The estrous cycle comprises the recurring physiologic changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous phases or pregnancies, estrous cycles continue until death. Some animals may display bloody vaginal discharge, often mistaken for menstruation, species vary significantly in the detailed functioning. One difference is that animals that have estrous cycles reabsorb the endometrium if conception does not occur during that cycle, animals that have menstrual cycles shed the endometrium through menstruation instead. In species with estrous cycles, females are generally only sexually active during the phase of their cycle. This is referred to as being in heat, in contrast, females of species with menstrual cycles can be sexually active at any time in their cycle, even when they are not about to ovulate. Humans have menstrual cycles rather than estrous cycles and they, unlike other species, were thought to not have any obvious external signs to signal estral receptivity at ovulation.
Some research suggests, that tend to have more sexual thoughts and are far more prone to sexual activity right before ovulation. Estrus is derived via Latin oestrus, from Greek οἶστρος, this refers to the gadfly that Hera sent to torment Io, who had been won in her heifer form by Zeus. Euripides used oestrus to indicate frenzy, and to describe madness, homer uses the word to describe panic. Plato uses it to refer to a drive and to describe the soul driven. Somewhat more closely aligned to current meaning and usage of estrus, Herodotus uses oistros to describe the desire of fish to spawn, the earliest use in English is of frenzied passion. In 1900 it was first used to describe rut in animals, in British English, the spelling is oestrus or œstrus. In all English spellings, the ends in -us and the adjective in -ous. Thus in American English, a mammal may be described as in estrus when it is in particular part of the estrous cycle. Estrum is sometimes used as a synonym for estrus, one or several follicles of the ovary start to grow.
Typically this phase can last as little as one day or as long as three weeks, depending on the species, under the influence of estrogen the lining in the uterus starts to develop. Some animals may experience vaginal secretions that could be bloody, estrus refers to the phase when the female is sexually receptive
A methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms — CH3. In formulas, the group is often abbreviated Me, such hydrocarbon groups occur in many organic compounds. It is a stable group in most molecules. While the methyl group is part of a larger molecule. The anion has eight electrons, the radical seven and the cation six. All three forms are highly reactive and rarely observed, the methylium cation exists in the gas phase, but is otherwise not encountered. Some compounds are considered to be sources of the CH3+ cation, the methanide anion exists only in rarefied gas phase or under exotic conditions. It can be produced by electrical discharge in ketene at low pressure, such reagents are generally prepared from the methyl halides, M + CH3X → MCH3 where M is an alkali metal. The methyl radical has the formula CH3 and it exists in dilute gases, but in more concentrated form it readily dimerizes to ethane. It can be produced by decomposition of only certain compounds.
The reactivity of a methyl group depends on the adjacent substituents, methyl groups can be quite unreactive. For example, in compounds, the methyl group resists attack by even the strongest acids. The oxidation of a group occurs widely in nature and industry. The oxidation products derived from methyl are CH2OH, CHO, for example, permanganate often converts a methyl group to a carboxyl group, e. g. the conversion of toluene to benzoic acid. Ultimately oxidation of methyl groups gives protons and carbon dioxide, as seen in combustion, demethylation is a common process, and reagents that undergo this reaction are called methylating agents. Common methylating agents are dimethyl sulfate, methyl iodide, and methyl triflate, the source of natural gas, arises via a demethylation reaction. Certain methyl groups can be deprotonated, for example, the acidity of the methyl groups in acetone is about 1020 more acidic than methane. The resulting carbanions are key intermediates in many reactions in organic synthesis and biosynthesis, fatty acids are produced in this way
Roussel Uclaf S. A. was a French pharmaceutical company and one of several predecessor companies of todays Sanofi. Roussel Uclafs agrochemical operations had transferred to Hoechst Schering AgrEvo GmbH in 1994. HMR subsequently merged in 1999 with Rhône-Poulenc to form Aventis, which merged in 2004 with Sanofi-Synthélabo to form Sanofi-Aventis. Two days later, the French government ordered Roussel-Uclaf to distribute mifepristone in the interests of public health, French Health Minister Claude Évin explained that, I could not permit the abortion debate to deprive women of a product that represents medical progress. From the moment Government approval for the drug was granted, RU-486 became the property of women. On May 16,1994, Roussel-Uclaf announced that it was donating without remuneration all rights for medical uses of mifepristone in the U. S, in 1999, Exelgyn won approval of Mifegyne in 11 additional countries, and in 28 more countries over the following decade. International directory of company histories, Volume 1, international directory of company histories, Volume 8.
The pharmaceutical industry, a history & calendar, gaston Roussel to Sanofi-Aventis, nearly a century of Romainville pharmaceutical history and heritage. Paris, Society for the History of Pharmacy, photo gallery - Our factory is a novel
Testosterone is the primary male sex hormone and an anabolic steroid. In addition, testosterone is essential for health and well-being, insufficient levels of testosterone in men may lead to abnormalities including frailty and bone loss. Testosterone is used as a medication to treat male hypogonadism, since testosterone levels gradually decrease as men age, synthetic testosterone is sometimes prescribed to older men to counteract this deficiency. Testosterone is a steroid from the class containing a keto. It is biosynthesized in several steps from cholesterol and is converted in the liver to inactive metabolites and it exerts its action through binding to and activation of the androgen receptor. In humans and most other vertebrates, testosterone is secreted primarily by the testicles of males and, to a lesser extent, small amounts are secreted by the adrenal glands. On average, in males, levels of testosterone are about 7–8 times as great as in adult females. As the metabolic consumption of testosterone in males is greater, the production is about 20 times greater in men.
Females are sensitive to the hormone. In general, androgens such as testosterone promote protein synthesis and thus growth of tissues with androgen receptors, Testosterone can be described as having virilising and anabolic effects. Anabolic effects include growth of mass and strength, increased bone density and strength. Many of these fall into the category of secondary sex characteristics. Testosterone effects can be classified by the age of usual occurrence, for postnatal effects in both males and females, these are mostly dependent on the levels and duration of circulating free testosterone. Effects before birth are divided into two categories, classified in relation to the stages of development, the first period occurs between 4 and 6 weeks of the gestation. There is development of the gland and seminal vesicles. During the second trimester, androgen level is associated with gender formation and this period affects the femininization or masculinization of the fetus and can be a better predictor of feminine or masculine behaviours such as sex typed behaviour than an adults own levels.
Early infancy androgen effects are the least understood, in the first weeks of life for male infants, testosterone levels rise. The levels remain in a range for a few months
In vitro studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. In contrast, in studies are those conducted in animals, including humans. In vitro studies are conducted using components of an organism that have been isolated from their biological surroundings, such as microorganisms, cells. For example, microrganisms or cells can be studied in artificial culture media, colloquially called test-tube experiments, these studies in biology and their subdisciplines are traditionally done in test tubes, Petri dishes, etc. They now involve the range of techniques used in molecular biology. In contrast, studies conducted in living beings are called in vivo, polymerase chain reaction is a method for selective replication of specific DNA and RNA sequences in the test tube. Protein purification involves the isolation of a protein of interest from a complex mixture of proteins. In vitro fertilization is used to allow spermatozoa to fertilize eggs in a culture dish before implanting the resulting embryo or embryos into the uterus of the prospective mother and these ADME process parameters can be integrated into so called physiologically based pharmacokinetic models or PBPK.
In vitro studies permit a species-specific, more convenient, just as studies in whole animals more and more replace human trials, so are in vitro studies replacing studies in whole animals. This complexity makes it difficult to identify the interactions between individual components and to explore their basic biological functions, in vitro work simplifies the system under study, so the investigator can focus on a small number of components. Another advantage of in vitro methods is that cells can be studied without extrapolation from an experimental animals cellular response. Investigators doing in vitro work must be careful to avoid over-interpretation of their results, for example, scientists developing a new viral drug to treat an infection with a pathogenic virus may find that a candidate drug functions to prevent viral replication in an in vitro setting. However, before this drug is used in the clinic, it must progress through a series of in vivo trials to determine if it is safe and effective in intact organisms.
Results obtained from in vitro experiments cannot usually be transposed, as is, building a consistent and reliable extrapolation procedure from in vitro results to in vivo is therefore extremely important. However, increasingly sophisticated in vitro experiments collect increasingly numerous, mathematical models, such as systems biology models, are much needed here. In pharmacology, IVIVE can be used to approximate pharmacokinetics or pharmacodynamics and that indicates that extrapolating effects observed in vitro needs a quantitative model of in vivo PK. Physiologically based PK models are generally accepted to be central to the extrapolations, in these conditions, developing a simple PD model of the dose–response relationship observed in vitro, and transposing it without changes to predict in vivo effects is not enough
A filly is a female horse that is too young to be called a mare. There are two definitions in use, In most cases, a filly is a female horse under four years old. In some nations, such as the United Kingdom and the United States, fillies are sexually mature by two and are sometimes bred at that age, but generally, they should not be bred until they themselves have stopped growing, usually by four or five. Some fillies may exhibit estrus as yearlings, the equivalent term for a male is a colt. When horses of either sex are less than one year, they are referred to as foals, horses of either sex between one and two years old may be called yearlings
ChEMBL or ChEMBLdb is a manually curated chemical database of bioactive molecules with drug-like properties. It is maintained by the European Bioinformatics Institute, of the European Molecular Biology Laboratory, based at the Wellcome Trust Genome Campus, the database, originally known as StARlite, was developed by a biotechnology company called Inpharmatica Ltd. acquired by Galapagos NV. The data was acquired for EMBL in 2008 with an award from The Wellcome Trust, resulting in the creation of the ChEMBL chemogenomics group at EMBL-EBI, the ChEMBL database contains compound bioactivity data against drug targets. Bioactivity is reported in Ki, Kd, IC50, and EC50, data can be filtered and analyzed to develop compound screening libraries for lead identification during drug discovery. ChEMBL version 2 was launched in January 2010, including 2.4 million bioassay measurements covering 622,824 compounds and this was obtained from curating over 34,000 publications across twelve medicinal chemistry journals.
ChEMBLs coverage of available bioactivity data has grown to become the most comprehensive ever seen in a public database, in October 2010 ChEMBL version 8 was launched, with over 2.97 million bioassay measurements covering 636,269 compounds. ChEMBL_10 saw the addition of the PubChem confirmatory assays, in order to integrate data that is comparable to the type, ChEMBLdb can be accessed via a web interface or downloaded by File Transfer Protocol. It is formatted in a manner amenable to computerized data mining, ChEMBL is integrated into other large-scale chemistry resources, including PubChem and the ChemSpider system of the Royal Society of Chemistry. In addition to the database, the ChEMBL group have developed tools and these include Kinase SARfari, an integrated chemogenomics workbench focussed on kinases. The system incorporates and links sequence, structure and screening data, the primary purpose of ChEMBL-NTD is to provide a freely accessible and permanent archive and distribution centre for deposited data.
July 2012 saw the release of a new data service, sponsored by the Medicines for Malaria Venture. The data in this service includes compounds from the Malaria Box screening set, myChEMBL, the ChEMBL virtual machine, was released in October 2013 to allow users to access a complete and free, easy-to-install cheminformatics infrastructure. In December 2013, the operations of the SureChem patent informatics database were transferred to EMBL-EBI, in a portmanteau, SureChem was renamed SureChEMBL. 2014 saw the introduction of the new resource ADME SARfari - a tool for predicting and comparing cross-species ADME targets
Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The yeast lineage originated hundreds of millions of years ago, and 1,500 species are currently identified and they are estimated to constitute 1% of all described fungal species. Yeast sizes vary greatly, depending on species and environment, typically measuring 3–4 µm in diameter, most yeasts reproduce asexually by mitosis, and many do so by the asymmetric division process known as budding. Yeasts, with their growth habit, can be contrasted with molds. Fungal species that can take both forms are called dimorphic fungi and it is a centrally important model organism in modern cell biology research, and is one of the most thoroughly researched eukaryotic microorganisms. Researchers have used it to information about the biology of the eukaryotic cell. Other species of yeasts, such as Candida albicans, are opportunistic pathogens, yeasts have recently been used to generate electricity in microbial fuel cells, and produce ethanol for the biofuel industry.
Yeasts do not form a taxonomic or phylogenetic grouping. The budding yeasts are classified in the order Saccharomycetales, within the phylum Ascomycota, the word yeast comes from Old English gist and from the Indo-European root yes-, meaning boil, foam, or bubble. Yeast microbes are probably one of the earliest domesticated organisms, archaeologists digging in Egyptian ruins found early grinding stones and baking chambers for yeast-raised bread, as well as drawings of 4, 000-year-old bakeries and breweries. In 1680, Dutch naturalist Anton van Leeuwenhoek first microscopically observed yeast, but at the time did not consider them to be living organisms, researchers were doubtful whether yeasts were algae or fungi, but in 1837 Theodor Schwann recognized them as fungi. In 1857, French microbiologist Louis Pasteur proved in the paper Mémoire sur la fermentation alcoolique that alcoholic fermentation was conducted by living yeasts and not by a chemical catalyst. Pasteur showed that by bubbling oxygen into the yeast broth, cell growth could be increased, by the late 18th century, two yeast strains used in brewing had been identified, Saccharomyces cerevisiae and S. carlsbergensis. S.
cerevisiae has been sold commercially by the Dutch for bread-making since 1780, around 1800, in 1825, a method was developed to remove the liquid so the yeast could be prepared as solid blocks. The industrial production of yeast blocks was enhanced by the introduction of the press in 1867. In 1872, Baron Max de Springer developed a process to create granulated yeast. Yeasts are chemoorganotrophs, as they use organic compounds as a source of energy, carbon is obtained mostly from hexose sugars, such as glucose and fructose, or disaccharides such as sucrose and maltose. Some species can metabolize pentose sugars such as ribose, Yeast species either require oxygen for aerobic cellular respiration or are anaerobic, but have aerobic methods of energy production
The horse is one of two extant subspecies of Equus ferus. It is an ungulate mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature, into the large, humans began to domesticate horses around 4000 BC, and their domestication is believed to have been widespread by 3000 BC. Horses in the subspecies caballus are domesticated, although some domesticated populations live in the wild as feral horses. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, colors, breeds and behavior. Horses anatomy enables them to use of speed to escape predators and they have a well-developed sense of balance. Related to this need to flee from predators in the wild is an unusual trait, female horses, called mares, carry their young for approximately 11 months, and a young horse, called a foal, can stand and run shortly following birth. Most domesticated horses begin training under saddle or in harness between the ages of two and four and they reach full adult development by age five, and have an average lifespan of between 25 and 30 years.
There are more than 300 breeds of horse in the world today, horses were historically used in warfare, from which a wide variety of riding and driving techniques developed, using many different styles of equipment and methods of control. Many products are derived from horses, including meat, hide, bone, humans provide domesticated horses with food and shelter, as well as attention from specialists such as veterinarians and farriers. Specific terms and specialized language are used to describe equine anatomy, different life stages, depending on breed and environment, the modern domestic horse has a life expectancy of 25 to 30 years. Uncommonly, a few animals live into their 40s and, the oldest verifiable record was Old Billy, a 19th-century horse that lived to the age of 62. In modern times, Sugar Puff, who had listed in Guinness World Records as the worlds oldest living pony. The exception is in endurance riding, where the age to compete is based on the animals actual calendar age. The following terminology is used to describe horses of various ages, Colt, a common terminology error is to call any young horse a colt, when the term actually only refers to young male horses.
Filly, A female horse under the age of four, foal, A horse of either sex less than one year old. A nursing foal is sometimes called a suckling and a foal that has been weaned is called a weanling, most domesticated foals are weaned at five to seven months of age, although foals can be weaned at four months with no adverse physical effects. Gelding, A castrated male horse of any age, mare, A female horse four years old and older
Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power.
The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations.
In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
A stallion is a male horse that has not been gelded. Stallion is used to refer to males of other equids, including zebras, contrary to popular myths, many stallions do not live with a harem of mares. Nor, in natural settings, do they fight each other to the death in competition for mares, being social animals, stallions who are not able to find or win a harem of mares usually band together in stallions-only bachelor groups which are composed of stallions of all ages. Even with a band of mares, the stallion is not the leader of a herd, the leadership role in a herd is held by a mare, known colloquially as the lead mare or boss mare. The mare determines the movement of the herd as it travels to obtain food and she determines the route the herd takes when fleeing from danger. When the herd is in motion, the dominant stallion herds the straggling members closer to the group, when the herd is at rest, all members share the responsibility of keeping watch for danger. The stallion is usually on the edge of the group, to defend the herd if needed, there is usually one dominant mature stallion for every mixed-sex herd of horses.
In some cases, a single mature male may be tolerated on the fringes of the herd. One theory is that young male is considered a potential successor. Fillies usually soon join a different band with a dominant stallion different from the one that sired them, colts or young stallions without mares of their own usually form small, all-male, bachelor bands in the wild. Living in a group gives these stallions the social and protective benefits of living in a herd, a bachelor herd may contain older stallions who have lost their herd in a challenge. Other stallions may directly challenge a herd stallion, or may attempt to steal mares and form a new. In either case, if the two meet, there rarely is a true fight, more often there will be bluffing behavior. Even if a fight for dominance occurs, rarely do opponents hurt each other in the wild because the weaker combatant has a chance to flee. Fights between stallions in captivity may result in injuries and other forms of confinement make it more difficult for the losing animal to safely escape.
In the wild, feral stallions have been known to steal or mate with domesticated mares, the stallions reproductive system is responsible for his sexual behavior and secondary sex characteristics. The external genitalia comprise, the testes, which are suspended horizontally within the scrotum. The testes of a stallion are ovoids 8 to 12 cm long,6 to 7 cm high by 5 cm wide