|
Keith Roberts Porter
Keith Roberts Porter (June 11, 1912 – May 2, 1997) was a Canadian- American cell biologist. He created pioneering biology techniques and research using electron microscopy of cells. Porter also contributed to the development of other experimental methods for cell culture and nuclear transplantation. He was also responsible for naming the endoplasmic reticulum, conducting work on the 9 + 2 microtubule structure in the axoneme of cilia, and coining the term " microtrabecular lattice." In collaborations with other scientists, he contributed to the understanding of scellular structures and concepts such as compartmentalization, flagella, centrioles, fibrin, collagen, T-tubules and sarcoplasmic reticulum. He also introduced microtome cutting Early life and education Keith Porter was born in Yarmouth, Nova Scotia, on June 11, 1912, the son of Aaron and Josephine Roberts Porter. He finished his undergraduate program at Acadia University in 1934, and became a graduate stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yarmouth, Nova Scotia
Yarmouth is a town in southwestern Nova Scotia, Canada. A port town, industries include fishing, and tourism. It is the terminus of a ferry service to Bar Harbor, Maine, run by Bay Ferries. History Originally inhabited by the Mi'kmaq, the region was known as "Keespongwitk" meaning "Lands End" due to its position at the tip of the Nova Scotia peninsula. European settlement The region was visited in 1604 by Samuel de Champlain, who named it "Cap-Fourchu", meaning "forked or cloven cape." The first Europeans to make a settlement on these shores were the French Acadians. They set up a small fishing settlement known as "Tebouque" in the mid 1600s and by 1750 the population was 50 people. During the Seven Years' War, New England Planters settled at what is now the town of Yarmouth in 1759; the grantees were from Yarmouth, Massachusetts and they requested that Yarmouth be named after their former home. Yarmouth was founded on June 9, 1761, when a ship carrying three families arrived fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flagellum
A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have from one to many flagella. A gram-negative bacterium ''Helicobacter pylori'' for example uses its multiple flagella to propel itself through the mucus lining to reach the stomach epithelium, where it may cause a gastric ulcer to develop. In some bacteria the flagellum can also function as a sensory organelle, being sensitive to wetness outside the cell. Across the three domains of Bacteria, Archaea, and Eukaryota the flagellum has a different structure, protein composition, and mechanism of propulsion but shares the same function of providing motility. The Latin word means " whip" to describe its lash-like swimming motion. The flagellum in archaea is called the archaellum to note its difference from the bacterial flagellum. Eukaryotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultramicrotome
A microtome (from the Greek ''mikros'', meaning "small", and ''temnein'', meaning "to cut") is a cutting tool used to produce extremely thin slices of material known as ''sections''. Important in science, microtomes are used in microscopy, allowing for the preparation of samples for observation under transmitted light or electron radiation. Microtomes use steel, glass or diamond blades depending upon the specimen being sliced and the desired thickness of the sections being cut. Steel blades are used to prepare histological sections of animal or plant tissues for light microscopy. Glass knives are used to slice sections for light microscopy and to slice very thin sections for electron microscopy. Industrial grade diamond knives are used to slice hard materials such as bone, teeth and tough plant matter for both light microscopy and for electron microscopy. Gem-quality diamond knives are also used for slicing thin sections for electron microscopy. Microtomy is a method for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrograph
A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken on a microscope but is only slightly magnified, usually less than 10 times. Micrography is the practice or art of using microscopes to make photographs. A micrograph contains extensive details of microstructure. A wealth of information can be obtained from a simple micrograph like behavior of the material under different conditions, the phases found in the system, failure analysis, grain size estimation, elemental analysis and so on. Micrographs are widely used in all fields of microscopy. Types Photomicrograph A light micrograph or photomicrograph is a micrograph prepared using an optical microscope, a process referred to as ''photomicroscopy''. At a basic level, photomicroscopy may be performed simply by connecting a camera to a microscope, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmium Tetroxide
Osmium tetroxide (also osmium(VIII) oxide) is the chemical compound with the formula OsO4. The compound is noteworthy for its many uses, despite its toxicity and the rarity of osmium. It also has a number of unusual properties, one being that the solid is volatile. The compound is colourless, but most samples appear yellow. This is most likely due to the presence of the impurity OsO2, which is yellow-brown in colour. In biology, its property of binding to lipids has made it a widely-used stain in electron microscopy. Physical properties Osmium(VIII) oxide forms monoclinic crystals. It has a characteristic acrid chlorine-like odor. The element name osmium is derived from ''osme'', Greek for ''odor''. OsO4 is volatile: it sublimes at room temperature. It is soluble in a wide range of organic solvents. It is also moderately soluble in water, with which it reacts reversibly to form osmic acid (see below). ''Pure'' osmium(VIII) oxide is probably colourless and it has been sugg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryonic Development
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of the body. Neurulation forms the nervous syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Rockefeller University
The Rockefeller University is a private biomedical research and graduate-only university in New York City, New York. It focuses primarily on the biological and medical sciences and provides doctoral and postdoctoral education. It is classified among "R2: Doctoral Universities – High research activity." Rockefeller is the oldest biomedical research institute in the United States. In 2018, the faculty included 82 tenured and tenure-track members, including 37 members of the National Academy of Sciences, 17 members of the National Academy of Medicine, seven Lasker Award recipients, and five Nobel laureates. As of March 2022, a total of 26 Nobel laureates have been affiliated with Rockefeller University. The university is located on the Upper East Side of Manhattan, between 63rd and 68th streets on York Avenue. Richard P. Lifton became the university's eleventh president on September 1, 2016. The Rockefeller University Press publishes the ''Journal of Experimental Medicine'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher learning in the United States and one of the most prestigious and highly ranked universities in the world. The university is composed of ten academic faculties plus Harvard Radcliffe Institute. The Faculty of Arts and Sciences offers study in a wide range of undergraduate and graduate academic disciplines, and other faculties offer only graduate degrees, including professional degrees. Harvard has three main campuses: the Cambridge campus centered on Harvard Yard; an adjoining campus immediately across Charles River in the Allston neighborhood of Boston; and the medical campus in Boston's Longwood Medical Area. Harvard's endowment is valued at $50.9 billion, making it the wealthiest academic institution in the world. Endowment inco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acadia University
Acadia University is a public, predominantly undergraduate university located in Wolfville, Nova Scotia, Canada, with some graduate programs at the master's level and one at the doctoral level. The enabling legislation consists of the Acadia University Act and the Amended Acadia University Act 2000. The Wolfville Campus houses Acadia University Archives and the Acadia University Art Gallery. Acadia offers over 200 degree combinations in the faculties of arts, pure and applied science, professional studies, and theology. The student-faculty ratio is 15:1 and the average class size is 28. Open Acadia offers correspondence and distance education courses. As of July 2017, Peter J. Ricketts is Acadia's current president. History Acadia began as an extension of Horton Academy (1828), which was founded in Horton, Nova Scotia, by Baptists from Nova Scotia and Queen's College (1838). The college was later named Acadia College. Acadia University, established at Wolfville, Nova Scotia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtome
A microtome (from the Greek ''mikros'', meaning "small", and ''temnein'', meaning "to cut") is a cutting tool used to produce extremely thin slices of material known as ''sections''. Important in science, microtomes are used in microscopy, allowing for the preparation of samples for observation under transmitted light or electron radiation. Microtomes use steel, glass or diamond blades depending upon the specimen being sliced and the desired thickness of the sections being cut. Steel blades are used to prepare histological sections of animal or plant tissues for light microscopy. Glass knives are used to slice sections for light microscopy and to slice very thin sections for electron microscopy. Industrial grade diamond knives are used to slice hard materials such as bone, teeth and tough plant matter for both light microscopy and for electron microscopy. Gem-quality diamond knives are also used for slicing thin sections for electron microscopy. Microtomy is a method for the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcoplasmic Reticulum
The sarcoplasmic reticulum (SR) is a membrane-bound structure found within muscle cells that is similar to the smooth endoplasmic reticulum in other Cell (biology), cells. The main function of the SR is to store calcium ions (Ca2+). Calcium in biology, Calcium ion levels are kept relatively constant, with the concentration of calcium ions within a cell being 10,000 times smaller than the concentration of calcium ions outside the cell. This means that small increases in calcium ions within the cell are easily detected and can bring about important cellular changes (the calcium is said to be a second messenger). Calcium is used to make calcium carbonate (found in chalk) and calcium phosphate, two compounds that the body uses to make teeth and bones. This means that too much calcium within the cells can lead to hardening (calcification) of certain intracellular structures, including the mitochondrion, mitochondria, leading to cell death. Therefore, it is vital that calcium ion levels a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-tubule
T-tubules (transverse tubules) are extensions of the cell membrane that penetrate into the center of skeletal and cardiac muscle cells. With membranes that contain large concentrations of ion channels, transporters, and pumps, T-tubules permit rapid transmission of the action potential into the cell, and also play an important role in regulating cellular calcium concentration. Through these mechanisms, T-tubules allow heart muscle cells to contract more forcefully by synchronising calcium release from the sarcoplasmic reticulum throughout the cell. T-tubule structure and function are affected beat-by-beat by cardiomyocyte contraction, as well as by diseases, potentially contributing to heart failure and arrhythmias. Although these structures were first seen in 1897, research into T-tubule biology is ongoing. Structure T-tubules are tubules formed from the same Lipid bilayer, phospholipid bilayer as the surface membrane or sarcolemma of skeletal or cardiac muscle cells. They c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
