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Topic Review
Table olives microbiota
Table olives fermentation is the result of a complex set of dynamics involving diverse microbial populations such as lactic acid bacteria, yeasts and moulds. Their metabolic activities determine the characteristics such as flavour, texture and safety of the final product. This chapter offers an overview on the main microbiota characterizing table olives and their role during fermentation.
  • 2.9K
  • 01 Jul 2020
Topic Review
CEA-708
CEA-708 is the standard for closed captioning for ATSC digital television (DTV) streams in the United States and Canada . It was developed by the Electronic Industries Alliance. Unlike RLE DVB and DVD subtitles, CEA-708 captions are low bandwidth and textual like traditional EIA-608 captions and EBU Teletext subtitles. However, unlike EIA-608 byte pairs, CEA-708 captions are not able to be modulated on an ATSC receiver's NTSC VBI line 21 composite output and must be pre-rendered by the receiver with the digital video frames, they also include more of the Latin-1 character set, and include stubs to support full UTF-32 captions, and downloadable fonts. CEA-708 caption streams can also optionally encapsulate EIA-608 byte pairs internally, a fairly common usage. CEA-708 captions are injected into MPEG-2 video streams in the picture user data. The packets are in picture order, and must be rearranged just like picture frames are. This is known as the DTVCC Transport Stream. It is a fixed-bandwidth channel that has 960 bit/s typically allocated for backward compatible "encapsulated" Line 21 captions, and 8640 bit/s allocated for CEA-708 captions, for a total of 9600 bit/s. The ATSC A/53 Standard contains the encoding specifics. The main form of signalling is via a PSIP caption descriptor which indicates the language of each caption and if formatted for "easy reader" (3rd grade level for language learners) in the PSIP EIT on a per event basis and optionally in the H.222 PMT only if the video always sends caption data. CEA-708 caption decoders are required in the U.S. by FCC regulation in all 13" (33 cm) diagonal or larger digital televisions. Further, some broadcasters are required by FCC regulations to caption a percentage of their broadcasts.
  • 2.9K
  • 20 Oct 2022
Topic Review
Wittig Reactions under Sonication Conditions
Carbonyl olefinations are among the most important organic syntheses that form C=C bonds, as they usually have high yields and in addition offer excellent stereoselectivity. Due to these advantages, carbonyl olefinations have important pharmaceutical and industrial applications. These reactions contain an additional step of an α-functionalized carbanion to an aldehyde or ketone to produce alkenes, but syntheses performed using metal carbene complexes are also known. The Wittig reaction is an example of carbonyl olefination, one of the best ways to synthesize alkenes.
  • 2.9K
  • 28 Jun 2023
Topic Review
Propellant Depot
An orbital propellant depot is a cache of propellant that is placed in orbit around Earth or another body to allow spacecraft or the transfer stage of the spacecraft to be fueled in space. It is one of the types of space resource depots that have been proposed for enabling infrastructure-based space exploration. Many different depot concepts exist depending on the type of fuel to be supplied, location, or type of depot which may also include a propellant tanker that delivers a single load to a spacecraft at a specified orbital location and then departs. In-space fuel depots are not necessarily located near or at a space station. Potential users of in-orbit refueling and storage facilities include space agencies, defense ministries and communications satellite or other commercial companies. Satellite servicing depots would extend the lifetime of satellites that have nearly consumed all of their orbital maneuvering fuel and are likely placed in a geosynchronous orbit. The spacecraft would conduct a space rendezvous with the depot, or vice versa, and then transfer propellant to be used for subsequent orbital maneuvers. In 2011, Intelsat showed interest in an initial demonstration mission to refuel several satellites in geosynchronous orbit, but all plans have been since scrapped. A low earth orbit (LEO) depot's primary function would be to provide propellant to a transfer stage headed to the moon, Mars, or possibly a geosynchronous orbit. Since all or a fraction of the transfer stage propellant can be off-loaded, the separately launched spacecraft with payload and/or crew could have a larger mass or use a smaller launch vehicle. With a LEO depot or tanker fill, the size of the launch vehicle can be reduced and the flight rate increased—or, with a newer mission architecture where the beyond-Earth-orbit spacecraft also serves as the second stage, can facilitate much larger payloads—which may reduce the total launch costs since the fixed costs are spread over more flights and fixed costs are usually lower with smaller launch vehicles. A depot could also be placed at Earth-Moon Lagrange point 1 (EML-1) or behind the Moon at EML-2 to reduce costs to travel to the moon or Mars. Placing a depot in Mars orbit has also been suggested.
  • 2.9K
  • 22 Nov 2022
Topic Review
Machine Learning and Student Performance Prediction
Improving the quality, developing and implementing systems that can provide advantages to students, and predicting students’ success during the term, at the end of the term, or in the future are some of the primary aims of education. Due to its unique ability to create relationships and obtain accurate results, artificial intelligence and machine learning are tools used in this field to achieve the expected goals.
  • 2.9K
  • 08 Dec 2021
Topic Review
One-Carbon Metabolism Modulates Ageing and Neurodegeneration
One-carbon metabolism (OCM) is a network of biochemical reactions delivering one-carbon units to various biosynthetic pathways. The folate cycle and methionine cycle are the two key modules of this network that regulate purine and thymidine synthesis, amino acid homeostasis, and epigenetic mechanisms. Intersection with the transsulfuration pathway supports glutathione production and regulation of the cellular redox state. Dietary intake of micronutrients, such as folates and amino acids, directly contributes to OCM, thereby adapting the cellular metabolic state to environmental inputs. The contribution of OCM to cellular proliferation during development and in adult proliferative tissues is well established. Nevertheless, accumulating evidence reveals the pivotal role of OCM in cellular homeostasis of non-proliferative tissues and in coordination of signaling cascades that regulate energy homeostasis and longevity. 
  • 2.9K
  • 12 Jan 2022
Topic Review
Phthalic Acid Esters
Phthalic acid esters (PAEs) are a class of lipophilic chemicals widely used as plasticizers and additives to improve various products’ mechanical extensibility and flexibility. At present, synthesized PAEs, which are considered to cause potential hazards to ecosystem functioning and public health, have been easily detected in the atmosphere, water, soil, and sediments; PAEs are also frequently discovered in plant and microorganism sources, suggesting the possibility that they might be biosynthesized in nature.
  • 2.9K
  • 29 Jul 2021
Topic Review
Entropy and Banks' Income Diversification
We collected data pertaining to Chinese listed commercial banks from 2008 to 2016 and found that the competition between banks is becoming increasingly fierce. Commercial banks have actively carried out diversification strategies for greater returns, and the financial reports show that profits are increasingly coming from the non-interest income benefits of diversification strategies. However, diversification comes with risk. We built a panel threshold model and investigated the effect of income diversification on a bank’s profitability and risk. Diversification was first measured by the Herfindahl–Hirschman index (HHI), and the results show that there is a nonlinear relationship between diversification and profitability or risk does exist. We introduced an interesting index based on the entropy to test the robustness of our model and found that a threshold effect exists in both our models, which is statistically significant. We believe the combination of the entropy index (ENTI) and the HHI enables more efficient study of the relationship between diversification and profitability or risk more efficiently. Bankers and their customers have increasingly been interested in income diversification, and they value risk as well. We suggest that banks of different sizes should adopt the corresponding diversification strategy to achieve sustainable development.
  • 2.9K
  • 02 Nov 2020
Topic Review
Pectolinarin and Pectolinarigenin
Flavonoids are metabolites widely distributed in plants and commonly present in foods, such as fruits and vegetables. Pectolinarin, which belongs to the flavone subclass, has attracted considerable attention due to its presence in many medicinal plants. It has turned out to be a good biological agent especially due to its antioxidant, anti-inflammatory, antidiabetic, and antitumor activities, evaluated both in vitro and in vivo. Its aglycone, the metabolite pectolinarigenin, is also known for a series of biological properties including anti-inflammatory and antidiabetic effects. In the first overview on the two metabolites here presented, their collection, isolation and the results of their biological evaluation are reported
  • 2.9K
  • 28 Dec 2020
Topic Review
Metal Bis(trimethylsilyl)amides
Metal bis(trimethylsilyl)amides (often abbreviated as metal silylamides) are coordination complexes composed of a cationic metal with anionic bis(trimethylsilyl)amide ligands and are part of a broader category of metal amides. Due to the bulky hydrocarbon backbone metal bis(trimethylsilyl)amide complexes have low lattice energies and are lipophilic . For this reason, they are soluble in a range of nonpolar organic solvents, in contrast to simple metal halides, which only dissolve in reactive solvents. These steric bulky complexes are molecular, consisting of mono-, di-, and tetramers. Having a built-in base, these compounds conveniently react with even weakly protic reagents. The class of ligands and pioneering studies on their coordination compounds were described by Bürger and Wannagat. The ligands are often denoted hmds (e.g. M(N(SiMe3)2)3 = M(hmds)3) in reference to the hexamethyldisilazane from which they are prepared.
  • 2.9K
  • 02 Dec 2022
Topic Review
Ferret
The ferret (Mustela furo) is a domestic species of small mustelid. The only domesticated species in Mustelidae, it is thought to be a descendant of the European polecat, a mammal belonging to the same genus as the weasel, Mustela. Their fur is typically brown, black, white, or mixed. They have an average length of 51 cm (20 in), including a 13 cm (5.1 in) tail, weigh about between 0.7 and 2.0 kg (1.5 and 4.4 lb), and have a natural lifespan of 7 to 10 years. Ferrets are sexually dimorphic predators, with males being substantially larger than females. The history of the ferret's domestication is uncertain, like that of most other domestic animals, but it is likely that they have been domesticated for at least 2,500 years. They are still used for hunting rabbits in some parts of the world, but increasingly they are kept only as pets. Being so closely related to polecats, ferrets easily hybridize with them, and this has occasionally resulted in feral colonies of polecat–ferret hybrids that have caused damage to native fauna, especially in New Zealand. As a result, New Zealand and some other parts of the world have imposed restrictions on the keeping of ferrets. Several other mustelids are also known as ferrets, such as the black-footed ferret, an endangered species native to North America.
  • 2.9K
  • 21 Oct 2022
Topic Review
The Perovskite Solar Cell
Perovskite, an organic–inorganic hybrid material, tends to be a promising light-harvesting material. PSCs (organic-inorganic perovskite solar cells) are considered a significant breakthrough in photovoltaics and have received great attention. Due to the inherent advantage of perovskite thin films that can be fabricated using simple solution techniques at low temperatures, PSCs are regarded as one of the most important low-cost and mass-production prospects.
  • 2.9K
  • 14 Sep 2022
Topic Review
Multiphase Flows
Multiphase flows appear in many industrial and environmental applications (dredging, oil industry, mining industry, cement industry, among others), quite often as two-phase flows, either solid/liquid, liquid/liquid or gas/liquid flows. When we speak about multiphase flows we are referring both to flow in channels or pipes or in other process units. In our studies we have been more directed to multiphase flows in pipes. Being able to model and accurately predict the behaviour of such flows and to monitor, as well, the flows themselves, is of high importance to guarantee a stable flow and to optimize energy consumption, by designing adequately the conveying system, without the need to overdimensioning conveying equipment to avoid, for instance, pipe blockage.
  • 2.9K
  • 28 Jan 2021
Topic Review
Thermochromic Hydrogel Smart Windows
Thermochromic smart windows technology can intelligently regulate indoor solar radiation by changing indoor light transmittance in response to thermal stimulation, thus reducing energy consumption of the building. In recent years, with the development of new energy-saving materials and the combination with practical technology, energy-saving smart windows technology has received more and more attention from scientific research.
  • 2.9K
  • 14 Mar 2022
Topic Review Peer Reviewed
Health-Promoting Nature-Based Paradigms in Urban Planning
Since the 19th century, urban planning has largely been guided by ambitions to improve the population’s wellbeing and living conditions. Parks and green areas have played a significant role in this work. However, the confidence in the function of green areas, and thus the motives for creating urban parks and green open spaces, have shifted over the years, which has affected both the planning and design of green areas. This entry describes three overarching paradigm shifts in urban planning, from the end of the 18th century to today, and the focus is on the major paradigm shift that is underway: how green areas can mitigate climate effects, increase biodiversity and at the same time support people’s health and living conditions in a smart city.
  • 2.9K
  • 14 Nov 2023
Topic Review
Chelicerata
The subphylum Chelicerata (from New Latin, from fr chélicère, from grc χηλή (Script error: No such module "Ancient Greek".) 'claw, chela', and κέρας (Script error: No such module "Ancient Greek".) 'horn') constitutes one of the major subdivisions of the phylum Arthropoda. It contains the sea spiders, horseshoe crabs, and arachnids (including harvestmen, scorpions, spiders, solifuges, ticks, and mites, among many others), as well as a number of extinct lineages, such as the eurypterids (sea scorpions) and chasmataspidids. The Chelicerata originated as marine animals in the Middle Cambrian period; the first confirmed chelicerate fossils, belonging to Sanctacaris, date from 508 million years ago. The surviving marine species include the four species of xiphosurans (horseshoe crabs), and possibly the 1,300 species of pycnogonids (sea spiders), if the latter are indeed chelicerates. On the other hand, there are over 77,000 well-identified species of air-breathing chelicerates, and there may be about 500,000 unidentified species. Like all arthropods, chelicerates have segmented bodies with jointed limbs, all covered in a cuticle made of chitin and proteins. The chelicerate body plan consists of two tagmata, the prosoma and the opisthosoma, except that mites have lost a visible division between these sections. The chelicerae, which give the group its name, are the only appendages that appear before the mouth. In most sub-groups, they are modest pincers used to feed. However, spiders' chelicerae form fangs that most species use to inject venom into prey. The group has the open circulatory system typical of arthropods, in which a tube-like heart pumps blood through the hemocoel, which is the major body cavity. Marine chelicerates have gills, while the air-breathing forms generally have both book lungs and tracheae. In general, the ganglia of living chelicerates' central nervous systems fuse into large masses in the cephalothorax, but there are wide variations and this fusion is very limited in the Mesothelae, which are regarded as the oldest and most basal group of spiders. Most chelicerates rely on modified bristles for touch and for information about vibrations, air currents, and chemical changes in their environment. The most active hunting spiders also have very acute eyesight. Chelicerates were originally predators, but the group has diversified to use all the major feeding strategies: predation, parasitism, herbivory, scavenging and eating decaying organic matter. Although harvestmen can digest solid food, the guts of most modern chelicerates are too narrow for this, and they generally liquidize their food by grinding it with their chelicerae and pedipalps and flooding it with digestive enzymes. To conserve water, air-breathing chelicerates excrete waste as solids that are removed from their blood by Malpighian tubules, structures that also evolved independently in insects. While the marine horseshoe crabs rely on external fertilization, air-breathing chelicerates use internal but usually indirect fertilization. Many species use elaborate courtship rituals to attract mates. Most lay eggs that hatch as what look like miniature adults, but all scorpions and a few species of mites keep the eggs inside their bodies until the young emerge. In most chelicerate species the young have to fend for themselves, but in scorpions and some species of spider the females protect and feed their young. The evolutionary origins of chelicerates from the early arthropods have been debated for decades. Although there is considerable agreement about the relationships between most chelicerate sub-groups, the inclusion of the Pycnogonida in this taxon has recently been questioned (see below), and the exact position of scorpions is still controversial, though they were long considered the most basal of the arachnids. Venom has evolved three times in the chelicerates; spiders, scorpions and pseudoscorpions, or four times if the hematophagous secretions produced by ticks are included. In addition there have been undocumented descriptions of venom glands in Solifugae. Chemical defense has been found in whip scorpions, shorttailed whipscorpions, harvestmen, beetle mites and sea spiders. Although the venom of a few spider and scorpion species can be very dangerous to humans, medical researchers are investigating the use of these venoms for the treatment of disorders ranging from cancer to erectile dysfunction. The medical industry also uses the blood of horseshoe crabs as a test for the presence of contaminant bacteria. Mites can cause allergies in humans, transmit several diseases to humans and their livestock, and are serious agricultural pests.
  • 2.9K
  • 18 Oct 2022
Topic Review
Cell Sheet Harvesting Techniques
Cell sheet engineering is an advanced scaffold-free tissue engineering technique applicable to repairing or regenerating defective tissues and organs. It has proven to be an important breakthrough technology in regenerative medicine. 
  • 2.9K
  • 24 Feb 2023
Topic Review
Self-Driving Cars
Self-driving cars are a hot research topic in science and technology, which has a great influence on social and economic development. Deep learning is one of the current key areas in the field of artificial intelligence research. It has been widely applied in image processing, natural language understanding, and so on. In recent years, more and more deep learning-based solutions have been presented in the field of self-driving cars and have achieved outstanding results. This paper presents a review of recent research on theories and applications of deep learning for self-driving cars. This survey provides a detailed explanation of the developments of self-driving cars and summarizes the applications of deep learning methods in the field of self-driving cars. Then the main problems in self-driving cars and their solutions based on deep learning methods are analyzed, such as obstacle detection, scene recognition, lane detection, navigation and path planning. In addition, the details of some representative approaches for self-driving cars using deep learning methods are summarized. Finally, the future challenges in the applications of deep learning for self-driving cars are given out.
  • 2.9K
  • 29 Jan 2021
Topic Review
Control System Design for Collaborative Robots
Human–robot collaboration is an innovative area aiming to construct an environment for safe and efficient collaboration between humans and robots to accomplish a specific task. Collaborative robots cooperate with humans to assist them in undertaking simple-to-complex tasks in several fields, including industry, education, agriculture, healthcare services, security, and space exploration. These robots play a vital role in the revolution of Industry 4.0, which defines new standards of manufacturing and the organization of products in the industry. Incorporating collaborative robots in the workspace improves efficiency, but it also introduces several safety risks.
  • 2.9K
  • 30 Jan 2023
Topic Review
Social Inclusion in Sport for People with Disabilities
The concept and practice of social inclusion in sport are still undefined, causing confusion both in the field of sport policy and practice. According to the United Nations (UN), a conceptual and analytical work on what constitutes inclusion is needed.
  • 2.9K
  • 24 Aug 2023
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