Persius/hicric huggingface dataset:
Content validity
In psychometrics, content validity (also known as logical validity) refers to the extent to which a measure represents all facets of a given social concept. For example, a depression scale may lack content validity if it only assesses the affective dimension of depression but fails to take into account the behavioral dimension. An element of subjectivity exists in relation to determining content validity, which requires a degree of agreement about what a particular personality trait such as extroversion represents. A disagreement about a personality trait will prevent the gain of a high content validity.
Content validity is related to face validity, though content validity should not be confused with face validity. The latter is not validity in the technical sense; it refers, not to what the test actually measures, but to what it appears superficially to measure. Face validity pertains to whether the test "looks valid" to the examinees who take it, the administrative personnel who decide on its use, and other technically untrained observers. Content validity requires more rigorous statistical tests than face validity, which only requires an intuitive judgement.  Content validity is most often addressed in academic and vocational testing, where test items need to reflect the knowledge actually required for a given topic area (e.g., history) or job skill (e.g., accounting).  In clinical settings, content validity refers to the correspondence between test items and the symptom content of a syndrome.
One widely used method of measuring content validity was developed by C. H. Lawshe. It is essentially a method for gauging agreement among raters or judges regarding how essential a particular item is. Lawshe (1975) proposed that each raters on the judging panel respond to the following question for each item: "Is the skill or knowledge measured by this item essential/useful but not essential/ not necessary to the performance of the construct?" According to Lawshe, if more than half the panelists indicate that an item is essential, that item has at least some content validity. Greater level of content validity exist as larger numbers of panelists agree that a particular item is essential. Using these assumptions, Lawshe developed a formula termed the content validity ratio:
CVR= content validity ratio, ne= number of panelists indicating "essential", N= total number of panelists.
And the minimum values of the CVR to ensure that agreement is unlikely to be due to chance can be found in the following table:
Conus medullaris

# Overview
The conus medullaris is the terminal end of the spinal cord. It occurs near lumbar nerves 1 (L1) and 2  (L2). After the spinal cord terminates, the spinal nerves continue as dangling nerves called the cauda equina. The upper end of the conus medullaris is usually not well defined.

# Blood supply
The blood supply consists of three spinal arterial vesselsthe anterior median longitudinal arterial trunk and two posterolateral trunks. Other less prominent sources of blood supply include radicular arterial branches from the aorta, lateral sacral arteries, and the fifth lumbar, iliolumbar, and middle sacral arteries. The latter contribute more to the vascular supply of the cauda equina.

# Pathology
The term "conus medullaris syndrome" is sometimes used to describe a condition similar to cauda equina syndrome.
Gene copy number
The gene copy number (also "copy number variants" or CNVs) is the number of copies  of a particular gene in the genotype of an individual.  Recent evidence shows that the gene copy number can be elevated in cancer cells. For instance, the EGFR copy number can be higher than normal in Non-small cell lung cancer.
In certain cases, such as rapidly growing Escherichia coli cells, the gene copy number can be 4-fold greater for genes located near the origin of DNA replication, rather than at the terminus of DNA replication. Elevating the gene copy number of a particular gene can increase the expression of the protein that it encodes.

# Sources and notes
- Iafrate A, et al. (2004) Detection of large-scale variation in the human genome. Nat Genet 36: 949-51
- Sebat J, et al. (2004) Large-scale copy number polymorphism in the human genome. Science 305: 525-528
- Cappuzzo F, Hirsch, et al. (2005) Epidermal growth factor receptor gene and protein and gefitinib sensitivity in non-small-cell lung cancer. J Natl Cancer Inst 97: 643655
- Atkinson M, Savageau M, Myers JT, Ninfa A (2003) Development of Genetic Circuitry Exhibiting Toggle Switch Behavior in Escherichia Coli. Cell 113: 601
- Freeman, JL, et al (2006) Copy number variation: New insights into genome diversity.  Genome Res 2006; 16: 949-61.

# Further reading
- Genome-wide analysis of DNA copy-number changes using cDNA microarrays "Gene amplifications and deletions frequently contribute to tumorigenesis. Characterization of these DNA copy-number changes is important for both the basic understanding of cancer and its diagnosis."
- New Scientist article Human DNA is far more varied than thought published November 22, 2006 "Two separate studies of the human genome have revealed an unsuspected amount of variation between people in the number of copies of genes they have.  They discovered that nearly 24 million nucleotides are involved in such copy number variants (CNVs).  They found 1447 CNVs, covering about 12% of the human genome."
- National Geographic article "DNA varies more widely from person to person, Genetic maps reveal" published Novermber 22, 2006
Coracoid process
The coracoid process is a small hook-like structure that comes off the scapula to point forward.

# Attachments
It is the site of attachment for several structures:
- The pectoralis minor muscle - to 3rd to 5th ribs.
- The short head of biceps brachii muscle - to Radial tuberosity.
- The coracobrachialis muscle - to medial humerus.
- The coracoclavicular ligament - to the clavicle. (It is formed by the conoid ligament and trapezoid ligament.)
- The coracoacromial ligament - to the acromion

# Structure
The coracoid process is a thick curved process attached by a broad base to the upper part of the neck of the scapula; it runs at first upward and medialward; then, becoming smaller, it changes its direction, and projects forward and lateralward.
The ascending portion, flattened from before backward, presents in front a smooth concave surface, across which the Subscapularis passes.
The horizontal portion is flattened from above downward; its upper surface is convex and irregular, and gives attachment to the Pectoralis minor; its under surface is smooth; its medial and lateral borders are rough; the former gives attachment to the Pectoralis minor and the latter to the coracoacromial ligament; the apex is embraced by the conjoined tendon of origin of the Coracobrachialis and short head of the Biceps brachii and gives attachment to the coracoclavicular fascia.
On the medial part of the root of the coracoid process is a rough impression for the attachment of the conoid ligament; and running from it obliquely forward and lateralward, on to the upper surface of the horizontal portion, is an elevated ridge for the attachment of the trapezoid ligament.

# Clinical relevance
The coracoid process is palpable just below the lateral end of the clavicle (collar bone).  It is otherwise known as the "Surgeon's Lighthouse" because it serves as a landmark to avoid neurovascular damage.  Major neurovascular structures enter the upper limb medial to the coracoid process so surgical approaches to the shoulder region always takes place lateral to the coracoid process.

# In other animals
In birds and reptiles, the coracoid is a separate bone.

# Etymology
Coracoid in itself means "like a raven's beak", with reference to its shape. (Greek "Korax" = Raven)

# Additional images
- Capsule of shoulder-joint (distended). Anterior aspect.
- Glenoid fossa of right side.
- Deep muscles of the chest and front of the arm, with the boundaries of the axilla.
Corneal reflexes
The corneal reflex, also known as the blink reflex, is an involuntary blinking of the eyelids elicited by stimulation (such as touching or a foreign body) of the cornea. Stimulation should elicit both a direct and consensual response (response of the opposite eye). The evolutionary purpose of this reflex is to protect the eyes from foreign bodies and bright lights. The blink reflex also occurs when sounds greater than 40-60 dB.
The reflex is mediated by:
- the nasociliary branch of the ophthalmic branch (V1) of the 5th cranial nerve (trigeminal nerve) sensing the stimulus on the cornea,
- the 7th cranial nerve (facial nerve) initiating the motor response.
Use of contact lenses may diminish or abolish this reflex.
The examination of the corneal reflex is a part of some neurological exams, particularly when evaluating coma. Damage to the ophthalmic branch (V1) of the 5th cranial nerve results in absent corneal reflex when the affected eye is stimulated. Stimulation of one cornea normally has a consensual response, with both eyelids normally closing.
Stroma of cornea
The substantia propria (or stroma of cornea) is fibrous, tough, unyielding, and perfectly transparent.
It is composed of about 200 flattened lamell, superimposed one on another. These fibrils run at different angles between  limbi. Fibres of the layers frequently interweave, the anterior lamell interweaving more than posterior lamell. The fibres of each lamella are parallel with one another, but at right angles to those of adjacent lamell. The lamell are produced by keratocytes, which occupy about 10% of the substantia propria.
These lamell are made up of bundles of modified connective tissue, the fibres of which are directly continuous with those of the sclera. More collagen fibres run in a temporal-nasal direction than run in the superior-inferior direction. This is often ignored by corneal transplant surgeons, leading to poor corneal mechanical strength in corneal transplant patients.
Keratoconus is a condition caused by disorganised lamell, leading to a bulbous cornea.
Cosmetic surgery

# Overview
Cosmetic surgery, as defined by the American Board of Cosmetic Surgery, is a subspecialty of medicine and surgery that uniquely restricts itself to the enhancement of appearance through surgical and medical techniques. It is specifically concerned with maintaining normal appearance, restoring it, or enhancing it beyond the average level toward some aesthetic ideal. Cosmetic surgery is a multi-disciplinary and comprehensive approach directed to all areas of the head, neck and body.
Special skill and knowledge are essential and specialists in cosmetic surgery are competent in the anatomy, physiology, pathology and basic sciences. The educational profile of this specialty is unique in that it begins with a fully trained and certified physician. Through continued post-residency education, training and experience, cosmetic surgery is taught and learned across traditional disciplinary boundaries. The subspecialty fully incorporates the participation and knowledge from all contributing disciplines to attain a high level of skill and understanding. Contributing disciplines include dermatology, general surgery, plastic surgery, otolaryngology, maxillofacial surgery, oculoplastic surgery, and others.
The cosmetic surgeon offers specialized expertise in patient education and counseling, procedural skills, and the early recognition and treatment of complications. As a specialty, cosmetic surgeons have enhanced the knowledge and training of fellow physicians and directly benefitted society through educational publications, scientific journals and in the development of safe and innovative techniques.
Competency in cosmetic surgery implies a combination of knowledge, surgical judgment, technical expertise and ethics in order to achieve the goal of providing aesthetic improvement.

# The American Academy of Cosmetic Surgery
The American Academy of Cosmetic Surgery founded in 1985 is a professional medical society whose members are dedicated to patient safety and physician education in cosmetic surgery. Most members of AACS are dermatological surgeons, facial plastic surgeons, head and neck surgeons, oral and maxillofacial surgeons, general surgeons, plastic surgeons or ocular plastic surgeons  all of whom specialize in cosmetic surgery. AACS is the organization that represents cosmetic surgeons in the American Medical Association through its seat in the AMA House of Delegates.

# ABMS
The American Board of Cosmetic Surgery is not currently a member board of the (ABMS) - American Board of Medical Specialties.
Cotton-wool spot
Cotton wool spots are an abnormal finding on fundoscopic exam of the retina. They appear as puffy white patches on the retina. They are caused by damage to nerve fibers. The nerve fibers are damaged by swelling in the surface layer of the retina. The cause of this swelling is due to the reduced axonal transport (and hence backlog of intracellular products) within the nerves because of the ischemia.
Diabetes and hypertension are the two most common diseases that cause these spots, and the best treatment would be to treat the underlying disease. In diabetes they are one of the hallmarks of pre-proliferative retinopathy.
More rarely, HIV and pancreatitis (Purtscher) retinopathy can also lead to the appearance of cotton wool spots.
Cremaster muscle

# Overview
The cremaster muscle is a muscle that covers the testis.

# Contraction
Its function is to raise and lower the scrotum in order to regulate the temperature of the testis and promote spermatogenesis.
In a cool environment the cremaster draws the testis closer to the body preventing heat loss, while when it is warmer the cremaster relaxes allowing the testis to cool.
Clinically, a reflex arc can be demonstrated by lightly stroking the skin of the inner thigh downwards from the hip towards the knee.  This causes the cremaster muscle on the same side to rapidly contract, raising that testicle.  This so called cremasteric reflex is much more pronounced in boys than in men.
The cremaster can also be contracted voluntarily, by contracting the PC muscle (using Kegels), or by sucking in the abdomen. Not all males are capable of doing this, as it requires pelvic muscle strength.

# Development and gender differences
The cremaster develops to its full extent only in males; in females it is represented by only a few muscle loops.
In human females, the cremaster muscle is smaller and is found on the round ligament.
In rats, it has been shown that cremaster muscles developed from the gubernacular bulb.

# Structure
In human males, the cremaster muscle is a thin layer of skeletal muscle found in the inguinal canal and scrotum between the external and internal layers of spermatic fascia, surrounding the testis and spermatic cord.  The cremaster muscle is a paired structure, there being one on each side of the body.
Anatomically, the lateral cremaster muscle originates from the internal oblique muscle, just superior to the inguinal canal, and the middle of the inguinal ligament. The medial cremaster muscle, which sometimes is absent, originates from the pubic tubercle and sometimes the lateral pubic crest. Both insert into the tunica vaginalis underneath the testis.

# Innervation and vascular supply
The cremaster muscle is innervated from the genital branch of the genitofemoral nerve and supplied by the cremasteric artery.
It receives distinctly different innervation and vascular supply in comparison to the internal oblique.

# Popular culture
Matthew Barney's film sequence The Cremaster Cycle used the cremaster muscle as its conceptual point of departure.

# Etymology
The word is derived from the Greek verb  = "I hang (transitive)", not from Latin cremare.

# Additional images
- The scrotum.
- The right testis, exposed by laying open the tunica vaginalis.
Cross-validation
Cross-validation, sometimes called rotation estimation  , is the statistical practice of partitioning a sample of data into subsets such that the analysis is initially performed on a single subset, while the other subset(s) are retained for subsequent use in confirming and validating the initial analysis.
The initial subset of data is called the training set; the other subset(s) are called validation or testing sets.
The theory of cross-validation was inaugurated by Seymour Geisser. It is important in guarding against testing hypotheses suggested by the data ("Type III error"), especially where further samples are hazardous, costly or impossible (uncomfortable science) to collect.

# Common types of cross-validation

## Holdout validation
Holdout validation is not cross-validation in the common sense, because the data never are crossed over. Observations are chosen randomly from the initial sample to form the validation data, and the remaining observations are retained as the training data. Normally, less than a third of the initial sample is used for validation data. 

## K-fold cross-validation
In K-fold cross-validation, the original sample is partitioned into K subsamples. Of the K subsamples, a single subsample is retained as the validation data for testing the model, and the remaining K  1 subsamples are used as training data. The cross-validation process is then repeated K times (the folds), with each of the K subsamples used exactly once as the validation data.  The K results from the folds then can be averaged (or otherwise combined) to produce a single estimation.

## Leave-one-out cross-validation
As the name suggests, leave-one-out cross-validation (LOOCV) involves using a single observation from the original sample as the validation data, and the remaining observations as the training data. This is repeated such that each observation in the sample is used once as the validation data. This is the same as a K-fold cross-validation with K being equal to the number of observations in the original sample. In the case of Tikhonov regularization, an efficient algorithm has been found.

# Error estimation
The parameter estimation error can be computed. Common error metrics are the mean average error (MAE) and the root mean square error (RMSE), respectively the estimated variance and standard deviation of the cross validation.
Cystica profunda

# Overview
Cystica profunda is a rare disease of the gut lining. It is characterized by formation of mucin cysts in the muscle layers of the gut lining, and it can occur anywhere along the gastrointestinal tract.
When the condition occurs in the stomach, it may be termed gastritis cystica profunda, and in the small intestine, enteritis cystica profunda.
When it occurs in the colon, it is termed colitis cystica profunda. Colitis cystica profunda is benign, but it may mimic a tumor.  When it occurs in the rectum it may be termed colitis cystica  profunda, or termed proctitis cystica profunda. Some consider this synonymous, or closely related to solitary rectal ulcer syndrome, a consequence of internal rectal intussusception.
It can have benign columnar epithelium and mucosal cysts deep to the muscularis mucosa on microscopy. Hence it can be mistaken for an invasive adenocarcinoma.
D-dimer overview

# Overview
D-dimer is a fibrin degradation product. D-dimer levels are elevated in the plasma after the acute formation of a blood clot. The majority of patients with pulmonary embolism have some degree of endogenous fibrinolysis with  an elevation in D-dimer levels, therefore there is a high negative predictive value in ruling out a pulmonary embolism when D-dimer levels are low. However a wide range of diseases are associated with mild degree of fibrinolysis which elevate D-dimer levels and contribute towards a reduced specificity and a poor positive predictive value of a high D-dimer level. This means that it is more likely that one can rule out a PE with a low D-dimer level, but cannot necessarily confirm the diagnosis of a PE based on a high D-dimer level. Other disease states  that can also have a high d-dimer level include pneumonia, congestive heart failure (CHF), myocardial infarction (MI) and malignancy. False-negative values may occur in patients with prolonged symptoms of venous thromboembolism (14 days), patients on therapeutic heparin therapy, and patients with suspected deep venous thrombosis on oral anticoagulation, as these patients have will have low D-dimer levels in the presence of a PE.

# D-dimer prognostic role in thromboembolism recurrence
The recurrence rate within the first few months following a first episode of VTE is not negligeable.  In fact, it is estimated to be around 6% at 6 months following the first episode. Because of this, the duration of treatment with oral anticoagulation therapy must be long enough to decrease the risk of recurrence while not too long to cause bleeding complications.  The duration of treatment of oral anticoagulation is most problematic in the category of patients suffering from their first episode of unprovoked VTE; therefore, a marker of risk of recurrence of VTE in this population in particular is needed to tailor the duration of their treatment.
An association between changes in D-dimer levels during and following discontinuation of oral anticoagulation was suggested more than a decade ago, and the prognostic role of D-dimer in predicting the rate of recurrence of VTE has been extensively studied.  Studies have been consistent in their findings of an association between elevated D-dimer levels and higher rates of recurrence of VTE; as such, they suggest a possible role for D-dimer in predicting recurrence of thromboembolism and tailoring the duration of treatment of oral anticoagulation following VTE.  Resuming oral anticoagulation treatment (OAT) in subjects with abnormal D-dimer levels following the discontinuation of the OAT reduced their risk of VTE recurrence.
DIPSS Plus Score

# Overview
Dynamic International Prognostic Scoring System (DIPSS)plus scoring system comprises of eight risk variables to predict the prognosis in myelofibrosis.

# DIPSS Plus Score Calculator

## DIPSS plus score for prognosis in myelofibrosis
- This handy calculator computes the prognosis in myelofibrosis using Dynamic International Prognostic Scoring System (DIPSS)plus. This scoring system comprises of eight risk variables.
Check all boxes that apply to your patient:
function calcScore(){
var score = 0;
if(document.forms.checked == 1){score += 1;}
if(document.forms.checked == 1){score += 1;}
if(document.forms.checked == 1){score += 1;}
if(document.forms.checked == 1){score += 1;}
if(document.forms.checked == 1){score += 1;}
if(document.forms.checked == 1){score += 1;}
if(document.forms.checked == 1){score += 1;}
if(document.forms.checked == 1){score += 1;}
document.forms.value = score;
if(score == 0){document.forms.value = "Low risk group: Estimated median survival is approximately 15.4 years";}
if(score == 1){document.forms.value = "Intermediate-1 risk group: Estimated median survival is approximately 6.5 years ";}
if(score == 2){document.forms.value = "Intermediate-2 risk group: Estimated median survival is approximately 2.9 years ";}
if(score == 3){document.forms.value = "Intermediate-2 risk group: Estimated median survival is approximately 2.9 years ";}
if(score >= 4){document.forms.value = " High risk group: Estimated median survival is approximately 1.3 years";}

## Interpretation of DIPSS plus score
- Score = 0: Low risk group; estimated median survival is approximately 15.4 years
- Score = 1: Intermediate-1 risk group; estimated median survival is approximately 6.5 years
- Score = 2 or 3: Intermediate-2 risk group; estimated median survival is approximately 2.9 years
- Score  4: High risk group; estimated median survival is approximately 1.3 years