The steady flow in a Hele-Shaw cell filled with fluids with a high viscosity contrast in the presence of fluid oscillations is experimentally studied.The control of oscillatory dynamics of multiphase systems with inte...The steady flow in a Hele-Shaw cell filled with fluids with a high viscosity contrast in the presence of fluid oscillations is experimentally studied.The control of oscillatory dynamics of multiphase systems with interfaces is a challenging technological problem.We consider miscible(water and glycerol)and immiscible(water and high-viscosity silicone oil PMS-1000)fluids under subsonic oscillations perpendicular to the interface.Observations show that the interface shape depends on the amplitude and frequency of oscillations.The interface is undisturbed only in the absence of oscillations.Under small amplitudes,the interface between water and glycerol widens due to mixing.When the critical amplitude is reached,the interface becomes unstable to the fingering instability:Aqueous fingers penetrate the high-viscosity glycerol and induce intensive mixing of miscible fluids and associated decay of the instability.After the disappearance of the fingers,the interface takes a U-shape in the central part of the cell.A similar effect is observed for immiscible fluids:The oscillating interface tends to bend to the side of a high-viscosity fluid.Again,when the critical amplitude is reached,the fingering instability arises at the convex interface.This paper focuses on the causes of bending of the initially undisturbed interface between miscible or immiscible fluids.For this purpose,we measure the steady flow velocity near the interface and in the bulk of a high-viscosity fluid using Particle Image Velocimetry(PIV).展开更多
The behavior of two immiscible low-viscosity liquids differing in density and viscosity in a vertical flat layer undergoing modulated rotation is experimentally studied.The layer has a circular axisymmetric boundary.I...The behavior of two immiscible low-viscosity liquids differing in density and viscosity in a vertical flat layer undergoing modulated rotation is experimentally studied.The layer has a circular axisymmetric boundary.In the absence of modulation of the rotation speed,the interphase boundary has the shape of a short axisymmetric cylinder.A new effect has been discovered,under the influence of rotation speed modulation,the interface takes on a new dynamic equilibrium state.A more viscous liquid covers the end boundaries of the layer in the form of thin films,which have the shape of round spots of almost constant radius;with increasing amplitude of the velocity modulation,the wetting boundary expands.It is found that upon reaching the critical amplitude of oscillations,the film of a viscous liquid loses stability,and the outer edge of the wetting spot collapses and takes on a feathery structure.It is shown that this threshold is caused by the development of the Kelvin-Helmholtz oscillatory instability of the film.The spreading radius of a spot of light viscous liquid and its stability are studied depending on the rotation rate,amplitude,and frequency of rotation speed modulation.The discovered averaged effects are determined by different oscillatory interaction of fluids with the end-walls of the cell,due to different viscosities.The effect of films forming can find application in technological processes to intensify mass transfer at interphase boundaries.展开更多
This work is devoted to the experimental study of inertial wave regimes in a non-uniform rotating cylinder with antiparallel inclined ends.In this setting,the cross-section of the cylinder is divided into two regions ...This work is devoted to the experimental study of inertial wave regimes in a non-uniform rotating cylinder with antiparallel inclined ends.In this setting,the cross-section of the cylinder is divided into two regions where the fluid depth increases or decreases with radius.Three different regimes are found:inertial wave attractor,global oscillations(the cavity’s resonant modes)and regime of symmetric reflection of wave beams.In linear wave regimes,a steady single vortex elongated along the rotation axis is generated.The location of the wave’s interaction with the sloping ends determines the vortex position and the vorticity sign.In non-linear regimes several pairs of the triadic resonance subharmonics are detected simultaneously.The instability of triadic resonance is accompanied by the periodic generation of mean vortices drifting in the azimuthal direction.Moreover,the appearance frequency of the vortices is consistent with the low-frequency subharmonic of the triadic resonance.The experimental results shed light on the mechanisms of the inertial wave interaction with zonal flow and may be useful for the development of new methods of mixing.展开更多
The article presents the biology of flowering and the daily dynamics of flowering of two species from the Lamiaceae family: ph. anisochila va ph. sogdiana of the distribution out in the Nuratau Mountains range.
In the field of stroke imaging, deep learning (DL) has enormousuntapped potential.When clinically significant symptoms of a cerebral strokeare detected, it is crucial to make an urgent diagnosis using available imagin...In the field of stroke imaging, deep learning (DL) has enormousuntapped potential.When clinically significant symptoms of a cerebral strokeare detected, it is crucial to make an urgent diagnosis using available imagingtechniques such as computed tomography (CT) scans. The purpose of thiswork is to classify brain CT images as normal, surviving ischemia or cerebralhemorrhage based on the convolutional neural network (CNN) model. In thisstudy, we propose a computer-aided diagnostic system (CAD) for categorizingcerebral strokes using computed tomography images. Horizontal flip datamagnification techniques were used to obtain more accurate categorization.Image Data Generator to magnify the image in real time and apply anyrandom transformations to each training image. An early stopping method toavoid overtraining. As a result, the proposed methods improved several estimationparameters such as accuracy and recall, compared to other machinelearning methods. A python web application was created to demonstrate theresults of CNN model classification using cloud development techniques. Inour case, the model correctly identified the drawing class as normal with 79%accuracy. Based on the collected results, it was determined that the presentedautomated diagnostic system could be used to assist medical professionals indetecting and classifying brain strokes.展开更多
According to one of the theses of optimal foraging theory,main prey species abundance in the hunting area is the main factor determining the diet and habitat choices of birds of prey.However other factors can also be ...According to one of the theses of optimal foraging theory,main prey species abundance in the hunting area is the main factor determining the diet and habitat choices of birds of prey.However other factors can also be important.The habitat structure influences the predators’diets as well.In this study we examined the influence of habitat structure on diet compositions of three species of birds:Long-eared Owl(Asio otus),Short-eared Owl(A.flammeus)and Common Kestrel(Falco tinnunculus).The study was carried out from 2007 to 2019 in a 48 km2area of the Crane’s Homeland Reserve,Moscow Region,Russia.The habitat structures of model species’hunting territories(ratio of different types of landscape elements)were classified in module"Semi-Automatic Classification Plugin"based on the QGIS.A boosted regression tree analysis identified that the share of the main prey species in the diet is primarily determined by the landscape structure of hunting territories.The largest share of Common Vole(Microtus arvalis)in birds’diet was determined by the shrubs area(15%of hunting area),the meadow area(75%),the habitat heterogeneity(70%)and the arable land area(5%).The same predictors determined the largest share of Root Vole(Microtus oeconomus):the shrubs area 25%,the meadow area 70%,and the arable land area 3%.The annual mean abundance of prey species did not determine their importance in the diet of birds of prey.Thus,the main prey abundance in the hunting area is not a determining factor for the formation of diet composition of birds of prey.展开更多
α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from d...α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from deficiency of ALA because most staple food oils are low or lack ALA content.Biotechnological enrichment of ALA in staple oil crops is a promising strategy.Chia(Salvia hispanica)has the highest ALA content in its seed oil among known oil crops.In this study,the FAD2 and FAD3 genes from chia were engineered into a staple oil crop,oilseed rape(Brassica napus),via Agrobaterium tumefaciens-mediated transformation of their LP4-2A fusion gene construct driven by the seed-specific promoter P_(NapA).In seeds of T0,T1,and T2 lines,the average ALA contents were 20.86,23.54,and 24.92%,respectively,which were 2.21,2.68,and 3.03 folds of the non-transformed controls(9.42,8.78,and 8.22%),respectively.The highest seed ALA levels of T0,T1,and T2 plants were 38.41,35.98,and 39.19%respectively,which were 4.10-4.77 folds of the respective controls.FA-pathway enzyme genes(BnACCD,BnFATA,BnSAD,BnSCD,BnDGAT1,BnDGAT2,and BnDGAT3)and positive regulatory genes(BnWRI1,BnLEC1,BnL1L,BnLEC2,BnABI3,BnbZIP67,and BnMYB96)were all significantly up-regulated.In contrast,BnTT1,BnTT2,BnTT8,BnTT16,BnTTG1,and BnTTG2,encoding negative oil accumulation regulators but positive secondary metabolism regulators,were all significantly down-regulated.This means the foreign ShFAD2-ShFAD3 fusion gene,directly and indirectly,remodeled both positive and negative loci of the whole FA-related network in transgenic B.napus seeds.展开更多
Communication in society had developed within cultural and geographical boundaries prior to the invention of digital technology.The latest advancements in communication technology have significantly surpassed the conv...Communication in society had developed within cultural and geographical boundaries prior to the invention of digital technology.The latest advancements in communication technology have significantly surpassed the conventional constraints for communication with regards to time and location.These new platforms have ushered in a new age of user-generated content,online chats,social network and comprehensive data on individual behavior.However,the abuse of communication software such as social media websites,online communities,and chats has resulted in a new kind of online hostility and aggressive actions.Due to widespread use of the social networking platforms and technological gadgets,conventional bullying has migrated from physical form to online,where it is termed as Cyberbullying.However,recently the digital technologies as machine learning and deep learning have been showing their efficiency in identifying linguistic patterns used by cyberbullies and cyberbullying detection problem.In this research paper,we aimed to evaluate shallow machine learning and deep learning methods in cyberbullying detection problem.We deployed three deep and six shallow learning algorithms for cyberbullying detection problems.The results show that bidirectional long-short-term memory is the most efficient method for cyberbullying detection,in terms of accuracy and recall.展开更多
In a wide variety of mechanical and industrial applications,e.g.,space cooling,nuclear reactor cooling,medicinal utilizations(magnetic drug targeting),energy generation,and heat conduction in tissues,the heat transfer...In a wide variety of mechanical and industrial applications,e.g.,space cooling,nuclear reactor cooling,medicinal utilizations(magnetic drug targeting),energy generation,and heat conduction in tissues,the heat transfer phenomenon is involved.Fourier’s law of heat conduction has been used as the foundation for predicting the heat transfer behavior in a variety of real-world contexts.This model’s production of a parabolic energy expression,which means that an initial disturbance would immediately affect the system under investigation,is one of its main drawbacks.Therefore,numerous researchers worked on such problem to resolve this issue.At last,this problem was resolved by Cattaneo by adding relaxation time for heat flux in Fourier’s law,which was defined as the time required to establish steady heat conduction once a temperature gradient is imposed.Christov offered a material invariant version of Cattaneo’s model by taking into account the upper-connected derivative of the Oldroyd model.Nowadays,both models are combinedly known as the Cattaneo-Christov(CC)model.In this attempt,the mixed convective MHD Falkner-Skan Sutterby nanofluid flow is addressed towards a wedge surface in the presence of the variable external magnetic field.The CC model is incorporated instead of Fourier’s law for the examination of heat transfer features in the energy expression.A two-phase nanofluid model is utilized for the implementation of nano-concept.The nonlinear system of equations is tackled through the bvp4c technique in the MATLAB software 2016.The influence of pertinent flow parameters is discussed and displayed through different sketches.Major and important results are summarized in the conclusion section.Furthermore,in both cases of wall-through flow(i.e.,suction and injection effects),the porosity parameters increase the flow speed,and decrease the heat transport and the influence of drag forces.展开更多
Breast milk is important for infant health. Some of its benefits are due to the presence of a specific population of bacteria in the microflora. However, the microbiome of breast milk is influenced by many parameters ...Breast milk is important for infant health. Some of its benefits are due to the presence of a specific population of bacteria in the microflora. However, the microbiome of breast milk is influenced by many parameters such as maternal diet, breastfeeding and geographic location. Culture and non-culture methods have been used in studies of this bacterial population worldwide. But in the DR Congo, there was no study reporting the use of culture-independent techniques to characterize the bacterial diversity of human milk. The aim of this study was to identify the bacterial 16S rRNA gene from two genera Lactobacillus and Bifidobacterium. The 16S rRNA gene was also identified from four species: Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacterium longum and Bifidobacterium lactis. This analytical cross-sectional study was conducted in Kinshasa. Breast milk from some healthy women was collected from February 2 to 28, 2018. A culture-independent protocol using the classical polymerase chain reaction (PCR) was used to identify the bacterial 16S rRNA gene. The 68 samples of breast milk were collected in a sterile condition. The bacteria-specific ribosomal gene 16S rRNA was detected in 91.18% of Lactobacillus and 32.35% of Bifidobacterium at genus level. At of species level, only Lactobacillus reuteri 16S rRNA gene was identified in 89.71%. The 16S rRNA gene from the other species could not be amplified. There was also an association between educational level and the presence of Bifidobacterium and Lactobacillus 16S rRNA genes in the breast milk (p = 0.008*, p Conclusion: This study demonstrates the presence of the bacterial 16S rRNA gene from Lactobacillus and Bifidobacterium in breast milk at the genus and Lactobacillus reuteri at species level. A further study on the diet, use of antibiotics during pregnancy and lactation practice will provide a better understanding of the microflora of breast milk.展开更多
In this work, we consider the second order nonlinear integro-differential Equation (IDEs) of the Volterra-Fredholm type. One of the popular methods for solving Volterra or Fredholm type IDEs is the method of quadratur...In this work, we consider the second order nonlinear integro-differential Equation (IDEs) of the Volterra-Fredholm type. One of the popular methods for solving Volterra or Fredholm type IDEs is the method of quadrature while the problem of consideration is a linear problem. If IDEs are nonlinear or integral kernel is complicated, then quadrature rule is not most suitable;therefore, other types of methods are needed to develop. One of the suitable and effective method is homotopy analysis method (HAM) developed by Liao in 1992. To apply HAM, we firstly reduced the IDEs into nonlinear integral Equation (IEs) of Volterra-Fredholm type;then the standard HAM was applied. Gauss-Legendre quadrature formula was used for kernel integrations. Obtained system of algebraic equations was solved numerically. Moreover, numerical examples demonstrate the high accuracy of the proposed method. Comparisons with other methods are also provided. The results show that the proposed method is simple, effective and dominated other methods.展开更多
Background and Objective: Despite the costs generated in the diagnosis of cardiac pathologies by the use of ultrasound, the ECG indices have demonstrated a high performance in the studies of developed countries in the...Background and Objective: Despite the costs generated in the diagnosis of cardiac pathologies by the use of ultrasound, the ECG indices have demonstrated a high performance in the studies of developed countries in the diagnosis of these pathologies, but the data of these in sub-Saharan Africa are limited. The objective of this study is to evaluate the performance of the Peguero-Lo Presti index in the diagnosis of LVH among Congolese in order to make it a means of LVH diagnosis in an under-equipped environment. Methods: Cross-sectional and analytical study including 413 patients followed and hospitalized at the CIMAK Hospital Center during the period from February 2019 to June 2021. Sociodemographic parameters, history, biology, ultrasound and ECG parameters were studied. The performance of the Peguero-Lo Presti Index was validated by the Youden Index reinforced by the Area under the ROC curve. Results: Of the 413 patients admitted to the study, 69.5% were men versus 30.5% women, i.e. a sex ratio of 2M/1F;the mean age of the patients was 51.1 ± 11.6 years. The frequency of LVH found by echocardiography was 55.9%, it was 50.8% using the Peguero-Lo Presti index, 22% and 10.2% using the Peguero-Lo Presti index, respectively. Sokolow-Lyon and Cornell (p 0.001). The Peguero-Lo Presti curve is higher than the Sokolow-Lyon and Cornell curves. The area under the curve was 0.80 for Peguero-Lo Presti, 0.73 for Sokolow-Lyon and 0.66 for cornell. Conclusion: The newly proposed Peguero-Lo Presti index provides high sensitivity and specificity for the diagnosis of LVH in black Africans as also reported in the European and American population.展开更多
This study aims to investigate the main sectors of economic development before and the current situation of COVID-19 for Sub-Saharan African countries by demonstrating country experiences,the role of vaccines,and the ...This study aims to investigate the main sectors of economic development before and the current situation of COVID-19 for Sub-Saharan African countries by demonstrating country experiences,the role of vaccines,and the SSA economy forecast.The study has four main sections,including an introduction,an overview of socioeconomic indicators before the pandemic,methods,results findings,and discussion.The study used mixed methods,including an approach based on secondary data.The quantitative results were analysed using both empirical methods and the researcher’s prior expertise.The analysis of the effects of the COVID-19 pandemic on SSA countries was based on long-term data collected by several international financial institutions.The research findings demonstrated conclusively that COVID-19 is causing the collapse of the SSA economy,the first economic recession in 25 years,$37-79 billion in lost GDP by 2020,and an export decrease of 10.6%.In education,for example,64%of primary and 50%of secondary students lack ICT training,89%(216 million)do not have access to a home computer,and 82%(199 million)do not have an Internet connection missed classes during the COVID-19 period.The agricultural sector in SSA is also impacted by over 239 million hungry people.COVID-19 mass vaccinations and public debt amount to over$154 billion in obligations to get the SSA economy back on its feet with zero tolerance for embezzlement of public funds.These results can be used to make the economies of SSA countries resilient to the current crises and to address some thematic issues,such as the implementation of the African Continental Free Trade Area(AfCFTA)in all SSA countries,which will save time and money by getting rid of border taxes.Therefore,policymakers can use the findings to begin formulating plans to address issues like economic development,education,and food insecurity.展开更多
The aim of this study was to evaluate the ethnomedical knowledge of the population of South Ubangi on Myrianthus arboreus,a plant consumed by chimpanzees,with the assumption that this bio-resource is also used by the ...The aim of this study was to evaluate the ethnomedical knowledge of the population of South Ubangi on Myrianthus arboreus,a plant consumed by chimpanzees,with the assumption that this bio-resource is also used by the population in African Traditional Medicine to treat common diseases.The results revealed that M.arboreus treats 23 diseases in the province of South Ubangi in Democratic Republic of the Congo.Of these diseases,six(anaemia,bronchitis,tooth decay,gastritis,hypertension,and spleen)are the most cited.Anaemia and spleen are treated by all socio-cultural groups.The leaf is the most used organ(48%)followed by sap,roots,stems,bark,flowers,and seeds.Expression(61.5%)is the most used method of preparation followed by decoction,maceration,and mastication.Oral(94.5%)is the most used method of administration followed by body bath,massage,anal and auricular route.M.arboreus is a vulnerable species(Iv≥2.5)in the study area.The diseases treated are influenced by the level of education and the profession of the respondents(p<0.05).While the mode of preparation of recipes is influenced by the family situation,also the composition of recipes is influenced by gender,age and occupation(p<0.05).The search for new sources of bio-inspired drugs through zoopharmacognosy may thus allow the development of effective phytomedicines for the health care of humans or non-human primates ex situ.Thus the need for advanced phytochemical and pharmacological studies and the domestication of M.arboreus for its multiple food and pharmacological uses is necessary.展开更多
The aim of this article is to prove a fixed point theorem in 2-Banach spaces and show its applications to the Ulam stability of functional equations. The obtained stability re- sults concern both some single variable ...The aim of this article is to prove a fixed point theorem in 2-Banach spaces and show its applications to the Ulam stability of functional equations. The obtained stability re- sults concern both some single variable equations and the most important functional equation in several variables, namely, the Cauchy equation. Moreover, a few corollaries corresponding to some known hyperstability outcomes are presented.展开更多
Land use and land cover(LULC) changes and their impact on the mountain environment were studied in six catchments(~10 km^2 each) in the Polish Western Carpathians from the mid-19^(th) century to the early 21^(st) cen...Land use and land cover(LULC) changes and their impact on the mountain environment were studied in six catchments(~10 km^2 each) in the Polish Western Carpathians from the mid-19^(th) century to the early 21^(st) century. The analysis of cadastral and orthophoto maps indicates that during the investigated period, the forest area increased, quantified by an annual change index(Annch), between +0.12% to +0.27%, with a decrease of arable land index to –0.45% and –2.28% in the analysed catchments. LULC changes were accompanied by a continuous increase in settlement developments(residential and farming houses) by 50%-140% as well as significant changes related to their spatial distribution. Abandonment of arable land and forest succession have resulted in the geomorphological transformation of hillslopes, which predominantly includes a decrease in used road density, their transformation to road cuts and gorges. Overpopulation and the domination agriculture in the past caused the expansion of unpaved roads density and then the fragmentation of hillslopes, as well as the development of agricultural terraces.展开更多
The Central Asian lowlands are characterized by an arid and continental climate. At the same time, the large streams and rivers have been providing water for the development of flourishing oases and extensive irrigate...The Central Asian lowlands are characterized by an arid and continental climate. At the same time, the large streams and rivers have been providing water for the development of flourishing oases and extensive irrigated farming areas. Bukhara is one of those oases. The population of 1.7 mln. and especially the agricultural sector (with an irrigated area of 275,000 ha) use a considerable amount of water. But as the flat topography does not provide sufficient natural drainage, water logging and raising groundwater tables have become serious problems for the agricultural productivity. The combination of the high salinity of the irrigation water and the generous application of fertilizers leads to a widespread soil salinization. Excessive leaching is supposed to reduce the top soil salinity, but as the drainage system is only covering a small portion of the irrigated areas and is in need of maintenance, this process only contributes to the ongoing salinization and the reduction of soil fertility and crop yields. The data presented here for the years 2000 to 2013 indicate that the groundwater table is rising throughout the region while the groundwater salinity is decreasing. The soil salinity on the other hand is, after an improvement during the first half of the study period, slightly increasing since 2009, which also is reflected in the slight worsening of the condition of the reclaimed land during the same period.展开更多
基金supported by the Ministry of Education of the Russian Federation(Project KPZU-2023-0002).
文摘The steady flow in a Hele-Shaw cell filled with fluids with a high viscosity contrast in the presence of fluid oscillations is experimentally studied.The control of oscillatory dynamics of multiphase systems with interfaces is a challenging technological problem.We consider miscible(water and glycerol)and immiscible(water and high-viscosity silicone oil PMS-1000)fluids under subsonic oscillations perpendicular to the interface.Observations show that the interface shape depends on the amplitude and frequency of oscillations.The interface is undisturbed only in the absence of oscillations.Under small amplitudes,the interface between water and glycerol widens due to mixing.When the critical amplitude is reached,the interface becomes unstable to the fingering instability:Aqueous fingers penetrate the high-viscosity glycerol and induce intensive mixing of miscible fluids and associated decay of the instability.After the disappearance of the fingers,the interface takes a U-shape in the central part of the cell.A similar effect is observed for immiscible fluids:The oscillating interface tends to bend to the side of a high-viscosity fluid.Again,when the critical amplitude is reached,the fingering instability arises at the convex interface.This paper focuses on the causes of bending of the initially undisturbed interface between miscible or immiscible fluids.For this purpose,we measure the steady flow velocity near the interface and in the bulk of a high-viscosity fluid using Particle Image Velocimetry(PIV).
基金financially supported by the Russian Science Foundation(Project 23-11-00242).
文摘The behavior of two immiscible low-viscosity liquids differing in density and viscosity in a vertical flat layer undergoing modulated rotation is experimentally studied.The layer has a circular axisymmetric boundary.In the absence of modulation of the rotation speed,the interphase boundary has the shape of a short axisymmetric cylinder.A new effect has been discovered,under the influence of rotation speed modulation,the interface takes on a new dynamic equilibrium state.A more viscous liquid covers the end boundaries of the layer in the form of thin films,which have the shape of round spots of almost constant radius;with increasing amplitude of the velocity modulation,the wetting boundary expands.It is found that upon reaching the critical amplitude of oscillations,the film of a viscous liquid loses stability,and the outer edge of the wetting spot collapses and takes on a feathery structure.It is shown that this threshold is caused by the development of the Kelvin-Helmholtz oscillatory instability of the film.The spreading radius of a spot of light viscous liquid and its stability are studied depending on the rotation rate,amplitude,and frequency of rotation speed modulation.The discovered averaged effects are determined by different oscillatory interaction of fluids with the end-walls of the cell,due to different viscosities.The effect of films forming can find application in technological processes to intensify mass transfer at interphase boundaries.
基金supported by the Ministry of Education of the Russian Federation(Project KPZU-2023-0002).
文摘This work is devoted to the experimental study of inertial wave regimes in a non-uniform rotating cylinder with antiparallel inclined ends.In this setting,the cross-section of the cylinder is divided into two regions where the fluid depth increases or decreases with radius.Three different regimes are found:inertial wave attractor,global oscillations(the cavity’s resonant modes)and regime of symmetric reflection of wave beams.In linear wave regimes,a steady single vortex elongated along the rotation axis is generated.The location of the wave’s interaction with the sloping ends determines the vortex position and the vorticity sign.In non-linear regimes several pairs of the triadic resonance subharmonics are detected simultaneously.The instability of triadic resonance is accompanied by the periodic generation of mean vortices drifting in the azimuthal direction.Moreover,the appearance frequency of the vortices is consistent with the low-frequency subharmonic of the triadic resonance.The experimental results shed light on the mechanisms of the inertial wave interaction with zonal flow and may be useful for the development of new methods of mixing.
文摘The article presents the biology of flowering and the daily dynamics of flowering of two species from the Lamiaceae family: ph. anisochila va ph. sogdiana of the distribution out in the Nuratau Mountains range.
文摘In the field of stroke imaging, deep learning (DL) has enormousuntapped potential.When clinically significant symptoms of a cerebral strokeare detected, it is crucial to make an urgent diagnosis using available imagingtechniques such as computed tomography (CT) scans. The purpose of thiswork is to classify brain CT images as normal, surviving ischemia or cerebralhemorrhage based on the convolutional neural network (CNN) model. In thisstudy, we propose a computer-aided diagnostic system (CAD) for categorizingcerebral strokes using computed tomography images. Horizontal flip datamagnification techniques were used to obtain more accurate categorization.Image Data Generator to magnify the image in real time and apply anyrandom transformations to each training image. An early stopping method toavoid overtraining. As a result, the proposed methods improved several estimationparameters such as accuracy and recall, compared to other machinelearning methods. A python web application was created to demonstrate theresults of CNN model classification using cloud development techniques. Inour case, the model correctly identified the drawing class as normal with 79%accuracy. Based on the collected results, it was determined that the presentedautomated diagnostic system could be used to assist medical professionals indetecting and classifying brain strokes.
文摘According to one of the theses of optimal foraging theory,main prey species abundance in the hunting area is the main factor determining the diet and habitat choices of birds of prey.However other factors can also be important.The habitat structure influences the predators’diets as well.In this study we examined the influence of habitat structure on diet compositions of three species of birds:Long-eared Owl(Asio otus),Short-eared Owl(A.flammeus)and Common Kestrel(Falco tinnunculus).The study was carried out from 2007 to 2019 in a 48 km2area of the Crane’s Homeland Reserve,Moscow Region,Russia.The habitat structures of model species’hunting territories(ratio of different types of landscape elements)were classified in module"Semi-Automatic Classification Plugin"based on the QGIS.A boosted regression tree analysis identified that the share of the main prey species in the diet is primarily determined by the landscape structure of hunting territories.The largest share of Common Vole(Microtus arvalis)in birds’diet was determined by the shrubs area(15%of hunting area),the meadow area(75%),the habitat heterogeneity(70%)and the arable land area(5%).The same predictors determined the largest share of Root Vole(Microtus oeconomus):the shrubs area 25%,the meadow area 70%,and the arable land area 3%.The annual mean abundance of prey species did not determine their importance in the diet of birds of prey.Thus,the main prey abundance in the hunting area is not a determining factor for the formation of diet composition of birds of prey.
基金This work was supported by the National Natural Science Foundation of China(31871549,32001441 and 32272015)the Chongqing Research Program of Basic Research and Frontier Technology,China(cstc2015jcyjBX0143)+2 种基金the Fundamental Research Funds for the Central Universities,China(XDJK2020C038)the National Key R&D Program of China(2016YFD0100506)the Young Eagles Program of Chongqing Municipal Commission of Education,China(CY220219)。
文摘α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from deficiency of ALA because most staple food oils are low or lack ALA content.Biotechnological enrichment of ALA in staple oil crops is a promising strategy.Chia(Salvia hispanica)has the highest ALA content in its seed oil among known oil crops.In this study,the FAD2 and FAD3 genes from chia were engineered into a staple oil crop,oilseed rape(Brassica napus),via Agrobaterium tumefaciens-mediated transformation of their LP4-2A fusion gene construct driven by the seed-specific promoter P_(NapA).In seeds of T0,T1,and T2 lines,the average ALA contents were 20.86,23.54,and 24.92%,respectively,which were 2.21,2.68,and 3.03 folds of the non-transformed controls(9.42,8.78,and 8.22%),respectively.The highest seed ALA levels of T0,T1,and T2 plants were 38.41,35.98,and 39.19%respectively,which were 4.10-4.77 folds of the respective controls.FA-pathway enzyme genes(BnACCD,BnFATA,BnSAD,BnSCD,BnDGAT1,BnDGAT2,and BnDGAT3)and positive regulatory genes(BnWRI1,BnLEC1,BnL1L,BnLEC2,BnABI3,BnbZIP67,and BnMYB96)were all significantly up-regulated.In contrast,BnTT1,BnTT2,BnTT8,BnTT16,BnTTG1,and BnTTG2,encoding negative oil accumulation regulators but positive secondary metabolism regulators,were all significantly down-regulated.This means the foreign ShFAD2-ShFAD3 fusion gene,directly and indirectly,remodeled both positive and negative loci of the whole FA-related network in transgenic B.napus seeds.
文摘Communication in society had developed within cultural and geographical boundaries prior to the invention of digital technology.The latest advancements in communication technology have significantly surpassed the conventional constraints for communication with regards to time and location.These new platforms have ushered in a new age of user-generated content,online chats,social network and comprehensive data on individual behavior.However,the abuse of communication software such as social media websites,online communities,and chats has resulted in a new kind of online hostility and aggressive actions.Due to widespread use of the social networking platforms and technological gadgets,conventional bullying has migrated from physical form to online,where it is termed as Cyberbullying.However,recently the digital technologies as machine learning and deep learning have been showing their efficiency in identifying linguistic patterns used by cyberbullies and cyberbullying detection problem.In this research paper,we aimed to evaluate shallow machine learning and deep learning methods in cyberbullying detection problem.We deployed three deep and six shallow learning algorithms for cyberbullying detection problems.The results show that bidirectional long-short-term memory is the most efficient method for cyberbullying detection,in terms of accuracy and recall.
基金Deanship of Scientific Research at King Khalid University for funding this work through Large Group Research Project(No.RGP2/19/44)。
文摘In a wide variety of mechanical and industrial applications,e.g.,space cooling,nuclear reactor cooling,medicinal utilizations(magnetic drug targeting),energy generation,and heat conduction in tissues,the heat transfer phenomenon is involved.Fourier’s law of heat conduction has been used as the foundation for predicting the heat transfer behavior in a variety of real-world contexts.This model’s production of a parabolic energy expression,which means that an initial disturbance would immediately affect the system under investigation,is one of its main drawbacks.Therefore,numerous researchers worked on such problem to resolve this issue.At last,this problem was resolved by Cattaneo by adding relaxation time for heat flux in Fourier’s law,which was defined as the time required to establish steady heat conduction once a temperature gradient is imposed.Christov offered a material invariant version of Cattaneo’s model by taking into account the upper-connected derivative of the Oldroyd model.Nowadays,both models are combinedly known as the Cattaneo-Christov(CC)model.In this attempt,the mixed convective MHD Falkner-Skan Sutterby nanofluid flow is addressed towards a wedge surface in the presence of the variable external magnetic field.The CC model is incorporated instead of Fourier’s law for the examination of heat transfer features in the energy expression.A two-phase nanofluid model is utilized for the implementation of nano-concept.The nonlinear system of equations is tackled through the bvp4c technique in the MATLAB software 2016.The influence of pertinent flow parameters is discussed and displayed through different sketches.Major and important results are summarized in the conclusion section.Furthermore,in both cases of wall-through flow(i.e.,suction and injection effects),the porosity parameters increase the flow speed,and decrease the heat transport and the influence of drag forces.
文摘Breast milk is important for infant health. Some of its benefits are due to the presence of a specific population of bacteria in the microflora. However, the microbiome of breast milk is influenced by many parameters such as maternal diet, breastfeeding and geographic location. Culture and non-culture methods have been used in studies of this bacterial population worldwide. But in the DR Congo, there was no study reporting the use of culture-independent techniques to characterize the bacterial diversity of human milk. The aim of this study was to identify the bacterial 16S rRNA gene from two genera Lactobacillus and Bifidobacterium. The 16S rRNA gene was also identified from four species: Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacterium longum and Bifidobacterium lactis. This analytical cross-sectional study was conducted in Kinshasa. Breast milk from some healthy women was collected from February 2 to 28, 2018. A culture-independent protocol using the classical polymerase chain reaction (PCR) was used to identify the bacterial 16S rRNA gene. The 68 samples of breast milk were collected in a sterile condition. The bacteria-specific ribosomal gene 16S rRNA was detected in 91.18% of Lactobacillus and 32.35% of Bifidobacterium at genus level. At of species level, only Lactobacillus reuteri 16S rRNA gene was identified in 89.71%. The 16S rRNA gene from the other species could not be amplified. There was also an association between educational level and the presence of Bifidobacterium and Lactobacillus 16S rRNA genes in the breast milk (p = 0.008*, p Conclusion: This study demonstrates the presence of the bacterial 16S rRNA gene from Lactobacillus and Bifidobacterium in breast milk at the genus and Lactobacillus reuteri at species level. A further study on the diet, use of antibiotics during pregnancy and lactation practice will provide a better understanding of the microflora of breast milk.
文摘In this work, we consider the second order nonlinear integro-differential Equation (IDEs) of the Volterra-Fredholm type. One of the popular methods for solving Volterra or Fredholm type IDEs is the method of quadrature while the problem of consideration is a linear problem. If IDEs are nonlinear or integral kernel is complicated, then quadrature rule is not most suitable;therefore, other types of methods are needed to develop. One of the suitable and effective method is homotopy analysis method (HAM) developed by Liao in 1992. To apply HAM, we firstly reduced the IDEs into nonlinear integral Equation (IEs) of Volterra-Fredholm type;then the standard HAM was applied. Gauss-Legendre quadrature formula was used for kernel integrations. Obtained system of algebraic equations was solved numerically. Moreover, numerical examples demonstrate the high accuracy of the proposed method. Comparisons with other methods are also provided. The results show that the proposed method is simple, effective and dominated other methods.
文摘Background and Objective: Despite the costs generated in the diagnosis of cardiac pathologies by the use of ultrasound, the ECG indices have demonstrated a high performance in the studies of developed countries in the diagnosis of these pathologies, but the data of these in sub-Saharan Africa are limited. The objective of this study is to evaluate the performance of the Peguero-Lo Presti index in the diagnosis of LVH among Congolese in order to make it a means of LVH diagnosis in an under-equipped environment. Methods: Cross-sectional and analytical study including 413 patients followed and hospitalized at the CIMAK Hospital Center during the period from February 2019 to June 2021. Sociodemographic parameters, history, biology, ultrasound and ECG parameters were studied. The performance of the Peguero-Lo Presti Index was validated by the Youden Index reinforced by the Area under the ROC curve. Results: Of the 413 patients admitted to the study, 69.5% were men versus 30.5% women, i.e. a sex ratio of 2M/1F;the mean age of the patients was 51.1 ± 11.6 years. The frequency of LVH found by echocardiography was 55.9%, it was 50.8% using the Peguero-Lo Presti index, 22% and 10.2% using the Peguero-Lo Presti index, respectively. Sokolow-Lyon and Cornell (p 0.001). The Peguero-Lo Presti curve is higher than the Sokolow-Lyon and Cornell curves. The area under the curve was 0.80 for Peguero-Lo Presti, 0.73 for Sokolow-Lyon and 0.66 for cornell. Conclusion: The newly proposed Peguero-Lo Presti index provides high sensitivity and specificity for the diagnosis of LVH in black Africans as also reported in the European and American population.
文摘This study aims to investigate the main sectors of economic development before and the current situation of COVID-19 for Sub-Saharan African countries by demonstrating country experiences,the role of vaccines,and the SSA economy forecast.The study has four main sections,including an introduction,an overview of socioeconomic indicators before the pandemic,methods,results findings,and discussion.The study used mixed methods,including an approach based on secondary data.The quantitative results were analysed using both empirical methods and the researcher’s prior expertise.The analysis of the effects of the COVID-19 pandemic on SSA countries was based on long-term data collected by several international financial institutions.The research findings demonstrated conclusively that COVID-19 is causing the collapse of the SSA economy,the first economic recession in 25 years,$37-79 billion in lost GDP by 2020,and an export decrease of 10.6%.In education,for example,64%of primary and 50%of secondary students lack ICT training,89%(216 million)do not have access to a home computer,and 82%(199 million)do not have an Internet connection missed classes during the COVID-19 period.The agricultural sector in SSA is also impacted by over 239 million hungry people.COVID-19 mass vaccinations and public debt amount to over$154 billion in obligations to get the SSA economy back on its feet with zero tolerance for embezzlement of public funds.These results can be used to make the economies of SSA countries resilient to the current crises and to address some thematic issues,such as the implementation of the African Continental Free Trade Area(AfCFTA)in all SSA countries,which will save time and money by getting rid of border taxes.Therefore,policymakers can use the findings to begin formulating plans to address issues like economic development,education,and food insecurity.
文摘The aim of this study was to evaluate the ethnomedical knowledge of the population of South Ubangi on Myrianthus arboreus,a plant consumed by chimpanzees,with the assumption that this bio-resource is also used by the population in African Traditional Medicine to treat common diseases.The results revealed that M.arboreus treats 23 diseases in the province of South Ubangi in Democratic Republic of the Congo.Of these diseases,six(anaemia,bronchitis,tooth decay,gastritis,hypertension,and spleen)are the most cited.Anaemia and spleen are treated by all socio-cultural groups.The leaf is the most used organ(48%)followed by sap,roots,stems,bark,flowers,and seeds.Expression(61.5%)is the most used method of preparation followed by decoction,maceration,and mastication.Oral(94.5%)is the most used method of administration followed by body bath,massage,anal and auricular route.M.arboreus is a vulnerable species(Iv≥2.5)in the study area.The diseases treated are influenced by the level of education and the profession of the respondents(p<0.05).While the mode of preparation of recipes is influenced by the family situation,also the composition of recipes is influenced by gender,age and occupation(p<0.05).The search for new sources of bio-inspired drugs through zoopharmacognosy may thus allow the development of effective phytomedicines for the health care of humans or non-human primates ex situ.Thus the need for advanced phytochemical and pharmacological studies and the domestication of M.arboreus for its multiple food and pharmacological uses is necessary.
文摘The aim of this article is to prove a fixed point theorem in 2-Banach spaces and show its applications to the Ulam stability of functional equations. The obtained stability re- sults concern both some single variable equations and the most important functional equation in several variables, namely, the Cauchy equation. Moreover, a few corollaries corresponding to some known hyperstability outcomes are presented.
文摘Land use and land cover(LULC) changes and their impact on the mountain environment were studied in six catchments(~10 km^2 each) in the Polish Western Carpathians from the mid-19^(th) century to the early 21^(st) century. The analysis of cadastral and orthophoto maps indicates that during the investigated period, the forest area increased, quantified by an annual change index(Annch), between +0.12% to +0.27%, with a decrease of arable land index to –0.45% and –2.28% in the analysed catchments. LULC changes were accompanied by a continuous increase in settlement developments(residential and farming houses) by 50%-140% as well as significant changes related to their spatial distribution. Abandonment of arable land and forest succession have resulted in the geomorphological transformation of hillslopes, which predominantly includes a decrease in used road density, their transformation to road cuts and gorges. Overpopulation and the domination agriculture in the past caused the expansion of unpaved roads density and then the fragmentation of hillslopes, as well as the development of agricultural terraces.
文摘The Central Asian lowlands are characterized by an arid and continental climate. At the same time, the large streams and rivers have been providing water for the development of flourishing oases and extensive irrigated farming areas. Bukhara is one of those oases. The population of 1.7 mln. and especially the agricultural sector (with an irrigated area of 275,000 ha) use a considerable amount of water. But as the flat topography does not provide sufficient natural drainage, water logging and raising groundwater tables have become serious problems for the agricultural productivity. The combination of the high salinity of the irrigation water and the generous application of fertilizers leads to a widespread soil salinization. Excessive leaching is supposed to reduce the top soil salinity, but as the drainage system is only covering a small portion of the irrigated areas and is in need of maintenance, this process only contributes to the ongoing salinization and the reduction of soil fertility and crop yields. The data presented here for the years 2000 to 2013 indicate that the groundwater table is rising throughout the region while the groundwater salinity is decreasing. The soil salinity on the other hand is, after an improvement during the first half of the study period, slightly increasing since 2009, which also is reflected in the slight worsening of the condition of the reclaimed land during the same period.