182 research outputs found
Оцінка якості води річки Лопань у межах Харківської області
The actuality of this article is in the implementation of a systematic approach to the study of natural water quality of the river Lopan (within Kharkiv region).Assessment of water quality in the rivers has been studied by such scholars as O.O. Alexin, A.M. Gorev, V.M. Zhukynsky, F.F. Kirkov, A.M. Nikanorov, A.V. Ogievsky, O.P. Oksijuk, N.P. Puzyrevsky, V.D.Romanenko, V.K. Khilchevsky, A.P. Yatsyk, et al. But they all studied mainly large river basins, and we propose to investigate changes in the chemical composition of an average river that flows in the industrialized region.The research has been conducted on the methodology of environmental assessment of surface water quality according to the respective categories, in three blocks: salt, trophy-saprobiological, and the block of specific toxic action substances.The results of the research have shown that according to the salt block water in the river is saline; according to the trophy-saprobiological block water in the rivers is the most heavily polluted with phosphate phosphorus, which often leads to significant eutrophication of the reservoirs, nitrite and nitrate nitrogen, low water clarity; according to the block of specific substances – with phenols; according to the environmental index surface water quality of the river Lopan virtually did not change during 1980-2014, 2-3 grade (water is quite clean, slightly contaminated), but in recent years there has been no improvement in water quality of the river.In previous years industry was the main source of water pollution of the river Lopan, but in recent years it is municipal services, industrial enterprises and agriculture. The river Lopan was the most polluted in 1990, the least - in 2010. The biggest pollutants in the river Lopan were nitrite nitrogen, nitrate nitrogen, phosphorus and phosphate phenols.The actuality of this article is in the implementation of a systematic approach to the study of natural water quality of the river Lopan (within Kharkiv region).Assessment of water quality in the rivers has been studied by such scholars as O.O. Alexin, A.M. Gorev, V.M. Zhukynsky, F.F. Kirkov, A.M. Nikanorov, A.V. Ogievsky, O.P. Oksijuk, N.P. Puzyrevsky, V.D.Romanenko, V.K. Khilchevsky, A.P. Yatsyk, et al. But they all studied mainly large river basins, and we propose to investigate changes in the chemical composition of an average river that flows in the industrialized region. The research has been conducted on the methodology of environmental assessment of surface water quality according to the respective categories, in three blocks: salt, trophy-saprobiological, and the block of specific toxic action substances.The results of the research have shown that according to the salt block water in the river is saline; according to the trophy-saprobiological block water in the rivers is the most heavily polluted with phosphate phosphorus, which often leads to significant eutrophication of the reservoirs, nitrite and nitrate nitrogen, low water clarity; according to the block of specific substances – with phenols; according to the environmental index surface water quality of the river Lopan virtually did not change during 1980-2014, 2-3 grade (water is quite clean, slightly contaminated), but in recent years there has been no improvement in water quality of the river. In previous years industry was the main source of water pollution of the river Lopan, but in recent years it is municipal services, industrial enterprises and agriculture. The river Lopan was the most polluted in 1990, the least - in 2010. The biggest pollutants in the river Lopan were nitrite nitrogen, nitrate nitrogen, phosphorus and phosphate phenols.В этой статье обсуждаются возможности исследования качества воды рек, оценки качества поверхностных вод за соответствующими категориями. В статье определены следующие основные проблемы недостаточно изучены: изменения гидрологических характеристик рек Лопань в Харьковской области за период 1980-2014 г.; определение основных факторов формирования поверхности воды качества средних рек, к которым относится река Лопань, а именно, основные из которых являются зависимость от времени прохождения половодья, характер его питания, от наличия стока из почвы, также длины реки, глубины ее эрозионного вреза, наличие приток; определили химический состав поверхностных вод та его изменения в период 1980-2014 гг.; подана оценка качества воды реки Лопань за методикой экологической оценки качества поверхностных за соответствующими категориями; определены основные источники загрязнения за соответственные годы и основные компоненты загрязнения вод.У статті розглядаються особливості дослідження якості води річок за методикою екологічної оцінки якості поверхневих вод за відповідними категоріями. У статті визначені наступні основні недостатньо вивчені проблеми: зміни гідрологічних характеристик річки Лопань в межах Харківської області за період 1980-2014 рр; визначенні основні фактори формування якості поверхневих вод середніх річок, до яких відноситься річка Лопань, а саме основними з яких є залежність від часу проходження водопілля, характеру його живлення, від наявності стоку з ґрунту, також довжина річки, глибина її ерозійного врізу, наявність приток; визначили хімічний склад поверхневих вод та його зміни за період 1980-2014 рр.; подана оцінка якості води річки Лопань за методикою екологічної оцінки якості поверхневих вод за відповідними категоріями; визначили основні джерела забруднення за відповідні роки та основні інгредієнти забруднення вод
Human papillomavirus E2 regulates SRSF3 (SRp20) to promote capsid protein expression in infected differentiated keratinocytes
The human papillomavirus (HPV) life cycle is tightly linked to differentiation of the infected epithelial cell suggesting a sophisticated interplay between host cell metabolism and virus replication. Previously we demonstrated in differentiated keratinocytes in vitro and in vivo that HPV16 infection caused increased levels of the cellular SR splicing factors (SRSFs) SRSF1 (ASF/SF2), SRSF2 (SC35) and SRSF3 (SRp20). Moreover, the viral E2 transcription and replication factor that is expressed at high levels in differentiating keratinocytes could bind and control activity of the SRSF1 gene promoter. Here we reveal that E2 proteins of HPV16 and HPV31 control expression of SRSFs 1, 2 and 3 in a differentiation-dependent manner. E2 has the greatest trans-activation effect on expression of SRSF3. siRNA depletion experiments in two different models of the HPV16 life cycle (W12E and NIKS16) and one model of the HPV31 life cycle (CIN612-9E) revealed that only SRSF3 contributed significantly to regulation of late events in the virus life cycle. Increased levels of SRSF3 are required for L1 mRNA and capsid protein expression. Capsid protein expression was regulated specifically by SRSF3 and appeared independent of other SRSFs. Taken together these data suggest a significant role of the HPV E2 protein in regulating late events in the HPV life cycle through transcriptional regulation of SRSF3 expression.
IMPORTANCE Human papillomavirus replication is accomplished in concert with differentiation of the infected epithelium. Virus capsid protein expression is confined to the upper epithelial layers so as to avoid immune detection. In this study we demonstrate that the viral E2 transcription factor activates the promoter of the cellular SRSF3 RNA processing factor. SRSF3 is required for expression of the E4̂L1 mRNA and so controls expression of the HPV L1 capsid protein. Thus we reveal a new dimension of virus-host interaction crucial for production of infectious virus. SRSF proteins are known drug targets. Therefore, this study provides an excellent basis for developing strategies to regulate capsid protein production in the infected epithelium and production of new virions
Excitons and singlet fission at hybrid inorganic-organic semiconductor interfaces
Excitons in organic crystalline semiconductors play a crucial role in the
operation of optoelectronic devices such as organic solar cells, light-emitting
diodes, and photodetectors. The excitonic properties of materials are
dramatically affected by the presence of surfaces and interfaces. In this work,
we investigate the influence of a neutral hydrogen-passivated 1x2 reconstructed
(100) silicon substrate on excitons within the crystalline tetracene layer
deposited on the top of it. Our findings reveal that singlet excitons in the
contact tetracene layer are situated within the continuum of unbound
Wannier-Mott excitonic states in silicon, with noteworthy hybridization between
these states. Consequently, in the contact tetracene layer, all singlet
excitons exhibit a pronounced interlayer charge transfer character, while the
triplet exciton remains confined to the tetracene layer. This makes the singlet
fission effect highly improbable for the contact tetracene layer. Additionally,
the presence of the silicon substrate results in a modification of the
singlet-triplet gap by 144 meV. This change is solely attributed to the
hybridization with excitons in silicon, which influences the exchange energy.
Our results show that the dynamic dielectric screening caused by the substrate
does not impact the singlet-triplet gap but alters the exciton binding
energies.Comment: 26 pages, 7 figure
Просторовий розподіл кліматичних показників на території лісостепу та степу лівобережної України
The features of average monthly air temperature distribution, monthly rainfall and the ground atmospheric pressure on the left-bank Ukraine during a year have been examined in the article. With the help of cluster analysis regularities of spatial changes in basic climatic indexes during a year for the period from 1951 to 2000 have been determined. North Atlantic influence on climatic characteristics of the studied territory has also been investigated. By means of statistical analysis the changes in temperature condition are specified on the territory of Kharkiv region for the period from 2001 to 2014. By means of cluster and component analyses climatic fields of average monthly air temperature values, monthly rainfalls and atmospheric pressure have been studied at 38 stations for the year in the second half of the last century. The cluster analysis is an heuristic algorithm based on the Euclidean distances determined with predetermined threshold values. Further study of the climate of Ukraine, as a component of the global climate, will identify features and rate of change of meteorological parameters. Cluster analysis characterizes the same type of districts on temperature conditions, moisture regime and atmospheric pressure within the limits of forest-steppe and steppe of the left-bank Ukraine. In autumn there is leveling of the climatic field of atmospheric pressure: northern district embraces almost all the territory of forest-steppe and steppe, displacing the southern to the coast of the Azov sea. Within the limits of Luhansk and Donetsk regions the south-eastern district recommences. Analysis of the average monthly values of air temperature on the presented territory have shown two main districts in an autumn-winter period: northern and southern, the border between them passes on the line of the north-west of Luhansk region, the north of Donetsk and the south of Dnipropetrovsk regions. It takes place near the barometric axis of Voyeikow, which is defined by atmospheric circulation. In a spring-summer period when the main value has the feature of laying surface, in forest-steppe and steppe of the left-bank Ukraine a local district is formed on the territory of the Azov-Donetsk ridge.В статье рассматриваются особенности распределения среднемесячной температуры воздуха, месячной суммы осадков и среднемесячного приземного атмосферного давления на территории лесостепи и степи левобережной Украины в течение года. Определено, что изменения временных рядов климатических показателей формируются под действием крупномасштабных атмосферных процессов и имеют свои вариации в течение сезонов. С использованием кластерного анализа были определены закономерности пространственного изменения климатических показателей в течение года за период 1951-2000 гг. Также исследуется влияние Северной Атлантики на климатические условия изучаемой территории, которое максимальное значение имеет в осенне-зимний период. Статистический анализ температурных рядов позволил определить дальнейшую тенденцию изменения температурного режима Харьковской области в период 2001-2014 гг., что характеризуется увеличением значений температуры воздуха. Полученные результаты уточняют информацию о пространственно-временных изменениях климатических показателей на региональном уровне.У статті розглядаються особливості розподілу середньомісячної температури повітря, місячної кількості опадів та середньомісячного приземного атмосферного тиску на території лісостепу і степу лівобережної України впродовж року. За допомогою кластерного аналізу були визначені закономірності просторової зміни кліматичних показників упродовж року за період 1951-2000 рр. Встановлено, що зміни часових рядів кліматичних показників формуються під впливом великомасштабних атмосферних процесів і мають свої варіації впродовж сезонів. Також досліджується вплив Північної Атлантики на кліматичні умови досліджуваної території, який максимально відчувається у осінньо-зимовий період. Статистичний аналіз температурних рядів дозволив визначити подальшу тенденцію зміни температурного режиму Харківської області за період 2001-2014 рр., що характеризується зростанням температури повітря. Отримані результати уточнюють інформацію про просторово-часові зміни основних кліматичних показників на регіональному рівні
Influence of tree-crown density on dominant plant species of the herb-shrub stratum in the zone of mixed forests
Forest ecosystems are among the most complex and dynamic biological systems of our planet. They play an important role in sustaining biodiversity, regulating the climate, and preserving water resources. Furthermore, they serve as natural filters, improving the quality of soil and air, and also preventing erosive processes. Forests create unique conditions for life of various species of plants and animals, which contributes to maintenance of the natural biodiversity and supports the stability of the ecosystem. Likewise, forests are important for the carbon cycle. They absorb a large amount of carbon, thus hindering global warming. Therefore, forest ecosystems are of paramount ecological value and their preservation is crucial for a balanced functioning of the planet. Our studies were carried out in the forest ecosystems of the Desna-Starohutskyi National Park, which is in the Ukrainian Polissia. The materials and methods of the study included systematic collection of the data on density of tree crowns, and also records of diversity of plants of the herb-shrub stratum in the chosen forest areas. Those data were analyzed using statistical methods. The study results revealed that the crown density has a significant effect on diversity of herb-shrub plants in the lower forest strata. Increase in crown density correlated with decrease in the light availability in the herb-shrub stratum. Change in the crown density towards increase significantly altered the conditions for competition between herbaceous and shrub species. Decrease in light availability led to shift in the competition ratio between the species, promoting dominance of more shade-loving species. Increase in crown density, which often reached 100%, made the competition more severe, especially for key resources (light, water, and nutrients). Because of this, species diversity in the herb-shrub stratum of the forest ecosystems was observed to decrease, and less adapted species were extruded. In general, change in tree-crown density in the forest ecosystem had a significant effect on the dynamics of herbaceous and shrub species, changing competitive relations and the structure of those plant communities. The results we obtained expand the knowledge about interactions between crown density and the structure of herb-shrub stratum, which gives perspectives for more efficient management of forest resources, and can also improve scientific identification and implementation of measures for protection of forest ecosystems
Population analysis of Asarum europaeum in the Northeast of Ukraine
An analysis of populations of Asarum europaeum L. in forest ecosystems of the North East of Ukraine during the growing periods of 2004–2015 was carried out. In carrying out field research we used standard methods of ecology, geobotany such as study plots of 400 m2, and for detailed elaboration of the surface layer we used study plots of 100 m2. According to the results of the examination of plots of the size 50 x 50 cm, we obtained data on the number and density of individuals within populations. We found that populations of this species often dominate in the lower tiers of broadleaf and mixed forests in the region under research. We identified the basic population characteristics of the species and described its growth and development in three subformations: Querceta roboris, Pineta sylvestris, Acereto (platanoiditis) – Querceta (roboris). It was found that according to the time gradient, depending on meteorological conditions, the projective cover and the average population density of the plants vary. Based on the average growth rate of the plants, the balance of morphogenesis in the course of the plants’ ontogenesis was determined. We found that the best conditions for the growth and development of A. europaeum are provided in the North East of Ukraine in the subformation of Querceta roboris. The results of the analysis of ontogenetic state of partial bushes in populations of A. europaeum are described. It was found that populations in the subformation Querceta roboris and Pineta sylvestris were full-membered, while in the subformation Acereto (platanoiditis) – Querceta (roboris) they were not fully-membered with fallout of seedlings and juvenile plants. It was found that the population of A. europaeum in the Pineta sylvestris subformation, is left sided, with the peak number in pregenerative partial bushes – this was the youngest population with the highest Index innovation value and the lowest Index senilis value. The Index senilis of the youngest population is 0.14 while the Index generative is 45.0%. The population of A. europaeum in the subformation of Querceta roboris was more mature: Index senilis is equal to 0.19, the age range of the left-hand side with the peak on the partial bushes g1, Index generative reaches 55.4%. In the population with the subformation Acereto (platanoiditis) – Querceta (roboris) Index senilis is significantly greater than one and equals 2.35. In the oldest population, the age spectrum is centered with the peak on generative partial bushes, the Index generative is high and equals 68.5%. This vital analysis of the population structure is based on a sample of more than 3,000 partial shrubs. The key signs of vitality were: total phytomass (W), leaf surface (A) and reproductive effort (RE1). It has been established that two of the three studied populations of A. europaeum are in equilibrium (from the subformations of Pineta sylvestris and Acereto (platanoiditis) – Querceta (roboris) and one is flourishing.An analysis of the populations of Asarum europaeum L. in forest ecosystems of the North East of Ukraine during the growing periods of 2004–2015 was carried out. In carrying out field research we used standard methods of ecology, geobotany such as study plots of 400 m2, and for detailed elaboration of the surface layer we used study plots of 100 m2. According to the results of the examination of plots of the size 50 x 50 cm, we obtained data on the number and density of individuals within populations. We found that populations of this species often dominate in the lower tiers of broadleaf and mixed forests in the region under research. We identified the basic population characteristics of the species and described its growth and development in three subformations: Querceta roboris, Pineta sylvestris, Acereto (platanoiditis) – Querceta (roboris). It was found that according to the time gradient, depending on meteorological conditions, the projective cover and the average population density of the plants vary. Based on the average growth rate of the plants, the balance of morphogenesis in the course of the plants’ ontogenesis was determined. We determined that the most optimal conditions for the growth and development of A. europaeum are provided in the North East of Ukraine in the subformation of Querceta roboris. The results of the analysis of ontogenetic state of partial bushes in populations of A. europaeum are described. It was found that populations in the subformation Querceta roboris and Pineta sylvestris were full-membered, while in the subformation Acereto (platanoiditis) – Querceta (roboris) it was unfully-membered with fallout of seedlings and juvenile plants. It was found that the population of A. europaeum in the Pineta sylvestris subformation, is left sided, with the peak number in pregenerative partial bushes – this was the youngest population with the highest Index innovation value and the lowest Index senilis value. The Index aetas of the youngest population is 0.14 while the Index generative is 45.0%. The population of A. europaeum in the subformation of Querceta roboris was more mature: Index aetas is equal to 0.19, the age range of the left-hand side with the peak on the partial bushes g1, Index generative reaches 55.4%. In the population with the subformation Acereto (platanoiditis) – Querceta (roboris) Index aetas is significantly greater than one and equals 2.35. In the oldest population, the age spectrum is centered with the peak on generative partial bushes, the Index generative is high and equals 68.5%. This vital analysis of the population structure is based on a sample of more than 3,000 partial shrubs. The key signs of vitality were: total phytomass (W), leaf surface (A) and reproductive effort (RE1). It has been established that two of the three populations studied A. europaeum are in equilibrium (from the subformations of Pineta sylvestris and Acereto (platanoiditis) – Querceta (roboris)) and one is flourishing.
Operation of a quantum dot in the finite-state machine mode: single-electron dynamic memory
A single electron dynamic memory is designed based on the non-equilibrium
dynamics of charge states in electrostatically-defined metallic quantum dots.
Using the orthodox theory for computing the transfer rates and a master
equation, we model the dynamical response of devices consisting of a charge
sensor coupled to either a single and or a double quantum dot subjected to a
pulsed gate voltage. We show that transition rates between charge states in
metallic quantum dots are characterized by an asymmetry that can be controlled
by the gate voltage. This effect is more pronounced when the switching between
charge states corresponds to a Markovian process involving electron transport
through a chain of several quantum dots. By simulating the dynamics of electron
transport we demonstrate that the quantum box operates as a finite-state
machine that can be addressed by choosing suitable shapes and switching rates
of the gate pulses. We further show that writing times in the ns range and
retention memory times six orders of magnitude longer, in the ms range, can be
achieved on the double quantum dot system using experimentally feasible
parameters thereby demonstrating that the device can operate as a dynamic
single electron memory.Comment: 18 pages, 8 figure
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