text:
necessarily globally) unique. If you require a globally unique identifier, you must ensure that the primary key is globally unique or use system-generated OIDs.
REF contains the following three logical components:
Referential integrity constraints on
REF columns ensure that there is a row object for the
REF. Referential integrity constraints on
REFs create the same relationship as specifying a primary key/foreign key relationship on relational data. In general, you should use referential integrity constraints wherever possible because they are the only way to ensure that the row object for the
REF exists. However, you cannot specify referential integrity constraints on
REFs that are in nested tables.
REF is constrained to contain only references to a specified object table. You can specify a scoped
REF when you declare a column type, collection element, or object type attribute to be a
REF. In general, you should use scoped
REFs whenever possible instead of unscoped
REFs because scoped
REFs are stored more efficiently. Scoped
REFs are stored on disk as just the OID, so each scoped
REF is 16 bytes long. In addition to the smaller size, the optimizer often can optimize queries that dereference a scoped
REF into efficient joins. This optimization is not possible for unscoped
REFs because the optimizer cannot determine the containing table(s) for unscoped
REFs at query optimization time.
However, unlike referential integrity constraints, scoped REFs do not ensure that the referenced row object exists; they only ensure that the referenced object table exists. Therefore, if you specify a scoped
REF to a row object and then delete the row object, the scoped
REF becomes a dangling
REF because the referenced object no longer exists.
REFs are useful if the application design requires that the objects referenced be scattered in multiple tables. Because rowid hints are ignored for scoped
REFs, you should use unscoped
REFs if the performance gain of the rowid hint, as explained below in the "Speeding up Object Access using the WITH ROWID Option" section, outweighs the benefits of the storage saving and query optimization of using scoped
You can build indexes on scoped
REF columns using the
INDEX command. Then, you can use the index to efficiently evaluate queries that dereference the scoped
REFs. Such queries are turned into joins implicitly. For certain types of queries, Oracle can use an index on the scoped
REF column to evaluate the join efficiently.
For example, suppose the object type
address_objtyp is used to create an object table named
people_reltab2 table can be created that has the same definition as the
people_reltab table discussed in "Column Object Storage", except that a
REF is used for the address:
CREATE TABLE people_reltab2 ( id NUMBER(4) CONSTRAINT pk_people_reltab2 PRIMARY KEY, name_obj name_objtyp, address_ref REF address_objtyp SCOPE IS address_objtab, phones_ntab phone_ntabtyp) NESTED TABLE phones_ntab STORE AS phone_store_ntab2 ;
Now, an index can be created on the
The following query dereferences the
When this query is executed, the
address_ref_idx index is used to efficiently evaluate it. Here,
address_ref is a scoped
REF column that stores references to addresses stored in the
address_objtab object table. Oracle implicitly transforms the above query into a query with a join:
SELECT p.id FROM people_reltab2 p, address_objtab a WHERE p.address_ref = ref(a) AND a.state = 'CA' ;
Oracle's optimizer might create a plan to perform a nested-loops join with
address_objtab as the outer table and look up matching addresses using the index on the
ROWID option is specified for a
REF column, Oracle maintains the rowid of the object referenced in the
REF. Then, Oracle can find the object referenced directly using the rowid contained in the
REF, without the need to fetch the rowid from the OID index. Therefore, you use the
ROWID option to specify a rowid hint. Maintaining the rowid requires more storage space because the rowid adds 16 bytes to the storage requirements of the
Bypassing the OID index search improves the performance of
REF traversal (navigational access) in applications. The actual performance gain may vary from application to application depending on the following factors:
REFtraversals an application does.
ROWID option is only a hint because, when you use this option, Oracle checks the OID of the row object with the OID in the
REF. If the two OIDs do not match, Oracle uses the OID index instead. The rowid hint is not supported for scoped
REFs with referential integrity constraints, or for primary key-based
An unnesting query on a collection allows the data to be viewed in a flat (relational) form. You can execute unnesting queries on both nested tables and varrays. This section contains examples of unnesting queries.
Nested tables can be unnested for queries using the
TABLE syntax, as in the following example:
phones_ntab specifies the attributes of the
phones_ntab nested table. To ensure that the parent rows with no children rows also are retrieved, use the outer join syntax as follows:
In the first case, if the query does not refer to any columns from the parent table (other than the nested table column in the
FROM clause), the query is optimized to execute only against the storage table.
You can also use the
TABLE syntax to query varrays. For example, suppose the
phones_ntab nested table is instead a varray named
phones_var. In this case, you still can use the
TABLE syntax to query the varray, as in the following example:
The unnesting query syntax is the same for varrays and nested tables.
You can create procedures and functions that you can then execute to perform unnesting queries. For example, you can create a function called
home_phones() that returns only the phone numbers where
location is 'home'. To create the
home_phones() function, you enter code similar to the following:
CREATE OR REPLACE FUNCTION home_phones(allphones IN phone_ntabtyp) RETURN phone_ntabtyp IS homephones phone_ntabtyp := phone_ntabtyp(); indx1 number; indx2 number := 0; BEGIN FOR indx1 IN 1..allphones.count LOOP IF allphones(indx1).location = 'home' THEN homephones.extend; -- extend the local collection indx2 := indx2 + 1; -- extend the local collection homephones(indx2) := allphones(indx1); END IF; END LOOP; RETURN homephones; END; /
Now, to query for a list of people and their home phone numbers, enter the following:
SELECT p.name_obj, n.num FROM people_reltab p, table( CAST(home_phones(p.phones_ntab) AS phone_ntabtyp)) n ;
To query for a list of people and their home phone numbers, including those people who do not have a home phone number listed, enter the following:
SELECT p.name_obj, n.num FROM people_reltab p, TABLE(CAST(home_phones(p.phones_ntab) AS phone_ntabtyp))(+) n ;
Oracle8i SQL Reference for more information about using the
The size of a stored varray depends only on the current count of the number of elements in the varray and not on the maximum number of elements that it can hold. The storage of varrays incurs some overhead, such as null information. Therefore, the size of the varray stored may be slightly greater than the size of the elements multiplied by the count.
Varrays are stored in columns either as raw values or
BLOBs. Oracle decides how to store the varray when the varray is defined, based on the maximum possible size of the varray computed using the
LIMIT of the declared varray. If the size exceeds approximately 4000 bytes, then the varray is stored in
BLOBs. Otherwise, the varray is stored in the column itself as a raw value. In addition, Oracle supports inline LOBs; therefore, elements that fit in the first 4000 bytes of a large varray (with some bytes reserved for the LOB locator) are stored in the column of the row itself.
If the entire collection is manipulated as a single unit in the application, varrays perform much better than nested tables. The varray is stored "packed" and requires no joins to retrieve the data, unlike nested tables.
The unnesting syntax can be used to access varray columns similar to the way it is used to access nested tables.
"Viewing Object Data in Relational Form with Unnesting Queries" for more information.
Piece-wise updates of a varray value are not supported. Thus, when a varray is updated, the entire old collection is replaced by the new collection.
The following sections contain design considerations for using nested tables.
Oracle stores the rows of a nested table in a separate storage table. A system generated
NESTED_TABLE_ID, which is 16 bytes in length, correlates the parent row with the rows in its corresponding storage table.
Figure 5-5 shows how the storage table works. The storage table contains each value for each nested table in a nested table column. Each value occupies one row in the storage table. The storage table uses the
NESTED_TABLE_ID to track the nested table for each value. So, in Figure 5-5, all of the values that belong to nested table
A are identified, all of the values that belong to nested table
B are identified, etc.
If a nested table has a primary key, you can


ations. Let R = k[t_0,..., t_n]. The homogeneous ideal R_+ = \bigoplus_{d \ge 1} R_d is called the maximal homogeneous ideal (see also irrelevant ideal). As in the affine case, we let: for a subset S \subseteq \mathbb{P}^n and a homogeneous ideal I of R,
\operatorname{I}_{\mathbb{P}^n}(S) &= \{ f \in R_+ | f = 0 \text{ on } S \}, \\
\operatorname{V}_{\mathbb{P}^n}(I) &= \{ x \in \mathbb{P}^n | f(x) = 0 \text{ for all }f \in I \}.
By f = 0 \text{ on } S we mean: for every homogeneous coordinates (a_0 : \cdots : a_n) of a point of S we have f(a_0,\ldots, a_n)=0. This implies that the homogeneous components of f are also zero on S and thus that \operatorname{I}_{\mathbb{P}^n}(S) is a homogeneous ideal. Equivalently, \operatorname{I}_{\mathbb{P}^n}(S) is the homogeneous ideal generated by homogeneous polynomials f that vanish on S. Now, for any homogeneous ideal I \subseteq R_+, by the usual Nullstellensatz, we have:
\sqrt{I} = \operatorname{I}_{\mathbb{P}^n}(\operatorname{V}_{\mathbb{P}^n}(I)),
and so, like in the affine case, we have:[4]
There exists an order-reversing one-to-one correspondence between proper homogeneous radical ideals of R and subsets of \mathbb{P}^n of the form \operatorname{V}_{\mathbb{P}^n}(I). The correspondence is given by \operatorname{I}_{\mathbb{P}^n} and \operatorname{V}_{\mathbb{P}^n}.
See also[edit]
 1. ^ Atiyah-MacDonald 1969, Ch. 7
 2. ^ Kollár, János (October 1988), "Sharp Effective Nullstellensatz", Journal of the American Mathematical Society 1 (4): 963–975, doi:10.2307/_PHONE_
 3. ^ Sombra, Martín (February 1999), "A Sparse Effective Nullstellensatz", Advances in Applied Mathematics 22 (2): 271–295, doi:10.1006/aama._PHONE_
 4. ^ This formulation comes from Milne, Algebraic geometry [1] and differs from Hartshorne 1977, Ch. I, Exercise 2.4


ProcedureHow to Set Up a Slave Server
 1. Become superuser or assume an equivalent role.
 2. Edit the /etc/hosts or /etc/inet/ipnodes file on the slave server to add the name and IP addresses of all the other NIS servers.
 3. Change directory to /var/yp on the slave server.
 Note –
 You must first configure the new slave server as an NIS client so that it can get the NIS maps from the master for the first time. See Setting Up NIS Clients for details.
 4. Initialize the slave server as a client.
 # /usr/sbin/ypinit -c
 The ypinit command prompts you for a list of NIS servers. Enter the name of the local slave you are working on first, then the master server, followed by the other NIS slave servers in your domain in order from the physically closest to the furthest in network terms.
 5. Determine if the NIS client is running, then start the client service as needed.
 # svcs network/nis/client
 STATE STIME FMRI
 online 20:32:56 svc:/network/nis/client:default
 If svc:/network/nis/client is displayed with an online state, then NIS is running. If the service state is disabled, then NIS is not running.
 1. If the NIS client is running, restart the client service.
 # svcadm restart network/nis/client
 2. If the NIS client is not running, start the client service.
 # svcadm enable network/nis/client
 6. Initialize this machine as a slave.
 # /usr/sbin/ypinit -s master
 Where master is the machine name of the existing NIS master server.
 Repeat the procedures described in this section for each machine you want configured as an NIS slave server.


text:
Jump High is a series of Chinese textbooks for the compulsory courses foreigners take in college, with five vertical skills (intensive reading, conversation, listening, writing, translation) and seven horizontal levels (0, 1, 2, 3, 4, 5, 6) matching with one another. All learners, ranging from total beginners to high-level ones, can find something suitable for themselves.
Conversation TEXTBOOK 1 is designed for the speaking course in the first semester of the first year in college, including 15 lessons altogether, each with four parts: Text, Vocabulary, Notes and Function Items. Considering the characteristics of conversation courses, this book emphasizes oral practice and pays great attention to communication tasks and expressive functions. The texts are designed with natural and practical topics and situations to combine classroom learning with verbal communication outside the classroom and to help the students communicate in natural and appropriate Chinese.
The texts and new words are recorded in the CD of MP3 files attached to the book.

source: openbmb/Ultra-FineWeb


t/sin(e)], Esky = rayleigh
· DOS4: TAUv = exp[-t/cos(sat_zenith)], TAUz = exp[-t/sin(e)], Esky = PI *
radiance_dark
Attention: Output radiance remain untouched (i.e. no set to 0.0 when it is negative) then
they are possible negative values. However, output reflectance is set to 0.0 when is
obtained a negative value.
NOTES
The output raster cell values can be rescaled with the scale parameter (e.g., with 100 in
case of using reflectance output in i.gensigset).
On Landsat-8 metadata file
NASA reports a structure of the L1G Metadata file (LDCM-DFCB-004.pdf) for Landsat Data
Continuity Mission (i.e. Landsat-8).
NASA retains in MIN_MAX_RADIANCE group the necessary information to transform Digital
Numbers (DN) in radiance values. Then, i.landsat.toar replaces the possible standard
values with the metadata values. The results match with the values reported by the metada
file in RADIOMETRIC_RESCALING group.
Also, NASA reports the same values of reflectance for all bands in max-min values and in
gain-bias values. This is strange that all bands have the same range of reflectance. Also,
they wrote in the web page as to calculate reflectance directly from DN, first with
RADIOMETRIC_RESCALING values and second divided by sin(sun_elevation).
This is a simple rescaling
· reflectance = radiance / sun_radiance = (DN * RADIANCE_MULT + RADIANCE_ADD) /
sun_radiance
· now reflectance = DN * REFLECTANCE_MULT + REFLECTANCE_ADD
· then REFLECTANCE_MULT = RADIANCE_MULT / sun_radiance
· and REFLECTANCE_ADD = RADIANCE_ADD / sun_radiance
The problem arises when we need ESUN values (not provided) to compute sun_radiance and
DOS. We assume that REFLECTANCE_MAXIMUM corresponds to the RADIANCE_MAXIMUM, then
· REFLECTANCE_MAXIMUM / sin(e) = RADIANCE_MAXIMUM / sun_radiance
· Esun = (PI * d^2) * RADIANCE_MAXIMUM / REFLECTANCE_MAXIMUM
where d is the earth-sun distance provided by metadata file or computed inside the
program.
The i.landsat.toar reverts back the NASA rescaling to continue using Lmax, Lmin, and Esun
values to compute the constant to convert DN to radiance and radiance to reflectance with
the "traditional" equations and simple atmospheric corrections. Attention: When MAXIMUM
values are not provided, i.landsat.toar tries to calculate Lmax, Lmin, and Esun from
RADIOMETRIC_RESCALING (in tests the results were the same).
Calibration constants
In verbose mode (flag --verbose), the program write basic satellite data and the
parameters used in the transformations.
Production date is not an exact value but it is necessary to apply correct calibration
constants, which were changed in the dates:
· Landsat-1 MSS: never
· Landsat-2 MSS: July 16, 1975
· Landsat-3 MSS: June 1, 1978
· Landsat-4 MSS: August 26, 1982 and April 1, 1983
· Landsat-4 TM: August 1, 1983 and January 15, 1984
· Landsat-5 MSS: April 6, 1984 and November 9, 1984
· Landsat-5 TM: May 4, 2003 and April, 2 2007
· Landsat-7 ETM+: July 1, 2000
· Landsat-8 OLI/TIRS: launched in 2013
EXAMPLES
Metadata file examples
Transform digital numbers of Landsat-7 ETM+ in band rasters 203_30.1, 203_30.2 [...] to
uncorrected at-sensor reflectance in output files 203_30.1_toar, 203_30.2_toar [...] and
at-sensor temperature in output files 293_39.61_toar and 293_39.62_toar:
i.landsat.toar input=203_30. output=_toar \
metfile=p203r030_7x20010620.met
or
i.landsat.toar input=L5121060_06020060714. \
output=L5121060_06020060714_toar \
metfile=L5121060_06020060714_MTL.txt
or
i.landsat.toar input=LC80160352013134LGN03_B output=toar \
metfile=LC80160352013134LGN03_MTL.txt sensor=oli8 date=2013-05-14
DOS1 example
DN to reflectance using DOS1:
# rename channels or make a copy to match i.landsat.toar's input scheme:
g.copy raster=lsat7_2002_10,lsat7_2002.1
g.copy raster=lsat7_2002_20,lsat7_2002.2
g.copy raster=lsat7_2002_30,lsat7_2002.3
g.copy raster=lsat7_2002_40,lsat7_2002.4
g.copy raster=lsat7_2002_50,lsat7_2002.5
g.copy raster=lsat7_2002_61,lsat7_2002.61
g.copy raster=lsat7_2002_62,lsat7_2002.62
g.copy raster=lsat7_2002_70,lsat7_2002.7
g.copy raster=lsat7_2002_80,lsat7_2002.8
Calculation of reflectance values from DN using DOS1 (metadata obtained from
p016r035_7x20020524.met.gz):
i.landsat.toar input=lsat7_2002. output=lsat7_2002_toar. sensor=tm7 \
method=dos1 date=2002-05-24 sun_elevation=64._PHONE_ \
product_date=2004-02-12 gain=HHHLHLHHL
The resulting Landsat channels are names lsat7_2002_toar.1 .. lsat7_2002_toar.8.
REFERENCES
· Chander G., B.L. Markham and D.L. Helder, 2009: Remote Sensing of Environment,
vol. 113
· Chander G.H. and B. Markham, 2003.: IEEE Transactions On Geoscience And Remote
Sensing, vol. 41, no. 11.
· Chavez P.S., jr. 1996. Image-based atmospheric corrections - Revisited and
Improved. Photogrammetric Engineering and Remote Sensing 62(9): _PHONE_.
· Huang et al: At-Satellite Reflectance, 2002: A First Order Normalization Of
Landsat 7 ETM+ Images.
· R. Irish: Landsat 7. Science Data Users Handbook. February 17, 2007; 15 May 2011.
· Markham B.L. and J.L. Barker, 1986: Landsat MSS and TM Post-Calibration Dynamic
Ranges, Exoatmospheric Reflectances and At-Satellite Temperatures. EOSAT Landsat
Technical Notes, No. 1.
· Moran M.S., R.D. Jackson, P.N. Slater and P.M. Teillet, 1992: Remote Sensing of
Environment, vol. 41.
· Song et al, 2001: Classification and Change Detection Using Landsat TM Data, When
and How to Correct Atmospheric Effects? Remote Sensing of Environment, vol. 75.
Use i.landsat.toargrass online using onworks.net services
Free Servers & Workstations
Download Windows & Linux apps
Linux commands
Ad


text:
THE North Coast Public Health Unit is reminding residents and visitors to the Mid North Coast to protect themselves against mosquitoes which are increasing in numbers as summer progresses.
"Mosquito numbers increase in summer and when there is water lying around," said Kerryn Lawrence, Senior Environmental Health Officer.
"As it is predicted that rainfall will be above average over the next three months, there will be more mosquito breeding sites around and a greater risk of being bitten."
Ross River and Barmah Forest viruses are common in the mid north coast and are transmitted by infected mosquitoes that breed in flooded, grassy and swampy areas and around waterways. On average in each year over the past decade about 500 people living on NSW north coast were diagnosed with either Ross River virus or Barmah Forest virus - in about equal numbers (about 250 cases of each are reported on average each year.)
Compared to the NSW average, people living on north coast are five to eight times more likely to be infected with Barmah Forest virus and three to five times more likely to be infected with Ross River virus.
Simple steps to avoid being bitten by mosquitoes include:
* When outside cover up as much as possible with light-coloured, loose-fitting clothing and covered footwear. \
* Use an effective repellent on all exposed skin. Re-apply repellent within a few hours, as protection wears off with perspiration. The best mosquito repellents contain Diethyl Toluamide (DEET) or Picaridin.
* Light mosquito coils or use vapourising mats indoors. Devices that use light to attract and electrocute insects are not effective.
* Cover all windows, doors, vents and other entrances with insect screens.
* When camping, use flyscreens on caravans and tents or sleep under mosquito nets.
"Preventing these viruses depends on avoiding mosquito bites, especially in the warmer months of the year when mosquitoes are most active," Mrs Lawrence said.
Sign up for our newsletter to stay up to date.

source: m-a-p/FineFineWeb


text:
Press Release - Peoples Liberation Front Enters The Hackers Space Race
Sunday - February 19, 2012 11:30 PM CT
Today the PLF announces the launch of "Operation Freedom Star". The mission of this Op is simple. The Peoples Liberation Front is entering the Hacker Space Race that was initiated with the announcement by the Chaos Computer Club that they intended to launch three communications satellites of their own to help circumvent internet censorship. The PLF states that we are in this race to win, and that WE firmly intend to be the first hackers in space.
Our plan for this involves the purchase of one of the many used communications satellites that are in orbit already, and are beyond their commercial usefulness. Many of these birds are low on fuel and have other issues related to their age, but are otherwise serviceable and useful for the purpose we intend - which is to provide broadband satellite communications to areas of the world that are in great need. We are currently looking at several possibilities, and whichever bird we chose - it will be called the "Freedom Star". The purpose of the Freedom Star Satellite will be to provide broadband internet connections using commercially available downlink hardware.
Once we have our first bird working, we will shift our focus to building our first custom bird from scratch. We will use the Amsat program to design and launch our own bird, and also study the open source communications satellites already launched as part of this incredible program for possible uses in circumventing censorship, internet shutdowns - and providing other services to freedom movements around the world.
To coordinate this massive effort, we hereby create the PLF Space Command - which will be staffed for the purpose of managing all the space related efforts of the Peoples Liberation Front. The attached Op Poster for Operation Freedom Star contains the new logo for the PLF Space Command. And finally, if you support this effort, we have set up a sand-boxed WePay fund to collect online donations of much needed cash which will be used specifically for this project. The budget just for the first year of this effort is in excess of 1 million USD, so please give generously if you support the idea.
SIGNED -- PLF Central Command
Operation Freedom Star Poster - _URL_


text:
The dam was constructed in the upper reaches of the Satsunai River, which is a tributary of the Tokachi River, and was completed in 1997. The dam lake was named Tokachi Ryutan (dragon pool) Lake because of the resemblance of its shape to a dragon when seen from above. The Satsunai-gawa Enchi campsite downstream of the dam has the Pyotan no Taki Falls, which is a scenic spot where splashing water falls from a height of 10 m, as well as an obstacle course, tennis, park golf and other leisure facilities.
Satsunai River of the Tokachi river system
Concrete gravity dam
Flood control, maintenance of normal water flow function, provision of city water, hydropower generation
Map code: 592 006 215*34


text:
Understanding universal health care, Part 4: Cost-Sharing for Patients in the Netherlands
There's a wealth of economic evidence demonstrating that cost-sharing requirements for medical care, alongside protections for the vulnerable, can temper demand for outpatient care without resulting in adverse consequences.
A recent study documents how Canada stands among a small minority of only six universal health-care countries (out of 28) that have not acted on this evidence and, generally, do not expect patients to share the cost of care. This blog post is part of a series of posts that documents how eight high-performing universal health-care systems utilize cost-sharing mechanisms (deductibles, coinsurance payments and copayments) while protecting vulnerable patient populations. While previous posts in this series have outlined how Australia, Belgium and France accomplish this, this post will focus on the Netherlands.
The Netherlands ensures universal coverage through a compulsory social health insurance scheme. Residents must purchase a standard insurance package from one of several private insurers, in a regulated but competitive market. Coverage definitions for the basic insurance package are broad, but must include core services provided by general practitioners, specialists and hospitals. The purchase of voluntary insurance is also common (83.9 per cent in 2021) in the Netherlands, which often covers costs of dental care, physiotherapy, glasses and co-payments for medications that exceed the reimbursement rate.
The universal system is primarily financed through income dependent contributions (50 per cent) and "community rated" premiums (50 per cent). While premiums can vary between insurance companies, each insurer must determine a flat premium for adults that applies uniformly across the country regardless of individual health status or other factors. And insurers must accept all applicants for coverage.
Deductibles are the major form of cost-sharing for core services. In 2020, Dutch residents were expected to pay an annual deductible of €385 (C$589.37) for most types of care including access to specialist consultations and hospital care. Patients may also choose higher deductibles (up to €500 or C$765.40) in exchange for discounts on their monthly premiums. Patients are covered for all the cost of care once this deductible is met. Pharmaceuticals are also covered by the basic insurance plan in the Netherlands, but are also subject to the same deductible cost-sharing requirements. However, patients may have to pay an additional "personal contribution" for medications that exceed the maximum reimbursement amount (for which there's an annual €250 or C$382.7 cap).
Dutch patients may also choose to expose themselves to other forms of cost-sharing depending on their choice of policy. "In-kind" policies allow patients to see contracted providers and receive no bill, with care from non-contracted providers being partially reimbursed (with patients responsible for the balance). In contrast, "restitution policies" allow for free choice of provider in exchange for paying for the bill out-of-pocket and receiving reimbursement afterwards.
Safety nets in the Netherlands include deductible exemptions for general practitioner visits, dental care for those < 18 years of age, obstetric/maternity care, and care for specific chronic illnesses.
The Dutch government also provides financial assistance as another form of protection. Low-income Dutch patients (individuals and families) may qualify for an "allowance" for their health-care premiums, based on the income of the individual and their "allowance partner" alongside the average premium price and compulsory deductible. In 2020, the income threshold to receive the smallest allowance was below €30,500 (C$46,690) or €39,000 (C$59,702) with a partner. In addition to this premium allowance, patients who've incurred "structural care expenses over time" due to chronic illness or disability are also able to receive financial compensation.
This fourth contribution to this blog series has provided a general overview of the Dutch health-care system, its cost-sharing arrangements and related protections. The next post in this series will examine the same topics for the universal system in New Zealand.
Subscribe to the Fraser Institute
Get the latest news from the Fraser Institute on the latest research studies, news and events.


text:
MALAKOFF DIGGINS STATE HISTORIC PARK
Malakoff Diggins State Historic Park is the site of California's largest "hydraulic" mine. Visitors can see huge cliffs carved by mighty streams of water, results of the gold mining technique of washing away entire mountains to find the precious metal. Legal battles between mine owners and downstream farmers ended this method. The park also contains a 7,847 foot bedrock tunnel that served as a drain. The visitor center has exhibits on life in the old mining town of North Bloomfield.
Established in 1965, the park located near Nevada City, California is famous for its historical significance related to gold mining. It was named after Malakoff Diggins which was a large hydraulic mine during the Gold Rush era of mid-19th century. The site became infamous due to environmental damage caused by hydraulic mining leading to America's first legal restraint against this method in 1884.
The ghost town of North Bloomfield found within the park boundaries provides visitors with an insight into life during that period. Today, it serves as a popular tourist attraction offering camping facilities and hiking trails while preserving important aspects of Californian history.
Malakoff Diggins State Historic Park is located near Grass Valley, Nevada City
Malakoff Diggins State Historic Park in California offers several picnicking options for visitors. The park has designated picnic areas with tables and grills where you can enjoy a meal amidst the natural beauty of the area. These spots are perfect for family outings or group gatherings, providing ample space to relax and dine outdoors. Some sites even offer stunning views of scenic landscapes like forests, cliffs, or historic mining structures that make your experience more enjoyable. Remember to pack out what you bring in as there may not be trash facilities available at every site.
1. Diggins Loop Trail: This 3-mile trail is the most popular in Malakoff Diggins State Historic Park, offering a comprehensive view of the historic hydraulic mining pit and its surrounding landscapes.
2. Rim Trail: A moderate level hiking path that runs along the rim of an old mining site for about 4 miles with panoramic views over diggings area and forested hillsides.
3. Blair Lake Pathway: An easy to moderately difficult hike leading you through lush greenery towards Blair Lake; it's approximately two miles long one-way trip from park headquarters.
4. North Bloomfield Town Site Walks - These are short walks around this preserved Gold Rush town which includes several historical buildings like churches, schoolhouse etc., providing insights into California's gold-mining history
5. Humbug Creek Falls Hike - It is a challenging but rewarding trek down steep slopes to reach these beautiful falls on Humbug creek within dense forests covering roughly three-quarters mile round-trip distance.
6 .Chute Hill Campground Trails- Several trails originate or pass by Chute hill campground including ones going up to scenic overlook points as well as connecting other parts of state park making them ideal base camp hikes
7 .Missouri Bar Trail-This strenuous five-mile loop takes hikers across rugged terrain featuring remnants from past mining operations giving unique perspective into region's rich history
8.Hiller Tunnel & Cemetery Route - Short half-a-mile walk leads visitors both above ground cemetery where miners were buried during Gold rush era and below surface via tunnel dug out by miners themselves
9.Badger Hill Road Track - Easy walking route following former road used during peak days of hydraulic mine operation stretching little more than mile each way
10.South Yuba River Canyon Viewpoint Trek - Moderate difficulty pathway taking hikers downhill all way till South Yuba river canyon floor while also passing multiple viewpoints overlooking stunning vistas
The park offers a variety of birding options, with over 100 species recorded. It is home to birds like the Pileated Woodpecker and Northern Pygmy Owl that can be spotted in its mixed coniferous forest. The Blair Lake area within the park provides opportunities for waterfowl observation while Humbug Creek attracts riparian-loving species such as American Dippers and Belted Kingfishers. Birdwatchers may also spot raptors including Red-tailed Hawks or Golden Eagles soaring above open areas.
From Nevada City, travel 11-miles north on highway-49 toward Downieville. North Bloomfield Road is not recommended. Turn right on Tyler Foote Rd. turnoff from Highway 49 and follow the main paved road to the park.The main road changes names a few times (Cruzon Grade Road, Back Bone Road, Derbec Road, North Bloomfield Road). You will stay on paved roads all the way to the park. These are not high-speed roads. The park is 26-miles (50 min drive time) from Nevada City.


text:
EAT-2Turboclinic's Electronic Actuator Tester empowers the turbocharger reconditioning industry with an intuitive and advanced tool that...
Turbo Electronic Actuator Tester
There are 2 products.
In the intricate world of automotive engineering, turbochargers stand as monumental advancements that significantly enhance engine performance. Central to the operation of a mechanism is the turbocharger electronic actuator, a component tasked with regulating the turbo's variable nozzle turbine or wastegate.
What is a turbo electronic actuator tester?
However, ensuring the correct functioning of these actuators is paramount, which is where a turbo electronic actuator tester becomes an indispensable tool. The actuator tester's role in routine maintenance and troubleshooting is critical for both automotive enthusiasts and professional mechanics alike. Understanding its functions not only contributes to prolonging the life of turbocharged engines but also ensures that they operate at peak efficiency.
A turbo electronic actuator tester is a specialized diagnostic tool designed to calibrate and troubleshoot the actuator of a turbocharger, which controls the variable geometry or wastegate of the turbo. This device sends precise signals to the actuator, mimicking the engine's control unit commands, to test its responsiveness and functionality. It ensures the actuator operates correctly, helping maintain optimal turbocharger performance and prevent issues related to turbo lag or overboost conditions.
Key features to consider when choosing a turbo actuator tester?
When selecting a electronic turbo actuator tester, consider its compatibility with different actuator types, including variable geometry turbochargers (VGT) and wastegate actuators. Look for devices offering precise control over actuation to diagnose issues accurately. User-friendly interfaces with clear diagnostics, real-time feedback, and comprehensive error code libraries are essential for efficient troubleshooting. Robust construction and software update capabilities ensure longevity and adaptability to evolving technologies.
Advantages of using the turbo actuator tester
Utilizing a turbo actuator tester confers several benefits to mechanics and technicians.
- First, it enables accurate diagnostics of actuator health, pinpointing faults with precision. This ensures that only necessary repairs are made, saving time and money.
- Additionally, the tester can verify the success of repairs by simulating engine conditions, confirming that the actuator responds appropriately. This reduces the likelihood of recurring issues, enhancing vehicle performance and customer satisfaction.
The ability to conduct these tests without a full vehicle test drive streamlines the troubleshooting process significantly.
Why choose us?
Selecting our turbo electronic actuator tester ensures precision and reliability. Our state-of-the-art product boasts advanced diagnostics, enabling accurate troubleshooting of turbo actuator issues. We prioritize user-friendliness, ensuring our tester is intuitive and easy to operate. By cooperating with us, you benefit from exceptional customer service, comprehensive after-sales support, and competitive pricing. Trust our expertise for a seamless and efficient testing experience. You can buy turbo electronic actuator tester online at an affordable price.


text:
July 17, 2005 WINSTON-SALEM, N.C. -- A Wake Forest University Baptist Medical Center team is launching a high-tech study to determine if early screening using a special camera and images transmitted over the Internet can prevent blindness in Medicaid patients with diabetes.
"Medicaid patients are rarely screened and are at risk of becoming blind," said Ramon Velez, M.D., M. Sc., the principal investigator. Diabetes is the leading cause of preventable blindness in the United States and Velez said the study will determine if early referral to ophthalmologists will help.
The project -- "I See in NC" -- is being pilot-tested at Downtown Health Plaza of Baptist Hospital, where Velez is medical director, and then will be offered to two rural networks of Community Care of North Carolina. One is Central Piedmont Access II, the other is Access III of the Lower Cape Fear. About 2,000 Medicaid adults with diabetes will be asked to participate.
The other networks of Community Care will get the usual treatment, and Velez and his colleagues will determine whether the screening indeed reduces blindness among patients with diabetic retinopathy because ophthalmologists can act early. Diabetes can lead to changes in blood vessels in the retina called diabetic retinopathy.
Digital photography is the key to the proposal. Trained nurses will take retinal photographs using a special digital camera, and the digital images will be transmitted over the Internet and read at a new screening center at Wake Forest University School of Medicine, Velez said.
The project is being supported by a $465,034 grant from the Duke Endowment to establish the reading center; a $456,203 grant from the Kate B. Reynolds Charitable Trust will pay for the screening in the two networks, and the North Carolina Rural Health Foundation will pay for evaluation.
Velez said Medicaid data would be used to follow the patient outcomes in both the screening group and in the controls.
"Adults with diabetes continue to go blind despite the availability of effective treatment for sight-threatening diabetic retinopathy," said Velez. "These cases of blindness are partially attributable to the low levels of screening. Screening identifies changes in the eye that the patient may not recognize. If treated early, blindness can be prevented."
But, he said, among Medicare patients who have diabetes, more that 30 percent do not get the recommended annual eye screening examination by ophthalmologists. The rate of screening among N.C. Medicaid patients is about 14 percent.
"Primary care physicians rarely perform dilated eye examinations, and the reliability of their examination has been shown to be low," said Velez, a professor of medicine at Wake Forest University School of Medicine and a primary care physician himself. "A recent review of diabetic patients at the Downtown Health Plaza showed that fewer than 20 percent reported having been to an ophthalmologist in the previous three years."
He said that taking retinal photographs in primary care settings is a potential alternative to early testing by ophthalmologists. He said that early trials using film or Polaroid cameras had been effective.
"The recent development of digital retinal photography has spurred a movement to employ this new technology with images transmitted by the Internet to central reading centers," Velez said.
He said that in the pilot testing stage, the team is using a Canon retinal camera, acquired through a grant from the North Carolina Lions Foundation. A diabetic retinopathy reading center is being established at the School of Medicine in cooperation with the Department of Ophthalmology. William P. Moran, M.D., formerly head of the Section on General Internal Medicine, is co-investigator.
Other social bookmarking and sharing tools:
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Note: If no author is given, the source is cited instead.

source: HuggingFaceFW/fineweb-edu


Loose Parts for Active Play & Learning
Loose Parts For Active Play and Learning - Sharron Krull
Benefits of Loose Parts:
 - Helps children actively construct knowledge from their own experiences.
 - Encourages interaction among children and cooperative play
 - Increases risk-taking, conflict resolution, and communication
 - Deepens critical thinking and problem solving
 - Promotes divergent and creative thinking
 - More symbolic and imaginative play
 - Supports gross and fine motor skills
 - Developmentally inclusive
Loose parts are all about active play and learning!
Product Recommendations:
High-Bounce Play Balls Set of 6 (BOUNCE)
Excellerations Brawny Tough Rainbow Parachutes (P6)
Brawny Tough Activity Hoops (HOOPSET)
Zebra Hoops Set of 6 (HULA)
Nylon Jump Ropes (RPST)
Rainbow Movement Scarf Classroom Pack (SCARFSET)
Excellerations Super Sensory Beanbags Set of 12 (COOLBEAN)
Colored Beanbags Set of 12 (CBB)
Colored Cones Set of 10 (SETC)
Pet Pinecones
sharron pet pinecone 4
Yes, there are such things and the grandchildren loved making and playing with them. Making them is easy…just find a favorite pinecone, a stick, and some string or twine and, last but not least, an able and willing Daddy to make them. I had never heard of such make-believe pets, until Daddy Dave shared a favorite activity invented by his dad…
When I was 10 we were on a family backpacking trip with a group that included two other boys around my age. During the hike out we were constantly throwing pinecones at each other and generally being destructive as boys of that age are wont to do. My Dad talked us into tying pinecones to a piece of string and seeing how long a string we could keep them on while still controlling them. He kept score of who was able to keep their pinecones from hitting the most large rocks in the trail and it kept us under control. All in all it was just a good way to channel our 10 year old boy energy into something other than hurting each other.
sharron pet pinecone 2
This is how traditions start and this is our second year of making Pet Pinecones…and it won't be our last! Perhaps, you might want to try this with your children or the children in your care. Get outside, explore, create, and let your imaginations run wild!
Twine or string
sharron pet pinecone 1
 1. Find a favorite stick
 2. Find a large pinecone
 3. Tie the pinecone to the stick with twine or string
 4. Name your pet pinecone– "Piney," "Brownie," "Mr Cone"
 5. Go for a walk or a run with your pet pinecone
 6. Have fun!
sharron pet pinecone 3
Did you know that the stick was inducted into the National Toy Hall of Fame in 2008?
Stay tuned…the BEST is yet to come…sharing more stick fun in my next post!
It's Screen-Free Week! Let's Play Outside!
Did you know that–
sharron kid watching tv
sharron kids climbing trees
sharron kids running
Discount School Supply® Product Recommendations:
Decorate a Kite, kit for 12 (KIDSKITE)
Colorations® Washable Sidewalk Chalk, 50 pieces (SIDEWALK)
Shapes Walking Rope (WALKROPE)
Kickball Kit (KICKBALL)
Flying Discs (FLYD) and Soft Flying Discs (SFDISC)
14′ ClassicRider® Trike (REDRDR14)
Excellerations™ Junior Hoop Ball Goal (HOOP3)
Obstacle Course Activity Set (OCSET)
Rainbow Dancing Wrist Bands (RNBW)
This Rope's Not Just for Jumping!
The jump rope is one of the most inexpensive and versatile pieces of equipment your child or school can own. The jump rope has been neglected, made available primarily for girls, and has been used for a single purpose: jumping. The rope should be 7-8 feet in length and be flexible and pliable. With a little imagination and creativity, look at the rope and think of all the things you can do with it besides jumping.
Snakes: Two people hold each end of the rope and wiggle it by the feet of the children like it's a snake. The object is that the kids have to jump over the "snake."
Walking the Snake: Place a 16' jump rope on the ground in a zigzag pattern. Invite the children to walk on the rope as if it were a tightrope. This simple activity builds a surprising number of skills! Eye-foot coordination…balance…taking turns…and more.
High Water – Low Water: Two people hold each end of the rope. Children take turns leaping over the rope. Increase the height after everyone has had a turn. Provide a mat for safe landings.
Wind the Clock: One person spins around while holding one end of the rope. The rope is swung around in a circle along the ground. Children jump over the rope as it nears their feet. The children usually chant a nursery rhyme like "Hickory Dickory Dock" or some other rhyme to make it more fun.
Jump the Brook: Two ropes placed on the ground in the shape of a "V" become the "brook." The ropes touch at one end and are angled so that each jump across the brook is longer and becomes a bigger jump.
Rope Obstacle Course: Thread a rope between the slots or notches in the top of two cones for jumping over or crawling under. Make three circles with three ropes. Jump from one circle to the next. Lay a rope in a straight line that is to be followed or straddled. Place two ropes parallel to each other and one foot apart. This can be a path for walking, jogging, jumping or hopping.
All Aboard: Young children don't really have the coordination to jump rope, but they can hang onto the rope with a bunch of their friends and pretend to be a train. Make your very own Wooden Train Whistle and with a "Choo! Choo!" children can move from place to place while having fun!
Make A Shape: Ask children to place their rope on the ground and make a circle. Call out directions for children to, "Jump into the circle. Turn around inside the circle. Jump out of the circle. Walk around the circle. Put your foot in the circle. Put your whole body over the circle." After children know the game, move on to other shapes such as a triangle or square.
Remember, most of these activities can be accomplished using your homemade Bread Bag Jump Rope or even a thick piece of yarn.
Discount School Supply® Product Recommendations:
Nylon Jump Ropes (RPST or JMPRP16)
Angeles® Tumbling Mat (TMAT)
Obstacle Course Activity Set (OCSET)
Wooden Train Whistles (CHOO)
Jumbo Roving Yarn (ROVING)
An Egg-cellent Game!
I must share with you a new "find" that I just LOVE! It encourages movement and provides a multitude of other benefits too — balance, coordination, cooperation, and fine motor skills. The item, Egg and Spoon Race (AP25028J) gives a new twist to the old classic Egg and Spoon Pass. This new version is definitely appropriate for the toddler and preschoolers but school-agers love it too. Parents and teachers will also "crack-up" when they see what happens when the egg drops from the spoon. Instead of chocolate bunnies and Easter candy, I'm planning on adding Egg and Spoon Race to all five of my grandchildren's baskets! What fun we'll have as we play the following game.
Egg and Spoon Race
Egg and Spoon Race (4 plastic spoons, 4 egg bean bags, 4 re-breakable eggshells) – AP25028J
Colored Cones – SETC
Hop Around StepsHOPPA
Available indoor or outdoor space
Set Up:
1. Place cones 10-20 feet across from each other to designate "start" and "finish" lines.
2. Place Hop Around Steps two feet apart from each other between the start and finish lines.
Let's Get Started:1. Divide the children into four groups (teams or squads) of equal numbers. Children in each team stand in a straight line or row, one person behind the other.
2. Provide the first child on each team with a spoon and egg.
3. The first child places the egg in the bowl of the spoon.
4. On the command, "Ready, Set, GO!" the race begins as the child walks in and around the Hop Around Steps to the "finish" cone on the opposite side, circles around it, and walks back to his team.
5. He gives the egg and spoon to the second member of his team who then walks holding the egg and spoon and weaving in and out of the Hop Around Steps and back to the start where he passes the egg to next member on his team.
6. The game is over when every child has had a turn carrying the egg in the spoon and the child who started the relay returns to the head of the line.
7. If the egg drops


text:
: the study of the conformation of the skull based on the belief that it is indicative of mental faculties and character
Study of the shape of the skull as an indication of mental abilities and character traits. Franz Joseph Gall stated the principle that each of the innate mental faculties is based in a specific brain region (organ), whose size reflects the faculty's prominence in a person and is reflected by the skull's surface. He examined the skulls of persons with particular traits (including criminal traits) for a feature he could identify with it. His followers Johann Kaspar Spurzheim (1776–1832) and George Combe (1788–1858) divided the scalp into areas they labeled with traits such as combativeness, cautiousness, and form perception. Though popular well into the 20th century, phrenology has been wholly discredited.


text:
Winners Recognized during Farm Science Review
REYNOLDSBURG, Ohio (Sept. 24, 2021) – The Ohio Department of Agriculture recognized five families as winners of the 2021 Conservation Farm Family Awards at the Farm Science Review in London.
The five families honored were: Rodabaugh Family of Hardin County; Sluss Family of Stark County; Jeannie and the late Cliff Miller of Carroll County; Harrod Family of Darke County; and White Clover Farms of Highland County.
Since 1984, the Conservation Farm Family Awards program has recognized Ohio farm families for their exemplary efforts conserving soil, water, woodland, wildlife and other natural resources on the land they farm. Conservation farm families also host a variety of educational programs, opening their farms to schools, scout groups, farm organizations and others.
The families each receive $400 from the Ohio Farm Bureau Federation, are featured in the September issue of Ohio Farmer magazine. Ohio Farmer magazine has sponsored the Ohio Conservation Farm Family Awards since the program's inception. Nominations are sought annually between January and May, and Ohio farming families are encouraged to apply. For more information or to apply, individuals can contact their local Soil and Water Conservation District (SWCD).


text:
Parker Kraus - Biogeochemistry
Colorado College, Fort Collins
Carbon Monoxide Flux in Four Wetland Communities
The production of carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4) by sediment from four wetland communities was measured over a period of 4 days. CO production was documented in intact cores from freshwater wetlands, but not brackish wetland sites. Sediment slurries were incubated anoxically in serum bottles, half of which had CO added to the headspace. Bottles were treated with either sodium molybdate, BES, or a control. Sodium molybdate was used to inhibit sulfate reduction and BES was used to inhibit methanogenesis. Inhibition of microbial processes did not result in significant differences in CO concentrations. Freshwater wetlands were found to produce CO at a greater rate than brackish wetlands, absent the addition of CO. Soils were only observed to consume CO when the gas was added to the headspace. Brackish wetlands were found to consume CO at a greater rate than freshwater wetlands. These results conflict with previous studies, which assumed soils to be net consumers of CO.


Students With Drinking Problems Think They Can't Cope, UF Research Shows
November 20, 1997
"We were interested in finding why drinking becomes a problem for some students," said Jon Kassel, a clinical psychologist in UF's College of Health Professions.
"We found answers to 'ability to cope' questions to be better predictors of problem drinking than other important information, such as whether the person is depressed or anxious, and as good a predictor as knowing how much alcohol a person consumes," he said.
Kassel presented his findings Friday at the Association for the Advancement of Behavior Therapy conference in Miami.
Despite legal restrictions, alcohol flows freely through the college social scene. For many students, it poses few problems: They have a beer now and then but still complete school work, get along well with friends and family and don't drive drunk. But for other students, alcohol spells trouble: They skip classes because they are hung over; they avoid people who criticize their drinking; they get into fights or get arrested.
In the UF research, 100 students from an introductory psychology class filled out questionnaires designed to reveal how they coped with difficulties, whether they expected their efforts to control their mood would be successful and whether they were problem drinkers or suffered from anxiety or depression. All of the students acknowledged having had at least one alcoholic drink during the two months before filling out their final questionnaires.
Kassel, an assistant professor of clinical and health psychology, and two UF graduate students, Shannon Jackson and Marina Unrod, used statistical techniques to determine which factors were related to problem drinking.
"Previous research has shown that people use drugs or alcohol when they do not have more effective ways of coping with problems," Kassel said. "But nobody has looked at it from this angle: Does a person's perception of his ability to cope play a role in problem drinking?
"What we found is that people who had low expectations of being able to handle bad moods or situations were more prone to having problems with alcohol," Kassel said.
Kassel suggests problem drinkers should be taught new coping strategies, such as how to meet problems head-on rather than ignore them and how to enlist the support of friends and family. "But they also need to believe these ways will be effective," he said. "In other words, you might have the ability to cope, but if you don't believe it works, you might turn to alcohol instead."
Kassel said it would take more research to determine whether problem drinkers in the general population also believe they cannot cope well with problems.
"College students sometimes behave differently than the world around them, but I suspect we would have similar findings if we surveyed a cross-section of the public," he said.
(For more information contact Victoria White, Health Science Center Communications, 352/_PHONE_ or E-mail: )
University of Florida
Related Alcohol Articles from Brightsurf:
Alcohol use changed right after COVID-19 lockdown
Changes in hospitalizations for alcohol use disorder in US
New alcohol genes uncovered
Do you have what is known as problematic alcohol use?
Does estrogen influence alcohol use disorder?
Alcohol-induced deaths in US


While btrfs may be relatively "new" in regards to file systems, it is receiving widespread adoption, being included as the default FS in many distros. They is because it provides many advantages when compared to the traditional luks on lvm encrypted linux install:
 1. Subvolume Snapshots: btrfs is a copy-on-write FS (CoW) meaning changes to an individual file result in a new file being written. This means that each subvolume can be snapshotted, where a complete version of every file is captured at a moment in time. This enables simple backup and rollback in case of failure.
 2. Automatic Compression: btrfs subvolumes can store files with dynamic compression. This is extremely configurable across subvolumes with tradeoffs is speed and compression ratio to support the variance in subvolume usage.
 3. Subvolume Resizing: Files are tracked using simple pointers (actually quite complex, but I know very little and can explain even less). This means that unlike traditional disk partitions, which are defined as a collection of disk blocks, data on a single subvolume may span the entire disk and subvolumes contents are tracked with the file descriptors. This means changing subvolume sizes does not mean physically redefining disk partitions but is rather handled quickly and efficiently in metadata.
 4. Many More: But this is not a post on the merits of btrfs.
The problem is that I run debian stable (current version 11). The beauty (and the curse) of this distribution choice is that things move a little slower. As such, the debian installer does not currently support installing btrfs with subvolumes.
Fortunately, there is a fantastic article by Jake Bauer describing how this can be done in debian 10. Unfortunately, the instructions still configure LUKS on LVM with the btrfs subvolumes in an LVM volume group rather than directly within the LUKS crypt. Therefore, I've decided to write up this brief tutorial to provide the later.
Begin the Installation
Push the USB in, and being the installing by choosing Advanced options > Expert install. This is important because it enables us to manually configure btrfs subvolumes later.
Partition Devices
In the partition scheme definition choose Manual partitioning.
We need to create 2 partitions:
 1. EFI partition: I set this to 512MB and the installer should default to vfat and automatically handle /boot/efi mount.
 2. boot partition: This can be 512MB as well and should set the Use as: field to ext2 and set the mount point to /boot.
Then use the Configure encrypted volumes option to create an encrypted LUKS partition with the remaining space. On this LUKS encrypted partition (mine is nvme0n1p3_crypt) set the Use as: field to btrfs journaling file system and the mount point /.
Finish partitioning and write changes to disk
But what about a swapspace?
I typically do not install with swapspace. My machine is equipped with more than adequate RAM and therefore it is only useful for hibernation, which I seldom use. If you want a swapspace, there are a variety of options:
 1. As a separate disk partition.
 2. As an individual btrfs subvolume.
 3. As a btrfs swapfile.
Manually Create and Mount btrfs Subvolumes
One the partitions are written, and BEFORE continuing the installation, we need to manually create and mount the btrfs subvolumes.
There are two trains of though for organizing btrfs subvolumes:
 - hierarchical: subvolumes are defined within other subvolumes.
 - flat: subvolumes are mounted within other subvolumes but are define externally.
I prefer a flat layout, probably because it results in more clearly defined partitions. If you would rather install with a hierarchical system, you can probably figure out the requisite changes.
Begin by pressing Ctrl+Alt+F2 to drop into a shell and press Enter to activate it.
Use the df command to view the current mounted partitions. There should be three important mounts:
 1. The luks encrypted btrfs root subvolume mounted to /target - mine is the device /dev/mapper/nvme0n1p3_crypt.
 2. The boot partition mounted to /target/boot - mine is the device /dev/nvme0n1p2.
 3. The EFI partition mounted to /target/boot/efi - mine is the device /dev/nvme0n1p1.
We need to umount the partitions in reverse order:
~ # umount /target/boot/efi
~ # umount /target/boot
~ # umount /target
Then we mount our existing root subvolume to /mnt.
~ # mount /dev/mapper/nvme0n1p3_crypt /mnt
Create new subvolumes. I have chosen separate for /root, /home, and /var. /snapshots is used to store btrfs snapshots. You can easily update this to your preference.
~ # btrfs subvolume create @
~ # btrfs subvolume create @home
~ # btrfs subvolume create @var
~ # btrfs subvolume create @snapshots
And mount them underneath the installation directory /target. There are tons of different mount configuration options, these are a sane default selection.
~ # mount -o noatime,compress=lzo,space_cache,subvol=@ /dev/mapper/nvme0n1p3_crypt /target
~ # mkdir /target/home
~ # mount -o noatime,compress=lzo,space_cache,subvol=@home /dev/mapper/nvme0n1p3_crypt /target/home
~ # mkdir /target/snapshots
~ # mount -o noatime,compress=lzo,space_cache,subvol=@snapshots /dev/mapper/nvme0n1p3_crypt /target/snapshots
~ # mkdir /target/var
~ # mount -o noatime,compress=lzo,space_cache,subvol=@var /dev/mapper/nvme0n1p3_crypt /target/var
Remount the /boot and /boot/efi partitions.
~ # mkdir /target/boot
~ # mount /dev/nvme0n1p2 /target/boot
~ # mount /dev/nvme0n1p1 /target/boot/efi
Copy over the /etc metadata.
~ # mkdir /target/etc
~ # cp /mnt/etc/fstab /target/etc
~ # cp /mnt/etc/crypttab /target/etc/crypttab
Update the fstab file (now located at /target/etc/fstab) to include our new btrfs subvolume mounts. It should end up looking something like the example below:
# <file system> <mount point> <type> <options> <dump> <pass>
#/dev/mapper/nvme0n1p3_crypt / btrfs defaults,subvol=@rootfs 0 0
# /boot was on /dev/nvme0n1p2 during installation
UUID=f434d69d-c351-498d-bb6c-0b78d44754dc /boot ext2 defaults 0 2
# /boot/efi was on /dev/nvme0n1p1 during installation
UUID=BF50-85A0 /boot/efi vfat umask=0077 0 1
# btrfs subvolumes mounted manually during installation
/dev/mapper/nvme0n1p3_crypt / btrfs noatime,compress=lzo,space_cache,subvol=@ 0 0
/dev/mapper/nvme0n1p3_crypt /home btrfs noatime,compress=lzo,space_cache,subvol=@home 0 0
/dev/mapper/nvme0n1p3_crypt /snapshots btrfs noatime,compress=lzo,space_cache,subvol=@snapshots 0 0
/dev/mapper/nvme0n1p3_crypt /var btrfs noatime,compress=lzo,space_cache,subvol=@var 0 0
And finally cleanup the btrfs root, otherwise these directories will remain in the final installation.
~ # rm -r /mnt/boot /mnt/etc /mnt/media
~ # umount /mnt
Once this is done you can exit out of the terminal with Ctrl+D and return to the installation with Ctrl+Alt+F1.


text:
| Cancer Tree |
| Camptotheca acuminata|
| Uses: Medicinal
|| Duration: Perennial (hardy in zones 9+) |
| When to Sow: Anytime
|| Ease of Germination: Moderate |
| (Xi Shu, Happy Tree, Tree of Life)
Chinese tree with proven anti-cancer properties. The bark, stem and leaves contain camptothecin, an alkaloid effective against leukemia, colon cancer and other tumours, and it blocks the replication of the HIV virus that causes AIDS. Drugs derived from the tree are ringing up sales in excess of $1 billion. In traditional Chinese medicine it is used for the treatment of colds, psoriasis, cancers and leukemia of the liver, gallbladder and stomach. Due to overharvesting in China it is endangered in the wild, but it is now in cultivation in India and Japan. It was introduced to America in 1930s and is growing in Florida and Georgia. The tree reaches 20m/65ft.


Home / Life Science / Plasmolysis
What is Plasmolysis: Its Relation to Osmosis
Plasmolysis is the process of contraction or shrinkage of the cytoplasm and the plasma membrane of a plant cell due to excessive water loss. It occurs under the influence of osmosis. Plasmolysis rarely happens in nature but is observed in extreme situations under strict laboratory conditions or during experiments. Apart from plant cells, it is also found to occur in bacteria. The state of a cell that went through plasmolysis is said to 'plasmolyzed'.
The term plasmolysis is derived from the Latin word 'plasma' meaning 'matrix' and the Greek word 'lysis', meaning 'loosening'.
When Does It Occur
It occurs when a cell is placed in a solution having a higher concentration of solutes than inside the cell (hypertonic solution), causing water to move out into the surrounding extracellular fluid.
What Happens in Plasmolysis: Its Process
The cell membrane is semipermeable. It is responsible for maintaining cell turgidity by allowing the selective entry of water and ions while blocking others. The turgor pressure generated by water molecules against the cell wall is necessary to the vitality of the plant structure. A turgid plant cell prevents the further intake of water. The plant vacuole also plays a vital role in this regulation process.
When a cell is exposed to a hypertonic solution, water starts to flow down its concentration gradient. It thus moves from a region of low solute concentration inside the cell to the high solute concentration in the extracellular fluid. The net water movement across the plasma membrane through osmosis causes the plant cell wall to lose its turgor pressure. Finally, it causes the central vacuole and the cytoplasm (together known as protoplast) to detach from the cell wall, and the cell is said to be in plasmolyzed state.
After plasmolysis, the size of the protoplast gets reduced. Simultaneously the pressure on the cell wall decreases, causing it to contract and reduce in size. At times, if water is lost severely, the cell walls may collapse, which results in the death of the cell.
When a cell is exposed to an isotonic solution, it loses its turgor pressure. At this stage, although the cell does not get plasmolyzed, it is not turgid either. As a result, the green parts of the plant droop and cannot hold the leaves up in the sunlight.
Plasmolysis hardly happens in nature. Instead, it is induced in the laboratory by immersing living cells in strong saline or sugar solutions to undergo exosmosis. Generally, the cells of Tradescantia or Rheo plant, Elodea plants, or onion epidermal cells are used for this experiment. The reason is that they have colored sap, making them easily observable and identifiable under the microscope.
Stages of Plasmolysis in Plant Cell
The whole process of plasmolysis can be described in three stages:
 1. Incipient Plasmolysis: It is the first plasmolysis stage during which no morphological changes appear in the cell. The first sign of shrinkage of cell contents from the cell wall is evident at this stage as water starts flowing out of the cell. During this stage, the cell wall exerts no pressure on the cell contents, but the protoplast moves away from the corners of the cell wall. This stage is reversible, and the cell is in flaccid condition.
 2. Evident Plasmolysis: It is the next stage in which the protoplasm reaches the limit of contraction. The cytoplasm and plasma membrane get detached from the cell wall (except one or a few points) and turns spherical due to exosmosis. During this stage the cell wall is not in touch with the protoplasm and the leaves appear wilted. This stage is also reversible.
 3. Final Plasmolysis: It is the final stage of plasmolysis when the cytoplasm completely detaches itself from the cell wall and moves to the cell center.
Types of Plasmolysis
Plasmolysis can be classified into two types depending on the appearance of shrunken protoplasm.
 1. Concave Plasmolysis: In this case, both the plasma membrane and protoplasm shrinks and get detached from the cell wall due to water efflux. A 'half-moon shape' is formed in the cell due to detachment of cytoplasm, thus giving its name concave. Concave plasmolysis can be reversed by keeping the cell in a hypotonic solution, helping them regain the lost water.
 2. Convex Plasmolysis: Excessive water loss from the cell causes the cell membrane and protoplasm to shrink away from the cell wall. As convex plasmolysis is irreversible, it eventually leads to cytorrhysis, i.e., the complete collapse of the cell.
Do Cells Recover from the State of Plasmolysis
As stated above, plasmolysis is generally a reversible decrease in the volume of a plant cell. When exposed to a hypotonic solution or water, a plasmolyzed cell swells up and becomes turgid due to endosmosis. This phenomenon is called deplasmolysis or cytolysis. It is only possible if the cell is placed in a hypotonic solution immediately after plasmolysis; otherwise, the cell protoplast gets damaged permanently.
During deplasmolysis, water again passively diffuses into the protoplast, i.e., the central vacuole and cytoplasm. As a result, the protoplast swells up. Initially, it comes in contact with the cell wall and then develops the turgor pressure.
Its Importance
 - Helping to prove that the cell membrane is semipermeable in nature.
 - Helping to prove that the cell wall is elastic as well as permeable.
 - Measuring the osmotic pressure (OP) of a cell. This is because the OP of a cell is roughly equivalent to the osmotic pressure of the extracellular solution causing incipient plasmolysis.
 - Determining if a cell is dead or alive, as only living cells exhibit plasmolysis.
 - Making tennis lawns free of weeds by salting, which kills the weeds by permanent plasmolysis.
 - Inhibiting plant growth in the cracks of the walls by salting.
 - Preventing the microbial decay of foods. For example, salting pickles, meat, and fish and sweetening of the jams and jellies.
Examples in Daily Life
 - Shrinking of vegetables when kept in a hypertonic environment.
 - Contraction of blood cells, like RBCs, when placed in a hypertonic environment.
 - Depositing salts by ocean water during extreme coastal flooding.
 - Killing weeds in lawns, orchards, and agricultural fields by spraying weedicides.
 - Salting of foods like jams, jellies, and pickles, which act as preservatives. As microorganism cells lose water due to a higher concentration of the solute outside the cell by plasmolysis, the foods become less susceptible to their growth.
Q1. What are the differences between plasmolysis and hemolysis?
Ans. Plasmolysis refers to shrinking the plant cell protoplast due to the excessive loss of water from it. In contrast, hemolysis refers to the destruction of red blood cells (RBCs), which leads to the release of hemoglobin from the RBCs into the blood plasma. Unlike plasmolysis, hemolysis is a natural phenomenon by which old RBCs are replaced.
Article was last reviewed on Monday, June 7, 2021
Leave a Reply


Rare 1652 NE Threepence silver coinToday we take a look at the fascinating 1652 NE Threepence silvercoin.
In 1652, the first metallic currency was struck in England's American colonies. During this time period, the American colonies were suffering from a currency shortage. The English government had banned the export of its silver coins to its own colonies. England was experiencing a coin shortage itself and wanted to keep its small coin denominations at home, but the government also believed that the colonies should be sending wealth to England (certainly not the other way around). Even if the English government had wanted to send coins to the colonies, they were unable to do so until they had solved their own currency problems. Of the coins in circulation in the colonies, many were counterfeits. The local businesses struggled to maintain a healthy economy, particularly in bustling port towns like Boston which was already engaging in a healthy import/export trade by the mid 1600s.
The colony of Massachusetts Bay, laboring under the small change coin shortage, resolved to solve the problem on its own. Without bothering to ask approval from the English government, the General Court of Massachusetts Bay charged silversmiths John Hull and Robert Sanderson to create shilling, sixpence, and threepence coins.
The first coins struck in America were made by an illicit mint in Boston, Massachusetts. The coins were struck in silver and are known as the "NE" or "New England" type coins. The coins were struck for only three months in 1652 and are exceedingly rare. The coins were simple, irregularly shaped discs with no decoration or date. One side bore the punched initials of "NE" for New England, while the reverse bore the denomination on the reverse in Roman numerals (III for threepence, VI for sixpence, XII for shilling).
Rare 1652 NE Threepence silver coinOnly one specimen of the 1652 NE Threepence coin is known to exist, and is held in the collections of the Massachusetts Historical Society, though every denomination of the surviving 1652 New England coins is a genuine rarity.
We recently came across an interesting 19th century facsimile coin designed after the extraordinarily rare 1652 New England Threepence. The 1652 NE coins were already known and valued as scarce by this time. In the mid 19th century, the hobby of coin collecting exploded into wild popularity. The surge in interest in coins led to the eternal collector's dilemma: there are only a very limited number of rare coins, and passionate collectors may never see, let alone own, the most interesting and exciting examples in their field of interest. While counterfeiting coins for use as currency has existed as long as currency has itself, the coin collecting boom now saw an increase in the creation of facsimiles of rare and desirable coins. Some of these facsimiles were honestly sold as interesting copies for the passionate and knowledgeable collector who simply wanted a version of a rarity for his own enjoyment. However, some unscrupulous people would sell the facsimiles as authentic, duping their trusting customers.
The 1652 NE Threepence coin is a fascinating glimpse into the history of the American colonies. Our version of this coin can be found in our store.
Or, click here to visit our store and see everything currently available!
The 1652 NE Threepence Silver Coin
Tagged on:


text:
The winter night sky
Storrs - posted Feb, 22 2013
STORRSThe Connecticut State Museum of Natural History, part of the College of Liberal Arts and Sciences at UConn, will hold an astronomy workshop on Friday, March 8, at 6 p.m. The workshop "Look Up! Viewing Winter's Night Sky" will be presented by Dr. Cynthia Peterson from the University of Connecticut's Physics Department. Start with a visit to UConn's Planetarium during this exploration of the winter night sky! Learn how to identify the stars, planets, and other celestial objects observable throughout this season. During this program, Astronomy Professor Dr. Cynthia Peterson will offer a general orientation to the constellations, planets, and special celestial objects visible in the night sky using binoculars. The discussion will also include comets and the expected trajectory of the newfound Bright Comet PanSTARRS. While in the planetarium participants can also examine an orrery, a mechanical device illustrating the relative positions and motions of the planets in the solar system. Weather permitting, the session will conclude with a trip to the UConn Observatory on the roof of the physics building. Using binoculars and, if the conditions permit, the telescope, observers may see the Bright Comet PanSTARRS in the west, open clusters in the late winter Milky Way, the Andromeda Galaxy (M31), the H Chi double star cluster, Jupiter, and the Orion Nebula (M42). Dress warmly for the outdoor session and please bring binoculars! The program fee is $20, $15 for Museum members, and is open to adults and children ages 8 and above. Children must be accompanied by an adult. Advance registration is required. For further information visit _URL_ or call _PHONE_.


Using Breakpoints to Step through Code
Breakpoints can be set on one or more lines of code. When a line of code that has an associated breakpoint is reached, code execution stops and you can then choose to Step Into, Step Over, or Step Out of the code. Selecting the Step Into option from the Debug menu will run the current line of code at the breakpoint. The Step Over option will skip the current line of code at the breakpoint and move on to the next line of code.
Try It Out Setting and Using Breakpoints
It's your turn to set a breakpoint and use it to step through code.
1. Navigate to the TestLoop procedure you created previously in the modBusinessLogic standard module.
2. Set a breakpoint on the Debug.Print and the Next intCounter lines of code, as shown in Figure 2.33. You can set a breakpoint by pointing and clicking the cursor just to the left of the line of code where you want to add a breakpoint.
Figure 2.33
3. Next, open the Immediate Window and run the TestLoop procedure. The code will stop execution at the first breakpoint, as shown in Figure 2.34.
Figure 2.34
4. While at the breakpoint, use the Immediate Window to inquire about the current value of the intCounter variable. To do so, type ? intCounter and press Enter, as shown in Figure 2.35.
Immediate
"ST
testloop
a.
? intcountei
1
<
Figure 2.35
5. The current value of intCounter is displayed in the Immediate Window. You should press F5 or select Run C> Continue to keep executing the lines of code. Execution will stop on each breakpoint.
0 0
Responses
 - bodo
 How to use breakpoints in access vba?
 8 years ago
Post a comment


Postoperative seroma formation in breast reconstruction with latissimus dorsi flaps: A retrospective study of 174 consecutive cases
Koichi Tomita, Kenji Yano, Takeshi Masuoka, Ken Matsuda, Akiyoshi Takada, Ko Hosokawa
 Research output: Contribution to journalArticlepeer-review
 55 Citations (Scopus)
 Abstract
 The latissimus dorsi flap has been widely used in breast reconstruction surgery. Despite its potential advantages such as low donor morbidity and vascular reliability, the complication of donor-site seroma formation frequently occurs. Consecutive 174 patients who underwent breast reconstruction with the latissimus dorsi flap from 2001 to 2006 were retrospectively reviewed. The age, body mass index (BMI), smoking history, timing of reconstruction, type of breast surgery and nodal dissection, and several other intraoperative data were analyzed. The overall incidence of postoperative seroma was 21%. Increased age (>50 years) and obesity (BMI >23 kg/m) were significant risk factors for seroma formation (P = 0.02 and 0.004, respectively). The patients who underwent skin-sparing mastectomy or modified radical mastectomy had higher incidence of seroma formation (28% and 33%, respectively) as compared with those who had breast-conservative surgery (11%). A significant correlation was found between the type of breast surgery and the incidence of seroma (P = 0.04). The type of nodal dissection did not affect the incidence of postoperative seroma (P = 0.66). We concluded that increased age, obesity, and invasive breast surgery are risk factors for donor-site seroma formation after breast reconstruction with the latissimus dorsi flap. Close attention should be paid to prevent development of postoperative seroma when operating on such high-risk patients.
 Original languageEnglish
 Pages (from-to)149-151
 Number of pages3
 JournalAnnals of Plastic Surgery
 Volume59
 Issue number2
 DOIs
 Publication statusPublished - 2007 Aug
 Keywords
 - Breast reconstruction
 - Donor-site seroma
 - Latissimus dorsi flap
 - Risk factor
 ASJC Scopus subject areas
 - Surgery
 Fingerprint
 Dive into the research topics of 'Postoperative seroma formation in breast reconstruction with latissimus dorsi flaps: A retrospective study of 174 consecutive cases'. Together they form a unique fingerprint.
 Cite this


Simple Guide to Cosmetic Clay Types & their Uses!
Updated: Jul 24, 2020
There is an endless number of ways in which to use cosmetic clays, and we encourage you to find your creative outlet!
BENTONITE CLAY Bentonite clay is composed of volcanic ash sediments that have been weathered over a long period of time. Sodium bentonite clay is known for its swelling properties, as it acts like a sponge when mixed with water. This clay is very popular for facial masks, foot baths, or bath soaking blends.
Dry Characteristics: The dry clay has a neutral scent and a pale, off-white color. The texture is slightly grainy, but it smooths out when pressed between the fingers. While it does leave something of a powdery coating behind when brushed off, the dry clay doesn't stick to skin too much.
Wet Characteristics: When wet, the clay paste is off-white in color with a smooth consistency. If liquid is added in too slowly, clumps will form, and the use of a whisk is helpful for keeping a smooth consistency. This wet clay spreads smoothly on skin, and its thick texture is reminiscent of cooked oatmeal.
Bowls and spoons with wet and dry bentonite and French green clays.
FRENCH GREEN CLAY French green clay is so named because some of the first recorded deposits of this clay were found in France, although it is now known to be found in many different spots around the globe. This fine-textured clay takes its verdant color from decomposed plant matter. Many people find French green clay helpful for occasional blemishes, and it is generally used by those with average to oily skin.
Dry Characteristics: French green clay has a neutral earthy aroma and pale green color. This clay doesn't "puff" (create a cloud of fine mist) out of the bag and has a fine texture, with a slight graininess.
Wet Characteristics: When water is added, the paste of this clay tends to have a slight lumpiness. Be sure to mix slowly and thoroughly with a whisk when adding liquid for smoother clay preparations. This clay has a somewhat darker green hue when moistened then in its dry form. The texture has a tendency to be a bit grainy when applied to the skin and is similar to the Rhassoul clay in consistency.
FULLER'S EARTH CLAY Fuller's earth clay has very strong oil absorbing abilities, and because of this, it is recommended for those with very oily skin. This clay is also helpful in stain removal and has mild natural bleaching properties.
Dry Characteristics: The dry clay has a lightly earthy scent and an off-white to greenish and tan color. The texture is fine and powdery. It is also very lightweight, so watch out, it can get everywhere!
Wet Characteristics: Fuller's earth clay is very smooth and easy to mix with liquids. The color is dark grey to dark tan, and it retains a fairly thick consistency when wet.
Plate with 4 sections, filled with the earth-toned clays Fuller's earth and rhassoul.
RHASSOUL CLAY Rhassoul clay is a fine, red-colored clay from Morocco that has been used for centuries in the realm of natural skin care. While it will still absorb oils from the skin, it is much gentler than many other clays and is typically recommended for more sensitive or mature skin types.
Dry Characteristics: When dry, this clay has a light reddish-brown color and a fine texture; its slight grain feels similar to French green clay. However, unlike French clay, its lightness gives it a tendency to slightly puff out of an opened bag.
Wet Characteristics: This clay mixes easily into water to create a darker, red-brown colored paste without lumps. It still retains a slight graininess, though this goes away as the clay absorbs water. It's easy to smooth onto skin and has a thin consistency when spread out.
Bowl and spoon with constituted beige clay and a spoon of dried white Kaolin clay spilling off of it.
WHITE COSMETIC CLAY White cosmetic clay (aka Kaolin clay), is not as absorbent as other clays, making it appropriate for skin that tends to be drier or more sensitive. Often, this clay is found as an ingredient in mineral makeup.
Dry Characteristics: This clay has a neutral scent with a light tan color that can vary to off-white. The texture is very fine and soft, and it will coat skin with a thin powdery layer when handled.
Wet Characteristics: When liquid is added, this clay takes on a much darker tan color. The texture remains fine and mixes easily with water, and it is smooth and grit-free.
25 views0 comments
Recent Posts
See All


text:
RIVERHEAD, N.Y. – SQ4D Inc., announced today that its robotic construction system has built the largest permitted 3D-printed home in the world, using less than $6,000 in materials.
The Patchogue, N.Y.-based company's Autonomous Robotic Construction System (ARCS) constructed a 1,900-square-foot home, taking 48 hours of print time over an eight-day period, the company said. It added that due to ARCS enhancements implemented post-construction, future print times are expected to be cut in half.
The ARCS platform robotically builds foundations, exterior walls, interior walls, utility conduits, and more, SQ4D said. The company said the digitally driven system can reduce labor to as little as three people – labor costs accounting for up to 41% of the total construction cost of a home. The system's low-power consumption technology also allows homes and buildings to be built using less energy than traditional construction methods, creating an environmentally friendly impact, the company added.
The robotic platform eliminates and consolidates more than 20 manual labor intensive processes, which include siding, framing, and sheathing. "This revolutionary technology will be replacing and eliminating more expensive and inferior building materials, causing the printed structures to be stronger and safer," the company said in a statement. "Utilizing concrete will reduce the cost by at least 30%, as well as making the structure more fire resistant than traditional methods. This home will have the strength to last into the next century."
3D-printing robots are part of an overall construction robotics market that is expected to reach $190 million by 2025, according to a report by Infoholic Research. Other segments in this space include demolition robots, brick-laying robots and autonomous construction vehicles and equipment. "3D printing will revolutionize the construction industry by changing the traditional planning and development methods," said Arjun Das, senior research analyst at Infoholic Research. "High level of scalability in 3D printing will help construction companies build custom projects and building on demand (BOD) quickly, along with eliminating the need for transporting large goods."
Similarly, ABI Research said automation technology advances are helping to drive "the next frontier of robotics adoption" in the construction and mining segments. However, ABI said most of the growth initially in this space will be around autonomous mobile robots performing haulage tasks, rather than specific tasks such as brick-laying, painting, loading, or bulldozing."


Correlation in R: Pearson & Spearman with Matrix Example
A bivariate relationship describes a relationship -or correlation- between two variables, and . In this tutorial, we discuss the concept of correlation and show how it can be used to measure the relationship between any two variables.
There are two primary methods to compute the correlation between two variables.
 - Pearson: Parametric correlation
 - Spearman: Non-parametric correlation
Pearson Correlation
The Pearson correlation method is usually used as a primary check for the relationship between two variables.
The coefficient of correlation , , is a measure of the strength of the linear relationship between two variables and . It is computed as follow:
Learn Java Programming with Beginners Tutorial
with
 - , i.e. standard deviation of
 - , i.e. standard deviation of
The correlation ranges between -1 and 1.
 - A value of near or equal to 0 implies little or no linear relationship between and .
 - In contrast, the closer comes to 1 or -1, the stronger the linear relationship.
We can compute the t-test as follow and check the distribution table with a degree of freedom equals to :
Spearman Rank Correlation
A rank correlation sorts the observations by rank and computes the level of similarity between the rank. A rank correlation has the advantage of being robust to outliers and is not linked to the distribution of the data. Note that, a rank correlation is suitable for the ordinal variable.
Spearman's rank correlation, , is always between -1 and 1 with a value close to the extremity indicates strong relationship. It is computed as follow:
with stated the covariances between rank and . The denominator calculates the standard deviations.
In R, we can use the cor() function. It takes three arguments, , and the method.
cor(x, y, method)
Arguments :
 - x: First vector
 - y: Second vector
 - method: The formula used to compute the correlation. Three string values:
 - "pearson"
 - "kendall"
 - "spearman"
An optional argument can be added if the vectors contain missing value: use = "complete.obs"
We will use the BudgetUK dataset. This dataset reports the budget allocation of British households between 1980 and 1982. There are 1519 observations with ten features, among them:
 - wfood: share food share spend
 - wfuel: share fuel spend
 - wcloth: budget share for clothing spend
 - walc: share alcohol spend
 - wtrans: share transport spend
 - wother: share of other goods spend
 - totexp: total household spend in pound
 - income total net household income
 - age: age of household
 - children: number of children
Example
library(dplyr) PATH <-"_URL_ data <-read.csv(PATH) filter(income < 500) mutate(log_income = log(income), log_totexp = log(totexp), children_fac = factor(children, order = TRUE, labels = c("No", "Yes"))) select(-c(X,X.1, children, totexp, income)) glimpse(data)
Code Explanation
 - We first import the data and have a look with the glimpse() function from the dplyr library.
 - Three points are above 500K, so we decided to exclude them.
 - It is a common practice to convert a monetary variable in log. It helps to reduce the impact of outliers and decreases the skewness in the dataset.
Output:
Observations: 1,516## Variables: 10 ## $ wfood 0.4272, 0.3739, 0.1941, 0.4438, 0.3331, 0.3752, 0… ## $ wfuel 0.1342, 0.1686, 0.4056, 0.1258, 0.0824, 0.0481, 0… ## $ wcloth 0.0000, 0.0091, 0.0012, 0.0539, 0.0399, 0.1170, 0… ## $ walc 0.0106, 0.0825, 0.0513, 0.0397, 0.1571, 0.0210, 0… ## $ wtrans 0.1458, 0.1215, 0.2063, 0.0652, 0.2403, 0.0955, 0… ## $ wother 0.2822, 0.2444, 0.1415, 0.2716, 0.1473, 0.3431, 0… ## $ age 25, 39, 47, 33, 31, 24, 46, 25, 30, 41, 48, 24, 2… ## $ log_income 4.867534, 5.010635, 5.438079, 4.605170, 4.605170,… ## $ log_totexp 3.912023, 4.499810, 5.192957, 4.382027, 4.499810,… ## $ children_fac Yes, Yes, Yes, Yes, No, No, No, No, No, No, Yes, …
We can compute the correlation coefficient between income and wfood variables with the "pearson" and "spearman" methods.
cor(data$log_income, data$wfood, method = "pearson")
output:
[1] -0._PHONE_
cor(data$log_income, data$wfood, method = "spearman")
Output:
[1] -0._PHONE_
Correlation Matrix
The bivariate correlation is a good start, but we can get a broader picture with multivariate analysis. A correlation with many variables is pictured inside a correlation matrix . A correlation matrix is a matrix that represents the pair correlation of all the variables.
The cor() function returns a correlation matrix. The only difference with the bivariate correlation is we don't need to specify which variables. By default, R computes the correlation between all the variables.
Note that, a correlation cannot be computed for factor variable. We need to make sure we drop categorical feature before we pass the data frame inside cor().
A correlation matrix is symmetrical which means the values above the diagonal have the same values as the one below. It is more visual to show half of the matrix.
We exclude children_fac because it is a factor level variable. cor does not perform correlation on a categorical variable.
the last column of data is a factor level. We don't include it in the code mat_1 <-as.dist(round(cor(data[,1:9]),2)) mat_1
Code Explanation
 - cor(data): Display the correlation matrix
 - round(data, 2): Round the correlation matrix with two decimals
 - as.dist(): Shows the second half only
Output:
wfood wfuel wcloth walc wtrans wother age log_income ## wfuel 0.11 ## wcloth -0.33 -0.25 ## walc -0.12 -0.13 -0.09 ## wtrans -0.34 -0.16 -0.19 -0.22 ## wother -0.35 -0.14 -0.22 -0.12 -0.29 ## age 0.02 -0.05 0.04 -0.14 0.03 0.02 ## log_income -0.25 -0.12 0.10 0.04 0.06 0.13 0.23 ## log_totexp -0.50 -0.36 0.34 0.12 0.15 0.15 0.21 0.49
Significance level
The significance level is useful in some situations when we use the pearson or spearman method. The function rcorr() from the library Hmisc computes for us the p-value. We can download the library from conda and copy the code to paste it in the terminal:
conda install -c r r-hmisc
The rcorr() requires a data frame to be stored as a matrix. We can convert our data into a matrix before to compute the correlation matrix with the p-value.
library("Hmisc") data_rcorr <-as.matrix(data[, 1: 9]) mat_2 <-rcorr(data_rcorr) # mat_2 <-rcorr(as.matrix(data)) returns the same output
The list object mat_2 contains three elements:
 - r: Output of the correlation matrix
 - n: Number of observation
 - P: p-value
We are interested in the third element, the p-value. It is common to show the correlation matrix with the p-value instead of the coefficient of correlation.
p_value <-round(mat_2[["P"]], 3) p_value
Code Explanation
 - mat_2[["P"]]: The p-values are stored in the element called P
 - round(mat_2[["P"]], 3): Round the elements with three digits
Output:
wfood wfuel wcloth walc


Download The Moments of Student's t distribution
Survey
yes no Was this document useful for you?
 Thank you for your participation!
* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project
Document related concepts
History of statistics wikipedia, lookup
Student's t-test wikipedia, lookup
Taylor's law wikipedia, lookup
Bootstrapping (statistics) wikipedia, lookup
Degrees of freedom (statistics) wikipedia, lookup
Gibbs sampling wikipedia, lookup
Transcript
The Moments of Student's t Distribution

The kurtosis of Student's t is infinite when df ≤ 4. Otherwise it is 6/(df – 4)

The skewness of Student t is 0, unless df ≤ 3, in which case it is not defined.

The standard deviation of Student's t distribution is the square root of df / (df – 2),
unless df ≤ 2, in which case it is not defined.

The mean of Student's t distribution is 0, unless df = 1, in which case it is not
defined.
I have my students run a little Monte Carlo to create the sampling distribution of t
and then fiddle with sample size and the shape of the population from which the scores
are sampled. This allows them to demonstrate the consistency of the mean and the
variance, the central limit theorem, and so on. When I ran it with sample sizes of 4, I
found that the obtained distributions of sample means (100,000 to 1,000,000 samples in
each distribution) had outrageous values for g1 and g2, and these values changed wildly
from one replication to the next. For example, on one run, g1 = .04 and g2 = 102. On
the next run g1 = .4.66 and g2 = 707. On a third run g1 = -26 and g2 = 8,063. Now I
know why – neither skewness nor kurtosis are defined for Student's t on 3 degrees of
freedom.
It was Robert J. MacG. Dawson who explained this to me, answering a query
about it on Edstat-L:
The skewness (in the third-moment sense) is only defined
for df >= 4. It's a matter of convergence of improper integrals.
T_1 (two data, one degree of freedom) is the Cauchy
distribution, and has no mean. This is because in computing it
you are dividing one normally distributed RV by another - hence
[in polar coordinates] the CDF is basically arctangent - hence
the pdf is 1/(1+x^2)and the mean is the integral from -infinity
to infinity of x/(1+x^2)which is easily seen to diverge. Its
Cauchy principle value is 0 as befits a symmetric function, but
the limits at -infinity and infinity cannot be evaluated
independently. If you try to compute a sample mean for a T_1
simulation it will not converge as the sample size increases.
By a similar argument T,_2 (3 data, pdf 1/{(2+x^2)^(3/2)}
is of order x^-3 at infinity and has a mean but no standard
deviation; and T_3 (4 data) has mean, SD, but no third moment.
There are also measures of skewness (eg, Q1+Q3-2M, which is
completely order based) that are defined even for T_1. They are
also zero.
Karl L. Wuensch, East Carolina University, November, 2009


text:
Search results for: History
Page 3/3 21 items
Contesting the Curriculum: An Examination of Professionalism as Defined and Enacted by Australian History Teachers
In this article, the author presents an analysis of professionalism as defined and enacted by the History Teachers' Association of New South Wales (HTANSW). The author's aim for this project was to explore what professionalism means in practice for a unique group of teachers: those who have made an active and fundamental commitment to their subject community by voluntarily serving on the executive committee of their subject-based professional association.
Updated: Feb. 17, 2008