314 research outputs found
Genetic and phenotypic mapping for leaf rust resistance; Lr34 in Indian bread wheat population
Marker assisted approach for incorporating durable rust resistance in popular Indian wheat cultivars
Isolation, identification and antibiotic susceptibility profiling of antimicrobial resistant Listeria monocytogenes from dairy milk
Abstract The objective of the present study wa
Germplasm characterization, association and clustering for salinity and waterlogging tolerance in bread wheat (Triticum aestivum)
A study was conducted for characterizing germplasm, estimating interrelationship of traits and clustering of wheat genotypes in five environments covering salinity, waterlogging and neutral soils using, 100 elite but diverse genotypes with eight checks of bread wheat (Triticum aestivum L.). These genotypes were planted under five distinct environments during rabi 2009-10 under augmented design in four blocks wherein each check was repeated twice. The genetic variance, correlation coefficients and cluster analysis were carried out for assessment of lines through seven metric traits, namely, plant stand, plant height, days to heading, days to maturity, tillers/meter, 1000-grain weight and grain yield. Analysis of variance revealed wide variability for most of the traits under study. The phenotypic coefficient of variation (PCV) was high for tillers/meter and grain yield, while high heritability coupled with high genetic advance were found for tillers/meter, 1000-grain weight and grain yield under all five environments. At phenotypic level, positive and significant correlation coefficients revealed that under all the normal and stressed environments used here, grain yield is directly influenced by plant stand, tillers/meter and thousand grain weights. Significant and positive correlations were estimated between tillers/meter (r = 0.31 to 0.66), and 1000 grain weight (r = 0.24 to 0.61) with grain yield under all five environments. Under waterlogged conditions there were significant negative correlations of plant height to grain yield (r = –0.38 to –0.39) across two sites. These results, thereby suggests that yield improvement in bread wheat could be possible by emphasizing these traits through selection in these diverse environments. On the basis of D2 values of pooled data, 108 genotypes were grouped into four clusters. In all, only 26 lines were found common in cluster III under two waterlogging environments (Faizabad and Karnal), while only 15 lines were common in cluster I under non waterlogging (Faizabad, CSSRI and DWR) conditions. These results indicate different constraints exist in waterlogged and non-waterlogged condition at these sites. Genetic diversity available for these traits may be utilized for yield improvement in bread wheat under different soil conditions through planned hybridization and selection in target environments
Diversity and Recognition Efficiency of T Cell Responses to Cancer
BACKGROUND: Melanoma patients vaccinated with tumor-associated antigens frequently develop measurable peptide-specific CD8+ T cell responses; however, such responses often do not confer clinical benefit. Understanding why vaccine-elicited responses are beneficial in some patients but not in others will be important to improve targeted cancer immunotherapies. METHODS AND FINDINGS: We analyzed peptide-specific CD8+ T cell responses in detail, by generating and characterizing over 200 cytotoxic T lymphocyte clones derived from T cell responses to heteroclitic peptide vaccination, and compared these responses to endogenous anti-tumor T cell responses elicited naturally (a heteroclitic peptide is a modification of a native peptide sequence involving substitution of an amino acid at an anchor residue to enhance the immunogenicity of the peptide). We found that vaccine-elicited T cells are diverse in T cell receptor variable chain beta expression and exhibit a different recognition profile for heteroclitic versus native peptide. In particular, vaccine-elicited T cells respond to native peptide with predominantly low recognition efficiency—a measure of the sensitivity of a T cell to different cognate peptide concentrations for stimulation—and, as a result, are inefficient in tumor lysis. In contrast, endogenous tumor-associated-antigen-specific T cells show a predominantly high recognition efficiency for native peptide and efficiently lyse tumor targets. CONCLUSIONS: These results suggest that factors that shape the peptide-specific T cell repertoire after vaccination may be different from those that affect the endogenous response. Furthermore, our findings suggest that current heteroclitic peptide vaccination protocols drive expansion of peptide-specific T cells with a diverse range of recognition efficiencies, a significant proportion of which are unable to respond to melanoma cells. Therefore, it is critical that the recognition efficiency of vaccine-elicited T cells be measured, with the goal of advancing those modalities that elicit T cells with the greatest potential of tumor reactivity
Cost-effectiveness of public-health policy options in the presence of pretreatment NNRTI drug resistance in sub-Saharan Africa : a modelling study
BACKGROUND: There is concern over increasing prevalence of non-nucleoside reverse-transcriptase inhibitor (NNRTI) resistance in people initiating antiretroviral therapy (ART) in low-income and middle-income countries. We assessed the effectiveness and cost-effectiveness of alternative public health responses in countries in sub-Saharan Africa where the prevalence of pretreatment drug resistance to NNRTIs is high. METHODS: The HIV Synthesis Model is an individual-based simulation model of sexual HIV transmission, progression, and the effect of ART in adults, which is based on extensive published data sources and considers specific drugs and resistance mutations. We used this model to generate multiple setting scenarios mimicking those in sub-Saharan Africa and considered the prevalence of pretreatment NNRTI drug resistance in 2017. We then compared effectiveness and cost-effectiveness of alternative policy options. We took a 20 year time horizon, used a cost effectiveness threshold of US$500 per DALY averted, and discounted DALYs and costs at 3% per year. FINDINGS: A transition to use of a dolutegravir as a first-line regimen in all new ART initiators is the option predicted to produce the most health benefits, resulting in a reduction of about 1 death per year per 100 people on ART over the next 20 years in a situation in which more than 10% of ART initiators have NNRTI resistance. The negative effect on population health of postponing the transition to dolutegravir increases substantially with higher prevalence of HIV drug resistance to NNRTI in ART initiators. Because of the reduced risk of resistance acquisition with dolutegravir-based regimens and reduced use of expensive second-line boosted protease inhibitor regimens, this policy option is also predicted to lead to a reduction of overall programme cost. INTERPRETATION: A future transition from first-line regimens containing efavirenz to regimens containing dolutegravir formulations in adult ART initiators is predicted to be effective and cost-effective in low-income settings in sub-Saharan Africa at any prevalence of pre-ART NNRTI resistance. The urgency of the transition will depend largely on the country-specific prevalence of NNRTI resistance. FUNDING: Bill & Melinda Gates Foundation, World Health Organization
Subcortical brain atrophy persists even in HAART-regulated HIV disease
The purpose of this study was to determine the pattern and extent of caudate nucleus and putamen atrophy in HIV-infected men with well-controlled immune status and viral replication. 155 men underwent structural brain magnetic resonance imaging; 84 were HIV-infected and 71 were uninfected controls. MRI data were processed using the Fully Deformable Segmentation routine, producing volumes for the right and left caudate nucleus and putamen, and 3-D maps of spatial patterns of thickness. There was significant atrophy in the HIV-infected men in both the caudate and putamen, principally in the anterior regions. The volume of the basal ganglia was inversely associated with the time since first seropositivity, suggesting that either there is a chronic, subclinical process that continues in spite of therapy, or that the extent of the initial insult caused the extent of atrophy
Fog computing security: a review of current applications and security solutions
Fog computing is a new paradigm that extends the Cloud platform model by providing computing resources on the edges of a network. It can be described as a cloud-like platform having similar data, computation, storage and application services, but is fundamentally different in that it is decentralized. In addition, Fog systems are capable of processing large amounts of data locally, operate on-premise, are fully portable, and can be installed on heterogeneous hardware. These features make the Fog platform highly suitable for time and location-sensitive applications. For example, Internet of Things (IoT) devices are required to quickly process a large amount of data. This wide range of functionality driven applications intensifies many security issues regarding data, virtualization, segregation, network, malware and monitoring. This paper surveys existing literature on Fog computing applications to identify common security gaps. Similar technologies like Edge computing, Cloudlets and Micro-data centres have also been included to provide a holistic review process. The majority of Fog applications are motivated by the desire for functionality and end-user requirements, while the security aspects are often ignored or considered as an afterthought. This paper also determines the impact of those security issues and possible solutions, providing future security-relevant directions to those responsible for designing, developing, and maintaining Fog systems
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