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Topic Review
Thalidomide Scandal
In the late 1950s and early 1960s, the use of thalidomide in pregnant women in 46 countries resulted in the "biggest man‐made medical disaster ever," with over 10,000 children born with a range of severe deformities, such as phocomelia, and thousands of miscarriages. Thalidomide was introduced in 1956 and was aggressively marketed by the German pharmaceutical company Chemie Grünenthal as a medication for anxiety, trouble sleeping, "tension", and morning sickness. It was introduced as a sedative and medication for morning sickness without having been tested on pregnant women. While initially deemed to be safe in pregnancy, concerns regarding birth defects were noted in 1961, and the medication was removed from the market in Europe that year.
  • 5.4K
  • 09 Nov 2022
Topic Review
Air Mass
In astronomy, air mass or airmass is a measure of the amount of air along the line of sight when observing a star or other celestial source from below Earth's atmosphere (Green 1992). It is formulated as the integral of air density along the light ray. As it penetrates the atmosphere, light is attenuated by scattering and absorption; the thicker atmosphere through which it passes, the greater the attenuation. Consequently, celestial bodies when nearer the horizon appear less bright than when nearer the zenith. This attenuation, known as atmospheric extinction, is described quantitatively by the Beer–Lambert law. "Air mass" normally indicates relative air mass, the ratio of absolute air masses (as defined above) at oblique incidence relative to that at zenith. So, by definition, the relative air mass at the zenith is 1. Air mass increases as the angle between the source and the zenith increases, reaching a value of approximately 38 at the horizon. Air mass can be less than one at an elevation greater than sea level; however, most closed-form expressions for air mass do not include the effects of the observer's elevation, so adjustment must usually be accomplished by other means. Tables of air mass have been published by numerous authors, including Bemporad (1904), Allen (1976), and Kasten and Young (1989).
  • 5.4K
  • 11 Oct 2022
Topic Review
Malaysia’s Housing Policy, Low-Income Households' Housing Affordability
Housing affordability is a long-held issue in Malaysia and housing policies for low-income households have been implemented over years. However, there is a contradiction that housing affordability of low-income households has not been met, while a bulk of affordable housing is still vacant. In 2019, Malaysia enacted the National Affordable Housing Policy (DRMM) which was intended to improve housing affordability for low-income groups. In such circumstances, the questions are, why Malaysia’s long-term implementation of affordable housing policies cannot guarantee housing affordability and whether the DRMM can effectively improve housing affordability as expected.
  • 5.4K
  • 02 Dec 2021
Topic Review
Cotton Seed
Seed germination is the basis for the proliferation of sexual-reproducing plants, efficient crop production, and a successful crop improvement research program. While seeds are a vital form of dispersal and propagation of plants in the environment, they had to develop mechanisms in unfavorable circumstances to ensure the preservation of the next generation. One of the major survival adaptations of seeds is dormancy. This phenomenon allows the seed to delay and coordinate germination according to environmental conditions and it is essential to the conservation and proliferation of a species. Generally, dormant seeds naturally start or resume the germination process once they detect environmental signals indicating suitable conditions for plant development such as temperature fluctuations, water availability, and even smoke. If unfavorable conditions persist and seeds halt germination for a long period, aging might negatively impact this process. Modifications in the seed structure like the hard seed trait in cotton can also affect germination. Often referred to as physical dormancy, hard seeds are water impermeable and prevent gas exchange and water uptake by the embryo.
  • 5.4K
  • 23 Dec 2021
Topic Review
Applications of Nanostructured Materials
In the last few decades, the vast potential of nanomaterials for biomedical and healthcare applications has been extensively investigated. Several case studies demonstrated that nanomaterials can offer solutions to the current challenges of raw materials in the biomedical and healthcare fields. The different nanoparticles and nanostructured material synthesis approaches were described.
  • 5.4K
  • 11 Apr 2022
Topic Review Peer Reviewed
The Foundation of Classical Mechanics
Mechanics is the science of the equilibrium and motion of bodies subject to forces. The adjective classical, hence Classical Mechanics , was added in the 20th century to distinguish it from relativistic mechanics which studies motion with speed close to light speed and quantum mechanics which studies motion at a subatomic level.
  • 5.4K
  • 13 Apr 2022
Topic Review
Extensive Sheep and Goat Production
Sheep and goat extensive production systems are conducted in many different parts of the world, and they often use essentially marginal areas unsuitable for crop production, characterized by low productivity per animal and per surface area. They positively impact local socio-economic activities, playing an essential role in the maintenance of rural communities, on ecosystems, and in the production of unique, valued foods such as lamb meat or cheeses. However, such systems are under significant pressure, mainly because there is little labor availability, and they have traditionally low productivity and often poor economic viability.
  • 5.4K
  • 08 Dec 2022
Topic Review
Continuationism
Continuationism is a Christian theological belief that the gifts of the Holy Spirit have continued to the present age, specifically those sometimes called "sign gifts", such as tongues and prophecy. Continuationism is the opposite of cessationism. Continuationists believe that the miraculous gifts of the Holy Spirit are still distributed today, are still in use, and are still needed in the church. The same Holy Spirit that the Apostle Paul wrote of, claiming that it gave him supernatural abilities, was also written about in the Old Testament, which claims that it also endowed such abilities upon those whom God chose to accomplish his works, as in the New Testament. Historically, the Lutheran, Methodist, Moravian, and Pentecostal traditions of Christianity have espoused the doctrinal position of continuationism.
  • 5.4K
  • 11 Oct 2022
Topic Review
Pomegranate Juice Processing by Membranes
Pomegranate juice exhibits high antioxidant capacity because of its rich content of polyphenols, which represent the highest proportion of phytochemicals in pomegranate. Conventional pressure-driven membrane operations and innovative membrane operations, such as osmotic distillation and pervaporation, are discussed in relation to their potential in juice clarification, fractionation, concentration and aroma recovery. Their implementation in integrated systems offer new opportunities to improve the healthiness and quality of the juice as well as to recover, purify and concentrate bioactive compounds for the formulation of functional ingredients.
  • 5.4K
  • 15 Jul 2020
Topic Review
Impact of Automobility on Urban Sprawl
Urban sprawl has become a controversial issue. Lines of thought among academics, practitioners, and local authorities have been diverse. Some academics advocate the compact city as an antidote to urban sprawl, some scholars doubt the ability of conventional notions of containments to create sustainability, and others are fascinated by urban technologies and believe in the feasibility of these technologies, whereas local authorities impose policies, one after the other, without effective results.
  • 5.4K
  • 29 Sep 2022
Topic Review
DNA Barcoding
DNA barcoding is a method of species identification using a short section of DNA from a specific gene or genes. The premise of DNA barcoding is that, by comparison with a reference library of such DNA sections (also called "sequences"), an individual sequence can be used to uniquely identify an organism to species, in the same way that a supermarket scanner uses the familiar black stripes of the UPC barcode to identify an item in its stock against its reference database. These "barcodes" are sometimes used in an effort to identify unknown species, parts of an organism, or simply to catalog as many taxa as possible, or to compare with traditional taxonomy in an effort to determine species boundaries. Different gene regions are used to identify the different organismal groups using barcoding. The most commonly used barcode region for animals and some protists is a portion of the cytochrome c oxidase I (COI or COX1) gene, found in mitochondrial DNA. Other genes suitable for DNA barcoding are the internal transcribed spacer (ITS) rRNA often used for fungi and RuBisCO used for plants. Microorganisms are detected using different gene regions. The 16S rRNA gene for example is widely used in identification of prokaryotes, whereas the 18S rRNA gene is mostly used for detecting microbial eukaryotes. These gene regions are chosen because they have less intraspecific (within species) variation than interspecific (between species) variation, which is known as the "Barcoding Gap". Some applications of DNA barcoding include: identifying plant leaves even when flowers or fruits are not available; identifying pollen collected on the bodies of pollinating animals; identifying insect larvae which may have fewer diagnostic characters than adults; or investigating the diet of an animal based on its stomach content, saliva or feces. When barcoding is used to identify organisms from a sample containing DNA from more than one organism, the term DNA metabarcoding is used, e.g. DNA metabarcoding of diatom communities in rivers and streams, which is used to assess water quality.
  • 5.4K
  • 16 Nov 2022
Topic Review
Transtheoretical Model
The transtheoretical model of behavior change is an integrative theory of therapy that assesses an individual's readiness to act on a new healthier behavior, and provides strategies, or processes of change to guide the individual. The model is composed of constructs such as: stages of change, processes of change, levels of change, self-efficacy, and decisional balance. The transtheoretical model is also known by the abbreviation "TTM" and sometimes by the term "stages of change", although this latter term is a synecdoche since the stages of change are only one part of the model along with processes of change, levels of change, etc. Several self-help books—Changing for Good (1994), Changeology (2012), and Changing to Thrive (2016)—and articles in the news media have discussed the model. It has been called "arguably the dominant model of health behaviour change, having received unprecedented research attention, yet it has simultaneously attracted criticism".
  • 5.4K
  • 21 Oct 2022
Topic Review
List of SpaceX Starship Launches
Prototypes of the upper stage of the SpaceX Starship have been flown nine times.[lower-alpha 1] Designed and operated by private manufacturer SpaceX, the flown prototypes of Starship have been Starhopper, SN5, SN6, SN8, SN9, SN10, SN11, and SN15. Starship is planned to be a fully-reusable two-stage super heavy-lift launch vehicle and unusual for previous launch vehicle and spacecraft designs, the upper stage of Starship is intended to function both as a second stage to reach orbital velocity on launches from Earth, and also eventually be used in outer space as an on-orbit long-duration spacecraft. It is being designed to take people to Mars and beyond into the Solar System.
  • 5.4K
  • 20 Oct 2022
Topic Review
Heterosis
The phenomenon of heterosis has fascinated plant breeders ever since it was first described by Charles Darwin in 1876 in the vegetable kingdom and later elaborated by George H Shull and Edward M East in maize during 1908. Heterosis is the phenotypic and functional superiority manifested in the F1 crosses over the parents. Various classical complementation mechanisms gave way to the study of the underlying potential cellular and molecular mechanisms responsible for heterosis. In cereals, such as maize, heterosis has been exploited very well, with the development of many single-cross hybrids that revolutionized the yield and productivity enhancements.
  • 5.4K
  • 29 Oct 2020
Topic Review
Sustainability Green Industry 4.0
The Sustainability Green Industry (SGI) 4.0 framework captures the relations of Industry 4.0, green processes and sustainability in manufacturing. The framework is structured into three vertical levels: technological, process and development, integrated through the circular economy. The SGI 4.0 framework’s purpose is to explain how Industry 4.0 technologies create sustainability outcomes through green processes. The facilitating, enabling and supporting functions of green processes allow to understand how modern technologies can be linked to the concept of sustainability. In the literature we can find various concepts connecting Industry 4.0 and sustainability, however, the key role of green processes is not mentioned.
  • 5.4K
  • 25 Jun 2021
Topic Review
Taiji
Taiji or Tai chi (simplified Chinese: 太极; traditional Chinese: 太極; pinyin: tàijí; literally: 'great pole') is a Chinese cosmological term for the "Supreme Ultimate" state of undifferentiated absolute and infinite potential, the oneness before duality, from which Yin and Yang originate. It can be compared with the old Wuji (無極, "without pole"). The term Taiji and its other spelling T'ai chi (using Wade–Giles as opposed to Pinyin) are most commonly used in the West to refer to Taijiquan (or T'ai chi ch'uan, 太極拳), an internal martial art, Chinese meditation system and health practice. This article, however, refers only to the use of the term in Chinese philosophy and in Confucianism, Taoism and Buddhism.
  • 5.4K
  • 24 Oct 2022
Topic Review
Trigonometry
Trigonometry (from grc τρίγωνον (trígōnon) 'triangle', and μέτρον (métron) 'measure') is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies. The Greeks focused on the calculation of chords, while mathematicians in India created the earliest-known tables of values for trigonometric ratios (also called trigonometric functions) such as sine. Throughout history, trigonometry has been applied in areas such as geodesy, surveying, celestial mechanics, and navigation. Trigonometry is known for its many identities. These trigonometric identities are commonly used for rewriting trigonometrical expressions with the aim to simplify an expression, to find a more useful form of an expression, or to solve an equation.
  • 5.4K
  • 31 Oct 2022
Topic Review
Matrix Metalloproteinases and Their Inhibitors
Matrix metalloproteinases (MMPs) are a family of zinc-dependent extracellular matrix (ECM) remodeling endopeptidases that have the capacity to degrade almost every component of the ECM. The degradation of the ECM is of great importance, since it is related to embryonic development and angiogenesis. It is also involved in cell repair and the remodeling of tissues. When the expression of MMPs is altered, it can generate the abnormal degradation of the ECM. This is the initial cause of the development of chronic degenerative diseases and vascular complications generated by diabetes. In addition, this process has an association with neurodegeneration and cancer progression. Within the ECM, the tissue inhibitors of MMPs (TIMPs) inhibit the proteolytic activity of MMPs. TIMPs are important regulators of ECM turnover, tissue remodeling, and cellular behavior. Therefore, TIMPs (similar to MMPs) modulate angiogenesis, cell proliferation, and apoptosis. An interruption in the balance between MMPs and TIMPs has been implicated in the pathophysiology and progression of several diseases.
  • 5.4K
  • 18 Sep 2021
Topic Review
Time Management
Time management is the process of planning and exercising conscious control of time spent on specific activities, especially to increase effectiveness, efficiency, and productivity. It involves a juggling act of various demands upon a person relating to work, social life, family, hobbies, personal interests and commitments with the finiteness of time. Using time effectively gives the person "choice" on spending/managing activities at their own time and expediency. Time management may be aided by a range of skills, tools, and techniques used to manage time when accomplishing specific tasks, projects, and goals complying with a due date. Initially, time management referred to just business or work activities, but eventually the term broadened to include personal activities as well. A time management system is a designed combination of processes, tools, techniques, and methods. Time management is usually a necessity in any project development as it determines the project completion time and scope. It is also important to understand that both technical and structural differences in time management exist due to variations in cultural concepts of time. The major themes arising from the literature on time management include the following:
  • 5.4K
  • 04 Nov 2022
Topic Review
Cyanophyceae
Cyanobacteria (/saɪˌænoʊbækˈtɪəri.ə/), also known as Cyanophyta, are a phylum of Gram-negative bacteria that obtain energy via photosynthesis. The name cyanobacteria refers to their color (from grc κυανός (kuanós) 'blue'), which similarly forms the basis of cyanobacteria's common name, blue-green algae.[note 1] They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plastids that are thought to have their ancestry in cyanobacteria, acquired long ago via a process called endosymbiosis. These endosymbiotic cyanobacteria in eukaryotes then evolved and differentiated into specialized organelles such as chloroplasts, chromoplasts, etioplasts, and leucoplasts, collectively known as plastids. Cyanobacteria are the first organisms known to have produced oxygen. By producing and releasing oxygen as a byproduct of photosynthesis, cyanobacteria are thought to have converted the early oxygen-poor, reducing atmosphere into an oxidizing one, causing the Great Oxidation Event and the "rusting of the Earth", which dramatically changed the composition of the Earth's life forms. The cyanobacteria Synechocystis and Cyanothece are important model organisms with potential applications in biotechnology for bioethanol production, food colorings, as a source of human and animal food, dietary supplements and raw materials. Cyanobacteria produce a range of toxins known as cyanotoxins that can pose a danger to humans and animals.
  • 5.4K
  • 01 Nov 2022
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