188 research outputs found

    Physiological Effects on the Expression of Aquaporin 1-Like HC-1 in Cope\u27s Gray Tree Frog, \u3cem\u3eHyla Chrysoscelis\u3c/em\u3e

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    Aquaporin 1 is a cell membrane integral protein, which functions for water transport through the hydrophobic cell membrane to the cytoplasm. HC-1 is an aquaporin 1-like protein expressed in Hyla chrysoscelis and amphibian that survives at sub-freezing temperatures in its natural habitat. The goal of the current study was to investigate the expression of HC-1 during changing physiological conditions. The expression level of HC-1 was determined in skin, muscle, liver, kidney, and intestines of warm, cold, frozen, and dehydrated frogs using Western blot and immunohistofluorescence. Although HC-1 was widely distributed, the expression level varied among tissues and physiological conditions. In addition, HC-1 was present in both glycosylated and deglycosylated forms, the pattern of glycosylation also varied with tissues and physiological conditions. Thus, I conclude that HC-1 is widely expressed in tissues of Hyla chrysoscelis, and that it is regulated in these tissues according to physiological demands

    Modeling and Analysis of the Spread of Japanese Encephalitis with Environmental Effects

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    A nonlinear mathematical model for the spread of Japanese Encephalitis, caused by infected mosquito feeding on susceptible human population incorporating demographic and environmental factors is proposed and analyzed. In the modeling process, it is assumed that the growth rates of reservoir animal population and vector mosquito population are enhanced due to environmental discharges caused by human population related factors. The model is analyzed by stability theory of differential equations and computer simulation. Both the disease-free and the endemic equilibria are found and their stability is investigated. It is found that whenever the disease-free equilibrium is locally asymptotically stable, the endemic equilibrium does not exist. The analysis of the model shows that if the growth rates of reservoir animal population and vector mosquito population caused by environmental factors increase, the spread of Japanese Encephalitis increases and the disease becomes more endemic due to human immigration. Numerical simulations are also carried out to investigate the influence of certain parameters on the spread of disease, to support the analytical results and illustrate possible behavioral scenario of the model

    Modeling the Effect of Environmental Factors on the Spread of Bacterial Disease in an Economically Structured Population

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    We have proposed and analyzed a nonlinear mathematical model for the spread of bacterial disease in an economically structured population (rich and poor) including the role of vaccination. It is assumed that rich susceptible get infected through direct contact with infectives in the same class and with infectives from the poor class who work as service providers in the houses of rich people, living in much cleaner environment. The susceptible in the poor class are assumed to become infected through direct contact with infectives in the same class as well as by bacteria present in their own environment, degraded due to unhygienic environmental conditions. It is further assumed that the bacteria population affects only the population in the degraded environment of the poor class but does not survive in the clean environment of rich people. The density of bacteria population is assumed to be governed by a logistic model and is dependent on environmental discharges conducive to the growth of bacteria population. The cumulative density of environmental discharges depends upon the human population related factors of the poor class. The model analysis shows that the increased growth rate of environmental discharges increases the bacteria population density in the poor class due to unhygienic environmental conditions leading to increase the infectives in the poor class i.e., service providers. As a consequence, due to interaction with these service providers the spread of disease increases in the rich class. The improved environmental conditions of the region inhabited by service providers along with suitable vaccination strategy can be helpful in reducing the spread of the disease

    Characterizing the tolerance of near infrared fluorescent bacterial phytochromes to random backbone fission and circular permutation

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    Protein fission, fusion, and circular permutation have been used to convert green fluorescent protein (GFP) family members into biosensors that dynamically report on cellular processes, ranging from protein expression and metabolite concentrations to protein solubility, protein-protein interactions, and ligand-binding. Unfortunately, GFP are unsuitable for deep tissue reporting in animal models because the wavelengths of light used with these reporters is highly absorbed by tissues. In contrast, near infrared fluorescent protein (IFP and iRFP) reporters derived from bacterial phytochrome proteins (BphP) are excited by light in the near-infrared spectrum (~700 nm, less absorptive) and are better suited for probing cellular processes within tissues. IFP and iRFP can report on biological processes under anaerobic conditions because it uses biliverdin (BV) as a chromophore and does not require oxygen for maturation, a requisite for GFP maturation. Unlike GFP, IFP and iRFP are not yet able to report on wide-range of biological processes beyond gene expression. To report on gene expression, BphP must interlace its Per/ARNT/Sim (PAS) and cGMP phosphodiesterase/adenylcyclase/FhlA (GAF) domains into a topological knot. The extent to which this complex topology tolerates mutations (fission, fusion, and circular permutation) used to convert proteins into biosensors is not known. To better understand the tolerance of BphP to these types of mutational lesions, I have subjected IFP to random backbone fragmentation and iRFP to circular permutation using transposase mutagenesis. Screening a library of split IFP for fluorescent variants yielded thirteen unique fragmented IFP and with parent like spectral properties. These two-fragment IFP all required assistance from associating proteins for maximal fluorescence. These split sites displayed AND gate logic behavior when the ORFs encoding the different fragment are placed under distinct transcriptional regulation. In addition, screening a library of circularly permuted iRFP led to the discovery of twenty seven permuted iRFP variants with near infrared fluorescence. These variants arose from backbone fission in both the PAS and GAF domains, although the brightest permuted iRFP initiated at residues near the domain linker and termini. Biochemical analysis revealed that permuted iRFP display similar oligomerizatoin, quantum yield, and stability as native iRFP. These proteins also retained sufficient BV affinity serve as reporters of gene expression in mammalian cells without the addition of exogenous BV. The results described in this thesis represent the first study to map the tolerance of a BphP to random fragmentation and circular permutation. These results demonstrate that knotted BphP retain the ability to fold as their contact order changes, suggesting that these proteins can be further developed as reporters of biological processes like GFP. The split IFP represent a suite of assays that will be useful for monitoring the dynamics of a protein-protein interactions under conditions where split GFP do not yield strong signals. These split IFP can also be used to report on protein-ligand interactions that regulate protein oligomerization. The permuted iRFP should be useful for building molecular switches through domain insertion, in which the set of permuted iRFP is randomly inserted into other protein domains to couple the ligand binding to iRFP fluorescence

    Analysis of a Vaccination Model for Carrier Dependent Infectious Diseases with Environmental Effects

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    We have proposed and analyzed a nonlinear mathematical model for the spread of carrier dependent infectious diseases in a population with variable size structure including the role of vaccination. It is assumed that the susceptibles become infected by direct contact with infectives and/or by the carrier population present in the environment. The density of carrier population is assumed to be governed by a generalized logistic model and is dependent on environmental and human factors which are conducive to the growth of carrier population. The model is analyzed using stability theory of differential equations and numerical simulation. We have found a threshold condition, in terms of vaccine induced reproduction number R(φ) which is, if less than one, the disease dies out in the absence of carriers provided the vaccine efficacy is high enough, and otherwise the infection is maintained in the population. The model also exhibits backward bifurcation at R(φ) = 1. It is also shown that the spread of an infectious disease increases as the carrier population density increases. In addition, the constant immigration of susceptibles makes the disease more endemic

    BCT-CS : blockchain technology applications for cyber defense and cybersecurity : a survey and solutions

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    Blockchain technology has now emerged as a ground-breaking technology with possible solutions to applications from securing smart cities to e-voting systems. Although it started as a digital currency or cryptocurrency, bitcoin, there is no doubt that blockchain is influencing and will influence business and society more in the near future. We present a comprehensive survey of how blockchain technology is applied to provide security over the web and to counter ongoing threats as well as increasing cybercrimes and cyber-attacks. During the review, we also investigate how blockchain can affect cyber data and information over the web. Our contributions included the following: (i) summarizing the Blockchain architecture and models for cybersecurity (ii) classifying and discussing recent and relevant works for cyber countermeasures using blockchain (iii) analyzing the main challenges and obstacles of blockchain technology in response to cyber defense and cybersecurity and (iv) recommendations for improvement and future research on the integration of blockchain with cyber defense. © 2022,International Journal of Advanced Computer Science and Applications. All Rights Reserved

    Effect of age of plantation on seed characters and growth performance of Tokopatta (Livistona jinkensiana Griff.) seedling

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    Tokopatta palm (Livistona jinkensiana) is a valuable non timber multiple end uses forest species of Arunachal Pradesh. In order to establish improved plantation, the production of quality seedling of this species is essential. The present study was undertaken to determine tree age effects on seed characters, seed germination and performance of seedlings. The 500 seeds sample from each plantations aged 18, 25, 35, 45, 54, 63 and 74 years old around Pasighat town under East Siang district, Arunachal Pradesh, India were taken to see the effect of tree ageon seed morphological characters, seed germination and seedling performance. Significant variation was observed for seed diameter and seed weight between plantations of different ages. The age effect was also seen in the germination patterns with middle aged plantations producing most superior seeds in terms of seed morphological parameters and germination behavior. Seedling attributes after 12 months showed that seedling obtained from young and middle aged plantations (between 18 to 45 years) performed better than those beyond 50 years

    Projected distribution of the westernmost subpopulation of Assamese macaques (Macaca assamensis pelops) under climate change: conservation implications of a threatened population

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    Anthropogenic climate change can have a negative impact on the distribution of habitat specialist species with narrow distributional ranges. Among the many areas around the world affected by climate change, the Himalayan region in particular is experiencing marked effects of global warming on its climatic patterns and life forms. This study assessed the current distribution of Assamese macaques (Macaca assamensis) in western Nepal, and projected their likely distribution (via habitat suitability modeling) for the years 2050 and 2070 under the two most plausible greenhouse gas emission scenarios (RCP4.5 and RCP6.0). We recorded a total of 159 Assamese macaques belonging to 10 groups (nine of them residing outside of protected area networks) between 684m and 2550m asl in western Nepal. Climatic niche modeling predicted that 37.03% (25,114 km2) of the total area of western Nepal (67,813 km2) represented suitable habitat of the species, the majority of which ranged between 1000 m and 2000 m asl. Future projections of the current climatic niche of the Assamese macaques revealed a consistent decrease in the suitable habitat for 2050 and 2070 in both of the greenhouse emission scenarios tested. With the RCP6.0 scenario, almost 57% of the current highly suitable habitat would be lost by 2070 with remaining suitable habitat shifted towards higher elevations. The loss of habitat directly affects the species survival and the range shift towards higher elevation exposes them to new areas for conflict with humans. Therefore, the Assamese macaque population in western Nepal requires a high conservation priority with the establishment of new protected areas

    Surface properties of AlInGaN/GaN heterostructure

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    Surface structural, electronic and electrical properties of the quaternary alloy AlInGaN/GaN heterostructures are investigated. Surface termination, atomic arrangement, electronic and electrical properties of the (0001) surface and (10-11) V-defect facets have been experimentally analyzed using various surface sensitive techniques including spectroscopy and microscopy. Moreover, the effect of sub-band gap (of the barrier layer) illumination on contact potential difference (VCPD) and the role of oxygen chemisorption have been studied
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