LCRA transmission line crew
Buchanan Dam construction crew
Comal Power Plant
LCRA has deep roots in Texas, dating as far back as the Great Depression of the 1930s.
We were created by the state Legislature in 1934 to improve the lives of people living in a region challenged by devastating floods, extreme droughts and limited access to reliable electricity.
The early years
When our doors opened for business in 1935, we went to work. We built a chain of dams that tamed the lower Colorado River and formed the Highland Lakes, significantly reducing the impact of cycles of drought and flood that had devastated the region for centuries. We also produced hydroelectricity and built transmission lines that brought reliable, affordable power to residents of the rural Texas Hill Country for the first time.
An important mission
In the decades that followed, LCRA continued to help Texans respond to population growth and other challenges. We built power plants and transmission facilities to meet the increasing demand for power, provided a clean, reliable water supply for a growing region, developed parks and recreation areas to provide public access to the river and lakes, and supported economic development throughout our service territory.
While our services have evolved to meet the changing needs of the state over the past 85 years, our mission has remained constant: LCRA exists to enhance the lives of the people of Texas.


text:
"Random Computed Tomography and Protein Structuring"
Abstract: In this talk we present a reconstruction algorithm for the 3D atomic structure of randomly oriented proteins using modified graph laplacians. The 2003 Nobel Prize in Chemistry was co-awarded to R. MacKinnon who was the first to structure a protein channel (the potassium channel) in 1998 by crystallizing the protein and using the classical X-ray computed tomography (CT). However, most membrane proteins cannot be crystallized and the classical CT cannot be used.
In our experimental setup, the data consists of thousands of real noisy 2D projections (electron microscope images) of the protein given in random unknown directions, because the proteins are randomly oriented rather than being aligned as in MacKinnon's setup. Still, we show that the reconstruction is made possible by a certain modification of the images' graph laplacian coupled with the 3D Fourier slice theorem. The reconstruction is a particular case of a more general spectral non-linear independent component analysis (ICA) algorithm that combines local principal component analysis (PCA) with the graph laplacian.
No prior knowledge of graph laplacians, tomography and proteins is needed for this talk.
This is a joint work with Ronald Coifman, Yoel Shkolnisky and Fred Sigworth (Yale University).


Autonomous Robotic Suction to Clear the Surgical Field for Hemostasis using Image-based Blood Flow Detection
Autonomous robotic surgery has seen significant progression over the last decade with the aims of reducing surgeon fatigue, improving procedural consistency, and perhaps one day take over surgery itself. However, automation has not been applied to the critical surgical task of controlling tissue and blood vessel bleeding–known as hemostasis. The task of hemostasis covers a spectrum of bleeding sources and a range of blood velocity, trajectory, and volume. In an extreme case, an un-controlled blood vessel fills the surgical field with flowing blood. In this work, we present the first, automated solution for hemostasis through development of a novel probabilistic blood flow detection algorithm and a trajectory generation technique that guides autonomous suction tools towards pooling blood. The blood flow detection algorithm is tested in both simulated scenes and in a real-life trauma scenario involving a hemorrhage that occurred during thyroidectomy. The complete solution is tested in a physical lab setting with the da Vinci Research Kit (dVRK) and a simulated surgical cavity for blood to flow through. The results show that our automated solution has accurate detection, a fast reaction time, and effective removal of the flowing blood. Therefore, the proposed methods are powerful tools to clearing the surgical field which can be followed by either a surgeon or future robotic automation developments to close the vessel rupture.
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02/02/2021
Model-Predictive Control of Blood Suction for Surgical Hemostasis using Differentiable Fluid Simulations
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What breathes life into an embodied agent or avatar? While body motions ...
I Introduction
Since the deployment of surgical robotic devices such as the da Vinci® Surgical System, efforts to automate surgical tasks have become a popular area of research [29]
. The automation of surgery has promised to help reduce surgeon fatigue and improve the procedural consistency between surgeries, and perhaps one day take over the surgery itself. Success in realizing surgical automation has accelerated in recent years, with improvements in available open-source platforms such as the da Vinci Research Toolkit (dVRK)
[9] and simulators [21], coupled with significant advances to data-driven controller synthesis. Successful demonstrations of automated tasks have included cutting [18, 27], suture needle hand-off [4], suturing [24, 30], and debridement removal [10]. Recent developments in perception for surgical robotics helps bridge these autonomous policies in ideal scenarios to realistic, deformable and noisy tissue environments such as the SuPer frameworks [12, 15].
While progress in developing autonomous surgical tasks has leapt forward, a key area that has been given little attention are reactive policies to traumatic events, such as hemostasis. Hemostasis describes a state of the surgical field that is fulfilled when there is no site of active bleeding and the tissues are unobstructed by blood. The bleeding can originate from a visible or macroscopic blood vessel (artery or vein), or from the microvasculature and capillary network within tissues. Unlike previously automated tasks that occur in a more predictable cadence within a procedure, bleeding can be unpredictable which necessitates hemostasis maneuvers at any time during any surgery. Surgical manipulation of any type–suction, grasping, retraction, cutting, dissection–can immediately cause bleeding. Bleeding can also occur in a delayed manner, for example if a vessel is not definitively sealed, it can rupture spontaneously without direct contact. This work specifically addresses the problem of small/medium vessel rupture. Overall, there are four distinct stages in hemostasis of this scenario: (1) clearing the surgical field of blood; (2) identification of the bleeding source (vessel rupture); (3) grasping the identified vessel to temporarily stop bleeding; (4) closing the vessel rupture, usually with an energy device, clip, or suture. Each stage requires a complex set of manipulation skills as well as perception algorithms that make it non-trivial to implement.
In this paper, we describe an automated solution to the first task, clearing the surgical field, as shown in Fig. 1. This task involves first recognizing blood in a scene, then tracking blood flow temporally, and finally prescribing a real-time trajectory generation strategy that will intelligently control a suction tool to siphon the blood to efficiently suction it. To this end, we present the following novel contributions:
 1. the first complete automated solution for clearing the surgical field of flowing blood from a ruptured vessel using a robotic suction tool,
 2. a novel blood flow detection and tracking method by utilizing temporal visual information, and
 3. a trajectory generation technique from blood regions in the image frame for a surgical suction tool to follow and clear the surgical field.
The blood flow detection and tracking method is tested within various simulated scenes as well as an real-life case involving a vessel rupture during thyroidectomy. The complete solution is tested in a lab setting with the da Vinci Research Kit (dVRK) [9] and a simulated surgical cavity for blood to flow through and collect in. The results from the experiments show the effectiveness of the blood flow tracking and surgical suction tool trajectory generation developed in this work.
Ii Related Works
Previous work on blood detection largely is from the context of Wireless Capsule Endoscopy (WCE) where image processing for detections is used to speed up clinician workflow [13]
. The typical approach to blood detection in WCE is to classify either on a pixel level or using patch-based methods
[7]. The feature space used for classification is either direct Red, Green, Blue (RGB) [14] channels or the transformed Hue, Saturation, Value (HSV) channels [8]
. To efficiently process these color spaces, techniques such as support vector machines
[19]
, chromium moments combined with binary pattern textures
[11]
, and neural networks
[20, 6] have been demonstrated. While these methods are robust to small individual lesions, in a surgical scene there can be stains from previous ruptures and larger amounts of blood flow that make the problem of blood detection and, specifically, tracking, a more challenging and complex problem.
There has been previous research on robots interacting with liquids in the act of pouring [17]. However, these methods cannot be applied to a surgical setting since they are limited to specific objects for pouring and capturing liquids. Schenck and Fox applied deep neural networks to detect fluids [22] that can be combined with differential fluid dynamics to reconstruct 3D information [23]
. This detection method however requires labelled real-world data which are challenging to collect in a surgical context. Yamaguchi and Atkeson instead used the heuristic of optical flow to detect moving fluid
[28]
. The work presented here also uses optical flow to detect blood flow. However, instead of the classical method used by Yamaguchi and Atkeson, we applied a deep learning technique for improved performance of optical flow estimation in a surgical environment and fused the detections temporally with a novel temporal filter.
1
Initialize image frame probability map of blood:
2 Initialize optical flow CNN with image frame inputs
3 Initialize counts of being blood:
4 while new image, , arrives do
5 // Blood Region Detection
6
7 for pixel do
8 // Detect:
9 if then
10
11 else
12
13 Predict: with (8) and
14 Update: with (7) and
15
16 is set to the largest connected region in binary mask
17 if then
18 continue
19
20 // Suction Trajectory Generation
21 Update Blood Count:
22 End point:
23 Start point:
24 generateTrajectoryForSuction(, , )
25 if length then
26 break
27
28
executeTrajectory()
Algorithm 1 Blood Suction
Iii Methods
An overview of the proposed algorithms for blood region estimation and trajectory generation for an autonomous suction tool on a surgical robot is provided in Algorithm 1. At a high level, the blood region is estimated by updating a probability map on the scene, which describes the probability of each pixel in the image frame being blood or not. From the probability map, the blood region is extracted. A trajectory is then generated for the suction tool to follow in order to clear the surgical field from blood. The trajectory is constrained to stay within the blood region to maximize the blood removed.
Fig. 2:
The above images are generated by optical flow estimation from an in-vivo surgical scene. The left image shows the vectors of estimated image motion from optical flow, and the right image