JOURNAL OF ADVANCES IN NATURAL SCIENCES
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Published By Cirworld

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2021 ◽  
Vol 8 ◽  
pp. 39-45
Author(s):  
Robert Glenn Johnson

The extremely heavy precipitation that initiated the Last Ice Age (the Wisconsin Glaciation in Canada) was caused by a strong and persistent atmospheric low-pressure system centered over the northern Labrador Sea and southern Baffin Bay. This system, called the Labrador Low, was dependent on strong deep-water formation in the northern end of Baffin Bay. The replacement for the sinking deep water consisted of warmer and more saline Irminger Current water that mixed into the northward-flowing West Greenland Current near the center of the Labrador Low. The heavy precipitation in northeastern Canada began after the stratification in Baffin Bay was eliminated by the southward flow of denser Atlantic water through the Nares Strait. This temporary flow began when the oscillating Atlantic Meridional Oceanic Circulation (AMOC) flow reached a maximum greater than today. This sent Atlantic water westward, north of Greenland and through the Nares Strait. Although the extremely heavy snowfall began the Wisconsin Glaciation in Canada, the initiation of the Last Ice Age in Eurasia was a more complex process and was delayed by about 4,000 years by formation of the Hudson Strait ice dam.


2021 ◽  
Vol 8 ◽  
pp. 24-38
Author(s):  
Jelena Raukar

This study aimed to determine prevalences for anti-FCoV antibody, FeLV antigen, FeLV proviral DNA, and anti-FIV antibody among client-owned cats from the cities of Zagreb and Varaždin in Croatia. Subjects included 106 client-owned cats tested at the Faculty of Veterinary Medicine, Vienna, Austria. Blood samples were tested with IFA for anti-FCoV antibody and IFA FCoV antibody titeres, with ELISA for FeLV p27 antigen, with PCR for FeLV proviral DNA, and with RIM for anti-FIV antibody. Prevalence of FCoV and FeLV was 41.51% and 6.60%, respectively. A coinfection with FeLV/FCoV and FIV/FCoV prevalence was 7.55% and 5.66%. No cats were coinfected with FIV and FeLV. All three viruses were detected, confirming their presence in Croatia. The seroepidemiological findings demonstrate that both feline retroviruses and feline coronavirus are important feline pathogens in Croatia.


2021 ◽  
Vol 18 ◽  
pp. 1-11
Author(s):  
Robert Glenn Johnson

The Younger Dryas cold climate event in Europe began abruptly at about 12,679 years BP. The abruptness of the onset was caused by the rapid collapse of a dynamic ice dam that had existed because of ice stream flow across the east end of Hudson Strait in northern Canada. The resulting flood of icebergs into the southern half of the Northern Gyre adjacent to the Gulf Stream converted western Europe’s mild climate to an arctic climate. The collapse event was caused by the last large accumulation of glacial ice in the thick ice dome of Hudson Bay. The accumulation created a pressure gradient that forced an ice stream flow eastward in Hudson Strait. A highly saline sub-glacial lake had formed earlier in the western part of the strait. The ice stream flow entrained saline lake water in a network of channels at the seabed between the lake and the ice dam, melting and extending the network eventually to and beneath the ice dam. This detached much of the ice dam from its frozen bed and caused its catastrophic collapse and the onset of the Younger Dryas in only one year.


2020 ◽  
Vol 7 ◽  
pp. 11-18
Author(s):  
Robert G. Johnson

This paper proposes an explanation for the well-watered savanna on the presently barren western Sahara Desert during the mid-Holocene and near the ends of other earlier Canadian deglaciations. Between 7,500 and 4,000 years before present, a humidity index indicates moist conditions and a savanna in the western Sahara. During this interval, a stronger and warmer Canaries Current return flow of the Gulf Stream nullified the effect of cold water that upwells off the northwest African coast due to the westward movement of surface water by trade winds. The return flow was stronger than today because less eastward Gulf Stream flow was lost to the northward flow of the Atlantic Meridional Overturning Current. The Canaries Current was warmer than today because cold southern Canadian meltwater no longer entered the Gulf Stream, and the high latitude climate was warmer then. Similar conditions probably prevailed at the ends of many other deglaciations, which were separated by 20,000 to 70,000 years due to orbital factors and variable glaciation. The savanna connections across the Sahara would have allowed each Hominin population to evolve in the isolated Moroccan-Algerian coastal zone to extend its range into the larger Africa. The intermittent savannas could therefore have played a significant role in the evolution of the many Hominin species found in the African fossil record over the last three million years.


2020 ◽  
Vol 7 ◽  
pp. 1-10
Author(s):  
Prof. RAE. Z.H. Aliyev

The radial growth of the trunks of the following flora species which do not have special protection on the southern hillsides of Greater Caucasus was studied in the article: Georgioan oak- Quercus iberica M.Bieb Common hornbeam - Caprinus betulus L. Common chestnut - Castanea sativa Mill. Black walnut - Juglans nigra L., Heart leaved alder - Alnus subcordata C.A.Mey. During the dendrochronological analyses, the dynamics of growth over the years were analysed based on the distances between the tree rings. The impact of the climatic factors on the growth of the trees was analysed and the ages of tree species were investigated. Based on the dendrochronological historical application, according to the numbers of tree rings, the ages of the trees were defined in the studied species. According to the numbers of tree rings, the oldest type of the rare and scanty flora types which have no special protection was identified as Caprinus betulus L. in the Zagatala region. The tree was taken from Zagatala district, planted in 1944, was 75 years old and had 330 cm diameter. The observation of dendrochronological researches indicates the formation of a new microclimate. It was observed that in the investigated species, radial growth was more intense during matureness, then it was weakened with age. In the comparative analysis, it was observed that the minimum radial growth was in 2010 and 2015, and the maximum growth was between 1973 and 1985 in the Zagatala region


2019 ◽  
Vol 6 ◽  
pp. 490-497
Author(s):  
Prof.RAE. Z.H. Aliyev

The article discusses the issues of scientific and theoretical justification for the use of automated irrigation in agriculture, that these systems can reduce the capital costs of their construction, as well as ensure the principle of "rain" and "drip irrigation" with daily water consumption of plants. There are optimal conditions for the growth and development of plants during their growing season. It is proved that the automated irrigation of agricultural crops establishes high yields and increased labor productivity. Therefore, the elements and devices of the used automatic machine require a reliable and uninterrupted operation. This is due to the fact that the problem is that the problem lies not only in technical reliability but also in economic efficiency. , including micro-irrigation systems. Reliability, performance, and performance. Initially, the existing irrigation technique, stationary irrigation system consisted of a large number of elements of the same type, necessary for conducting field cultural events.


2019 ◽  
Vol 6 ◽  
pp. 484-489
Author(s):  
Dildora Mahmudova ◽  
Master Mashrapov B.O.

Domestic wastewater is an important, from an environmental point of view, sources of pollution of water bodies in the country. They usually account for up to 30 percent of all wastewater discharged into reservoirs [1].


2019 ◽  
Vol 6 ◽  
pp. 467-474
Author(s):  
RAE. Z.H. Aliyev

The study of the world experience and the results of long-term experiments with drip irrigation systems in the Republic in various climatic and soil conditions shows that the creation of irrigation systems of this type is effective and economically profitable when irrigation of various perennial plantations, vegetable, tilled crops, ornamental plantations, nurseries etc. Drip irrigation has almost universal application, in particular, it is applicable where other methods of irrigation can not be used or ineffective: With a complex relief and a large slope of the site (up to 45 degrees or more); In areas with prolonged droughts and constant strong winds; For local water sources with a relatively limited amount of water; On soils with low power and very low or high hygroscopicity; On soils prone to salinity; When used for irrigation of water with a high content of water-soluble salts, etc.


2019 ◽  
Vol 6 ◽  
pp. 475-483
Author(s):  
RAE. Z.H. Aliyev ◽  
B.H. Aliyev

The results of the study revealed that the mismatch intensity rain rate of water absorption into the soil formation of a surface relief and soil erosion, uneven and shallow soaking imperfection open irrigation system at a superficial irrigation, the need for different irrigation methods in the growing and not growing periods, low coefficient land utilization, high cost of irrigation and other features are, to a certain extent in conflict with the requirements of watering cultivated with techniques for / of crops in an area at the deep groundwater


2019 ◽  
Vol 6 ◽  
pp. 444-466
Author(s):  
Robert Glenn Johnson ◽  
Andre Berger

To explain the abundance of species of genus Homo in the fossil record of Africa south of the Sahara, the small Moroccan-Algerian coastal zone that was isolated by the barren Sahara is proposed to have been a refuge in which cyclic evolution occurred. A dry climate in combination with a small population enabled natural selection to generate new sub species or species during each climate cycle. As generalized from the last two major glaciations, in each cycle three coastal zone climates of differing aridity occurred, depending on the latitudinal zonality of high latitude Gulf Stream flow. When initially isolated with minimal zonality (strong northward North Atlantic Drift of Gulf Stream water), the coastal climate was like today’s, with warm summers and mild winter rains. Subsequently during intervals of ice sheet growth with intermediate zonality (weaker Drift), winters were colder, the climate was drier, and the environmental stresses increased. Finally, with the quite strong or complete zonality associated with Northern Hemisphere deglaciations (little or no Drift), extreme aridity often reduced the inhabitable area of the coastal zone. When each Eurasian deglaciation was completed, the isolation was probably briefly interrupted, as it was in the mid Holocene, by a well-watered savanna that developed across the Sahara. The savannas enabled each small and genetically modified population to increase and extend its range southward into the larger Africa. The pulses of evolution are directly related to glacial cycles by way of Earth’s orbital eccentricity and precession of the equinox. The intervals of coastal zone isolation usually lasted almost 22,000 years, which is the time needed for the precession of the equinox to move summer around on Earth’s orbit from one perihelion point to the next where monsoons are strong, and deglaciation and the savannas tend to occur. However, isolations as long as ~76,000 years also are found in the record because Eurasian ice sheet growth sometimes resumed before deglaciation was complete. In the last million years there may have been at least 18 pluvial savanna intervals when populations of new species or sub species of hominids would have extended their range by expanding on the savanna into the larger Africa or Eurasia. Periodic pulses of evolution of primitive hominids probably also occurred much earlier in the Pliocene with brief savannas but without large Northern glaciations. Generation of new species of hominids in the coastal zone and their injection into the larger Africa by savanna connections may therefore have been largely responsible for the abundance of genus Homo and predecessors in the fossil record and for our own Homo sapiens that we know today.


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