Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Thermoregulation Strategies in Domestic Animals
Animals adopt several strategies to regulate their body temperature by promoting heat loss or gain in hot and cold environments, respectively. This mechanism of heat loss or production is performed in thermal windows. A thermal window is a structure where many blood capillaries facilitate thermal exchange in this region. The presence of feathers, hair, or glabrous (hairless) skin and their structural characteristics greatly influence each species’ capacity to maintain thermal comfort. This factor needs to be considered when implementing new monitoring or measuring techniques such as infrared thermography since interpretations may vary due to the presence or absence of these structures. It is essential to recognize the effects of glabrous skin, hair, and feathers on thermoregulation to identify species-specific thermal windows that allow accurate evaluations of the thermal state of domestic animals.
  • 3.8K
  • 19 Apr 2022
Topic Review
Short-Faced Bear
The short-faced bear (Arctodus sp.) is an extinct bear genus that inhabited North America during the Pleistocene epoch from about 1.8 Mya until 11,000 years ago. It was the most common tremarctine bear in North America and many of its fossils have been found in the La Brea tar pits in southern California . There are two recognized species: the lesser short-faced bear (Arctodus pristinus) and the giant short-faced bear (Arctodus simus), with the latter considered to be one of the largest known terrestrial mammalian carnivores that has ever existed. It has been hypothesized that their extinction coincides with the Younger Dryas period of global cooling commencing around 10,900 BC.
  • 3.8K
  • 05 Nov 2022
Topic Review
Dhunge Dhara
A dhunge dhara (Nepali:ढुङ्गे धारा Listen (help·info)) or hiti (Newari) is a traditional stone drinking fountain found in Nepal. It is an intricately carved stone waterway through which water flows uninterrupted from underground sources. Dhunge dharas are part of a comprehensive drinking water supply system, commissioned by various rulers of Ancient and Medieval Nepal. The system is supported by numerous ponds and canals that form an elaborate network of water bodies, created as a water resource during the dry season and to help alleviate the water pressure caused by the monsoon rains. After the introduction of modern, piped water systems, starting in the late 19th century, this old system has fallen into disrepair and some parts of it are lost forever. Nevertheless, many people of Nepal still rely on the old hitis on a daily basis.
  • 3.8K
  • 21 Oct 2022
Topic Review
Flocculus (Cerebellar)
The flocculus (Latin: tuft of wool, diminutive) is a small lobe of the cerebellum at the posterior border of the middle cerebellar peduncle anterior to the biventer lobule. Like other parts of the cerebellum, the flocculus is involved in motor control. It is an essential part of the vestibulo-ocular reflex, and aids in the learning of basic motor skills in the brain. It is associated with the nodulus of the vermis; together, these two structures compose the vestibular part of the cerebellum. At its base, the flocculus receives input from the inner ear's vestibular system and regulates balance. Many floccular projections connect to the motor nuclei involved in control of eye movement.
  • 3.8K
  • 02 Nov 2022
Topic Review
Dracorex
Dracorex is a controversial dinosaur genus of the family Pachycephalosauridae, from the Late Cretaceous of North America. The type (and only known) species is Dracorex hogwartsia, meaning "dragon king of Hogwarts". This dinosaur is named for the wizard school in Harry Potter books. It is known from one nearly complete skull (the holotype TCMI 2004.17.1), as well as four cervical vertebrae: the atlas, third, eighth and ninth. These were discovered in the Hell Creek Formation in South Dakota by three amateur paleontologists from Sioux City, in the U.S. state of Iowa. The skull was subsequently donated to the Children's Museum of Indianapolis for study in 2004, and was formally described by Bob Bakker and Robert Sullivan in 2006. However, Jack Horner et al. suspect that it is a juvenile Pachycephalosaurus and an analysis of pachycephalosaur fossils by a joint team from the University of California, Berkeley and the Museum of the Rockies has questioned the validity of two named genera of pachycephalosaur, Dracorex and Stygimoloch. According to the team, specimens of Dracorex and Stygimoloch might actually represent earlier growth stages of Pachycephalosaurus. This has been supported in a 2016 analysis of the youngest Pachycephalosaurus material known, which indicates that the unique features of Dracorex represent instead ontogenetically variant features on a Pachycephalosaurus growth curve.
  • 3.8K
  • 03 Nov 2022
Topic Review
Perinatal Stem Cells
Perinatal tissues refer to tissues that are discarded at birth, such as the placenta, umbilical cord, cord blood, and amniotic fluid, and different stem and progenitor cell types can be isolated from these tissues. Regenerative medicine has found in the perinatal medical wastes one of the most promising sources of various cells and tissues for use in cell therapy and tissue engineering, both in experimental and clinical settings. The primary source of perinatal stem cells is cord blood. Cord blood has been a well-known source of hematopoietic stem/progenitor cells. Other perinatal tissues contain non-hematopoietic cells with potential therapeutic value. Indeed, in advanced perinatal cell therapy trials, mesenchymal stromal cells are the most commonly used.
  • 3.8K
  • 14 Jan 2021
Topic Review
Dosage Compensation
Dosage compensation is the process by which organisms equalize the expression of genes between members of different biological sexes. Across species, different sexes are often characterized by different types and numbers of sex chromosomes. In order to neutralize the large difference in gene dosage produced by differing numbers of sex chromosomes among the sexes, various evolutionary branches have acquired various methods to equalize gene expression among the sexes. Because sex chromosomes contain different numbers of genes, different species of organisms have developed different mechanisms to cope with this inequality. Replicating the actual gene is impossible; thus organisms instead equalize the expression from each gene. For example, in humans, females (XX) silence the transcription of one X chromosome of each pair, and transcribe all information from the other, expressed X chromosome. Thus, human females have the same number of expressed X-linked genes as do human males (XY), both sexes having essentially one X chromosome per cell, from which to transcribe and express genes. There are three main mechanisms of achieving dosage compensation which are widely documented in the literature and which are common to most species. These include random inactivation of one female X chromosome (as observed in Mus musculus; this is called X-inactivation), a two-fold increase in the transcription of a single male X chromosome (as observed in Drosophila melanogaster), and decreased transcription by half in both of the X chromosomes of a hermaphroditic organism (as observed in Caenorhabditis elegans). These mechanisms have been widely studied and manipulated in model organisms commonly used in the laboratory research setting. A summary of these forms of dosage compensation is illustrated below. However, there are also other less common forms of dosage compensation, which are not as widely researched and are sometimes specific to only one species (as observed in certain bird and monotreme species).
  • 3.8K
  • 31 Oct 2022
Topic Review
Dukkha
Dukkha (/ˈduːkə/; Pāli; Sanskrit: duḥkha; Tibetan: སྡུག་བསྔལ་ sdug bsngal, pr. "duk-ngel") is an important Buddhist concept, commonly translated as "suffering", "pain", "unsatisfactoriness" or "stress". It refers to the fundamental unsatisfactoriness and painfulness of mundane life. It is the first of the Four Noble Truths. The term is also found in scriptures of Hinduism, such as the Upanishads, in discussions of moksha (spiritual liberation).
  • 3.8K
  • 24 Oct 2022
Topic Review
Leucine Metabolism
Leucine, an essential branched amino acid, has anti-obesity effects on glucose tolerance, lipid metabolism, and insulin sensitivity. The catabolism of Leucine is a conserved regulator of physiological aging, participating in diverse physiological and pathological processes. This topic review offers an up-to-date report on the decomposition and metabolites of leucine in mammals, as α-ketoisocaproate (KIC) and β-hydroxy-β-methylbutyrate (HMB).
  • 3.8K
  • 29 Oct 2020
Topic Review
Fault-Tolerant Control
Fault-tolerant controllers (FTCs) can be defined as controllers that are able to tolerate faults and keep the control performance in the ideal range in the presence of faults. FTC approaches can be categorized into two main categories: Passive FTCs and Active FTC. Passive FTCs are not dependent on fault detection and isolation (FDI) modules and can keep the desired controller performance without considering the type and size of fault. Active FTCs are equipped with the FDI module and behave differently to different kinds of fault.
  • 3.8K
  • 27 Oct 2020
  • Page
  • of
  • 5357
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
ScholarVision Creations
Feedback