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Topic Review
Armenian Highlands
The Armenian Highlands (Armenian: Հայկական լեռնաշխարհ, romanized: Haykakan leṙnašxarh; also known as the Armenian Upland, Armenian plateau, or Armenian tableland) is the most central and the highest of the three plateaus that together form the northern sector of Western Asia. Clockwise starting from the west, the Armenian Highlands are bounded by the Anatolian plateau, the Caucasus, the Kura-Aras lowlands, the Iranian Plateau, and Mesopotamia. The highlands are divided into western and eastern regions, defined by the Ararat Valley where Mount Ararat is located. Western Armenia is nowadays referred to as eastern Anatolia, and Eastern Armenia as the Lesser Caucasus or Caucasus Minor, and historically as the Anti-Caucasus, meaning "opposite the Caucasus". During the Iron Age, the region was known by variations of the name Ararat (Urartu, Uruatri, Urashtu). Later, the Highlands were known as Armenia Major, a central region to the history of Armenians, and one of the four geopolitical regions associated with Armenians, the other three being Armenia Minor, Sophene, and Commagene. The population of the region has been primarily Armenian for most of its known history. Prior to the appearance of nominally Armenian people in historical records, historians have hypothesized that the region must have been home to various ethnic groups who became homogenous when the Armenian language came to prominence. The population of the Armenian Highlands seem to have had a high level of regional genetic continuity for over 6,000 years. Recent studies have shown that the Armenian people are indigenous to the Armenian Highlands and form a distinct genetic isolate in the region. The region was also inhabited during Antiquity by minorities such as Assyrians, Georgians, Greeks, Jews, and Iranians. During the Middle Ages, Arabs and particularly Turkmens and Kurds settled in large numbers in the Armenian Highlands. The Christian population of the western half of the region was exterminated during the Armenian genocide of 1915. Today, the eastern half is mainly inhabited by Armenians, Azerbaijanis and Georgians, while the western half is mainly inhabited by Kurds (including Yazidis), Turks, Azerbaijanis, Armenians (included crypto-Armenians and Hemshins) and Zazas. The region was administered for most of its known history by Armenian nobility and states, whether it was as part of a fully independent Armenian state, as vassals, or as part of a foreign state. Since the 1040s, the highlands have been under the rule of various Turkic peoples and the Safavid dynasty, with pockets of Armenian autonomy in places such as Artsakh. Much of Eastern Armenia, which had been ruled by the Safavids from the 16th century, became part of the Russian Empire in 1828 and was later incorporated into the Soviet Union, while much of Western Armenia was under the rule of the Ottoman Empire and later incorporated into Turkey. Today, the region is divided between Turkey, Georgia, Armenia, Azerbaijan and Iran.
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  • 07 Nov 2022
Biography
Rick Santorum
Richard John Santorum (born May 10, 1958) is an American politician, attorney, and political commentator. A member of the Republican Party, he served as a United States senator from Pennsylvania from 1995 to 2007 and was the Senate's third-ranking Republican from 2001 to 2007. Santorum ran for the 2012 Republican presidential nomination, finishing second to Mitt Romney. In January 2017, he becam
  • 3.8K
  • 24 Nov 2022
Topic Review
Sustainability Vision Theory
Sustainability vision theory means a vision should convey enduring values and a lasting higher-order purpose, so as to guide employees and all other stakeholders to what is really meaningful to them in their path toward realizing the vision. Strong, productive culture always starts with a vision statement. When a vision statement is genuine and simply displayed prominently, it can assist in orienting stakeholders toward achieving the vision. In doing so, corporate sustainability strategies should be formulated according to the vision. Certainly, the strategic focus is on maximizing values to a wide range of stakeholders. A vision statement as a leadership tool reflects a clear indication whether organizational leaders care about strategic sustainability. Indeed, ensuring corporate sustainability requires an integration of the two dimensions of society and environment into the vision, culture and operations, which suggests a large-scale transformation is needed, as these two dimensions are not often taken into account in organizational visions.
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  • 09 Jul 2021
Topic Review
IEEE 802.11ax-2021
IEEE 802.11ax-2021 or 802.11ax is an IEEE standard for wireless local-area networks (WLANs) and the successor of 802.11ac. It is marketed as Wi-Fi 6 (2.4 GHz and 5 GHz) and Wi-Fi 6E (6 GHz) by the Wi-Fi Alliance. It is also known as High Efficiency Wi-Fi, for the overall improvements to Wi-Fi 6 clients under dense environments. It is designed to operate in license-exempt bands between 1 and 7.125 GHz, including the 2.4 and 5 GHz bands already in common use as well as the much wider 6 GHz band (5.925–7.125 GHz in the US). The main goal of this standard is enhancing throughput-per-area[lower-alpha 1] in high-density scenarios, such as corporate offices, shopping malls and dense residential apartments. While the nominal data rate improvement against 802.11ac is only 37%,:qt the overall throughput improvement (over an entire network) is 400% (hence High Efficiency).:qt This also translates to 75% lower latency. The quadruplication of overall throughput is made possible by a higher spectral efficiency. The key feature underpinning 802.11ax is orthogonal frequency-division multiple access (OFDMA), which is equivalent to cellular technology applied into Wi-Fi.:qt Other improvements on spectrum utilization are better power-control methods to avoid interference with neighboring networks, higher order 1024‑QAM, up-link direction added with the down-link of MIMO and MU-MIMO to further increase throughput, as well as dependability improvements of power consumption and security protocols such as Target Wake Time and WPA3. The IEEE 802.11ax-2021 standard was approved in February 9th, 2021.
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  • 11 Nov 2022
Topic Review
The Composition and Structure of Silk Fibroin
Silk fibroin is the principal component of raw silk and represents an extensively studied and utilized biopolymer. Silk fibroin is composed by three chains, light, heavy, and P25 protein. Heavy chain is rigorously organized in redundant aminoacidic sequences rich in glycine and alanine, secondary structure is organized in anti-parallel β-sheets that in turn form β-crystallites stacked in nano-fibrils. Those peculiar fibroin’s structural and compositional elements are crucial to determine the excellent physical properties, such as strength and toughness. Besides these characteristics, the processability and biocompatibility have attracted significant attention for the fabrication of several biomaterials suitable in many fields of application.
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  • 20 Mar 2024
Topic Review
Impacts of Lighting on Psychology, Physiology, and Productivity
People spend almost 90% of their time in indoor environments. Indoor environment quality has begun to play a more important role in people’s daily lives. The impact on occupants of various environmental factors of buildings has been actively studied. Among them, lighting conditions have been shown to have a significant influence on all aspects of human life and health.
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  • 30 Jun 2022
Topic Review
Paleo-Hebrew Leviticus Scroll
Paleo-Hebrew Leviticus scroll, known also as 11QpaleoLev, is an ancient text preserved in one of the Qumran group of caves, and which provides a rare glimpse of the script used formerly by the nation of Israel in writing Torah scrolls during its pre-exilic history. The fragmentary remains of the Torah scroll is written in the Paleo-Hebrew script and was found stashed-away in a cave at Qumran, showing a portion of Leviticus. The scroll is thought to have been penned by the scribe between the late 2nd-century BCE to early 1st-century BCE, while others place its writing in the 1st-century CE. The Paleo-Hebrew Leviticus scroll, although many centuries more recent than the well-known earlier ancient paleo-Hebrew epigraphic materials, such as the Royal Steward inscription from Siloam, Jerusalem (eighth century BCE), now in the Museum of the Ancient Orient, Istanbul, and the Phoenician inscription on the sarcophagus of King Eshmun-Azar at Sidon, dating to the fifth-fourth century BCE, the Lachish ostraca (ca. 6th-century BCE), the Gezer calendar (ca. 950–918 BCE), and the paleo-Hebrew sacerdotal blessing discovered in 1979 near the St Andrew's Church in Jerusalem, is of no less importance to palaeography - even though the manuscript is fragmentary and only partially preserved on leather parchment. Today, the paleo-Hebrew Leviticus scroll (11QpaleoLev) is housed at the Israel Antiquities Authority (IAA), but is not on public display.
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  • 09 Oct 2022
Topic Review
Metabolic Equivalent
The Metabolic Equivalent of Task (MET), or simply metabolic equivalent, is a physiological measure expressing the energy cost of physical activities and is defined as the ratio of metabolic rate (and therefore the rate of energy consumption) during a specific physical activity to a reference metabolic rate, set by convention to 3.5 ml O2·kg−1·min−1 or approximately: [math]\displaystyle{ \text{1 MET}\ = 1 \dfrac{\text{kcal}}{\text{kg}*\text{h}}\ = 4.184 \dfrac{\text{kJ}}{\text{kg}*\text{h}} = 1.1622222... \dfrac{\text{W}}{\text{kg}} }[/math] Still another definition of 1 MET is 58.2 W/m2 (18.4 Btu/h·ft2), which is equal to the rate of energy produced per unit surface area of an average person seated at rest. The surface area of an average person is 1.8 m2 (19 ft2). Metabolic rate is usually expressed in terms of unit area of the total body surface (ANSI/ASHRAE Standard 55). Originally, 1 MET was considered as the Resting Metabolic Rate (RMR) obtained during quiet sitting. MET values of activities range from 0.9 (sleeping) to 23 (running at 22.5 km/h or a 4:17 mile pace). Although the RMR of any person may deviate from the reference value, MET can be thought of as an index of the intensity of activities: for example, an activity with a MET value of 2, such as walking at a slow pace (e.g., 3 km/h) would require twice the energy that an average person consumes at rest (e.g., sitting quietly). MET is used as a means of expressing the intensity and energy expenditure of activities in a way comparable among persons of different weight. Actual energy expenditure (e.g., in calories or joules) during an activity depends on the person's body mass; therefore, the energy cost of the same activity will be different for persons of different weight. However, since the RMR is also dependent on body mass in a similar way, it is assumed that the ratio of this energy cost to the RMR of each person will remain more or less stable for the specific activity and thus independent of each person's weight. The 1 MET reference value of 1 kcal·kg−1·h−1, is used by convention and refers to a typical metabolism at rest of an "average" individual. It is not an approximation of Basal Metabolic Rate (BMR), which is the minimum metabolic rate obtained under specified conditions. This is illustrated by sleeping having a MET of 0.9, while an individual's normal sleeping metabolism may be greater than the BMR.
  • 3.8K
  • 14 Oct 2022
Topic Review
Collagen in Wound Healing
Collagens are the most abundant protein found throughout the body. In the healing wound, these collagens are synthesized by cells such as fibroblasts and modified into complex morphologies . The type, amount and organization of collagen changes in the healing wound and determines the tensile strength of the healed skin. Collagen III is the first to be synthesized in the early stages of wound healing and is replaced by collagen I, the dominant skin collagen. The initial random deposition of collagen during the granulation tissue formation is further enhanced by lysyl oxidase enzyme-induced covalent cross-linking. This process matures the collagen into complex structures that are reoriented for tensile strength restoration. Collagen remodeling continues for months after wound closure and the tensile strength of the repaired tissue increases to about 80–85% of normal tissue if all processes proceed without any perturbations.In the skin, the fibrillar collagens types I, III and V are the most common, followed by fibril-associated collagens type XII, XIV, XVI, and VI. The non-fibrillar collagens type IV, XVIII are found in the basement membrane of the skin
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  • 23 Jun 2021
Topic Review
Mechanical Properties and Microstructure of Ti6Al4V by LPBF
Ti6Al4V alloy is an ideal lightweight structural metal for a huge variety of engineering applications due to its distinguishing combination of high specific mechanical properties, excellent corrosion resistance and biocompatibility. Laser Powder Bed Fusion (LPBF) provides very different mechanical properties from that of casting or wrought Ti6Al4V. The inherent specificities of the LPBF process, as the layer-by-layer building strategy; the powder feedstock; the melting phenomena and thermal gradients, define the mechanical properties, once they will dictate the microstructural features (e.g. grain size, crystal growth direction, residual porosity and defects, among other). 
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  • 16 Jun 2022
Topic Review
Environmental Hydraulics
Environmental Hydraulics (EH) is the scientific study of environmental water flows and their related transport and transformation processes in natural water systems. 
  • 3.8K
  • 14 Apr 2021
Topic Review
Amadori Rearrangement Products
Flavor is one of the most important factors in attracting consumers and maximizing food quality, and the Maillard reaction (MR) is highly-involved in flavor formation. However, Maillard reaction products have a big drawback in their relatively low stability in thermal treatment and storage. Amadori rearrangement products (ARPs), MR intermediates, can alternatively act as potential flavor additives for their better stability and fresh flavor formation ability.
  • 3.8K
  • 18 Jan 2023
Topic Review
Aryl-hydrocarbon Receptor
The aryl-hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates numerous cellular responses. Originally investigated in toxicology because of its ability to bind environmental contaminants, AhR has attracted enormous attention in the field of immunology in the last 20 years. In addition, the discovery of endogenous and plant-derived ligands points to AhR also having a crucial role in normal cell physiology. Thus, AhR is emerging as a promiscuous receptor that can mediate either toxic or physiologic effects upon sensing multiple exogenous and endogenous molecules. Within this scenario, several factors appear to contribute to the outcome of gene transcriptional regulation by AhR, including the nature of the ligand as such and its further metabolism by AhR-induced enzymes, the local tissue microenvironment, and the presence of coregulators or specific transcription factors in the cell.
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  • 07 Dec 2021
Topic Review
Sonic Hedgehog
Sonic hedgehog is a protein encoded for by the SHH gene. The protein is named after the character Sonic the Hedgehog. This signaling molecule is key in regulating embryonic morphogenesis in all different types of animals. SHH controls organogenesis and the organization of the central nervous system, limbs, digits and many other parts of the body. Sonic hedgehog is a morphogen that patterns the developing embryo using a concentration gradient characterized by the French Flag model. This model has a non-uniform distribution of SHH molecules which governs different cell fates according to concentration. Mutations in this gene can cause holoprosencephaly, a failure of splitting in the cerebral hemispheres, as demonstrated in an experiment using SHH knock-out mice in which the forebrain midline failed to develop and instead only a single fused telencephalic vesicle resulted. Sonic hedgehog still plays a role in differentiation, proliferation, and maintenance of adult tissues. Abnormal activation of SHH signaling in adult tissues has been implicated in various types of cancers including breast, skin, brain, liver, gallbladder and many more.
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  • 21 Nov 2022
Topic Review
Ptah
In Egyptian mythology, Ptah (/pəˈtɑː/; Ancient Egyptian: ptḥ, reconstructed [piˈtaħ]; Ancient Greek:; Coptic: ⲡⲧⲁϩ) is the demiurge of Memphis, god of craftsmen and architects. In the triad of Memphis, he is the husband of Sekhmet and the father of Nefertum. He was also regarded as the father of the sage Imhotep.
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  • 22 Nov 2022
Topic Review
Citrus Uses in the Food Industry
Citrus fruits occupy an important position in the context of the fruit trade, considering that both fresh fruits and processed products are produced on a large scale. Citrus fruits are recognized as an essential component of the human diet, thanks to their high content of beneficial nutrients such as vitamins, minerals, terpenes, flavonoids, coumarins and dietary fibers. Among these, a wide range of positive biological activities are attributed to terpenes and flavonoids derivatives.
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  • 03 Mar 2023
Topic Review
Potato Virus Y
Potato virus Y origin, emergence and evolution.
  • 3.8K
  • 21 Dec 2020
Topic Review
Vinaya
The Vinaya (Pali & Sanskrit) is the division of the Buddhist canon (Tripitaka) containing the rules and procedures that govern the Buddhist monastic community, or sangha. Three parallel Vinaya traditions remain in use by modern monastic communities: the Theravada (Sri Lanka & Southeast Asia), Mulasarvastivada (Tibetan Buddhism and the Himalayan region) and Dharmaguptaka (East Asian Buddhism). In addition to these Vinaya traditions, Vinaya texts of several extinct schools of Indian Buddhism are preserved in the Tibetan and East Asian canons, including those of the Kāśyapīya, the Mahāsāṃghika, the Mahīśāsaka, and the Sarvāstivāda The word Vinaya is derived from a Sanskrit verb that can mean to lead, take away, train, tame, or guide, or alternately to educate or teach. It is often translated as 'discipline', with Dhamma-vinaya, 'doctrine and discipline', used by the Buddha to refer to his complete teachings, suggesting its integral role in Buddhist practice.
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  • 08 Oct 2022
Topic Review
Prospective Memory
Prospective memory is a form of memory that involves remembering to perform a planned action or recall a planned intention at some future point in time. Prospective memory tasks are common in daily life and range from the relatively simple to extreme life-or-death situations. Examples of simple tasks include remembering to put the toothpaste cap back on, remembering to reply to an email, or remembering to return a rented movie. Examples of highly important situations include a patient remembering to take medication or a pilot remembering to perform specific safety procedures during a flight. In contrast to prospective memory, retrospective memory involves remembering people, events, or words that have been encountered in the past. Whereas retrospective memory requires only the recall of past events, prospective memory requires the exercise of retrospective memory at a time that has not yet occurred. Prospective memory is thus considered a form of "memory of the future". Retrospective memory involves the memory of what we know, containing informational content; prospective memory focuses on when to act, rather than focusing on informational content. There is some evidence demonstrating the role of retrospective memory in the successful execution of prospective memory, but this role seems to be relatively small.
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  • 30 Oct 2022
Topic Review
Chemical Composition of Kombucha
Kombucha is a fermented sweetened tea with a mixed fermenting culture of yeast and acetic acid bacteria. The proponents of kombucha consumption tout the varied health benefits it can provide. The final kombucha flavor and composition is a function of both the initial tea used and the fermentation process.
  • 3.8K
  • 29 Aug 2022
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