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Electrical Penetration Graph
The electrical penetration graph or EPG is a system used by biologists to study the interaction of insects such as aphids, thrips, and leafhoppers with plants. Therefore, it can also be used to study the basis of plant virus transmission, host plant selection by insects and the way in which insects can find and feed from the phloem of the plant. It is a simple system consisting of a partial Electronic circuit, circuit which is only completed when a species such as aphids, which are the most abundantly studied, inserts its stylet (anatomy), stylet into the plant in order to ''probe'' the plant as a suitable host for feeding. The completed circuit is displayed visually as a graph with different waveforms indicating either different insect activities such as saliva excretion or the ingestion of cellular contents or indicating which tissue type has been penetrated (i.e. phloem, xylem or Leaf#Mesophyll, mesophyll). So far, around ten different graphical waveforms are known, correlating wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orosius Orientalis EPG
Paulus Orosius (; born 375/385 – 420 AD), less often Paul Orosius in English language, English, was a Western Roman Empire, Roman priest, historian and theology, theologian, and a student of Augustine of Hippo. It is possible that he was born in ''Bracara Augusta'' (now Braga, Portugal), then capital of the Roman province of Gallaecia, which would have been the capital of the Kingdom of the Suebi by his death. Although there are some questions regarding his biography, such as his exact date of birth, it is known that he was a person of some prestige from a cultural point of view, as he had contact with the greatest figures of his time such as Augustine of Hippo and Jerome of Stridon. In order to meet with them Orosius travelled to cities on the southern coast of the Mediterranean Sea, such as Hippo Regius, Alexandria, and Jerusalem. These journeys defined his life and intellectual output. Orosius did not just discuss theological matters with Augustine; he also collaborated wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platinum
Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarer elements in Earth's crust, with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for ~80% of the world production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it is highly valuable and is a major precious metal commodity. Platinum is one of the least reactive metals. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entomology Equipment
Entomology () is the scientific study of insects, a branch of zoology. In the past the term "insect" was less specific, and historically the definition of entomology would also include the study of animals in other arthropod groups, such as arachnids, myriapods, and crustaceans. This wider meaning may still be encountered in informal use. Like several of the other fields that are categorized within zoology, entomology is a taxon-based category; any form of scientific study in which there is a focus on insect-related inquiries is, by definition, entomology. Entomology therefore overlaps with a cross-section of topics as diverse as molecular genetics, behavior, neuroscience, biomechanics, biochemistry, systematics, physiology, developmental biology, ecology, morphology, and paleontology. Over 1.3 million insect species have been described, more than two-thirds of all known species. Some insect species date back to around 400 million years ago. They have many kinds of interact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. Their blood is not totally contained in vessels; some circulates in an open cavity known as the haemocoel. Insects are the most diverse group of animals; they include more than a million described species and represent more than half of all known living organisms. The total number of extant species is estimated at between six and ten million; In: potentially over 90% of the animal life forms on Earth are insects. Insects may be found in nearly all environments, although only a small number of species reside in the oceans, which are dominated by another arthropod group, crustaceans, which recent research has indicated insects are nested within. Nearly all insects hatch from eggs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphididae
The Aphididae are a very large insect family in the aphid superfamily ( Aphidoidea), of the order Hemiptera. These insects suck the sap from plant leaves. Several thousand species are placed in this family, many of which are considered plant/crop pests. They are the family of insects containing most plant virus vectors (around 200 known) with the green peach aphid ('' Myzus persicae'') being one of the most prevalent and indiscriminate carriers. Evolution Aphids originated in the late Cretaceous about (Mya), but the Aphidinae which comprises about half of the 4700 described species and genera of aphids alive today come from their most recent radiation which occurred in the late Tertiary less than 10 Mya.Von Dohlen CD, Moran NA (2000) Molecular data support a rapid radiation of aphids in the Cretaceous and multiple origins of host alternation. Biol J Linnean Soc 71: 689–717Von Dohlen CD, Rowe CA, Heie OE (2006) A test of morphological hypotheses for tribal and subtribal relat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidemiology
Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decisions and evidence-based practice by identifying risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results (including peer review and occasional systematic review). Epidemiology has helped develop methodology used in clinical research, public health studies, and, to a lesser extent, basic research in the biological sciences. Major areas of epidemiological study include disease causation, transmission, outbreak investigation, disease surveillance, environmental epidemiology, forensic epidemiology, occupational epidemiology, screening, biomonitoring, and comparisons of treatment effects such as in clinical t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Virus
Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. Plant viruses can be pathogenic to higher plants. Most plant viruses are rod-shaped, with protein discs forming a tube surrounding the viral genome; isometric particles are another common structure. They rarely have an envelope. The great majority have an RNA genome, which is usually small and single stranded (ss), but some viruses have double-stranded (ds) RNA, ssDNA or dsDNA genomes. Although plant viruses are not as well understood as their animal counterparts, one plant virus has become very recognizable: ''tobacco mosaic virus'' (TMV), the first virus to be discovered. This and other viruses cause an estimated US$60 billion loss in crop yields worldwide each year. Plant viruses are grouped into 73 genera and 49 families. However, these figures relate only to cultivated plants, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EPG Circuit
Electronic programming guides (EPGs) and interactive programming guides (IPGs) are menu-based systems that provide users of television, radio and other media applications with continuously updated menus that display scheduling information for current and upcoming broadcast programming (most commonly, TV listings). Some guides also feature backward scrolling to promote their catch up content. They are commonly known as guides or TV guides. Non-interactive electronic programming guides (sometimes known as "navigation software") are typically available for television and radio, and consist of a digitally displayed, non-interactive menu of programming scheduling information shown by a cable or satellite television provider to its viewers on a dedicated channel. EPGs are transmitted by specialized video character generation (CG) equipment housed within each such provider's central headend facility. By tuning into an EPG channel, a menu is displayed that lists current and upcoming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplifier
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It may increase the power significantly, or its main effect may be to boost the voltage or current ( power, voltage or current amplifier). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a greater amplitude signal at its output. The ratio of output to input voltage, current, or power is termed gain (voltage, current, or power gain). An amplifier, by definition has gain greater than unity (if the gain is less than unity, the device is an attenuator). An amplifier can either be a separate piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are widely used in almost all electronic equipment. Amplifiers can be cat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resistor
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity. Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in electronic equipment. Practical resistors as discrete components can be composed of various compounds and forms. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gigaohm
Ohm (symbol Ω) is a unit of electrical resistance named after Georg Ohm. Ohm or OHM may also refer to: People * Georg Ohm (1789–1854), German physicist and namesake of the term ''ohm'' * Germán Ohm (born 1936), Mexican boxer * Jörg Ohm (born 1944), former East German football player * Martin Ohm (1792–1872), German mathematician * Rebecca Ohm, United States Air Force officer and fighter pilot * Rune Ohm (born 1980), Danish handball player * Thorsten Ohm, CEO of VDM Publishing * Pawat Chittsawangdee, Thai actor, nicknamed Ohm Places Germany * Ohm (river), right tributary of the Lahn near Cölbe * Zwester Ohm, left tributary of the Lahn near Fronhausen Outer space * 24750 Ohm, an outer main belt asteroid * Ohm (crater) on the Moon Science and technology * Acoustic ohm, a unit of measurement of acoustic impedance * Ohm's law, law that relates electrical resistance, current, and voltage * OHM (Observe. Hack. Make.), a 2013 outdoor hacker conference * OpenHistoricalMap, a coll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal in a pure form. Chemically, gold is a transition metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions. Gold often occurs in free elemental (native state), as nuggets or grains, in rocks, veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium ( gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
