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Lawrence Henderson
Lawrence Joseph Henderson (June 3, 1878, Lynn, Massachusetts – February 10, 1942, Cambridge, Massachusetts) was a physiologist, chemist, biologist, philosopher, and sociologist. He became one of the leading biochemists of the early 20th century. His work contributed to the Henderson–Hasselbalch equation, used to calculate pH as a measure of acidity. Early life Lawrence Henderson was born in Lynn, Massachusetts the son of a business man Joseph Henderson and his wife. He entered Harvard at the age of 16 in 1894. His father was a ship chandler whose principal business was located in nearby Salem, but who also conducted business in Saint Pierre and Miquelon, a French Overseas collectivity off the coast of Canada. Career Lawrence Henderson graduated from Harvard College in 1898 and from Harvard Medical School in 1902, receiving the M.D. (Medical Doctor) degree cum laude. Then followed two years in chemical research at the University of Strasbourg with advanced scientific tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lynn, Massachusetts
Lynn is the eighth-largest municipality in Massachusetts and the largest city in Essex County. Situated on the Atlantic Ocean, north of the Boston city line at Suffolk Downs, Lynn is part of Greater Boston's urban inner core. Settled by Europeans in 1629, Lynn is the 5th oldest colonial settlement in the Commonwealth. An early industrial center, Lynn was long colloquially referred to as the "City of Sin", owing to its historical reputation for crime and vice. Today, however, the city is known for its contemporary public art, immigrant population, historic architecture, downtown cultural district, loft-style apartments, and public parks and open spaces, which include the oceanfront Lynn Shore Reservation; the 2,200-acre, Frederick Law Olmsted-designed Lynn Woods Reservation; and the High Rock Reservation and Park designed by Olmsted's sons. Lynn also is home to Lynn Heritage State Park, the southernmost portion of the Essex Coastal Scenic Byway, and the seaside, Natio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Hofmeister
Franz Hofmeister (30 August 1850, in Prague – 26 July 1922, in Würzburg) was an early protein scientist, and is famous for his studies of salts that influence the solubility and conformational stability of proteins. In 1902, Hofmeister became the first to propose that polypeptides were amino acids linked by peptide bonds, although this model of protein primary structure was independently and simultaneously conceived by Emil Fischer. Early life Hofmeister's father was a doctor in Prague, where Hofmeister first began his studies, under the physiologist Karl Hugo Huppert, himself a student of Carl Lehmann. Hofmeister's ''Habilitationsschrift'' in 1879 concerned the peptic products of digestion. Hofmeister became a Professor of Pharmacology at the First Faculty of Medicine, Charles University in Prague in 1885, then eventually moved to Strasbourg in 1896. The Hofmeister series Hofmeister discovered a series of salts that have consistent effects on the solubility of protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Social Systems
In sociology, a social system is the patterned network of relationships constituting a coherent whole that exist between individuals, groups, and institutions. It is the formal structure of role and status that can form in a small, stable group. An individual may belong to multiple social systems at once; examples of social systems include nuclear family units, communities, cities, nations, college campuses, corporations, and industries. The organization and definition of groups within a social system depend on various shared properties such as location, socioeconomic status, race, religion, societal function, or other distinguishable features. Notable theorists The study of social systems is integral to the fields of sociology and public policy. Social systems have been studied for as long as sociology has existed. Talcott Parsons Talcott Parsons was the first to formulate a systematic theory of social systems, which he did as a part of his AGIL paradigm. He defined a so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Environment (biophysical)
A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale from microscopic to global in extent. It can also be subdivided according to its attributes. Examples include the marine environment, the atmospheric environment and the terrestrial environment. The number of biophysical environments is countless, given that each living organism has its own environment. The term ''environment'' can refer to a singular global environment in relation to humanity, or a local biophysical environment, e.g. the UK's Environment Agency. Life-environment interaction All life that has survived must have adapted to the conditions of its environment. Temperature, light, humidity, soil nutrients, etc., all influence the species within an environment. However, life in turn modifies, in various forms, its conditions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fine Tuning
In theoretical physics, fine-tuning is the process in which parameters of a model must be adjusted very precisely in order to fit with certain observations. This had led to the discovery that the fundamental constants and quantities fall into such an extraordinarily precise range that if it did not, the origin and evolution of conscious agents in the universe would not be permitted. Theories requiring fine-tuning are regarded as problematic in the absence of a known mechanism to explain why the parameters happen to have precisely the observed values that they return. The heuristic rule that parameters in a fundamental physical theory should not be too fine-tuned is called naturalness. Background The idea that naturalness will explain fine tuning was brought into question by Nima Arkani-Hamed, a theoretical physicist, in his talk "Why is there a Macroscopic Universe?", a lecture from the mini-series "Multiverse & Fine Tuning" from the "Philosophy of Cosmology" project, a Unive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nomograms
A nomogram (from Greek , "law" and , "line"), also called a nomograph, alignment chart, or abac, is a graphical calculating device, a two-dimensional diagram designed to allow the approximate graphical computation of a mathematical function. The field of nomography was invented in 1884 by the French engineer Philbert Maurice d'Ocagne (1862–1938) and used extensively for many years to provide engineers with fast graphical calculations of complicated formulas to a practical precision. Nomograms use a parallel coordinate system invented by d'Ocagne rather than standard Cartesian coordinates. A nomogram consists of a set of n scales, one for each variable in an equation. Knowing the values of n-1 variables, the value of the unknown variable can be found, or by fixing the values of some variables, the relationship between the unfixed ones can be studied. The result is obtained by laying a straightedge across the known values on the scales and reading the unknown value from whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Albert Hasselbalch
Karl Albert Hasselbalch (; 1 November 1874 – 19 September 1962) was a Danish physician and chemist known for his work on the Henderson–Hasselbalch equation. Early life and education Hasselbalch was born in Åstrup, near Hjørring, Denmark on 1 November 1874. Hasselbalch received his medical degree in 1898 and his doctorate in 1899 for his thesis on the respiratory metabolism in the chicken embryo. Career Hasselbalch was a pioneer in the use of pH measurement in medicine (with Christian Bohr, father of Niels Bohr), and he described how the affinity of blood for oxygen was dependent on the concentration of carbon dioxide. He was also first to determine the pH of blood. In 1916, he converted the 1908 equation of Lawrence Joseph Henderson to logarithmic form, which is now known as the Henderson–Hasselbalch equation In chemistry and biochemistry, the Henderson–Hasselbalch equation :\ce = \ceK_\ce + \log_ \left( \frac \right) relates the pH of a chemical solution of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buffer Solution
A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean. Principles of buffering Buffer solutions resist pH change because of a chemical equilibrium between the weak acid HA and its conjugate base A−: When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, hydrogen ions (H+) are added, and the equilibrium is shifted to the left, in accordance with Le Chatelier's principle. Because of this, the hydrogen io ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kidneys
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blood exits into the paired renal veins. Each kidney is attached to a ureter, a tube that carries excreted urine to the bladder. The kidney participates in the control of the volume of various body fluids, fluid osmolality, acid–base balance, various electrolyte concentrations, and removal of toxins. Filtration occurs in the glomerulus: one-fifth of the blood volume that enters the kidneys is filtered. Examples of substances reabsorbed are solute-free water, sodium, bicarbonate, glucose, and amino acids. Examples of substances secreted are hydrogen, ammonium, potassium and uric acid. The nephron is the structural and functional unit of the kidney. Each adult human kidney contains around 1 million nephrons, while a mouse kidney contai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Blood Cells
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "hollow vessel", with ''-cyte'' translated as "cell" in modern usage), are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O2) to the body tissues—via blood flow through the circulatory system. RBCs take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillaries. The cytoplasm of a red blood cell is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million hemoglobin molecules. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lung
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the air and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their different muscles to support and foster breathing. In earlier tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the main muscle of respiration that drives breathing is the diaphragm. The lungs also provide airflow that makes vocal sounds including human speech possible. Humans have two lungs, one on the left an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
