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Atlantic cod

The Atlantic cod is a benthopelagic fish of the family Gadidae consumed by humans. It is commercially known as cod or codling. Dry cod may be prepared as as cured salt cod or clipfish. In the western Atlantic Ocean, cod has a distribution north of Cape Hatteras, North Carolina, around both coasts of Greenland and the Labrador Sea; the largest individual on record was 1.8 m long and weighed 96 kg, but the cod is between 61 cm and 1.2 m long and weighs up to 40 kg. Males and females are similar in weight. Atlantic cod can live for 25 years, attain sexual maturity between ages two and four, although cod in the northeast Arctic can take as long as eight years to mature fully. Colouring is green, with spots on the dorsal side, shading to silver ventrally. A stripe along its lateral line is visible, its habitat ranges from the coastal shoreline down to 305 m along the continental shelf. Several cod stocks collapsed in the 1990s and have failed to recover with the cessation of fishing; this absence of the apex predator has led to a trophic cascade in many areas.

Many other cod stocks remain at risk. The Atlantic cod is labelled vulnerable on the IUCN Red List of Threatened Species. Adult cod form spawning aggregations from late winter to spring. Females release their eggs in batches, males compete to fertilize them. Fertilized eggs develop into larvae. Age of maturation varies between cod stocks, from ages two to four in the west Atlantic, but as late as eight years in the northeast Arctic. Cod can live for 13 years or more; the Atlantic cod is one of three cod species in the genus Gadus along with Pacific cod and Greenland cod. A variety of fish species are colloquially known as cod, but they are not all classified within the Gadus, though some are in the Atlantic cod family, Gadidae. Atlantic cod are a shoaling move in large, size-structured aggregations. Larger fish act as scouts and lead the shoal's direction during post spawning migrations inshore for feeding. Cod feed during migration and changes in shoal structure occur when food is encountered. Shoals are thought to be leaderless, with all fish having equal status and an equal distribution of resources and benefits.

However, some studies suggest. One study of a migrating Atlantic cod shoal showed significant variability in feeding habits based on size and position in the shoal. Larger scouts consumed a more variable, higher quantity of food, while trailing fish had less variable diets and consumed less food. Fish distribution throughout the shoal seems to be dictated by fish size, the smaller lagging fish benefit from shoaling because they are more successful in feeding in the shoal than they would be if migrating individually, due to social facilitation. Atlantic cod are apex predators in the Baltic and adults are free from the concerns of predation. Juvenile cod, may serve as prey for adult cod, which sometimes practice cannibalism. Juvenile cod make substrate decisions based on risk of predation. Substrates refer to different swimming environments. Without apparent risk of predation, juvenile cod demonstrated a preference for finer-grained substrates such as sand and gravel-pebble. However, in the presence of a predator, they preferred to seek safety in the space available between stones of a cobble substrate.

Selection of cobble reduces the risk of predation. Without access to cobble, the juvenile cod tries to escape a predator by fleeing. Additionally, juvenile Atlantic cod vary their behaviour according to the foraging behaviour of predators. In the vicinity of a passive predator, cod behaviour changes little; the juveniles prefer finer-grained substrates and otherwise avoid the safer kelp, steering clear of the predator. In contrast, in the presence of an foraging predator, juveniles are avoidant and hide in cobble or in kelp if cobble is unavailable. Heavy fishing of cod in the 1990s and the collapse of American and Canadian cod stocks resulted in trophic cascades; as cod are apex predators, overfishing them removed a significant predatory pressure on other Atlantic fish and crustacean species. Population-limiting effects on several species including American lobsters and shrimp from cod predation have decreased and the abundance of these species and their increasing range serve as evidence of the Atlantic cod's role as a major predator rather than prey.

Atlantic cod have been recorded to swim at speeds of a minimum of 2–5 cm/s and a maximum of 21–54 cm/s with a mean swimming speed of 9–17 cm/s. In one hour, cod have been recorded to cover a mean range of 99 to 226 m2. Swimming speed was higher during the day than at night; this is reflected in the fact that cod more search for food during the day. Cod modify their activity pattern according to the length of daylight, thus activity varies with time of year. Swimming and physiological behaviours change in response to fluctuations in water temperature. Respirometry experiments show that heart rates of Atlantic cod change drastically with changes in temperature of only a few degrees. A rise in water temperature causes marked increases in cod swimming activity. Cod avoid new temperature conditions, the te

Yevpatoria RT-70 radio telescope

The Yevpatoria RT-70 radio telescope is an RT-70 radio telescope and planetary radar at the Center for Deep Space Communications, Crimea. In the scientific literature is called Evpatoria Planetary Radar. With its 70-meter antenna diameter, it is among the largest single dish radio telescopes in the world, it has an advantage in comparison with other large radio telescopes in the fact that the complex includes powerful transmitters that allow active space experiments. Powerful electromagnetic beams can be targeted and the signals received can be analyzed. For this reason, the Yevpatoria RT-70 radio telescope is one of only two in the world that are able to transmit messages to extraterrestrial civilizations, i.e. the multiple Cosmic Calls, Teen Age Messages or AMFE. Radio telescopes are sensitive detectors of signals from outer space; the radiotelescope is depicted on Russia's commemorative 100-ruble banknote of 2015. The telescope has participated in Soviet space program since 1978 for the exploration of deep space: Venera 11 and Venera 12 VLBI Salyut 6 KRT-10 radio observatory — RT-70 Venera 13, Venera 14, Venera 15, Venera 16 Vega program Astron Phobos program Granat Interball Fobos-Grunt Spektr-RIn 1999, 2001, 2003, 2008, transmit messages to extraterrestrial civilizations: Cosmic Call Teen Age Message Cosmic Call 2 A Message From EarthRadar studies of planets and asteroids.

Observatory code 255. 4179 Toutatis 6489 Golevka. 1998 WT24 1999 RQ36 Goldstone Deep Space Communications Complex Galenki RT-70 radio telescope – at the Ussuriysk Astrophysical Observatory Suffa RT-70 radio telescope – at the Suffa Radio Observatory Complex “Pluton-M” – at Center for Deep Space Communications Радиотелескоп РТ-70 National Space Facilities Control and Testing Center, Eupatoria 3D Maker version

Lineatin

Lineatin is a pheromone produced by female striped ambrosia beetle, Trypodendron lineatum Olivier. These kinds of beetles are responsible for extensive damage of coniferous forest infestation in Europe and North America. Since lineatin can act as lures used for mass-trapping of T. lineatum, it is being studied to apply as a pest control reagent. Lineatin was first isolated in 1977 by MacConnell; the absolute configuration of the biologically active form was determined as --3,3,7-trimethyl-2,9- dioxatricyclononane, whereas other enatinomers process no biological attraction activity. After the absolute structure was determined, lineatin attracted considerable synthetic interests due to its natural occurrence, biological activity, unique structural features. A few routes describing the total synthesis of lineatin was proposed with yields of 0.5–2%. A new total synthesis route that adopted a photochemical cycloaddition approach to construct diastereoselective cyclobutene and a regiocontrolled oxymercuration reaction was proposed.

This route achieved in synthesizing pure -lineatin through 14 steps and resulted in 14% overall yield from a homochiral 2-furanone.. Lineatin is a monoterprene with unique tricyclic acetal structure. Most of the studies regarding lineatin were focused on the total synthesis, it is suggested that lineatin is derived through oxidation and cyclization of a monoterponid precursor, but no experimental has been done on proving this route. Based on its partial structure similarity to iridoid class of terprenoids, here, a possible biosynthesis pathway was proposed and outlined in figure 2