Persius/hicric huggingface dataset:
Step function
In mathematics, a function on the real numbers is called a step function (or staircase function) if it can be written as a finite linear combination of indicator functions of intervals. Informally speaking, a step function is a piecewise constant function having only finitely many pieces.

# Definition and first consequences
A function f: \mathbb{R} \rightarrow \mathbb{R} is called a step function if it can be written as
where n\ge 0, \alpha_i are real numbers, A_i are intervals, and \chi_A\, is the indicator function of A:
\left\{
\right.
In this definition, the intervals A_i can be assumed to have the following two properties:
- The intervals are disjoint, A_i\cap A_j=\emptyset for i\ne j
- The union of the intervals is the entire real line, \cup_{i=1}^n A_i=\mathbb R.
Indeed, if that is not the case to start with, a different set of intervals can be picked for which these assumptions hold. For example, the step function
can be written as

# Examples
- A constant function is a trivial example of a step function. Then there is only one interval, A_0=\mathbb R.
- The Heaviside function H(x) is an important step function. It is the mathematical concept behind some test signals, such as those used to determine the step response of a dynamical system.
- The rectangular function, the normalized boxcar function, is the next simplest step function, and is used to model a unit pulse.

## Non-examples
- The integer part function is not a step function according to the definition of this article, since it has an infinite number of "steps".

# Properties
- The sum and product of two step functions is again a step function. The product of a step function with a number is also a step function. As such, the step functions form an algebra over the real numbers.
- A step function takes only a finite number of values. If the intervals A_i, i=0, 1, \dots, n, in the above definition of the step function are disjoint and their union is the real line, then f(x)=\alpha_i\, for all x\in A_i.
- The Lebesgue integral of a step function f = \sum\limits_{i=0}^n \alpha_i \chi_{A_i}\, is \int \!f\,dx = \sum\limits_{i=0}^n \alpha_i \ell(A_i),\, where \ell(A) is the length of the interval A, and it is assumed here that all intervals A_i have finite length. In fact, this equality (viewed as a definition) can be the first step in constructing the Lebesgue integral.
- The derivative of a step function is the Dirac delta function
Steroid cycle
A steroid cycle is a term commonly used to describe a period in time where an individual intakes anabolic steroids.
A "cycle" can last from two weeks to more commonly 6-12 weeks, or even longer. Supplying the body with exogenous hormones will suppress its own testosterone production.
The longer the body's endogenous  supply of testosterone is suppressed, the harder it will be for their hypothalamus/pituitary/testicular axis (HPTA) to recover. More serious health risks are associated with longer cycles, such as testicular atrophy, gynecomastia, heart problems, liver diseases, and in extreme cases, permanent suppression of the HPTA, necessitating permanent testosterone therapy.
Many steroid cycles involve combining two or more drugs together, usually one being a potent androgen. Other drugs which act through more anabolic pathways can then be added as well. Professional and novice bodybuilders all over the world combine many drugs together in what is commonly referred to as a steroid stack.
Steve Andreas
Steve Andreas, born John O. Stevens, is an American psychotherapist and author specializing in  Neuro-linguistic programming. Since 1979, Steve and his partner Connirae Andreas have edited and published a number of titles on the subject. They are best known in the field for their annotated transcripts of a variety of early NLP seminars.
Steve is the son of Barry Stevens, a writer and well-known gestalt therapist. He founded Real People Press, a publisher of works on psychology and personal change in 1967, in order to publish a book by Carl Rogers and Barry Stevens entitled "Person to Person".
Steve Andreas worked as a chemist until 1958, then went to graduate school at Brandeis University under Abraham Maslow for two years, receiving an MA in psychology. After working as a chemist again for a year, he got a junior college teaching credential, and taught psychology and social science at Diablo Valley College in Pleasant Hill CA for 7 years.  He was introduced to Gestalt therapy in 1967, and edited Fritz Perls books, Gestalt Therapy Verbatim and In and Out the Garbage Pail, and wrote Awareness, a book of exercises based on Gestalt Therapy in 1971. He became interested in Neuro-linguistic programming in 1977. and has been active in the field ever since.
In 1979 Steve and Connirae established NLP of Colorado, now known as NLP Comprehensive, to develop the training arm of their business. They transferred ownership of  to Tom Dotz in 1998. They continue to own Real People Press.

# Books and publications
Richard Bandler and John Grinder titles edited by Steve and Connirae Andreas which are well known in the NLP field include:
- Frogs Into Princes (Bandler & Grinder), 1979)
- Trance-Formations (Grinder & Bandler), 1981)
- Reframing (Bandler and Grinder, 1982)
- Using Your Brain for a Change (Bandler, 1985)
- Change Your Mind and Keep the Change (1987)
- Heart of the Mind (1989)
- Core Transformations (Connirae & Tamara Andreas, 1994).
- Virginia Satir: The Patterns of Her Magic (1991)
- Transforming Your Self (2002)
- Six Blind Elephants, Volumes I & II (2006)
Steven Nissen
Steven Nissen (b.1949), a heart specialist, is chairman of cardiovascular medicine at the Cleveland Clinic.
He first gained prominence when he developed techniques in 1987 to thread miniaturized ultrasound imaging devices into a patient's heart to reveal the exact composition of plaques causing the early stages of artery damage. This allowed much easier evaluation of anticholesterol medications.
His efforts in 2004 linked COX-2 inhibitors such as Celebrex  and  Merck's Vioxx with heart attacks, and prevented Merck's similar product, Arcoxia, from being approved.   In 2005, he  attacked the experimental diabetes drug Pargluva, from Bristol-Myers Squibb, for its serious heart risks. A  Food and Drug Administration advisory panel had strongly recommended approval, but Pargluva was withdrawn.
In 2007, he found that the  Avandia diabetes drug produced by GlaxoSmithKline carried high cardiovascular risks, leading to a warning by the Food and Drug Administration and a sales loss of about 30 percent for the drug. 
In 2007, he was named one of the 100 Most Influential People in the world (Time 100) by Time Magazine.
Stool culture

# Overview
A stool test is one where fecal matter is collected for analysis to diagnose the presence or absence of a medical condition.

# Fecal occult blood test
One of the most common stool tests, the Fecal occult blood test can be used to diagnose many conditions that cause in bleeding in the gastrointestinal system including Colorectal cancer or Stomach cancer.

# Microbiology tests
Parasitic diseases such as Ascariasis, Hookworm, Strongyloidiasis and Whipworm can be diagnosed by examining stools under a microscope for the presence of worm larvae or eggs. Some bacterial diseases can be detected with a stool culture. Toxins from bacteria such as Clostridium difficile ('C. diff.') can also be identified. Viruses such as rotavirus can also be found in stools.

# Chemical tests
A fecal pH test may be used determine lactose intolerance or the presence of an infection. Steatorrhea can be diagnosed using a Fecal fat test that checks for the malabsorption of fat.
Stramenophile
The Stramenopile group is a recently recognised informal monophyletic grouping into which a number of microscopic parasitic organisms from the superkingdom Protista and a number of diatoms and brown seaweeds are placed, such as blastocystis hominis, which is the only organism of this group that is potentially pathogenic.
Labyrinthulomycota, Hyphochytriomycota, Phytophthora, Aphanomyces, Bremia, Pernospora and the Oomycetes are also protists that form part of the Stramenopile group. The Stramenopile group (or clade) is a sister group of another multicellular clade which includes Plantae, Animalia and Fungi.

# Notes
-  An all-taxa biodiversity inventory of the Huron Mountain Club retrieved June 6 2007
-  Stanford Blastocystis hominis retrieved June 9 2007
-  Genescope Blastocystis hominis: Whole genome shotgun retrieved June 6 2007
-  An all-taxa biodiversity inventory of the Huron Mountain Club retrieved June 6 2007
Stroke volume

# Overview
Stroke volume is the amount of blood pumped by the left ventricle of the heart in one contraction.
The stroke volume is not all of the blood contained in the left ventricle. The heart does not pump all the blood out of the ventricle. Normally, only about two-thirds of the blood in the ventricle is put out with each beat. What blood is actually pumped from the left ventricle is the stroke volume and it, together with the heart rate, determines the cardiac output.

# Calculation
Its value is obtained by subtracting end-systolic volume (ESV) from end-diastolic volume (EDV) for a given ventricle:
In a healthy 70-kg man, the left ventricular EDV is 120 ml and the corresponding ESV is 50 ml, giving a stroke volume of 70 ml.

# Determinants
Men, on average, have higher stroke volumes than women due to the larger size of their hearts. However, stroke volume depends on several factors such as heart size, contractility, duration of contraction, preload (end-diastolic volume), and afterload.

## Exercise
Prolonged aerobic exercise may also increase stroke volume, which frequently results in a slower heart rate. Reduced heart rate prolongs ventricular diastole (filling), increasing end-diastolic volume, and ultimately allowing more blood to be ejected.

## Preload
Stroke volume is intrinsically controlled by preload (the degree to which the ventricles are stretched prior to contracting). An increase in the volume or speed of venous return will increase preload and, through the Frank-Starling law of the heart, will increase stroke volume. Decreased venous return has the opposite effect, causing a reduction in stroke volume.

## Afterload
Elevated afterload (commonly measured as the aortic pressure during systole) reduces stroke volume. Though not usually affecting stroke volume in healthy individuals, increased afterload will hinder the ventricles in ejecting blood, causing reduced stroke volume. Increased afterload may be found in aortic stenosis and arterial hypertension.
Styphnolobium
Styphnolobium is a small genus of three or four species of small trees and shrubs in the subfamily Faboideae of the pea family Fabaceae, formerly included within a broader interpretation of the genus Sophora. The species of Styphnolobium differ from Sophora in lacking the ability to form symbioses with rhizobia (nitrogen fixing bacteria) on their roots. They also differ from the related genus Calia (mescalbeans) in having deciduous leaves and flowers in axillary, not terminal, racemes. The leaves are pinnate, with 9-21 leaflets, and the flowers in pendulous racemes similar to those of the Black locust.

# Species
- Styphnolobium affine (Torr. & A. Gray) Walp., the Coralbean or Eve's Necklace (syn. Sophora affinis) is native to the southern United States in Texas, Oklahoma, Arkansas and Louisiana. It is a large shrub or small tree, growing to 5-7 m tall, with white or pale violet flowers.
- Styphnolobium japonicum (L.) Schott, the Pagoda Tree (Chinese Scholar, Japanese pagodatree; syn. Sophora japonica), is native to eastern Asia (mainly China; despite the name, it is introduced in Japan), is a popular ornamental tree in Europe, North America and South Africa, grown for its white flowers, borne in late summer after most other flowering trees have long finished flowering. It grows into a lofty tree 10-20 m tall with an equal spread, and produces a fine, dark brown timber.
- Styphnolobium monteviridis is native to Central America.

# Uses
The Pagoda Tree is widely used in bonsai gardening. The Guilty Chinese Scholartree was a historic Pagoda Tree in Beijing, on which the last emperor of the Ming Dynasty, Chongzhen, hanged himself.
S. japonicum (Chinese: ; pinyin: huai; formerly Sophora japonica) is one of the 50 fundamental herbs used in traditional Chinese medicine.
Succinic acid

# Overview
Succinic acid (IUPAC systematic name: butanedioic acid; historically known as spirit of amber) is a dicarboxylic acid which plays a biochemical role in the citric acid cycle.

# Physical properties
At room temperature, pure succinic acid is a solid that forms colorless, odorless crystals. It has a melting point of 185  C and a boiling point of 235  C. It is a diprotic acid. The carboxylate anion is called 'succinate and esters of succinic acid are called alkyl succinates.

# Biochemical role
Succinate is a component of the citric acid cycle and is capable of donating electrons to the electron transfer chain via the following reaction:
This is catalysed by the enzyme succinate dehydrogenase (or complex II of the mitochondrial ETC). The complex is a 4 subunit membrane-bound lipoprotein which couples the oxidation of succinate to the reduction of ubiquinone. Intermediate electron carriers are FAD and three Fe2S2 clusters part of subunit B.
Mark Donnelly from Argonne National Laboratory developed one of the best strains (AFP 184) to convert raw hydrolysates from biomass to succinate.

# History
Spirit of amber was procured from amber by pulverising and distilling it using a sand bath. It was chiefly used externally for rheumatic aches and pains, and internally in inveterate gleets.

# Safety
The acid is combustible and corrosive, capable of causing burns. "Harmful by inhalation, ingestion and through skin absorption. Wash after handling. Eye contact may cause serious damage."
In nutraceutical form as a food additive and dietary supplement, is safe and approved by the FDA.

# Oxidition reaction
Succinic acid can be converted to fumaric acid by oxidation.
Sulfa allergy

# Overview
Sulfa allergies refer to medications that contain sulfa that may result in an adverse reaction. It is important to note that just because the medication name does not contain the sulfa does not mean it does not contain sulfa, particularly true for the generic names.
Antibiotics that contain sulfonamides include
- Sulfamethoxazole
- Trimethoprim-sulfamethoxazole (Septra, Bactrim)
- Erythromycin-sulfisoxazole
Two medications that are closely related to sulfonamides and should be avoided by those with sulfonamide allergy are:
- Sulfasalazine (Azulfidine)
- Dapsone
Several other medications related to sulfonamides should be used with caution are show below. Though risk of an allergic reaction is significantly lower with these medications you should consult with your health care provider who will weight the risk and benefits.
- Diuretics such as furosemide (Lasix) and hydrochlorothiazide (Microzide)
- Diabetes medications such as glyburide (Glynase, Diabeta, Micronase) and glimepiride (Amaryl)
- Particular nonsteroidal anti-inflammatory drugs, such as celecoxib (Celebrex)
- Migraine treatment with sumatriptan (Imitrex)
HIV/AIDS patients may be more sensitive to sulfonamides or medications similar to sulfonamides. Sulfites and sulfates food preservations are unlikely to cause adverse effects in people with a sulfa allergy.
Sulfadimidine

# Overview
Sulfadimidine or sulfamethazine is a sulfonamide antibacterial.
There are non-standardizeda abbreviations for it as "sulfadimidine" (abbreviated SDI and more commonly but less reliablyb SDD) and as "sulfamethazine" (abbreviated SMT and more commonly but less reliablyc SMZ). Other names include sulfadimerazine, sulfadimezine, and sulphadimethylpyrimidine.

# Notes
- ^a  Abbreviations are not found in the databases (such as ChemDB, ChemIDplus, PubChem), but often seen in the published literature.
- ^b  "SDD" is not found in databases, but often seen in the published literature; it could however be confused with Tiferron/Sodium catechol sulfate (1,2-Dihydroxybenzene-3,5-disulfonic acid disodium Salt), uncommon but found officially abbreviated SDD in the ChemIDplus database.
- ^c  "SMZ" is not found in databases, but often seen in the published literature; it could however be confused with sulfamethoxazole, also seen abbreviated SMZ.
Sulfamic acid
Sulfamic acid, also known as amidosulfonic acid, amidosulfuric acid, aminosulfonic acid, and sulfamidic acid, is a molecular compound with the formula H3NSO3.  This colorless, water-soluble compound finds many applications.
Sulfamic acid (H3NSO3) may be considered an intermediate compound between sulfuric acid (H2SO4), and sulfamide (H4N2SO2), effectively - though see below - replacing an -OH group with an -NH2 group at each step. This pattern can extend no further in either direction without breaking down the -SO2 group.

# Structure and reactivity
First, it should be noticed that the compound is well described by the formula H3NSO3, not the tautomer H2NSO2(OH).  The relevant bond distances are S=O, 1.44 and S-N 1.77 A.  The greater length of the S-N distance is consistent with a single bond.  Furthermore, a neutron diffraction study located the hydrogen atoms, all three of which are 1.03 A distant from nitrogen. The structures shown with this article are for the two main tautomers.
Sulfamic acid is a weak acid, Ka = 1.01 x 101.  Because the solid is non-hygroscopic, it is used as a standard in acidometry (quantitative assays of acid content).  Double deprotonation can be effected in NH3 solution to give 2.
Sulfamic acid melts at 205 C before decomposing at higher temperatures to  H2O, SO3, SO2, and N2.
With HNO2, sulfamic acid reacts to give N2, while with HNO3, it affords N2O.
The behavior of H3NSO3 resembles that of urea, (H2N)2CO, in some ways.  Both feature amino groups linked to electron-withdrawing centers that can participate in delocalized bonding.  Both liberate ammonia upon heating in water.

# Applications
The most famous application of sulfamic acid is in the synthesis of compounds that taste sweet.  Reaction with cyclohexylamine followed by addition of NaOH gives C6H11NHSO3Na, sodium cyclamate. Related compounds are also sweeteners, see acesulfame potassium.
Sulfamates (O-substituted-, N-substituted-, or di-/tri-substituted derivatives of sulfamic acid) have been used in the design of many types of therapeutic agents such as antibiotics, nucleoside/nucleotide human immunodeficiency virus (HIV) reverse transcriptase inhibitors, HIV protease inhibitors (PIs), anti-cancer drugs (steroid sulfatase and carbonic anhydrase inhibitors), anti-epileptic drugs, and weight loss drugs.
Sulfamic acid is used as an acidic cleaning agent, typically for metals and ceramics.  It is a replacement for hydrochloric acid for the removal of rust. In households, it is often found as a descaling agent in detergents used for removal of limescale.
Sulfamic acid is used in the S.C. Johnson & Sons, Inc. "Scrubbing Bubbles Fizz-Its Toilet Tablets."
- Catalyst for esterification process
- Dye and pigment manufacturing
- Herbicide
- Ingredient in Denture Tablets
- Coagulator for urea-formaldehyde resins
- Ingredient in fire extinguishing media
- Pulp and paper industry as a chloride stabilizer
- Synthesis of nitrous oxide by reaction with nitric acid
Sulfapyridine

# Overview
Sulfapyridine, original UK spelling sulphapyridine, is a sulfonamide antibacterial. At one time it was commonly referred to as M&B.
Sulfapyridine is no longer prescribed for treatment of infections in humans.  However, it may be used to treat linear IgA disease.  It is a good antibacterial drug, but its water solubility is very pH dependent.  Thus there is a risk of crystallization within the bladder or urethra, which could lead to pain or blockage. As with other sulfonamides, there is a significant risk of agranulocytosis, and this, rather than the development of resistance by bacteria, is the main reason for its decline in use.
It was discovered by Lionel Whitby at the British firm May & Baker Ltd and logged in their Test Book on 2 November, 1937 under Code No M&B 693. It was successfully used to treat Winston Churchill's bacterial pneumonia in 1942. In a subsequent radio broadcast he said: "This admirable M&B from which I did not suffer any inconvenience, was used at the earliest moment and, after a week's fever, the intruders were repulsed."
In 1944 M&B 693 also saved Nero, the Royal Circus lion, from pneumonia. 
The drug sulfasalazine is structurally one molecule of mesalamine linked to one molecule of sulfapyridine with an azo bond.
M&B 693 was one of the first generation of sulphonamide antibiotics. It has been reported as the first chemical cure for pneumonia. It could either be taken in tablet form or the powder could be placed in wounds. It was used so widely during the Second World War that May & Baker had difficulty keeping up with demand. It was later largely superseded by penicillin and other sulfonamides.

# Synthesis
Sulfathiazole

# Overview
Sulfathiazole is an organosulfur compound used as a short-acting sulfa drug. It is an organic compound. Formerly,  it was a common oral and topical antimicrobial, until less toxic alternatives were discovered. It is still occasionally used, sometimes in combination with sulfabenzamide and sulfacetamide, and in aquariums.
It exists in various forms (polymorphs).  The imide tautomer is dominant, at least in the solid state.  In this tautomer, the proton resides on the ring nitrogen, not the structure shown above.

# Cultural references
Sulfathiazole is mentioned in chapter 104 of Kurt Vonnegut's novel Cat's Cradle and New Dictonary, and several of his short stories.  Thoma Heggen's 1946 novel Mister Roberts mentions the use of sulfathiazole to treat gonorrhea, and Sonya Dorman's short story When I was Miss Dow in 1966.  Also the 1998 movie Dead Heat mentions the chemical as a drug used with reanimation of dead bodies.
Sulfathiazole is mentioned in "The World According To Garp" in chapter 1 where Garps mother winesses it being dispensed to WWII soldiers.