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Topic Review
NASDAQ
The Nasdaq Stock Market (/ˈnæzˌdæk/ (listen), also known simply as Nasdaq) is an American stock exchange. It is the second-largest exchange in the world by market capitalization, behind only the New York Stock Exchange located in the same city. The exchange platform is owned by Nasdaq, Inc., which also owns the Nasdaq Nordic (formerly known as OMX) and Nasdaq Baltic stock market network and several U.S. stock and options exchanges
  • 2.9K
  • 30 Nov 2022
Topic Review
Hesperidin and SARS-CoV-2
Among the flavonoids, hesperidin has recently attracted the attention of researchers, because it binds to the key proteins of the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several computational methods, independently applied by different researchers, showed that hesperidin has a low binding energy, both with the coronavirus “spike” protein, and with the main protease that transforms the early proteins of the virus into the complex responsible for viral replication. The binding energy of hesperidin to these important components is lower than that of lopinavir, ritonavir, and indinavir, suggesting that it could perform an effective antiviral action. Furthermore, both hesperidin and ascorbic acid counteract the cell damaging effects of the oxygen free radicals triggered by virus infection and inflammation.
  • 2.9K
  • 26 Oct 2020
Biography
Zera Yacob
Zera Yacob (/ˈzɪərə jæˈkoʊb/; Ge'ez: ዘርአ ፡ ያዕቆብ zar'ā yāʿiqōb "Seed of Jacob," modern Zer'a Yā'iqōb; also spelled Zärˀä Yaˁqob, Zar'a Ya'aqob, or Zar'a Ya'eqob; 31 August 1599 – 1692) was a seventeenth-century Ethiopian philosopher from the city Aksum. His 1667 treatise, developed around 1630 and known in the original Ge'ez language as the Hatata (Inquiry), has
  • 2.9K
  • 15 Nov 2022
Topic Review
Reintroduction Projects of the Przewalski’s Horse
Przewalski’s horse (Equus ferus przewalskii), also known as Przewalski’s wild horse, the Asian wild horse, Mongolian wild horse, Takhi or Junggar Horses, is classified by the IUCN as Extinct in the Wild (EW) as no Przewalski’s horse has been seen in the wild since 1969, despite efforts to find them in Mongolia or China. The wild horse has been successfully saved from extinction by captive breeding projects outside the historic range. Although multiple studies were conducted, the main problems such as loss of founder genes, inbreeding depression, hybridization with domestic horses, high morbidity and mortality, and a lack of reliable prevention strategies and treatment limitations of these problems are still unresolved and require further scientific effort.
  • 2.9K
  • 02 Dec 2022
Topic Review
Microbial Hyaluronic Acid Production
Microbial production of hyaluronic acid (HA) is an area of research that has been gaining attention in recent years due to the increasing demand for this biopolymer for several industrial applications. Hyaluronic acid is a linear, non-sulfated glycosaminoglycan that is widely distributed in nature and is mainly composed of repeating units of N-acetylglucosamine and glucuronic acid. It has a wide and unique range of properties such as viscoelasticity, lubrication, and hydration, which makes it an attractive material for several industrial applications such as cosmetics, pharmaceuticals, and medical devices.
  • 2.9K
  • 02 Mar 2023
Topic Review Peer Reviewed
Modulation of the Host Defence System by Nematophagous Fungi and Chitosan
Nematophagous fungi (NFs), which are responsible for soil suppression of plant-parasitic nematodes, are multitrophic biocontrol agents. This raises the question of the transition between lifestyles (e.g., endophytism vs. egg parasitism). The NF Pochonia chlamydosporia colonises food crops and promotes their growth and yield. When colonising the plant, P. chlamydosporia induces the plant immunity (PI). However, it also evades the PI. To do this, both endophytic NF and pathogenic fungi (PF) secrete LysM effectors (LysM-effs). LysM effectors have been shown to have diverse functions in different organisms, including the protection of fungal chitin from plant chitinases. P. chlamydosporia is resistant to chitosan, which modulates gene expression in fungi and plants and has antimicrobial properties. P. chlamydosporia chitin deacetylases (CDA) and chitosanases (CSN) also help P. chlamydosporia evade plant immunity, resist exogenous chitosan, and are induced during fungal infection of nematode eggs. NF-chitosan formulations are new biomanagement tools against plant parasitic nematodes, fungal wilt pathogens and insect pests that currently threaten food security crops. Furthermore, omics techniques are useful tools to elucidate the role of CDAs, CSNs, LysM-effs, adhesion proteins and carbohydrate-active enzymes in pathogen–BCA–plant interactions, adhesion and infection to nematode eggs and their modulation by chitosan.
  • 2.9K
  • 21 Feb 2024
Topic Review
Biogenic amines in Fish
The occurrence of biogenic amines in fish is directly associated with microorganisms with decarboxylase activity. These compounds are generally detoxified by oxidases in the intestinal tract of humans, but some conditions, such as alcohol consumption, enzyme deficiency, or monoamino-oxidase antidepressant use, can make their intake by food dangerous. Due to its toxicity, histamine is a unique biogenic amine with regulatory limits for fishery products. This review focuses on biogenic amines in fish, with a detailed picture of the number of alert notifications or intoxication events reported in the last years. The favoring conditions for their formation, as well as the main preventive and control measures to ensure public health, are also reviewed.
  • 2.9K
  • 18 Dec 2020
Topic Review
Intellectual Disability
Intellectual disability (ID), also known as general learning disability and formerly mental retardation (MR), is a generalized neurodevelopmental disorder characterized by significantly impaired intellectual and adaptive functioning. It is defined by an IQ under 70, in addition to deficits in two or more adaptive behaviors that affect everyday, general living. Intellectual functions are defined under DSM-V as reasoning, problem‑solving, planning, abstract thinking, judgment, academic learning, and learning from instruction and experience, and practical understanding confirmed by both clinical assessment and standardized tests. Adaptive behavior is defined in terms of conceptual, social, and practical skills involving tasks performed by people in their everyday lives. Once focused almost entirely on cognition, the definition now includes both a component relating to mental functioning and one relating to an individual's functional skills in their daily environment. As a result of this focus on the person's abilities in practice, a person with an unusually low IQ may still not be considered to have an intellectual disability. Intellectual disability is subdivided into syndromic intellectual disability, in which intellectual deficits associated with other medical and behavioral signs and symptoms are present, and non-syndromic intellectual disability, in which intellectual deficits appear without other abnormalities. Down syndrome and fragile X syndrome are examples of syndromic intellectual disabilities. Intellectual disability affects about 2 to 3% of the general population. Seventy-five to ninety percent of the affected people have mild intellectual disability. Non-syndromic, or idiopathic cases account for 30 to 50% of these cases. About a quarter of cases are caused by a genetic disorder, and about 5% of cases are inherited from a person's parents. Cases of unknown cause affect about 95 million people (As of 2013).
  • 2.9K
  • 20 Oct 2022
Topic Review
High-Spectral-Resolution Lidar
High-spectral-resolution lidar (HSRL) is a powerful tool for atmospheric aerosol remote sensing. A ground-based high-spectral-resolution lidar (HSRL), operated at 532 nm wavelength, has been developed at Zhejiang University (ZJU) for aerosols and clouds studies. This lidar provides vertical profiles of aerosol scattering ratio together with lidar ratio and particle depolarization ratio at 532 nm. Determination of overlap function is a key step in the calibration of a high-spectral-resolution lidar (HSRL) and important guarantee of data retrieval, an iterative-based general determination (IGD) method for overlap function in HSRL is proposed. The standard method to retrieve the extinction coefficient from HSRL signals depends heavily on the signal-to-noise ratio (SNR). An iterative image reconstruction (IIR) method is proposed for the retrieval of the aerosol extinction coefficient based on HSRL data under low SNR condition. With the optical properties, a state-of-the-art method for feature detection and classification is proposed to automatically identify the features attributed to dust/polluted dust, urban/smoke, maritime aerosols, as well as ice and liquid water cloud during day and night.
  • 2.9K
  • 22 Feb 2021
Topic Review
Olmec Influences on Mesoamerican Cultures
The causes and degree of Olmec influences on Mesoamerican cultures has been a subject of debate over many decades. Although the Olmecs are considered to be perhaps the earliest Mesoamerican civilization, there are questions concerning how and how much the Olmecs influenced cultures outside the Olmec heartland. This debate is succinctly, if simplistically, framed by the title of a 2005 The New York Times article: “Mother Culture, or Only a Sister?”.
  • 2.9K
  • 14 Oct 2022
Topic Review
Ganapati Atharvashirsa
The Ganapati Atharvashirsa (Sanskrit: गणपत्यथर्वशीर्ष, Gaṇapatyatharvaśīrṣa) is a Sanskrit text and a minor Upanishad of Hinduism. It is a late Upanishadic text dedicated to Ganesha, the deity representing intellect and learning. It asserts that Ganesha is same as the eternal underlying reality, Brahman. The text is attached to the Atharvaveda, and is also referred to as the Sri Ganapati Atharva Sirsha, the Ganapati Atharvashirsha, the Ganapati Atharvasirsa, or the Ganapati Upanishad. The text exists in several variants, but with the same message. Ganesha is described to be same as other Hindu gods, as ultimate truth and reality (Brahman), as satcitananda, as the soul in oneself (Atman) and in every living being, as Om.
  • 2.9K
  • 17 Nov 2022
Topic Review
Blockchain Technology and Its Components
The Internet of Things (IoT) is a recent technology that uses smart connected systems to create a global network of physical devices that exchange and communicate data with each other. Blockchain is essentially a system for recording data that makes it much more difficult to change or hack. Blockchain uses a distributed networking system of machines that replicate and create a chain of data. This chain of data can be considered a ledger, with each of these becoming a block. This chain of data is turned into a block which is linked to the previous block creating a chain of blocks, hence the name blockchain.
  • 2.9K
  • 23 Jun 2022
Topic Review
Side Lobe
In antenna engineering, side lobes or sidelobes are the lobes (local maxima) of the far field radiation pattern of an antenna or other radiation source, that are not the main lobe. The radiation pattern of most antennas shows a pattern of "lobes" at various angles, directions where the radiated signal strength reaches a maximum, separated by "nulls", angles at which the radiated signal strength falls to zero. This can be viewed as the diffraction pattern of the antenna. In a directional antenna in which the objective is to emit the radio waves in one direction, the lobe in that direction is designed to have a larger field strength than the others; this is the "main lobe". The other lobes are called "side lobes", and usually represent unwanted radiation in undesired directions. The side lobe directly behind the main lobe is called the back lobe. The longer the antenna relative to the radio wavelength, the more lobes its radiation pattern has. In transmitting antennas, excessive side lobe radiation wastes energy and may cause interference to other equipment. Another disadvantage is that confidential information may be picked up by unintended receivers. In receiving antennas, side lobes may pick up interfering signals, and increase the noise level in the receiver. The power density in the side lobes is generally much less than that in the main beam. It is generally desirable to minimize the sidelobe level (SLL), which is measured in decibels relative to the peak of the main beam. The main lobe and side lobes occur for both transmitting and receiving. The concepts of main and side lobes, radiation pattern, aperture shapes, and aperture weighting, apply to optics (another branch of electromagnetics) and in acoustics fields such as loudspeaker and sonar design, as well as antenna design. Because an antenna's far field radiation pattern is a Fourier Transform of its aperture distribution, most antennas will generally have sidelobes, unless the aperture distribution is a Gaussian, or if the antenna is so small as to have no sidelobes in the visible space. Larger antennas have narrower main beams, as well as narrower sidelobes. Hence, larger antennas have more sidelobes in the visible space (as the antenna size is increased, sidelobes move from the evanescent space to the visible space).
  • 2.9K
  • 28 Nov 2022
Topic Review
(1,3;1,4)-β-D-Glucans
(1,3;1,4)-β-D-Glucans, also named as mixed-linkage glucans, are unbranched non-cellulosic polysaccharides containing both (1,3)- and (1,4)-β-linkages. The linkage ratio varies depending upon species origin and has a significant impact on the physicochemical properties of the (1,3;1,4)-β-D-glucans.
  • 2.9K
  • 24 Sep 2021
Topic Review
Granular Organic Fertilizers
Granular organic fertilizers' production has recently become more popular, with the main aim of converting high-moisture organic matter, such as manure, manure mixtures, meat and bone waste or other organic matter, into pellets that are convenient to spread in the field. The pellets are usually produced with the diameter of 4 or 6 mm so that they can be easily spread with mineral or organic fertilizer spreaders. Once in the soil, organic fertilizer pellets become wet, decompose and release nutrients.
  • 2.9K
  • 11 Sep 2021
Topic Review
Bispecific Antibodies in Cancer Immunotherapy
Immunotherapy has redefined the treatment of cancer patients and it is constantly generating new advances and approaches. Among the multiple options of immunotherapy, bispecific antibodies (bsAbs) represent a novel thoughtful approach. These drugs integrate the action of the immune system in a strategy to redirect the activation of innate and adaptive immunity toward specific antigens and specific tumor locations.
  • 2.9K
  • 22 Jun 2022
Topic Review
Trace Gas Orbiter
The ExoMars Trace Gas Orbiter (TGO or ExoMars Orbiter) is a collaborative project between the European Space Agency (ESA) and Roscosmos that sent an atmospheric research orbiter and the Schiaparelli demonstration lander to Mars in 2016 as part of the European-led ExoMars programme. The Trace Gas Orbiter delivered the Schiaparelli lander on 16 October 2016, which crashed on the surface. The orbiter began aerobraking in March 2017 to lower its initial orbit of 200 by 98,000 km (120 by 60,890 mi). Aerobraking concluded on 20 February 2018 when a final thruster firing resulted in an orbit of 200 by 1,050 km (120 by 650 mi). Additional thruster firings every few days raised the orbiter to a circular "science" orbit of 400 km (250 mi), which was achieved on 9 April 2018. A key goal is to gain a better understanding of methane (CH4) and other trace gases present in the Martian atmosphere that could be evidence for possible biological activity. The programme will follow with the Kazachok lander and the Rosalind Franklin rover in 2020, which will search for biomolecules and biosignatures; the TGO will operate as the communication link for the ExoMars lander and rover and provide communication for other Mars surface probes with Earth.
  • 2.9K
  • 27 Oct 2022
Topic Review
DNA Circuits
Deoxyribonucleic acid (DNA), a genetic material, encodes all living information and living characteristics, e.g., in cell, DNA signaling circuits control the transcription activities of specific genes. In recent years, various DNA circuits have been developed to implement a wide range of signaling and for regulating gene network functions. In particular, a synthetic DNA circuit, with a programmable design and easy construction, has become a crucial method through which to simulate and regulate DNA signaling networks. Importantly, the construction of a hierarchical DNA circuit provides a useful tool for regulating gene networks and for processing molecular information. Moreover, via their robust and modular properties, DNA circuits can amplify weak signals and establish programmable cascade systems, which are particularly suitable for the applications of biosensing and detecting. Furthermore, a biological enzyme can also be used to provide diverse circuit regulation elements. 
  • 2.9K
  • 13 Dec 2021
Topic Review
Transient Execution CPU Vulnerability
Transient execution CPU vulnerabilities are vulnerabilities in a computer system in which a speculative execution optimization implemented in a microprocessor is exploited to leak secret data to an unauthorized party. The classic example is Spectre that gave its name to this kind of side-channel attack, but since January 2018 many different vulnerabilities have been identified.
  • 2.9K
  • 14 Nov 2022
Topic Review
Radioactivity in Plastic Materials
All fossil combustible materials, such as coal and crude oil, contain radioactive elements, which origin from the natural decay series of uranium and thorium. The basic material for the synthesis of plastics is crude oil. Therefore, plastics may contain radionuclides. The gamma ray analysis of different rubbish bags used in the city of Basel show a clear contamination with uranium, radium (226Ra and 228Ra) and lead (210Pb), resulting in a yearly charge of 300, 300, 150 and 3,000 MBq each. In comparison with the contamination level of the burning ashes, these charges are not relevant (less than 1% of the content in the slags from the waste incineration). Nonetheless, we note a permanent displacement of long-lived natural radionuclides to landfill-sites.
  • 2.9K
  • 05 Jul 2021
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