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Topic Review
Zomia (Region)
Zomia is a geographical term coined in 2002 by historian Willem van Schendel of the University of Amsterdam to refer to the huge mass of mainland Southeast Asia that has historically been beyond the control of governments based in the population centers of the lowlands.
  • 5.5K
  • 25 Oct 2022
Topic Review
Natural Reservoir
In infectious disease ecology and epidemiology, a natural reservoir, also known as a disease reservoir or a reservoir of infection, is the population of organisms or the specific environment in which an infectious pathogen naturally lives and reproduces, or upon which the pathogen primarily depends for its survival. A reservoir is usually a living host of a certain species, such as an animal or a plant, inside of which a pathogen survives, often (though not always) without causing disease for the reservoir itself. By some definitions a reservoir may also be an environment external to an organism, such as a volume of contaminated air or water. Because of the enormous variety of infectious microorganisms capable of causing disease, precise definitions for what constitutes a natural reservoir are numerous, various, and often conflicting. The reservoir concept applies only for pathogens capable of infecting more than one host population and only with respect to a defined target population – the population of organisms in which the pathogen causes disease. The reservoir is any population of organisms (or any environment) which harbors the pathogen and transmits it to the target population. Reservoirs may comprise one or more different species, may be the same or a different species as the target, and, in the broadest sense, may include vector species, which are otherwise distinct from natural reservoirs and should not be confused with them. Significantly, species considered reservoirs for a given pathogen may not experience symptoms of disease when infected by the pathogen. Identifying the natural reservoirs of infectious pathogens has proven useful in treating and preventing large outbreaks of disease in humans and domestic animals, especially those diseases for which no vaccine exists. In principle, zoonotic diseases can be controlled by isolating or destroying the pathogen's reservoirs of infection. The mass culling of animals confirmed or suspected as reservoirs for human pathogens, such as birds that harbor avian influenza, has been effective at containing possible epidemics in many parts of the world; for other pathogens, such as the ebolaviruses, the identity of the presumed natural reservoir remains obscure.
  • 5.5K
  • 26 Oct 2022
Topic Review
Derringer
A derringer is a small handgun that is neither a revolver nor a semi/fully automatic pistol. It is not to be confused with mini-revolvers or pocket pistols, although some later derringers were manufactured with the pepperbox configuration. The modern derringer is often multi-barreled, and is generally the smallest usable handgun of any given caliber and barrel length due to the lack of a moving action, which takes up more space behind the barrel. It is frequently used by women because it is easily concealable in a purse or a stocking. The original Philadelphia Deringer was a muzzleloading caplock single-shot pistol introduced in 1825 by Henry Deringer. In total, approximately 15,000 Deringer pistols were manufactured. All were single barrel pistols with back-action percussion locks, typically .41 caliber with rifled bores, and walnut stocks. Barrel length varied from 1.5 to 6 in (38 to 152 mm), and the hardware was commonly a copper-nickel alloy known as "German silver". The term "derringer" (/ˈdɛrɪndʒər/) became a genericized misspelling during the reporting of the Lincoln assassination, which was committed with a concealed Philadelphia Deringer. Many copies of the original Philadelphia Deringer pistol were made by other gunmakers worldwide, and the name remained often misspelled; this misspelling soon became an alternative generic term for any pocket pistol, along with the generic phrase "palm pistol'", which Deringer's competitors invented and used in their advertising. With the advent of metallic cartridges, pistols produced in the modern form are still commonly called "derringers".
  • 5.5K
  • 01 Nov 2022
Topic Review
Schizoid Personality Disorder
Schizoid personality disorder (/ˈskɪtsɔɪd, ˈskɪdzɔɪd/, often abbreviated as SPD or SzPD) is a personality disorder characterized by a lack of interest in social relationships, a tendency toward a solitary or sheltered lifestyle, secretiveness, emotional coldness, detachment and apathy. Affected individuals may be unable to form intimate attachments to others and simultaneously possess a rich and elaborate but exclusively internal fantasy world. Other associated features include stilted speech, a lack of deriving enjoyment from most activities, feeling as though one is an "observer" rather than a participant in life, an inability to tolerate emotional expectations of others, apparent indifference when praised or criticized, a degree of asexuality, and idiosyncratic moral or political beliefs. Symptoms typically start in late childhood or adolescence. The cause of SPD is uncertain, but there is some evidence of links and shared genetic risk between SPD, other cluster A personality disorders (such as schizotypal personality disorder) and schizophrenia. Thus, SPD is considered to be a "schizophrenia-like personality disorder". It is diagnosed by clinical observation, and it can be very difficult to distinguish SPD from other mental disorders (such as autism spectrum disorder, with which it may sometimes overlap). The effectiveness of psychotherapeutic and pharmacological treatments for the disorder has yet to be empirically and systematically investigated. This is largely because people with SPD rarely seek treatment for their condition. Originally, low doses of atypical antipsychotics were also used to treat some symptoms of SPD, but their use is no longer recommended. The substituted amphetamine bupropion may be used to treat associated anhedonia. However, it is not general practice to treat SPD with medications, other than for the short-term treatment of acute co-occurring disorders (e.g. depression). Talk therapies such as cognitive behavioral therapy (CBT) may not be effective, because people with SPD may have a hard time forming a good working relationship with a therapist. SPD is a poorly studied disorder, and there is little clinical data on SPD because it is rarely encountered in clinical settings. Studies have generally reported a prevalence of less than 1% It is more common in males than in females. SPD is linked to negative outcomes, including a significantly compromised quality of life, reduced overall functioning even after 15 years and one of the lowest levels of "life success" of all personality disorders (measured as "status, wealth and successful relationships"). Bullying is particularly common towards schizoid individuals. Suicide may be a running mental theme for schizoid individuals, though they are not likely to actually attempt it. Some symptoms of SPD (e.g. solitary lifestyle and emotional detachment), however, have been stated as general risk factors for serious suicidal behaviour.
  • 5.5K
  • 20 Oct 2022
Topic Review
Polymer 3D Printing
Polymer 3D printing is an emerging technology with recent research translating towards increased use in diverse industries. The polymer 3D printing process works by depositing a polymer in a directed fashion to form a completed part, generally through layer by layer deposition.  Polymer printing is advantageous because it enables printing low-cost functional parts with diverse properties and capabilities. An important aspect polymer 3D printing is the consideration of materials, processes, and design strategies that all influence a parts performance. Research in materials has led to the development of polymers with advantageous characteristics for mechanics and biocompatibility, with tuning of mechanical properties achieved by altering printing process parameters. Suitable polymer printing processes include extrusion, resin, and powder 3D printing, which enable directed material deposition for the design of advantageous and customized architectures.  Through careful consideration of material, process, and design it is possible to create a 3D printed polymer part of complex geometry that is tuned for a specific application on a per-print basis.
  • 5.5K
  • 23 Jun 2021
Topic Review
Xian JH-7
The Xian JH-7 (Jianjiji Hongzhaji – fighter-bomber; NATO reporting name Flounder), also known as the FBC-1 (Fighter/Bomber China-1) Flying Leopard, is a tandem two-seat, twin-engine fighter-bomber in service with the People's Liberation Army Naval Air Force (PLANAF), and the People's Liberation Army Air Force (PLAAF). The main contractors are Xi'an Aircraft Industrial Corporation (XAC) and the 603rd Aircraft Design Institute (later named the First Aircraft Institute of AVIC-I). The first JH-7s were delivered to the PLANAF in the mid-1990s for evaluation, with the improved JH-7A entering service in 2004.
  • 5.5K
  • 22 Nov 2022
Topic Review
Islam in Albania (1913–1944)
Islam in Albania (1913–1944) was characterised by an increasing secularisation of Albanian society which had begun with Albanian Independence in 1912 carrying on influences from the Albanian National Awakening. During the interwar period, new local Muslim institutions such as the Muslim Community of Albania arose that severed ties with the Ottoman Caliphate and placed a focus on localising Islam in Albania. The Albanian state also played a significant role in that process through state interference and pressuring the uptake of reforms by those institutions and wider Muslim society. Measures that were adopted were banning the veil and others which were interpreted as modernising Albania. These events caused tensions within parts of Muslim society between conservatives and those who viewed themselves as progressives which caused discussions and reflections about the future role of Islam in Albania and Albanian identity. The interwar era also saw Sufi Islam expand in Albania with various orders gaining new adherents with the largest, the Bektashi Order moving its world headquarters to Albania.
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  • 15 Nov 2022
Topic Review
Design of Block Shear Failure
The block shear failure was reported firstly in 1978 for joints with not optimal geometry from an internal forces point of view. The test results proved the potential failure mode of tearing out in the web of the beam. Several studies concerning block shear failure were published in the last twenty years predicting the block shear capacity as a combination of fracture on the tension and shear plane. Block shear rupture is the potential failure mode for gusset plates, fin plates, coped beams, single/double angles and tee connections, where significant tension/shear forces are present. 
  • 5.5K
  • 21 Jul 2021
Topic Review
The Intelligent Reflecting Surface
The Intelligent Reflecting Surface (IRS) is a revolutionary technology to improve the performance of wireless data transmission systems. In particular, the wireless signal transmission environment is reconfigured by jointly adjusting a large number of small reflective units
  • 5.5K
  • 08 Apr 2022
Topic Review
Luxury Vehicle
A luxury vehicle provides increased levels of comfort, equipment, amenities, quality, performance, and status relative to regular cars for an increased price. The term is subjective and reflects both the qualities of the car and the brand image of its manufacturer. Luxury brands rank above premium brands, though there is no fixed demarcation between the two. Traditionally, most luxury cars were large vehicles, though smaller sports-oriented models were always produced. “Compact“ luxury vehicles such as hatchbacks, and off-road capable sport utility vehicles, are relatively modern trends.
  • 5.5K
  • 27 Oct 2022
Biography
Jack Parsons
John Whiteside Parsons (born Marvel Whiteside Parsons;[1] October 2, 1914 – June 17, 1952) was an American rocket engineer, chemist, and Thelemite occultist. Associated with the California Institute of Technology (Caltech), Parsons was one of the principal founders of both the Jet Propulsion Laboratory (JPL) and the Aerojet Engineering Corporation. He invented the first rocket engine to use a
  • 5.5K
  • 15 Nov 2022
Topic Review
Context-Dependent Memory
In psychology, context-dependent memory is the improved recall of specific episodes or information when the context present at encoding and retrieval are the same. In a simpler manner, "when events are represented in memory, contextual information is stored along with memory targets; the context can therefore cue memories containing that contextual information". One particularly common example of context-dependence at work occurs when an individual has lost an item (e.g. lost car keys) in an unknown location. Typically, people try to systematically "retrace their steps" to determine all of the possible places where the item might be located. Based on the role that context plays in determining recall, it is not at all surprising that individuals often quite easily discover the lost item upon returning to the correct context. This concept is heavily related to the encoding specificity principle. This example best describes the concept of context-dependent forgetting. However, the research literature on context-dependent memory describes a number of different types of contextual information that may affect recall such as environmental context-dependent memory, state-dependent learning, cognitive context-dependent memory and mood-congruent memory. Research has also shown that context-dependence may play an important role in numerous situations, such as memory for studied material, or events that have occurred following the consumption of alcohol or other drugs.
  • 5.5K
  • 03 Nov 2022
Topic Review
Micronutrient Deficiency and Toxicity in Plants
Micronutrients are essential for plants. Their growth, productivity and reproduction are directly influenced by the supply of micronutrients. Currently, there are eight trace elements considered to be essential for higher plants: Fe, Zn, Mn, Cu, Ni, B, Mo, and Cl. Possibly, other essential elements could be discovered because of recent advances in nutrient solution culture techniques and in the commercial availability of highly sensitive analytical instrumentation for elemental analysis.
  • 5.5K
  • 27 Sep 2022
Topic Review
Sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) mineral particles or rock fragments. Most sandstone is composed of quartz or feldspar (both silicates) because they are the most resistant minerals to weathering processes at the Earth's surface, as seen in Bowen's reaction series. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, brown, yellow, red, grey, pink, white, and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are better able to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity. Quartz-bearing sandstone can be converted into quartzite through metamorphism, usually related to tectonic compression within orogenic belts.
  • 5.5K
  • 15 Nov 2022
Topic Review
Expectation–Disconfirmation Theory and Brand
Combining brand equity indicators with Expectation–Disconfirmation Theory (EDT) provides insight into the hardly measurable influential variables of brand loyalty and brand equity evaluation. The results suggest that the satisfaction level (i.e., product evaluation) can be explained in more depth by the divided response shift indicator in the case of a familiar, low involvement product such as mineral water. It can be stated that the positive and negative disconfirmations of the response shift, which measures the weight of a brand in the overall evaluation of a product, can provide accurate information for brand managers.
  • 5.5K
  • 26 Jul 2022
Topic Review
Bilaminar Blastocyst
Bilaminar blastocyst or bilaminar disc refers to the epiblast and the hypoblast, evolved from the embryoblast. These two layers are sandwiched between two balloons: the primitive yolk sac and the amniotic cavity. The inner cell mass, the embryoblast, begins to transform into two distinct epithelial layers just before implantation occurs. The epiblast is the outer layer that consists of columnar cells. The inner layer is called the hypoblast, or primitive endoderm, which is composed of cuboidal cells. As the two layers become evident, a basement membrane presents itself between the layers. The final two layers of the embryoblast are known collectively as the bilaminar embryonic disc as well as the bilaminar blastocyst or bilaminar blastoderm. This bilaminar blastocyst also defines the primitive dorsal ventral axis. Blastocyst implantation will occur during the second week of fetal development in the endometrium of the uterus; the epiblast is dorsal and the hypoblast is ventral.
  • 5.5K
  • 19 May 2023
Topic Review
Metallic Alloy Nanoparticles
Metallic alloy nanoparticles are synthesized by combining two or more different metals. Bimetallic or trimetallic nanoparticles are considered more effective than monometallic nanoparticles because of their synergistic characteristics. In this review, we outline the structure, synthesis method, properties, and biological applications of metallic alloy nanoparticles based on their plasmonic, catalytic, and magnetic characteristics.
  • 5.5K
  • 03 Aug 2020
Topic Review
Beeswax
Beeswax is one of the natural waxes that have been used as a support ingredient in cosmetic and pharmaceutical formulations. Although it has well-known healing properties, it remains a secondary and poorly valued product, particularly in South American countries' apiarian production. In Latin America, for example, the apiarian activity can be traced back to stingless bees in pre-Columbian times. Then, with the arrival of the Spaniards in the 16th century, honey bees (Apis mellifera iberian and A. m. mellifera) were introduced, which were joined afterward by other breeds such as A. m. ligustica and A. m. scutellata. Over the years, honey has been the main product from the apiarian farmers, being beeswax a secondary product, mainly used for the regular renewal procedure of the hives. Nowadays, beeswax's cosmetic and pharmaceutical use is found at the level of small laboratories and small businesses.
  • 5.5K
  • 10 Oct 2022
Topic Review
Can CFD Analysis Help PEM Fuel Cell Design and Operation?
Polymer electrolyte membrane (PEM) fuel cell system is an advanced power system for the future that is sustainable, clean and environmental friendly. PEM fuel cells are growing in importance as sources of sustainable energy and will doubtless form part of the changing program of energy resources in the future. PEM fuel cells are still undergoing intense development, and the combination of new and optimized materials, improved product development, novel architectures, more efficient transport processes, and design optimization and integration are expected to lead to major gains in performance, efficiency, reliability, manufacturability and cost-effectiveness. The difficult experimental environment of PEM fuel cell systems has stimulated efforts to develop models that could simulate and predict multi-dimensional coupled transport of reactants, heat and charged species using computational fluid dynamic (CFD) technology. The strength of the CFD numerical approach is in providing detailed insight into the various transport mechanisms and their interaction, and in the possibility of performing parameters sensitivity analyses. The results of CFD analyses are relevant in: conceptual studies of new designs, detailed product development, troubleshooting, and redesign. CFD analysis complements testing and experimentation, by reduces the total effort required in the experiment design and data acquisition. Relevant case studies and recent progress in CFD techniques used in PEM fuel cell development have been presented and analyzed. The CFD models are shown to be able to provide a computer-aided tool for design and optimize future PEM fuel cell with much higher power density, long cell life, and lower cost.
  • 5.5K
  • 26 Apr 2020
Topic Review
Salt-Tolerant Rice
Soil salinization and a degraded ecological environment are challenging agricultural productivity and food security.  Salt stress-inhibited growth and development of plants is the key limiting factor resulting in the reduction of rice yield, the contradiction of yield promotion and salt tolerance greatly affects salt-tolerant rice breeding.  Here, we  highlight current advances and challenges to breeding salt-tolerant rice, providing a basis for further studies and efforts aimed at breeding salt-tolerant rice varieties.
  • 5.5K
  • 17 Jan 2022
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