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Topic Review
Evolutionary History of Life
The evolutionary history of life on Earth traces the processes by which living and fossil organisms evolved, from the earliest emergence of life to the present. Earth formed about 4.5 billion years (Ga) ago and evidence suggests life emerged prior to 3.7 Ga. (Although there is some evidence of life as early as 4.1 to 4.28 Ga, it remains controversial due to the possible non-biological formation of the purported fossils.) The similarities among all known present-day species indicate that they have diverged through the process of evolution from a common ancestor. Approximately 1 trillion species currently live on Earth of which only 1.75–1.8 million have been named and 1.6 million documented in a central database. These currently living species represent less than one percent of all species that have ever lived on earth. The earliest evidence of life comes from biogenic carbon signatures and stromatolite fossils discovered in 3.7 billion-year-old metasedimentary rocks from western Greenland. In 2015, possible "remains of biotic life" were found in 4.1 billion-year-old rocks in Western Australia. In March 2017, putative evidence of possibly the oldest forms of life on Earth was reported in the form of fossilized microorganisms discovered in hydrothermal vent precipitates in the Nuvvuagittuq Belt of Quebec, Canada, that may have lived as early as 4.28 billion years ago, not long after the oceans formed 4.4 billion years ago, and not long after the formation of the Earth 4.54 billion years ago. Microbial mats of coexisting bacteria and archaea were the dominant form of life in the early Archean Epoch and many of the major steps in early evolution are thought to have taken place in this environment. The evolution of photosynthesis, around 3.5 Ga, eventually led to a buildup of its waste product, oxygen, in the atmosphere, leading to the great oxygenation event, beginning around 2.4 Ga. The earliest evidence of eukaryotes (complex cells with organelles) dates from 1.85 Ga, and while they may have been present earlier, their diversification accelerated when they started using oxygen in their metabolism. Later, around 1.7 Ga, multicellular organisms began to appear, with differentiated cells performing specialised functions. Sexual reproduction, which involves the fusion of male and female reproductive cells (gametes) to create a zygote in a process called fertilization is, in contrast to asexual reproduction, the primary method of reproduction for the vast majority of macroscopic organisms, including almost all eukaryotes (which includes animals and plants). However the origin and evolution of sexual reproduction remain a puzzle for biologists though it did evolve from a common ancestor that was a single celled eukaryotic species. Bilateria, animals having a left and a right side that are mirror images of each other, appeared by 555 Ma (million years ago). The earliest complex land plants date back to around 850 Ma, from carbon isotopes in Precambrian rocks, while algae-like multicellular land plants are dated back even to about 1 billion years ago, although evidence suggests that microorganisms formed the earliest terrestrial ecosystems, at least 2.7 Ga. Microorganisms are thought to have paved the way for the inception of land plants in the Ordovician. Land plants were so successful that they are thought to have contributed to the Late Devonian extinction event. (The long causal chain implied seems to involve the success of early tree archaeopteris (1) drew down CO2 levels, leading to global cooling and lowered sea levels, (2) roots of archeopteris fostered soil development which increased rock weathering, and the subsequent nutrient run-off may have triggered algal blooms resulting in anoxic events which caused marine-life die-offs. Marine species were the primary victims of the Late Devonian extinction.) Ediacara biota appear during the Ediacaran period, while vertebrates, along with most other modern phyla originated about 525 Ma during the Cambrian explosion. During the Permian period, synapsids, including the ancestors of mammals, dominated the land, but most of this group became extinct in the Permian–Triassic extinction event 252 Ma. During the recovery from this catastrophe, archosaurs became the most abundant land vertebrates; one archosaur group, the dinosaurs, dominated the Jurassic and Cretaceous periods. After the Cretaceous–Paleogene extinction event 66 Ma killed off the non-avian dinosaurs, mammals increased rapidly in size and diversity. Such mass extinctions may have accelerated evolution by providing opportunities for new groups of organisms to diversify.
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  • 24 Nov 2022
Topic Review
List of Dell PowerEdge Servers
Dell PowerEdge is a server line by Dell, following the naming convention for other Dell products: the PowerVault (data storage) and the PowerConnect (data transfer & switches). Below is an overview of current and former servers within Dell's PowerEdge product line. Different models are or were available as towers, 19-inch racks or blades. In the current naming scheme, towers are designated by T, racks by R, and blades by M (for modular). The 19″ rack-servers come in different physical heights expressed in rack units or U. Most modern servers are either 1U or 2U high while in the past the 4U was more common.
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  • 21 Oct 2022
Topic Review
Daihatsu Rocky
The Daihatsu Rocky (Japanese: ダイハツ・ロッキー, Daihatsu Rokkī) is an automobile nameplate used by Daihatsu for their lineup of SUVs. The nameplate was originally used as a ladder frame-based mini SUV that was sold in Japan and some international markets between 1989 and 2002. It was gradually replaced by the introduction of Terios in 1997. Beginning in 2019, the Rocky nameplate returned to Japan as a subcompact crossover SUV that replaces the Be‣go and is also rebadged and sold under Toyota brand as the Toyota Raize (Japanese: トヨタ・ライズ, Toyota Raizu).
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  • 27 Oct 2022
Topic Review
Potentially Toxic Elements
Potentially toxic element (PTE) pollution is a major abiotic stress, which reduces plant growth and affects food quality by entering the food chain, and ultimately poses hazards to human health.
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  • 18 May 2021
Topic Review
Internal Monologue
An internal monologue, also called self-talk, inner speech, inner discourse or internal discourse, is a person's inner voice which provides a running verbal monologue of thoughts while they are conscious. It is usually tied to a person's sense of self. It is particularly important in planning, problem solving, self-reflection, self-image, critical thinking, emotions, and subvocalization (reading in one's head). As a result, it is relevant to a number of mental disorders, such as depression, and treatments like cognitive behavioural therapy which seek to alleviate symptoms by providing strategies to regulate cognitive behaviour. It may reflect both conscious and subconscious beliefs. In some cases people may think of inner speech as coming from an external source, as with schizophrenic auditory hallucinations. Additionally, not everyone has a verbal internal monologue (see § Absence of an internal monologue). The looser flow of thoughts and experiences, verbal or not, is called a stream of consciousness, which can also refer to a related technique in literature. In a theory of child development formulated by Lev Vygotsky, inner speech has a precursor in private speech (talking to oneself) at a young age.
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  • 15 Nov 2022
Topic Review
National Liberal Club
The National Liberal Club (NLC) is a London private members' club, open to both men and women. It was established by William Ewart Gladstone in 1882 to provide club facilities for Liberal Party campaigners among the newly enlarged electorate following the Third Reform Act in 1884, and was envisioned as a more accessible version of a traditional London club. The club's Italianate building on the Embankment of the river Thames is the second-largest club-house built in London. (It was the largest ever at the time, but was superseded by the later Royal Automobile Club building completed in 1911.) Designed by Alfred Waterhouse, it was completed in 1887. Its facilities include a dining room, a bar, function rooms, a billiards room, a smoking room, a library and an outdoor riverside terrace. It is located at Whitehall Place, close to the Houses of Parliament, the Thames Embankment and Trafalgar Square.
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  • 29 Nov 2022
Topic Review
Xanthine Oxidoreductase Activities
Xanthine oxidoreductase (XOR) is the enzyme that catalyzes the oxidation of hypoxanthine to xanthine and xanthine to uric acid. XOR is widely distributed throughout living organisms and is highly conserved in prokaryotic, plant, and animal species. XOR activity is very versatile, generating both pro-oxidant (primarily within the cell) and anti-oxidant (primarily in plasma) products.
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  • 21 Sep 2020
Topic Review
Mental Chronometry
Mental chronometry is the study of reaction time (RT; also referred to as "response time") in perceptual-motor tasks to infer the content, duration, and temporal sequencing of mental operations. Mental chronometry is one of the core methodological paradigms of human experimental and cognitive psychology, but is also commonly analyzed in psychophysiology, cognitive neuroscience, and behavioral neuroscience to help elucidate the biological mechanisms underlying perception, attention, and decision-making across species. Mental chronometry uses measurements of elapsed time between sensory stimulus onsets and subsequent behavioral responses. It is considered an index of processing speed and efficiency indicating how fast an individual can execute task-relevant mental operations. Behavioral responses are typically button presses, but eye movements, vocal responses, and other observable behaviors can be used. RT is constrained by the speed of signal transmission in white matter as well as the processing efficiency of neocortical gray matter. Conclusions about information processing drawn from RT are often made with consideration of task experimental design, limitations in measurement technology, and mathematical modeling.
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  • 10 Oct 2022
Topic Review
Corn Processing by-Products
As an important food crop, corn has an important impact on people’s lives. The processing of corn produces many by-products, such as corn gluten meal, corn husk, and corn steep liquor, which are rich in protein, oil, carbohydrates, and other nutrients, all of which are inexpensive. Their accumulation in large quantities during the production process not only results in a burden on the environment but also the loss of potentially valuable food materials that can be processed. In fact, the by-products of corn processing have been partially used in functional foods, nutrients, feed, and other industries. There is no doubt that the secondary utilization of these by-products can not only solve the problem of waste pollution caused by them, but also produce high value-added products and improve the economic benefits of corn. 
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  • 01 Dec 2022
Topic Review
Porifera
Sponges, the members of the phylum Porifera (/pəˈrɪfərə/; meaning 'pore bearer'), are a basal animal clade as a sister of the Diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals.
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  • 18 Oct 2022
Topic Review
Pyrolysis and Gasification Mechanism of Biomass
Biomass can be converted to energy by using thermochemical and biochemical methodsecology; environmental; biomass; pyrolysis. Biochemical methods, including anaerobic digestion and fermentation, constitute the transformation of cellulose and hemicellulose into biofuel at the stages of hydrolysis and fermentation. At present, biochemical methods are cost-intensive, and involve problems with using lignin-rich biomass.
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  • 26 Nov 2021
Topic Review
The Hero with a Thousand Faces
The Hero with a Thousand Faces (first published in 1949) is a work of comparative mythology by Joseph Campbell. In this book, Campbell discusses his theory of the mythological structure of the journey of the archetypal hero found in world myths. Since the publication of The Hero with a Thousand Faces, Campbell's theory has been consciously applied by a wide variety of modern writers and artists. Filmmaker George Lucas acknowledged Campbell's theory in mythology, and its influence on the Star Wars films. The Joseph Campbell Foundation and New World Library issued a new edition of The Hero with a Thousand Faces in July 2008 as part of the Collected Works of Joseph Campbell series of books, audio and video recordings. In 2011, Time (magazine) placed the book in its list of the 100 best and most influential books written in English since the magazine was founded in 1923.
  • 5.1K
  • 20 Oct 2022
Topic Review
Group Work
Group work is a form of voluntary association of members benefiting from cooperative learning, that enhances the total output of the activity than when done individually. It aims to cater for individual differences, develop skills (e.g. communication skills, collaborative skills, critical thinking skills), generic knowledge and socially acceptable attitudes or to generate conforming standards of behavior and judgement, a "group mind". Specifically in psychotherapy and social work, "group work" refers to group therapy, offered by a practitioner trained in psychotherapy, psychoanalysis, counseling or other relevant discipline. The field of Social work includes all voluntary attempts to extend benefits in response to a bio-psycho-social needs and avails them through scientific knowledge and structured methods. There are six approaches in Social Work:
  • 5.1K
  • 31 Oct 2022
Topic Review
Starch Modification
Currently, new methods for producing starch citrates with improved functional and rheological properties while maintaining the highest possible content of resistant starch are being sought. The entry presents an overview of recent studies on the production, properties. And applicability of starch citrates with special attention paid to their role as preparations of resistant starch (RS). The use of citric acid for modification of starch is better for the technology process, while using cross-linking is better than simply using esterification.It may be concluded that the work on starch citrate esters represent a topical and meaningful direction of investigations on modified starch preparations. The possibility of modifying starch preparations by esterification/cross-linking with citric acid allows for the production of modified starch, which can be used in the pharmaceutical, packaging, or food industries. Especially significant may be investigations of resistant starch produced via esterification with citric acid because this method produces preparations exhibiting significant resistance and, simultaneously, good functional properties, which are potentially applicable as health-promoting additives that increase the dietary fiber content of food products.
  • 5.1K
  • 27 Oct 2020
Topic Review
Biosynthesis Pathway and Metabolism of Isoflavones
Isoflavones have been widely studied and have attracted extensive attention in fields ranging from chemotaxonomy and plant physiology to human nutrition and medicine. Isoflavones are often divided into three subgroups: simple O-substituted derivatives, prenylated derivatives, and glycosides. Simple O-substituted isoflavones and their glycosides, such as daidzein (daidzin), genistein (genistin), glycitein (glycitin), biochanin A (astroside), and formononetin (ononin), are the most common ingredients in legumes and are considered as phytoestrogens for daily dietary hormone replacement therapy due to their structural similarity to 17-β-estradiol. On the basis of the known estrogen-like potency, these above isoflavones possess multiple pharmacological activities such as antioxidant, anti-inflammatory, anticancer, anti-angiogenetic, hepatoprotective, antidiabetic, antilipidemic, anti-osteoporotic, and neuroprotective activities. 
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  • 22 Sep 2022
Topic Review
Descendants of the Bounty Mutineers
The descendants of the Bounty mutineers and their Tahitian consorts include the modern-day Pitcairn Islanders as well as a little less than half of the population of Norfolk Island. Their descendants also live in New Zealand, Australia, and the United States. Because of the scarcity of people on the island, many of the mutineers' children and grandchildren intermarried, with some marrying cousins and second cousins. Occasionally a new person would arrive on the island bringing with them a new surname (like the American Samuel Russell Warren, whose descendants still live on the island today).
  • 5.1K
  • 25 Oct 2022
Topic Review
Application of Natural Coagulants in Water Treatment
The most popular and conventional method for water treatment (WT)  is the use of chemical-based coagulants including ferric chloride (FeCl3), alum (AlCl3), synthetic polymers (polyacrylamide), and poly aluminum. However, the use of this approach is not sustainable as it leads to the production of a large volume of non-biodegradable sludge. Natural coagulants, on the other hand, serve as an alternative sustainable strategy for the removal of turbidity and WT, as they are cheap, safe, and biodegradable. Natural coagulants are derived from three major sources, which include plants, animals, and microorganisms.
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  • 02 Dec 2022
Topic Review
Objectivity
In philosophy, objectivity is the concept of truth independent from individual subjectivity (bias caused by one's perception, emotions, or imagination). A proposition is considered to have objective truth when its truth conditions are met without bias caused by the mind of a sentient being. Scientific objectivity refers to the ability to judge without partiality or external influence. Objectivity in the moral framework calls for moral codes to be assessed based on the well-being of the people in the society that follow it. Moral objectivity also calls for moral codes to be compared to one another through a set of universal facts and not through subjectivity.
  • 5.1K
  • 03 Nov 2022
Topic Review
Electric Vehicles Charging/Discharging and Battery Degradation
The high penetration of electric vehicles (EVs) will burden the existing power delivery infrastructure if their charging and discharging are not adequately coordinated. The degradation of lithium-ion batteries occurs throughout their lives due to several chemicals and mechanical processes that reduce the cyclable lithium and other active materials. Battery degradation depends on many factors, such as the charging and discharging rates, depth of discharge (DOD), temperature, voltage, cycle number, and storage stage of charge.
  • 5.1K
  • 17 Jan 2023
Topic Review
Prokaryotic Translation
Prokaryotic translation is the process by which messenger RNA is translated into proteins in prokaryotes.
  • 5.1K
  • 19 Oct 2022
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