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Saurischia ( , meaning "reptile-hipped" from the Greek () meaning 'lizard' and () meaning 'hip joint') is one of the two basic divisions of dinosaurs (the other being Ornithischia), classified by their hip structure. Saurischia and Ornithischia were originally called orders by Harry Seeley in 1888 though today most ... | Saurischia | Wikipedia | 483 | 6832171 | https://en.wikipedia.org/wiki/Saurischia | Biology and health sciences | Dinosaurs | Animals |
In his paper naming the two groups, Seeley reviewed previous classification schemes put forth by other paleontologists to divide up the traditional order Dinosauria. He preferred one that had been put forward by Othniel Charles Marsh in 1878, which divided dinosaurs into four orders: Sauropoda, Theropoda, Ornithopoda, ... | Saurischia | Wikipedia | 467 | 6832171 | https://en.wikipedia.org/wiki/Saurischia | Biology and health sciences | Dinosaurs | Animals |
One alternative hypothesis challenging Seeley's classification was proposed by Robert T. Bakker in his 1986 book The Dinosaur Heresies. Bakker's classification separated the theropods into their own group and placed the two groups of herbivorous dinosaurs (the sauropodomorphs and ornithischians) together in a separate ... | Saurischia | Wikipedia | 194 | 6832171 | https://en.wikipedia.org/wiki/Saurischia | Biology and health sciences | Dinosaurs | Animals |
A 2017 study by Matthew Grant Baron, David B. Norman and Paul M. Barrett did not find support for a monophyletic Saurischia, according to its traditional definition. Instead, the group was found to be paraphyletic. As a solution, Theropoda was removed from the group and placed as the sister group to the Ornithischia in... | Saurischia | Wikipedia | 327 | 6832171 | https://en.wikipedia.org/wiki/Saurischia | Biology and health sciences | Dinosaurs | Animals |
Stem-cell therapy uses stem cells to treat or prevent a disease or condition. , the only FDA-approved therapy using stem cells is hematopoietic stem cell transplantation. This usually takes the form of a bone marrow or peripheral blood stem cell transplantation, but the cells can also be derived from umbilical cord blo... | Stem-cell therapy | Wikipedia | 487 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
The FDA has approved five hematopoietic stem-cell products derived from umbilical cord blood, for the treatment of blood and immunological diseases.
In 2014, the European Medicines Agency recommended approval of limbal stem cells for people with severe limbal stem cell deficiency due to burns in the eye.
Research onl... | Stem-cell therapy | Wikipedia | 486 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
There has been more recent interest in the use of extra embryonic mesenchymal stem cells. Research is underway to examine the differentiating capabilities of stem cells found in the umbilical cord, yolk sac and placenta of different animals. These stem cells are thought to have more differentiating ability than their a... | Stem-cell therapy | Wikipedia | 472 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
In drug discovery and biomedical research
The ability to grow up functional adult tissues indefinitely in culture through Directed differentiation creates new opportunities for drug research. Researchers are able to grow up differentiated cell lines and then test new drugs on each cell type to examine possible interact... | Stem-cell therapy | Wikipedia | 495 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
Assumed regenerative models
Stem cells are thought to mediate repair via five primary mechanisms: 1) providing an anti-inflammatory effect, 2) homing to damaged tissues and recruiting other cells, such as endothelial progenitor cells, that are necessary for tissue growth, 3) supporting tissue remodeling over scar forma... | Stem-cell therapy | Wikipedia | 509 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
Frailty syndrome
In 2017, a small-scale study on individuals 60 years or older with aging frailty showed, after intravenous treatment with Mesenchymal stem cells (MSC) from healthy young donors, significant improvements in physical performance measures. MSC helps with the blockade of inflammation by decreasing it, caus... | Stem-cell therapy | Wikipedia | 436 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
Fully mature human red blood cells may be generated ex vivo by hematopoietic stem cells (HSCs), which are precursors of red blood cells. In this process, HSCs are grown together with stromal cells, creating an environment that mimics the conditions of bone marrow, the natural site of red-blood-cell growth. Erythropoiet... | Stem-cell therapy | Wikipedia | 502 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
Pancreatic beta cells
People with Type 1 diabetes lose the function of insulin-producing beta cells within the pancreas. In a 2007 publication of experiments, scientists have been able to coax embryonic stem cells to turn into beta cells in the lab. In theory, if the beta cell is transplanted successfully, they will be... | Stem-cell therapy | Wikipedia | 465 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
In 2013, studies of autologous bone marrow stem cells on ventricular function were found to contain "hundreds" of discrepancies. Critics report that of 48 reports, just five underlying trials seemed to be used, and that in many cases whether they were randomized or merely observational accepter-versus-rejecter, was con... | Stem-cell therapy | Wikipedia | 434 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
In 2021, stem cell injections in the US have caused grave infections in at least 20 patients who received umbilical cord blood-derived products marketed as "stem cell treatment". In 2023, the case of a woman who was infected with Mycobacterium abscessus and sustained meningitis after stem cell treatment for multiple sc... | Stem-cell therapy | Wikipedia | 500 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
Stem cells have been used to treat degenerative bone diseases in dogs. The normally recommended treatment for dogs that have Legg–Calve–Perthes disease is to remove the head of the femur after the degeneration has progressed. Recently, mesenchymal stem cells have been injected directly in to the head of the femur, with... | Stem-cell therapy | Wikipedia | 418 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
The use of embryonic stem cells has also been applied to tendon repair. The embryonic stem cells were shown to have a better survival rate in the tendon as well as better migrating capabilities to reach all areas of damaged tendon. The overall repair quality was also higher, with better tendon architecture and collagen... | Stem-cell therapy | Wikipedia | 450 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
2018 research, such as the European nTRACK research project, aims to demonstrate that multimodal nanoparticles can structurally and functionally track stem cell in muscle regeneration therapy. The idea is to label stem cells with gold nano-particles that are fully characterised for uptake, functionality, and safety. Th... | Stem-cell therapy | Wikipedia | 459 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
Stem cells are also in clinical phases for treatment in ophthalmology. Hematopoietic stem cells have been used to treat corneal ulcers of different origin of several horses. These ulcers were resistant to conventional treatments available, but quickly responded positively to the stem cell treatment. Stem cells were als... | Stem-cell therapy | Wikipedia | 495 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
Costs of stem cell therapies range widely by clinic, condition, and cell type, but most commonly range between $10,000-$20,000. Insurance does not cover stem cell injections at clinics so patients often use on-line fundraising. In 2018, the US Federal Trade Commission found health centers and an individual physician ma... | Stem-cell therapy | Wikipedia | 234 | 3853380 | https://en.wikipedia.org/wiki/Stem-cell%20therapy | Technology | Biotechnology | null |
In radio-frequency engineering and communications engineering, a waveguide is a hollow metal pipe used to carry radio waves. This type of waveguide is used as a transmission line mostly at microwave frequencies, for such purposes as connecting microwave transmitters and receivers to their antennas, in equipment such as... | Waveguide (radio frequency) | Wikipedia | 324 | 3854225 | https://en.wikipedia.org/wiki/Waveguide%20%28radio%20frequency%29 | Physical sciences | Electromagnetic radiation | Physics |
During the 1890s theorists did the first analyses of electromagnetic waves in ducts. Around 1893 J. J. Thomson derived the electromagnetic modes inside a cylindrical metal cavity. In 1897 Lord Rayleigh did a definitive analysis of waveguides; he solved the boundary value problem of electromagnetic waves propagating t... | Waveguide (radio frequency) | Wikipedia | 504 | 3854225 | https://en.wikipedia.org/wiki/Waveguide%20%28radio%20frequency%29 | Physical sciences | Electromagnetic radiation | Physics |
The waveguide was developed independently between 1932 and 1936 by George C. Southworth at Bell Telephone Laboratories and Wilmer L. Barrow at the Massachusetts Institute of Technology, who worked without knowledge of one another. Southworth's interest was sparked during his 1920s doctoral work in which he measured th... | Waveguide (radio frequency) | Wikipedia | 495 | 3854225 | https://en.wikipedia.org/wiki/Waveguide%20%28radio%20frequency%29 | Physical sciences | Electromagnetic radiation | Physics |
In the microwave region of the electromagnetic spectrum, a waveguide normally consists of a hollow metallic conductor. These waveguides can take the form of single conductors with or without a dielectric coating, e.g. the Goubau line and helical waveguides. Hollow waveguides must be one-half wavelength or more in dia... | Waveguide (radio frequency) | Wikipedia | 427 | 3854225 | https://en.wikipedia.org/wiki/Waveguide%20%28radio%20frequency%29 | Physical sciences | Electromagnetic radiation | Physics |
Waveguides are almost exclusively made of metal and mostly rigid structures. There are certain types of "corrugated" waveguides that have the ability to flex and bend but only used where essential since they degrade propagation properties. Due to propagation of energy in mostly air or space within the waveguide, it is ... | Waveguide (radio frequency) | Wikipedia | 485 | 3854225 | https://en.wikipedia.org/wiki/Waveguide%20%28radio%20frequency%29 | Physical sciences | Electromagnetic radiation | Physics |
In practice
In practice, waveguides act as the equivalent of cables for super high frequency (SHF) systems. For such applications, it is desired to operate waveguides with only one mode propagating through the waveguide. With rectangular waveguides, it is possible to design the waveguide such that the frequency band ov... | Waveguide (radio frequency) | Wikipedia | 479 | 3854225 | https://en.wikipedia.org/wiki/Waveguide%20%28radio%20frequency%29 | Physical sciences | Electromagnetic radiation | Physics |
† For historical reasons the outside rather than the inside dimensions of these waveguides are 2:1 (with wall thickness WG6–WG10: 0.08" (2.0 mm), WG11A–WG15: 0.064" (1.6 mm), WG16–WG17: 0.05" (1.3 mm), WG18–WG28: 0.04" (1.0 mm))
For the frequencies in the table above, the main advantage of waveguides over coaxial cab... | Waveguide (radio frequency) | Wikipedia | 495 | 3854225 | https://en.wikipedia.org/wiki/Waveguide%20%28radio%20frequency%29 | Physical sciences | Electromagnetic radiation | Physics |
The mode with the lowest cutoff frequency is termed the dominant mode of the guide. It is common to choose the size of the guide such that only this one mode can exist in the frequency band of operation. In rectangular and circular (hollow pipe) waveguides, the dominant modes are designated the TE1,0 mode and TE1,1 mod... | Waveguide (radio frequency) | Wikipedia | 355 | 3854225 | https://en.wikipedia.org/wiki/Waveguide%20%28radio%20frequency%29 | Physical sciences | Electromagnetic radiation | Physics |
Hospice care is a type of health care that focuses on the palliation of a terminally ill patient's pain and symptoms and attending to their emotional and spiritual needs at the end of life. Hospice care prioritizes comfort and quality of life by reducing pain and suffering. Hospice care provides an alternative to thera... | Hospice | Wikipedia | 467 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
This philosophy affects how hospice staff treat people and their families. Compared to general healthcare providers, hospice professionals take a different approach to talking to people and their families. They are more likely to make predictions or express uncertainty around future events (e.g., "He might die this w... | Hospice | Wikipedia | 510 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
The more influential early developers of hospice included the Irish Religious Sisters of Charity, who opened Our Lady's Hospice in Harold's Cross, Dublin, Ireland, in 1879. It served as many as 20,000 people—primarily with tuberculosis and cancer—dying there between 1845 and 1945. The Sisters of Charity expanded intern... | Hospice | Wikipedia | 402 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
She disseminated her philosophy internationally in a series of tours of the United States that began in 1963. In 1967, Saunders opened St Christopher's Hospice. Florence Wald, the dean of Yale School of Nursing, who had heard Saunders speak in America, spent a month working with Saunders there in 1969 before bringing t... | Hospice | Wikipedia | 461 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
In 2006, the United States–based National Hospice and Palliative Care Organization (NHPCO) and the United Kingdom's Help the Hospices jointly commissioned an independent, international study of worldwide palliative care practices. Their survey found that 15% of the world's countries offered widespread palliative care s... | Hospice | Wikipedia | 426 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
Africa
A hospice opened in 1980 in Harare (Salisbury), Zimbabwe, the first in Sub-Saharan Africa. In spite of skepticism in the medical community, the hospice movement spread, and in 1987 the Hospice Palliative Care Association of South Africa formed. In 1990, Nairobi Hospice opened in Nairobi, Kenya. As of 2006, Kenya... | Hospice | Wikipedia | 424 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
Canada
Canadian physician Balfour Mount, who first coined the term "palliative care", was a pioneer in medical research and in the Canadian hospice movement, which focused primarily on palliative care in a hospital setting. After meeting Kübler-Ross, Mount studied the experiences of the terminally ill at Royal Victoria... | Hospice | Wikipedia | 469 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
Florence Wald, Dean of the Yale School of Nursing, founded one of the first hospices in the United States in New Haven, Connecticut, in 1974. The first hospital-based palliative care consultation service developed in the US was the Wayne State University School of Medicine in 1985 at Detroit Receiving Hospital. The fir... | Hospice | Wikipedia | 316 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
The first hospice to open in the United Kingdom was the Trinity Hospice in Clapham south London in 1891, on the initiative of the Hoare banking family. More than half a century later, a hospice movement developed after Dame Cicely Saunders opened St Christopher's Hospice in 1967, widely considered the first modern hosp... | Hospice | Wikipedia | 477 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
Models of both home-based care and stand-alone hospices exist globally, but with the cultural and societal preferences of patients and their families to die at home in Egypt there is an inclination to focus on the development of home-based hospice and palliative care services.
Israel
The first hospice unit in Israel ... | Hospice | Wikipedia | 469 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
The hospice home health nurse must be skilled in both physical care and psychosocial care. Most nurses will work with a team that includes a physician, social worker and possibly a spiritual care counselor. Some of the nurse's duties will include reassuring family members, and ensuring adequate pain control. The nurse ... | Hospice | Wikipedia | 159 | 21464996 | https://en.wikipedia.org/wiki/Hospice | Biology and health sciences | Medical procedures: General | Health |
In mathematics, a morphism is a concept of category theory that generalizes structure-preserving maps such as homomorphism between algebraic structures, functions from a set to another set, and continuous functions between topological spaces. Although many examples of morphisms are structure-preserving maps, morphisms ... | Morphism | Wikipedia | 507 | 27716891 | https://en.wikipedia.org/wiki/Morphism | Mathematics | Category theory | null |
For a concrete category (a category in which the objects are sets, possibly with additional structure, and the morphisms are structure-preserving functions), the identity morphism is just the identity function, and composition is just ordinary composition of functions.
The composition of morphisms is often represented... | Morphism | Wikipedia | 419 | 27716891 | https://en.wikipedia.org/wiki/Morphism | Mathematics | Category theory | null |
Morphisms with left inverses are always monomorphisms, but the converse is not true in general; a monomorphism may fail to have a left inverse. In concrete categories, a function that has a left inverse is injective. Thus in concrete categories, monomorphisms are often, but not always, injective. The condition of being... | Morphism | Wikipedia | 471 | 27716891 | https://en.wikipedia.org/wiki/Morphism | Mathematics | Category theory | null |
While every isomorphism is a bimorphism, a bimorphism is not necessarily an isomorphism. For example, in the category of commutative rings the inclusion is a bimorphism that is not an isomorphism. However, any morphism that is both an epimorphism and a split monomorphism, or both a monomorphism and a split epimorphis... | Morphism | Wikipedia | 473 | 27716891 | https://en.wikipedia.org/wiki/Morphism | Mathematics | Category theory | null |
RYB (an abbreviation of red–yellow–blue) is a subtractive color model used in art and applied design in which red, yellow, and blue pigments are considered primary colors. Under traditional color theory, this set of primary colors was advocated by Moses Harris, Michel Eugène Chevreul, Johannes Itten and Josef Albers, a... | RYB color model | Wikipedia | 460 | 927051 | https://en.wikipedia.org/wiki/RYB%20color%20model | Physical sciences | Basics | Physics |
History
The first scholars to propose that there are three primary colors for painters were Scarmiglioni (1601), Savot (1609), de Boodt (1609) and Aguilonius (1613). From these, the most influential was the work of Franciscus Aguilonius (1567–1617), although he did not arrange the colors in a wheel.
Jacob Christoph Le... | RYB color model | Wikipedia | 478 | 927051 | https://en.wikipedia.org/wiki/RYB%20color%20model | Physical sciences | Basics | Physics |
In The Law of Simultaneous Color Contrast (1839) by the French industrial chemist Michel Eugène Chevreul discussed the creation of numerous color nuances and his color theories were underpinned by the RYB color model.
Separate to the RYB color model, cyan, magenta, and yellow primary colors are associated with CMYK co... | RYB color model | Wikipedia | 505 | 927051 | https://en.wikipedia.org/wiki/RYB%20color%20model | Physical sciences | Basics | Physics |
This model was used for printing by Jacob Christoph Le Blon in 1725 and called it Coloritto or harmony of colouring, stating that the primitive (primary) colors are yellow, red and blue, while the secondary are orange, green and purple or violet.
In 1766, Moses Harris developed an 18-color color wheel based on this mo... | RYB color model | Wikipedia | 306 | 927051 | https://en.wikipedia.org/wiki/RYB%20color%20model | Physical sciences | Basics | Physics |
The Guernsey is a breed of dairy cattle from the island of Guernsey in the Channel Islands. It is fawn or red and white in colour, and is hardy and docile. Its milk is rich in flavour, high in fat and protein, and has a golden-yellow tinge due to its high β-carotene content. The Guernsey is one of three Channel Island ... | Guernsey cattle | Wikipedia | 485 | 927572 | https://en.wikipedia.org/wiki/Guernsey%20cattle | Biology and health sciences | Cattle | Animals |
Use
The Guernsey is a dairy breed, and generally is reared for that purpose only. However, the cow is usually removed from the dairy herd around ages six to eight, and marketed for beef, and other processed meats. The milk has a golden-yellow tinge due to a high content of β-carotene, a provitamin for vitamin A. The m... | Guernsey cattle | Wikipedia | 108 | 927572 | https://en.wikipedia.org/wiki/Guernsey%20cattle | Biology and health sciences | Cattle | Animals |
HFS Plus or HFS+ (also known as Mac OS Extended or HFS Extended) is a journaling file system developed by Apple Inc. It replaced the Hierarchical File System (HFS) as the primary file system of Apple computers with the 1998 release of Mac OS 8.1. HFS+ continued as the primary Mac OS X file system until it was itself ... | HFS Plus | Wikipedia | 427 | 927752 | https://en.wikipedia.org/wiki/HFS%20Plus | Technology | Data storage and memory | null |
Mac OS X 10.3 also introduced another version of HFS Plus called HFSX. HFSX volumes are almost identical to HFS Plus volumes, except that they are never surrounded by the HFS Wrapper that is typical of HFS Plus volumes and they optionally support case sensitivity for file and folder names. HFSX volumes can be recognize... | HFS Plus | Wikipedia | 511 | 927752 | https://en.wikipedia.org/wiki/HFS%20Plus | Technology | Data storage and memory | null |
Design
HFS Plus volumes are divided into sectors (called logical blocks in HFS), that are usually 512 bytes in size. These sectors are then grouped together into allocation blocks which can contain one or more sectors; the number of allocation blocks depends on the total size of the volume. HFS Plus uses a larger valu... | HFS Plus | Wikipedia | 336 | 927752 | https://en.wikipedia.org/wiki/HFS%20Plus | Technology | Data storage and memory | null |
Formerly, HFS Plus volumes were embedded inside an HFS standard file system. This was phased out by the Tiger transition to Intel Macs, where the HFS Plus file system was not embedded inside a wrapper. The wrapper had been designed for two purposes; it allowed Macintosh computers without HFS Plus support in their ROM... | HFS Plus | Wikipedia | 223 | 927752 | https://en.wikipedia.org/wiki/HFS%20Plus | Technology | Data storage and memory | null |
Sectors 0 and 1 of the volume are HFS boot blocks. These are identical to the boot blocks in an HFS volume. They are part of the HFS wrapper.
Sector 2 contains the Volume Header, which is equivalent to the Master Directory Block in an HFS volume. The Volume Header stores a wide variety of data about the volume itself,... | HFS Plus | Wikipedia | 484 | 927752 | https://en.wikipedia.org/wiki/HFS%20Plus | Technology | Data storage and memory | null |
The Attributes File is a new B-tree in HFS Plus that does not have a corresponding structure in HFS. The Attributes File can store three different types of 4 KB records: Inline Data Attribute records, Fork Data Attribute records and Extension Attribute records. Inline Data Attribute records store small attributes that ... | HFS Plus | Wikipedia | 228 | 927752 | https://en.wikipedia.org/wiki/HFS%20Plus | Technology | Data storage and memory | null |
Criticisms
HFS Plus lacks several features considered staples of modern file systems like ZFS and NTFS. Data checksums are the most routinely cited missing feature.
Besides checksumming, features of modern file systems that HFS+ lacks include:
nanosecond timestamps
concurrent access (that is, more than one process ... | HFS Plus | Wikipedia | 483 | 927752 | https://en.wikipedia.org/wiki/HFS%20Plus | Technology | Data storage and memory | null |
, Paragon Software Group provided kernel drivers that allow full read-write access to HFS+ journaled volumes. The product is a proprietary implementation of HFS+ based on Paragon's proprietary UFSD library. There are both free and paid editions of the driver, and they include a utility for checking and repairing HFS+ v... | HFS Plus | Wikipedia | 425 | 927752 | https://en.wikipedia.org/wiki/HFS%20Plus | Technology | Data storage and memory | null |
Cross-platform
A free (GPL) alternative is HFSExplorer written by Erik Larsson. HFSExplorer is a Java application for viewing and extracting files from an HFS+ volume (Mac OS Extended) or an HFSX volume (Mac OS Extended, Case-sensitive). The volume can be located either on a physical disk, in various Apple disk image ... | HFS Plus | Wikipedia | 121 | 927752 | https://en.wikipedia.org/wiki/HFS%20Plus | Technology | Data storage and memory | null |
The grass snake (Natrix natrix), sometimes called the ringed snake or water snake, is a Eurasian semi-aquatic non-venomous colubrid snake. It is often found near water and feeds almost exclusively on amphibians.
Subspecies
Many subspecies are recognized, including:
Natrix natrix helvetica (Lacépède, 1789) was formerl... | Grass snake | Wikipedia | 465 | 928680 | https://en.wikipedia.org/wiki/Grass%20snake | Biology and health sciences | Snakes | Animals |
The preferred habitat appears to be open woodland and "edge" habitat, such as field margins and woodland borders, as these may offer adequate refuge while still affording ample opportunity for thermoregulation through basking. Pond edges are also favoured and the relatively high chance of observing this secretive speci... | Grass snake | Wikipedia | 375 | 928680 | https://en.wikipedia.org/wiki/Grass%20snake | Biology and health sciences | Snakes | Animals |
Ecdysis occurs at least once during the active season. As the outer skin wears and the snake grows, the new skin forms underneath the old, including the eye scales which may turn a milky blue/white colour at this time—referred to as being 'in blue'. The blue-white colour comes from an oily secretion between the old and... | Grass snake | Wikipedia | 463 | 928680 | https://en.wikipedia.org/wiki/Grass%20snake | Biology and health sciences | Snakes | Animals |
In the Baltic mythology, the grass snake (Lithuanian: žaltys, Latvian: zalktis) is seen as a sacred animal. It was frequently kept as a pet, living under a married couple's bed or in a special place near the hearth. Supposedly, snakes ate food given to them by hand.
After the Christianization of Lithuania and Latvia, ... | Grass snake | Wikipedia | 505 | 928680 | https://en.wikipedia.org/wiki/Grass%20snake | Biology and health sciences | Snakes | Animals |
Haemophilus influenzae (formerly called Pfeiffer's bacillus or Bacillus influenzae) is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium of the family Pasteurellaceae. The bacteria are mesophilic and grow best at temperatures between 35 and 37 °C.
H. influenzae was ... | Haemophilus influenzae | Wikipedia | 283 | 929532 | https://en.wikipedia.org/wiki/Haemophilus%20influenzae | Biology and health sciences | Gram-negative bacteria | Plants |
Structure
H. influenzae is a small Gram-negative bacterium, approximately 0.3 micrometer to 1 micrometer. Like other Gram-negative bacteria, H. influenzae has a thin peptidoglycan layer surrounded by an outer membrane containing lipopolysaccharide. Some types of H. influenzae contain a polysaccharide capsule around th... | Haemophilus influenzae | Wikipedia | 371 | 929532 | https://en.wikipedia.org/wiki/Haemophilus%20influenzae | Biology and health sciences | Gram-negative bacteria | Plants |
Penicillin binding proteins
Penicillin binding proteins (PBPs) catalyze steps in peptidoglycan metabolism. They carry out essential processes needed to build and modify the cell wall. These proteins are the targets blocked by penicillin and other beta-lactam antibiotics that bind to PBPs, hence their name. Some antib... | Haemophilus influenzae | Wikipedia | 497 | 929532 | https://en.wikipedia.org/wiki/Haemophilus%20influenzae | Biology and health sciences | Gram-negative bacteria | Plants |
Metabolism
H. influenzae uses the Embden–Meyerhof–Parnas (EMP) pathway for glycolysis and the pentose phosphate pathway, which is anabolic rather than catabolic. The citric acid cycle is incomplete and lacks several enzymes that are found in a fully functioning cycle. The enzymes missing from the TCA cycle are citrate... | Haemophilus influenzae | Wikipedia | 430 | 929532 | https://en.wikipedia.org/wiki/Haemophilus%20influenzae | Biology and health sciences | Gram-negative bacteria | Plants |
Role of transformation
H. influenzae mutants defective in their rec1 gene (a homolog of recA) are very susceptible to being killed by the oxidizing agent hydrogen peroxide. This finding suggests that rec1 expression is important for H. influenzae survival under conditions of oxidative stress. Since it is a homolog of ... | Haemophilus influenzae | Wikipedia | 435 | 929532 | https://en.wikipedia.org/wiki/Haemophilus%20influenzae | Biology and health sciences | Gram-negative bacteria | Plants |
Diagnosis of infections
Clinical features of a respiratory tract infection may include initial symptoms of an upper respiratory tract infection mimicking a viral infection, usually associated with low-grade fevers. This may progress to the lower respiratory tract within a few days, with features often resembling those... | Haemophilus influenzae | Wikipedia | 483 | 929532 | https://en.wikipedia.org/wiki/Haemophilus%20influenzae | Biology and health sciences | Gram-negative bacteria | Plants |
Molecular methods
Polymerase chain reaction (PCR) assays have been proven to be more sensitive than either LAT or culture tests and are highly specific. These PCR tests can be used for capsular typing of encapsulated H. influenzae strains.
Pathogenicity
Host colonization
Many microbes colonize within a host organis... | Haemophilus influenzae | Wikipedia | 512 | 929532 | https://en.wikipedia.org/wiki/Haemophilus%20influenzae | Biology and health sciences | Gram-negative bacteria | Plants |
Haemophilus influenzae type b (Hib) infection
Naturally acquired disease caused by H. influenzae seems to occur in humans only. In healthy children under the age of 5, H. influenzae type b was responsible for more than 80% of aggressive infections, before the introduction of the [Hib] vaccine. In infants and young chi... | Haemophilus influenzae | Wikipedia | 492 | 929532 | https://en.wikipedia.org/wiki/Haemophilus%20influenzae | Biology and health sciences | Gram-negative bacteria | Plants |
There are a few other possible diseases and conditions that can arise from the H. influenzae depending on the areas that they exist in within the human body. This bacterium can exist in the nasal passages (especially the nasopharynx), the ear canal, and the lungs. The bacterium's presence in these areas can lead to som... | Haemophilus influenzae | Wikipedia | 399 | 929532 | https://en.wikipedia.org/wiki/Haemophilus%20influenzae | Biology and health sciences | Gram-negative bacteria | Plants |
Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer test or "tunic" made of the polysaccharide cellulose.
Ascidians are found all over the world, usually in shallow wat... | Ascidiacea | Wikipedia | 453 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
The upper surface of the animal, opposite to the part gripping the substratum, has two openings, or siphons. When removed from the water, the animal often violently expels water from these siphons, hence the common name of "sea squirt". The body itself can be divided into up to three regions, although these are not cle... | Ascidiacea | Wikipedia | 487 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
The esophagus runs downwards to a stomach in the abdomen, which secretes enzymes that digest the food. An intestine runs upwards from the stomach parallel to the oesophagus and eventually opens, through a short rectum and anus, into a cloaca just below the atrial siphon. In some highly developed colonial species, clust... | Ascidiacea | Wikipedia | 484 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
Nervous system
The ascidian central nervous system is formed from a plate that rolls up to form a neural tube. The number of cells within the central nervous system is very small. The neural tube is composed of the sensory vesicle, the neck, the visceral or tail ganglion, and the caudal nerve cord. The anteroposterior ... | Ascidiacea | Wikipedia | 411 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
As a general rule, the larva possesses a long tail, containing muscles, a hollow dorsal nerve tube and a notochord, both features clearly indicative of the animal's chordate affinities. One group though, the molgulid ascidians, have evolved tailless species on at least four separate occasions, and even direct developme... | Ascidiacea | Wikipedia | 483 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
Colonial species
Colonial ascidians reproduce both asexually and sexually. Colonies can survive for decades. An ascidian colony consists of individual elements called zooids. Zooids within a colony are usually genetically identical and some have a shared circulation.
Sexual reproduction
Different colonial ascidian spe... | Ascidiacea | Wikipedia | 447 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
Fertilization
Sea squirt eggs are surrounded by a fibrous vitelline coat and a layer of follicle cells that produce sperm-attracting substances. In fertilization, the sperm passes through the follicle cells and binds to glycosides on the vitelline coat. The sperm's mitochondria are left behind as the sperm enters and d... | Ascidiacea | Wikipedia | 438 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
Promotion of out-crossing
Ciona intestinalis is a hermaphrodite that releases sperm and eggs into the surrounding seawater almost simultaneously. It is self-sterile, and thus has been used for studies on the mechanism of self-incompatibility. Self/non-self-recognition molecules play a key role in the process of interac... | Ascidiacea | Wikipedia | 449 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
Asexual reproduction
Many colonial sea squirts are also capable of asexual reproduction, although the means of doing so are highly variable between different families. In the simplest forms, the members of the colony are linked only by rootlike projections from their undersides known as stolons. Buds containing food st... | Ascidiacea | Wikipedia | 511 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
Sea squirts are the natural prey of many animals, including nudibranchs, flatworms, molluscs, rock crabs, sea stars, fish, birds, and sea otters. Some are also eaten by humans in many parts of the world, including Japan, Korea, Chile, and Europe (where they are sold under the name "sea violet"). As chemical defenses, m... | Ascidiacea | Wikipedia | 486 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
The ascidians were on morphological evidence treated as sister to the Thaliacea and Appendicularia, but molecular evidence has suggested that ascidians could be polyphyletic within the Tunicata, as shown in the following cladogram.
In 2017 and 2018, two studies were published, which suggested an alternate phylogeny, p... | Ascidiacea | Wikipedia | 480 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
Model organisms for research
Several factors make sea squirts good models for studying the fundamental developmental processes of chordates, such as cell-fate specification. The embryonic development of sea squirts is simple, rapid, and easily manipulated. Because each embryo contains relatively few cells, complex proc... | Ascidiacea | Wikipedia | 321 | 930016 | https://en.wikipedia.org/wiki/Ascidiacea | Biology and health sciences | Chordata (except vertebrates) | Animals |
In physics, the energy–momentum relation, or relativistic dispersion relation, is the relativistic equation relating total energy (which is also called relativistic energy) to invariant mass (which is also called rest mass) and momentum. It is the extension of mass–energy equivalence for bodies or systems with non-zero... | Energy–momentum relation | Wikipedia | 459 | 2875647 | https://en.wikipedia.org/wiki/Energy%E2%80%93momentum%20relation | Physical sciences | Theory of relativity | Physics |
The invariant mass (or rest mass) is an invariant for all frames of reference (hence the name), not just in inertial frames in flat spacetime, but also accelerated frames traveling through curved spacetime (see below). However the total energy of the particle and its relativistic momentum are frame-dependent; relativ... | Energy–momentum relation | Wikipedia | 486 | 2875647 | https://en.wikipedia.org/wiki/Energy%E2%80%93momentum%20relation | Physical sciences | Theory of relativity | Physics |
For a massive object moving at three-velocity with magnitude in the lab frame:
is the total energy of the moving object in the lab frame,
is the three dimensional relativistic momentum of the object in the lab frame with magnitude . The relativistic energy and momentum include the Lorentz factor defined by:
... | Energy–momentum relation | Wikipedia | 440 | 2875647 | https://en.wikipedia.org/wiki/Energy%E2%80%93momentum%20relation | Physical sciences | Theory of relativity | Physics |
In particle physics, energy is typically given in units of electron volts (eV), momentum in units of eV·−1, and mass in units of eV·−2. In electromagnetism, and because of relativistic invariance, it is useful to have the electric field and the magnetic field in the same unit (Gauss), using the cgs (Gaussian) system ... | Energy–momentum relation | Wikipedia | 451 | 2875647 | https://en.wikipedia.org/wiki/Energy%E2%80%93momentum%20relation | Physical sciences | Theory of relativity | Physics |
In the case of many particles with relativistic momenta and energy , where (up to the total number of particles) simply labels the particles, as measured in a particular frame, the four-momenta in this frame can be added;
and then take the norm; to obtain the relation for a many particle system:
where is the inv... | Energy–momentum relation | Wikipedia | 500 | 2875647 | https://en.wikipedia.org/wiki/Energy%E2%80%93momentum%20relation | Physical sciences | Theory of relativity | Physics |
Using the de Broglie relations for energy and momentum for matter waves,
where is the angular frequency and is the wavevector with magnitude , equal to the wave number, the energy–momentum relation can be expressed in terms of wave quantities:
and tidying up by dividing by throughout:
This can also be derived f... | Energy–momentum relation | Wikipedia | 184 | 2875647 | https://en.wikipedia.org/wiki/Energy%E2%80%93momentum%20relation | Physical sciences | Theory of relativity | Physics |
Potassium manganate is the inorganic compound with the formula . This green-colored salt is an intermediate in the industrial synthesis of potassium permanganate (), a common chemical. Occasionally, potassium manganate and potassium permanganate are confused, but each compound's properties are distinct.
Structure and ... | Potassium manganate | Wikipedia | 491 | 2876360 | https://en.wikipedia.org/wiki/Potassium%20manganate | Physical sciences | Metallic oxyanions | Chemistry |
This reaction is a laboratory method to prepare oxygen, but produces samples of potassium manganate contaminated with . The former is soluble and the latter is not.
Reactions
Manganate salts readily disproportionate to permanganate ion and manganese dioxide:
The colorful nature of the disproportionation has led the... | Potassium manganate | Wikipedia | 113 | 2876360 | https://en.wikipedia.org/wiki/Potassium%20manganate | Physical sciences | Metallic oxyanions | Chemistry |
An aqueduct is a watercourse constructed to carry water from a source to a distribution point far away. In modern engineering, the term aqueduct is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose. The term aqueduct also often refers specifically to a bridge carrying an... | Aqueduct (water supply) | Wikipedia | 506 | 38540045 | https://en.wikipedia.org/wiki/Aqueduct%20%28water%20supply%29 | Technology | Food, water and health | null |
These enabled large scale agriculture to flourish in a dry land environment.
Persia
In Persia, starting around 3000 years ago a system of underground aqueducts called qanāts were constructed, a series of well-like vertical shafts, connected by gently sloping tunnels. This technique:
taps into subterranean water in a... | Aqueduct (water supply) | Wikipedia | 476 | 38540045 | https://en.wikipedia.org/wiki/Aqueduct%20%28water%20supply%29 | Technology | Food, water and health | null |
The Guayabo National Monument of Costa Rica, a park covering the largest archaeological site in the country, contains a system of aqueducts. The complex network of uncovered and covered aqueducts still functions well. The aqueducts are constructed from rounded river stones, which are mostly made of volcanic rock. The c... | Aqueduct (water supply) | Wikipedia | 488 | 38540045 | https://en.wikipedia.org/wiki/Aqueduct%20%28water%20supply%29 | Technology | Food, water and health | null |
In Spain, the Tagus-Segura Water Transfer system of aqueducts opened in 1979 and transports water from north to south.
In China, the South–North Water Transfer Project aims to connect the Yangtze River basin to Beijing through three separate systems. The project will reuse part of the Grand Canal of China.
Design
O... | Aqueduct (water supply) | Wikipedia | 465 | 38540045 | https://en.wikipedia.org/wiki/Aqueduct%20%28water%20supply%29 | Technology | Food, water and health | null |
Tunnels
Aqueducts sometimes run for some or all of their path through tunnels constructed underground. A version of this common in North Africa and Central Asia that has vertical wells at regular intervals is called a qanat. One historic example found in Syria, the Qanat Firaun, extends over 100 kilometers.
Pipes
Mod... | Aqueduct (water supply) | Wikipedia | 355 | 38540045 | https://en.wikipedia.org/wiki/Aqueduct%20%28water%20supply%29 | Technology | Food, water and health | null |
Geophysical fluid dynamics, in its broadest meaning, refers to the fluid dynamics of naturally occurring flows, such as lava flows, oceans, and planetary atmospheres, on Earth and other planets.
Two physical features that are common to many of the phenomena studied in geophysical fluid dynamics are rotation of the flu... | Geophysical fluid dynamics | Wikipedia | 481 | 28996847 | https://en.wikipedia.org/wiki/Geophysical%20fluid%20dynamics | Physical sciences | Geophysics | Earth science |
Fluid that is less dense than its surroundings tends to rise until it has the same density as its surroundings. If there is not much energy input to the system, it will tend to become stratified. On a large scale, Earth's atmosphere is divided into a series of layers. Going upwards from the ground, these are the tropos... | Geophysical fluid dynamics | Wikipedia | 437 | 28996847 | https://en.wikipedia.org/wiki/Geophysical%20fluid%20dynamics | Physical sciences | Geophysics | Earth science |
Inkayacu is a genus of extinct penguins. It lived in what is now Peru during the Late Eocene, around 36 million years ago. A nearly complete skeleton was discovered in 2008 and includes fossilized feathers, the first known in penguins. A study of the melanosomes, pigment-containing organelles within the feathers, indic... | Inkayacu | Wikipedia | 471 | 29007035 | https://en.wikipedia.org/wiki/Inkayacu | Biology and health sciences | Prehistoric birds | Animals |
Fossils of Inkayacu were first found in 2008 on the Pacific coast of Ica, Peru. A nearly complete skeleton was uncovered from the Otuma Formation, in the Paracas National Reserve by an expedition team led by Rodolfo Salas and studied by a team led by Julia Clarke of the University of Texas. It was nicknamed, "Pedro," b... | Inkayacu | Wikipedia | 439 | 29007035 | https://en.wikipedia.org/wiki/Inkayacu | Biology and health sciences | Prehistoric birds | Animals |
The natural history of Earth concerns the development of planet Earth from its formation to the present day. Nearly all branches of natural science have contributed to understanding of the main events of Earth's past, characterized by constant geological change and biological evolution.
The geological time scale (GTS)... | History of Earth | Wikipedia | 380 | 2068726 | https://en.wikipedia.org/wiki/History%20of%20Earth | Physical sciences | Earth science | null |
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