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Topic Review
Gorgonopsia
Gorgonopsia (from the Greek Gorgon, a mythological beast, and óps 'aspect') is an extinct clade of sabre-toothed therapsids from the Middle to Upper Permian roughly 265 to 252 million years ago. They are characterised by a long and narrow skull, as well as elongated upper and sometimes lower canine teeth and incisors which were likely used as slashing and stabbing weapons. Postcanine teeth are generally reduced or absent. For hunting large prey, they possibly used a bite-and-retreat tactic, ambushing and taking a debilitating bite out of the target, and following it at a safe distance before its injuries exhausted it, whereupon the gorgonopsian would grapple the animal and deliver a killing bite. They would have had an exorbitant gape, possibly in excess of 90°, without having to unhinge the jaw. They markedly increased in size as time went on, growing from small skull lengths of 10–15 cm (4–6 in) in the Middle Permian to bear-like proportions of up to 60 cm (2 ft) in the Upper Permian. The latest gorgonopsians, Rubidgeinae, were the most robust of the group and could produce especially powerful bites. Gorgonopsians are thought to have been completely terrestrial and could walk with a semi-erect gait, with a similar terrestrial locomotory range as modern crocodilians. They may have been more agile than their prey items, but were probably inertial homeotherms rather than endotherms unlike contemporary therocephalians and cynodonts, and thus were probably comparatively less active. Though gorgonopsians were able to maintain a rather high body temperature, it is unclear if they would have also had sweat glands or fur (and by extension whiskers and related structures). Their brains were reminiscent of modern reptilian brains, rather than those of living mammals. Most species may have been predominantly diurnal (active during the day) though some could have been crepuscular (active at dawn or dusk) or nocturnal (active at night). They are thought to have had binocular vision, a parietal eye (which detects sunlight and maintains circadian rhythm), a keen sense of smell, a functional vomeronasal organ ("Jacobson's organ"), and possibly a rudimentary eardrum. The major therapsid groups had all evolved by 275 million years ago from a "pelycosaur" ancestor (a poorly defined group including all synapsids which are not therapsids). The therapsid takeover from pelycosaurs took place by the Middle Permian as the world progressively became drier. Gorgonopsians rose to become apex predators of their environments following the Capitanian mass extinction event which killed off the dinocephalians and some large therocephalians after the Middle Permian. Despite the existence of a single continent during the Permian, Pangaea, gorgonopsians have only been found in the Karoo Supergroup (primarily in South Africa, but also in Tanzania, Zambia, and Malawi), the Moradi Formation of Niger, and western Russia, with probable remains known from the Kundaram Formation of India. These places were semi-arid areas with highly seasonal rainfall. Gorgonopsian genera vary very little, and consequently, many species have been named based on flimsy and likely age-related differences since their discovery in the late 19th century, and the group has been subject to several taxonomic revisions. They became extinct during a phase of the Permian–Triassic extinction event taking place at the very end of the Permian, in which major volcanic activity (which would produce the Siberian Traps) and resultant massive spike in greenhouse gases caused rapid aridification due to temperature spike, acid rain, frequent wildfires, and potential breakdown of the ozone layer. The large predatory niches would be taken over by the archosaurs (namely crocodilians and dinosaurs) in the Mesozoic.
  • 3.0K
  • 17 Oct 2022
Topic Review
Hop
Hops is considered a short-day, temperate species, so the major challenge for the development of hop cultivation in Brazil, with high-yield capacity and with local typicity of bitterness and aroma, is the adaptation of cultivars to the photoperiod conditions in subtropical regions. 
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  • 20 May 2022
Topic Review
Ocotillol-Type Triterpenoids
Ginseng is one of the most widely consumed herbs in the world and plays an important role in counteracting fatigue and alleviating stress. The main active substances of ginseng are its ginsenosides. Ocotillol-type triterpenoid is a remarkably effective ginsenoside from Vietnamese ginseng that has received attention because of its potential antibacterial, anticancer and anti-inflammatory properties, among others. The semisynthesis, modification and biological activities of ocotillol-type compounds have been extensively studied in recent years.
  • 3.0K
  • 09 Dec 2020
Topic Review
Effects of Berberine against Pancreatic Cancer
The pancreas is a glandular organ with endocrine and exocrine functions necessary for the maintenance of blood glucose homeostasis and secretion of digestive enzymes. Pancreatitis is characterized by inflammation of the pancreas leading to temporary or permanent pancreatic dysfunction. Inflammation and fibrosis caused by chronic pancreatitis exacerbate malignant transformation and significantly increase the risk of developing pancreatic cancer, the world’s most aggressive cancer with a 5-year survival rate less than 10%. Berberine (BBR) is a naturally occurring plant-derived polyphenol present in a variety of herbal remedies used in traditional medicine to treat ulcers, infections, jaundice, and inflammation.
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  • 20 Dec 2022
Topic Review
Machine Learning in Mechanical Design and Optimization
Machine learning, by definition, refers to the development of knowledge by computers using input data. Mechanical engineering is a strong area for this technology. Older machine builders have gained significant knowledge through several case studies and efficient workflows. This creates the opportunity to approach new projects, to be able to either use their technical knowledge with familiar elements that have already been discovered or use their experience to learn and adapt to new challenges. Newcomers to the field learn in this way and gather their effectiveness and knowledge; when it comes to learning, engineering is one of the areas where much of the learning takes place at work. How well it pays depends on the ability to collect and process information.
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  • 15 Jun 2023
Topic Review
Electromigration
Electromigration is the transport of material caused by the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. The effect is important in applications where high direct current densities are used, such as in microelectronics and related structures. As the structure size in electronics such as integrated circuits (ICs) decreases, the practical significance of this effect increases.
  • 3.0K
  • 24 Nov 2022
Topic Review
Herfindahl Index
The Herfindahl index (also known as Herfindahl–Hirschman Index, HHI, or sometimes HHI-score) is a measure of the size of firms in relation to the industry and an indicator of the amount of competition among them. Named after economists Orris C. Herfindahl and Albert O. Hirschman, it is an economic concept widely applied in competition law, antitrust and also technology management. It is defined as the sum of the squares of the market shares of the firms within the industry (sometimes limited to the 50 largest firms), where the market shares are expressed as fractions. The result is proportional to the average market share, weighted by market share. As such, it can range from 0 to 1.0, moving from a huge number of very small firms to a single monopolistic producer. Increases in the Herfindahl index generally indicate a decrease in competition and an increase of market power, whereas decreases indicate the opposite. Alternatively, if whole percentages are used, the index ranges from 0 to 10,000 "points". For example, an index of .25 is the same as 2,500 points. The major benefit of the Herfindahl index in relationship to such measures as the concentration ratio is that it gives more weight to larger firms. The measure is essentially equivalent to the Simpson diversity index, which is a diversity index used in ecology; the inverse participation ratio (IPR) in physics; and the effective number of parties index in politics.
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  • 19 Oct 2022
Topic Review
Metal Matrix Composite
Composites are generally categorized into three main categories based on the matrix substance. They are called metal matrix composite (MMC), polymer matrix composite (PMC), and ceramic matrix composite (CMC), respectively. MMC gives more elevated ductile properties than CMCs and better environmental stability than PMCs. Additionally, MMCs offer good thermal conductivity (from 220 to 580 W·m−1·K−1), wear resistance (0.01025), wear rate (g·m−1), erosion, and shear strength.
  • 3.0K
  • 06 Sep 2021
Topic Review
Working Animal
A working animal is an animal, usually domesticated, that is kept by humans and trained to perform tasks instead of being slaughtered to harvest animal products. Some are beasts of burden (draught animals) that provide transportation (e.g. riding horses and camels) and aid in physical labor (e.g. oxens and elephants), while others are service animals trained to execute certain specialized tasks (e.g. hunting and guide dogs, messenger pigeons and fishing cormorants). They may also be used for milking or herding. Some, at the end of their working lives, may also be used for meat or other products such as leather. The history of working animals may predate agriculture, with dogs used by our hunter-gatherer ancestors. Around the world, millions of animals work in relationship with their owners. Domesticated species are often bred for different uses and conditions, especially horses and working dogs. Working animals are usually raised on farms, though some are still captured from the wild, such as dolphins and some Asian elephants. People have found uses for a wide variety of abilities in animals, and even industrialised societies use many animals for work. People use the strength of horses, elephants, and oxen to pull carts and move loads. Police forces use dogs for finding illegal substances and assisting in apprehending wanted persons, others use dogs to find game or search for missing or trapped people. People use various animals — camels, donkeys, horses, dogs, etc.—for transport, either for riding or to pull wagons and sleds. Other animals, including dogs and monkeys, help disabled people. On rare occasions, wild animals are not only tamed, but trained to perform work—though often solely for novelty or entertainment, as such animals tend to lack the trustworthiness and mild temper of true domesticated working animals. Conversely, not all domesticated animals are working animals. For example, while cats may catch mice, it is an instinctive behaviour, not one that can be trained by human intervention. Other domesticated animals, such as sheep or rabbits, may have agricultural uses for meat, hides and wool, but are not suitable for work. Finally, small domestic pets, such as most small birds (other than certain types of pigeon) are generally incapable of performing work other than providing companionship.
  • 3.0K
  • 14 Nov 2022
Topic Review
Integrated Photovoltaic-Fuel Cell Systems
Integrated photovoltaic-fuel cell (IPVFC) system uses photovoltaics and fuel cells to majorly generate power and hydrogen, using solar energy as the prime mover. IPVFC amongst other integrated energy generation methodologies are renewable and clean energy technologies that have received diverse research and development attentions over the last few decades due to their potential applications in a hydrogen economy.
  • 3.0K
  • 29 Oct 2021
Topic Review
Biological Roles and Applications of Aconitic Acid
Aconitic acid (propene-1,2,3-tricarboxylic acid) is the most prevalent 6-carbon organic acid that accumulates in sugarcane and sweet sorghum. As a top value-added chemical, aconitic acid may function as a chemical precursor or intermediate for high-value downstream industrial and biological applications. These downstream applications include use as a bio-based plasticizer, cross-linker, and the formation of valuable and multi-functional polyesters that have also been used in tissue engineering. Aconitic acid also plays various biological roles within cells as an intermediate in the tricarboxylic acid cycle (TCA) and in conferring unique survival advantages to some plants as an antifeedant, antifungal, and means of storing fixed pools of carbon. Aconitic acid has also been reported as a fermentation inhibitor, anti-inflammatory, and a potential nematicide. 
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  • 16 Mar 2022
Topic Review
Humboldt Current
The Humboldt Current, also called the Peru Current, is a cold, low-salinity ocean current that flows north along the western coast of South America. It is an eastern boundary current flowing in the direction of the equator, and extends 500–1,000 km (310–620 mi) offshore. The Humboldt Current is named after the Prussian naturalist Alexander von Humboldt. In 1846, von Humboldt reported measurements of the cold-water current in his book Cosmos. The current extends from southern Chile (~45th parallel south) to northern Peru (~4th parallel south) where cold, upwelled, waters intersect warm tropical waters to form the Equatorial Front. Sea surface temperatures off the coast of Peru, around 5th parallel south, reach temperatures as low as 16 °C (61 °F). This is highly uncharacteristic of tropical waters, as most other regions have temperatures measuring above 25 °C (77 °F). Upwelling brings nutrients to the surface, which support phytoplankton and ultimately increase biological productivity. The Humboldt Current is a highly productive ecosystem. It is the most productive eastern boundary current system. It accounts for roughly 18-20% of the total worldwide marine fish catch. The species are mostly pelagic: sardines, anchovies and jack mackerel. The system's high productivity supports other important fishery resources as well as marine mammals (eared seals and cetaceans) and seabirds. Periodically, the upwelling that drives the system's productivity is disrupted by the El Niño-Southern Oscillation (ENSO) event, often with large social and economic impacts. The Humboldt has a considerable cooling influence on the climate of Chile, Peru and Ecuador. It is also largely responsible for the aridity of Atacama Desert in northern Chile and coastal areas of Peru and also of the aridity of southern Ecuador. Marine air is cooled by the current and thus is not conducive to generating precipitation (although clouds and fog are produced).
  • 3.0K
  • 07 Oct 2022
Topic Review
PPIs' Drug Dosage Forms Development - Formulation Challenges
Proton Pump Inhibitors, also known as PPIs, belong to a group of antisecretory drugs. Since their introduction to pharmacotherapy, PPIs have been widely used in the treatment of numerous diseases manifested by excessive secretion of gastric acid. There are still unmet needs regarding their availability for patients of all age groups. Their poor stability hinders the development of formulations in which dose can be easily adjusted.
  • 3.0K
  • 31 Oct 2022
Topic Review
Gabapentin-Associated Movement Disorders
Gabapentin (GBP) is U.S. FDA-approved for the adjunctive treatment of focal seizures and the treatment of postherpetic neuralgia. GBP also exhibits analgesic properties, often used as the first line in managing neuropathic pain. GBP-induced movement disorders are under-recognized adverse drug reactions. They are commonly not discussed with patients, and their sudden occurrence can lead to misdiagnosis of a “seizure-like” condition. Also, first-contact physicians might treat them as seizures or psychiatric comorbidities, leading to unnecessary tests and aggressive management.
  • 3.0K
  • 12 Sep 2023
Topic Review
Balloon (Aeronautics)
In aeronautics, a balloon is an unpowered aerostat, which remains aloft or floats due to its buoyancy. A balloon may be free, moving with the wind, or tethered to a fixed point. It is distinct from an airship, which is a powered aerostat that can propel itself through the air in a controlled manner. Many balloons have a basket, gondola, or capsule suspended beneath the main envelope for carrying people or equipment (including cameras and telescopes, and flight-control mechanisms).
  • 3.0K
  • 27 Oct 2022
Topic Review
Sociological Abstraction
Sociological abstraction refers to the process of distilling and analyzing complex social phenomena by isolating and examining specific aspects or patterns. Sociologists often use abstraction as a method to simplify the study of society, allowing them to focus on key elements and relationships within social structures. By abstracting certain concepts or variables, researchers can develop theories and models that help explain and understand various social phenomena.
  • 3.0K
  • 25 Jan 2024
Topic Review
Aztreonam/Avibactam
The epidemiology of infections sustained by multidrug-resistant Gram-negative bacteria is rapidly evolving. New drugs are available or are on the horizon. Most are combinations of a β-lactam and a β-lactamase inhibitor. One part is the antibiotic cefiderocol that has a peculiar antibacterial mechanism of action. Dispensing of such an armamentarium requires in-depth knowledge of their microbiological spectrum of activity, pharmacokinetic/pharmacodynamic (PK/PD) properties, and clinical study results. The following will describe the antibacterial strategy of aztreonam in combination with avibactam.
  • 3.0K
  • 09 May 2022
Topic Review
Blue Gene
Blue Gene is an IBM project aimed at designing supercomputers that can reach operating speeds in the PFLOPS (petaFLOPS) range, with low power consumption. The project created three generations of supercomputers, Blue Gene/L, Blue Gene/P, and Blue Gene/Q. Blue Gene systems have often led the TOP500 and Green500 rankings of the most powerful and most power efficient supercomputers, respectively. Blue Gene systems have also consistently scored top positions in the Graph500 list. The project was awarded the 2009 National Medal of Technology and Innovation. As of 2015, IBM seems to have ended the development of the Blue Gene family though no public announcement has been made. IBM's continuing efforts of the supercomputer scene seems to be concentrated around OpenPower, using accelerators such as FPGAs and GPUs to battle the end of Moore's law.
  • 3.0K
  • 29 Sep 2022
Topic Review
Aggression
Aggression is overt or covert, often harmful, social interaction with the intention of inflicting damage or other harm upon another individual. It may occur either reactively or without provocation. In humans, aggression can be caused by various triggers, from frustration due to blocked goals to feeling disrespected. Human aggression can be classified into direct and indirect aggression; whilst the former is characterized by physical or verbal behavior intended to cause harm to someone, the latter is characterized by behavior intended to harm the social relations of an individual or group. In definitions commonly used in the social sciences and behavioral sciences, aggression is an action or response by an individual that delivers something unpleasant to another person. Some definitions include that the individual must intend to harm another person. In an interdisciplinary perspective, aggression is regarded as “an ensemble of mechanism formed during the course of evolution in order to assert oneself, relatives or friends against others, to gain or to defend resources (ultimate causes) by harmful damaging means [...] These mechanisms are often motivated by emotions like fear, frustration, anger, feelings of stress, dominance or pleasure (proximate causes) [...] Sometimes aggressive behavior serves as a stress relief or a subjective feeling of power." Predatory or defensive behavior between members of different species may not be considered aggression in the same sense. Aggression can take a variety of forms, which may be expressed physically, or communicated verbally or non-verbally: including anti-predator aggression, defensive aggression (fear-induced), predatory aggression, dominance aggression, inter-male aggression, resident-intruder aggression, maternal aggression, species-specific aggression, sex-related aggression, territorial aggression, isolation-induced aggression, irritable aggression, and brain-stimulation-induced aggression (hypothalamus). There are two subtypes of human aggression: (1) controlled-instrumental subtype (purposeful or goal-oriented); and (2) reactive-impulsive subtype (often elicits uncontrollable actions that are inappropriate or undesirable). Aggression differs from what is commonly called assertiveness, although the terms are often used interchangeably among laypeople (as in phrases such as "an aggressive salesperson").
  • 3.0K
  • 10 Nov 2022
Topic Review
The 4 Helix Model and Tourism Social Entrepreneurships
The COVID-19 crisis has promoted innovation, support, and incentives among the four helixes, in which the STEs have benefited. As conclusions, the four helix model is functional to face the adversities of COVID-19 as long as there is planning within the entrepreneurships and the link with said model helix participants.
  • 3.0K
  • 10 Jan 2022
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