Conformational and Structural Relaxations of Poly(ethylene oxide) and Poly(propylene oxide) Melts: Molecular Dynamics Study of Spatial Heterogeneity, Cooperativity, and Correlated Forward-Backward Motion

Performing molecular dynamics simulations for all-atom models, we characterize the conformational and structural relaxations of poly(ethylene oxide) and poly(propylene oxide) melts. The temperature dependence of these relaxation processes deviates from an Arrhenius law for both polymers. We demonstrate that mode-coupling theory captures some aspects of the glassy slowdown, but it does not enable a complete explanation of the dynamical behavior. When the temperature is decreased, spatially heterogeneous and cooperative translational dynamics are found to become more important for the structural relaxation. Moreover, the transitions between the conformational states cease to obey Poisson statistics. In particular, we show that, at sufficiently low temperatures, correlated forward-backward motion is an important aspect of the conformational relaxation, leading to strongly nonexponential distributions for the waiting times of the dihedrals in the various conformational statesComment: 13 pages, 13 figure

The Shapes of Cooperatively Rearranging Regions in Glass Forming Liquids

The shapes of cooperatively rearranging regions in glassy liquids change from being compact at low temperatures to fractal or ``stringy'' as the dynamical crossover temperature from activated to collisional transport is approached from below. We present a quantitative microscopic treatment of this change of morphology within the framework of the random first order transition theory of glasses. We predict a correlation of the ratio of the dynamical crossover temperature to the laboratory glass transition temperature, and the heat capacity discontinuity at the glass transition, Delta C_p. The predicted correlation agrees with experimental results for the 21 materials compiled by Novikov and Sokolov.Comment: 9 pages, 6 figure

Total Factor Productivity Change of Ethiopian Microfinance Institutions (MFIs): A Malmquist Productivity Index Approach (MPI)

By employing the Malmquist productivity index this study attempts to examine the total factor productivity change in the Ethiopian micro finance institutions (MFIs) using a balanced panel dataset of 114 observations from 19 micro finance institutions over the period 2004-2009. The selection of inputs and outputs for the study is based on the dual objectives of MFIs viz outreach and sustainability framework which is in line with the prior study of (Gutierrez et al 2007, 2009). Consequently, we specify two inputs and three outputs; the number of employees, and operating expenses are specified as inputs whereas the outputs are interests and fee income, gross loan portfolio, and number of loans outstanding (number). The result of the study indicated that over the period the malmquist productivity change experienced by the micro finance industry as a whole has averaged 3.8 % annually. With the exception of the year 2004-2005 (slight decline in productivity, which was 0.2 percent) the micro finance industry has reported productivity progress in the study period(i.e productivity rose of 5.5 percent, 5.8 percent,0.3 percent and 7.7 percent in the years 2005-2006, 2006-2007, 2007-2008 and 2008-2009 respectively. It is apparent from the analysis that the main source of total factor productivity (TFP) growth for the MFIs was attributed to the technical efficiency change(10.1 percent increase) as the result depicted that 16 out of 19 MFIs ( about 84 %) has shown improvement in technical efficiency changes. In contrast, only 5 out of 19 (26.3%) MFIs have shown improvement in technological change but still the industry as a whole has exhibited a decline in technological change (5.8 percent decrease over the period) and suggested that there has been a deterioration in the performance of the best practicing micro finance institutions. Further the result showed that pure technical efficiency increased by 8.9 percent while scale efficiency contributed on average 1.1 percent increase and hence suggested that during the study period the Ethiopian MFIs have experienced mainly an increment of pure technical efficiency( improvement in management practices) rather than an improvement in optimum size(scale efficiency change). Generally, an important implication for the Ethiopian micro finance industry is that they need to pursue a technological progress in order to meet the dual objectives of reaching many poor people and financial sustainability.Key words: Productivity Change, Malmquist Productivity Index, Ethiopian MFIs

Breeding practice and estrus synchronization evaluation of dairy cattle in central Zone of Tigray, northern Ethiopia

The study was conducted in central zone, Tigray, Northern Ethiopia, aimed with assessment of breeding practices and evaluation of estrus synchronization of dairy cattle. The study of the survey covered 180 households found in per-urban and rural areas of Ahferom, Adwa and Laelay michew district which included 113 in rural areas and 67 in per-urban areas of the districts. The Information was collected from secondary data, group discussion, AI technician, household level survey questionnaire, farm visit and personal observations. Seven hundred one synchronized cows were selected form record of artificial insemination centre and evaluated for conception rate and number of service per conception. For experimental study a total of 126 dairy cattle 42 cows from each district were selected for PGF2α treatment. Single shot of PGF2 were given for dairy cattle that exhibited estrus after first injection and double shot has given to cows that failed to show heat after single injection. Twenty conceived lactating cows were used for progesterone profile assay using hormonost micro lab farmers test to check pregnancy and embryo mortality. The data were analyzed using SPSS (16) and SAS (9.1). Dairy cattle were kept for generating income (35.6%), milk consumption (32.2%) and milk consumption and breeding (16.1%) in the study area. Purchased dairy cattle (69.9% and 68.7%) were the main foundation stock followed by own (20.35% and 17.91%) in rural and per-urban areas respectively. Mating system in the study area were AI (42.8%), AI with estrus synchronization (22.2%) and natural mating (35%). Households obtained breeding bull from neighboring (61.4%), own (21.3%) and village (17.3%). Individual performance and pedigree selection were used as selection criteria for dairy cattle. Trait preference of farmers were milk yield (1st) body weight (2nd)) and fertility (3rd) for both rural and per-urban areas. Production system significantly affected daily milk yield of local cattle and cross dairy cattle. In the study area AFC (3.9± 0.8, 3.0± 0.9) years, CI (1.7± 0.4, 1.3 ±0.5) years and DO (10.9 ±0.5, 6.9± 0.62) months were for local and cross cattle respectively. Overall CR and NSC of mass synchronization were 37.95% and 2.63 respectively. BCS, bull and AI technician significantly affected CR and NSC in mass synchronization. From single injection in the experimental study 84.9% cows responded to PGF2α and 51.4% of them were conceived. 89.5% Cows show estrus sign and 52.9% conceived with double injection. Among 20 cows assumed to be pregnant on basis of milk progesterone concentration on day 18-24 post insemination, 85% were confirmed to be pregnant and 15% showed late embryonic death. Community based breeding program is the best option to improve dairy breeding practice in the study area. Improvements in facilities and management should be necessary before implementing an estrous synchronization program. Giving second injection for cows not responded for first injection of PGF2α has complimentary advantage to single injection. Progesterone assay using hormonost micro lab farmers test is a practical solution for dairy farmers to detect estrus, pregnancy and embryo mortality

Corresponding States of Structural Glass Formers

The variation with respect to temperature T of transport properties of 58 fragile structural glass forming liquids (68 data sets in total) are analyzed and shown to exhibit a remarkable degree of universality. In particular, super-Arrhenius behaviors of all super-cooled liquids appear to collapse to one parabola for which there is no singular behavior at any finite temperature. This behavior is bounded by an onset temperature To above which liquid transport has a much weaker temperature dependence. A similar collapse is also demonstrated, over the smaller available range, for existing numerical simulation data.Comment: 6 pages, 2 figures. Updated References, Table Values, Submitted for Publicatio

Rna interference strategies for future management of plant pathogenic fungi: Prospects and challenges

Plant pathogenic fungi are the largest group of disease-causing agents on crop plants and represent a persistent and significant threat to agriculture worldwide. Conventional approaches based on the use of pesticides raise social concern for the impact on the environment and human health and alternative control methods are urgently needed. The rapid improvement and extensive implementation of RNA interference (RNAi) technology for various model and non-model organisms has provided the initial framework to adapt this post-transcriptional gene silencing technology for the management of fungal pathogens. Recent studies showed that the exogenous application of double-stranded RNA (dsRNA) molecules on plants targeting fungal growth and virulence-related genes provided disease attenuation of pathogens like Botrytis cinerea, Sclerotinia sclerotiorum and Fusarium graminearum in different hosts. Such results highlight that the exogenous RNAi holds great potential for RNAi-mediated plant pathogenic fungal disease control. Production of dsRNA can be possible by using either in-vitro or in-vivo synthesis. In this review, we describe exogenous RNAi involved in plant pathogenic fungi and discuss dsRNA production, formulation, and RNAi delivery methods. Potential challenges that are faced while developing a RNAi strategy for fungal pathogens, such as off-target and epigenetic effects, with their possible solutions are also discussed

Double-Stranded RNA Targeting Dicer-Like Genes Compromises the Pathogenicity of Plasmopara viticola on Grapevine

Downy mildew caused by Plasmopara viticola is one of the most devastating diseases of grapevine, attacking all green parts of the plant. The damage is severe when the infection at flowering stage is left uncontrolled. P. viticola management consumes a significant amount of classical pesticides applied in vineyards, requiring efficient and environmentally safe disease management options. Spray-induced gene silencing (SIGS), through the application of exogenous double-stranded RNA (dsRNA), has shown promising results for the management of diseases in crops. Here, we developed and tested the potential of dsRNA targeting P. viticola Dicer-like (DCL) genes for SIGS-based crop protection strategy. The exogenous application of PvDCL1/2 dsRNA, a chimera of PvDCL1 and PvDCL2, highly affected the virulence of P. viticola. The reduced expression level of PvDCL1 and PvDCL2 transcripts in infected leaves, treated with PvDCL1/2 dsRNA, was an indication of an active RNA interference mechanism inside the pathogen to compromise its virulence. Besides the protective property, the PvDCL1/2 dsRNA also exhibited a curative role by reducing the disease progress rate of already established infection. Our data provide a promising future for PvDCL1/2 dsRNA as a new generation of RNA-based resistant plants or RNA-based agrochemical for the management of downy mildew disease in grapevine

Global, regional, and national burden of tuberculosis, 1990–2016: results from the Global Burden of Diseases, Injuries, and Risk Factors 2016 Study

Background Although a preventable and treatable disease, tuberculosis causes more than a million deaths each year. As countries work towards achieving the Sustainable Development Goal (SDG) target to end the tuberculosis epidemic by 2030, robust assessments of the levels and trends of the burden of tuberculosis are crucial to inform policy and programme decision making. We assessed the levels and trends in the fatal and non-fatal burden of tuberculosis by drug resistance and HIV status for 195 countries and territories from 1990 to 2016. Methods We analysed 15 943 site-years of vital registration data, 1710 site-years of verbal autopsy data, 764 site-years of sample-based vital registration data, and 361 site-years of mortality surveillance data to estimate mortality due to tuberculosis using the Cause of Death Ensemble model. We analysed all available data sources, including annual case notifications, prevalence surveys, population-based tuberculin surveys, and estimated tuberculosis cause-specific mortality to generate internally consistent estimates of incidence, prevalence, and mortality using DisMod-MR 2.1, a Bayesian meta-regression tool. We assessed how the burden of tuberculosis differed from the burden predicted by the Socio-demographic Index (SDI), a composite indicator of income per capita, average years of schooling, and total fertility rate. Findings Globally in 2016, among HIV-negative individuals, the number of incident cases of tuberculosis was 9·02 million (95% uncertainty interval [UI] 8·05–10·16) and the number of tuberculosis deaths was 1·21 million (1·16–1·27). Among HIV-positive individuals, the number of incident cases was 1·40 million (1·01–1·89) and the number of tuberculosis deaths was 0·24 million (0·16–0·31). Globally, among HIV-negative individuals the age-standardised incidence of tuberculosis decreased annually at a slower rate (–1·3% [–1·5 to −1·2]) than mortality did (–4·5% [–5·0 to −4·1]) from 2006 to 2016. Among HIV-positive individuals during the same period, the rate of change in annualised age-standardised incidence was −4·0% (–4·5 to −3·7) and mortality was −8·9% (–9·5 to −8·4). Several regions had higher rates of age-standardised incidence and mortality than expected on the basis of their SDI levels in 2016. For drug-susceptible tuberculosis, the highest observed-to-expected ratios were in southern sub-Saharan Africa (13·7 for incidence and 14·9 for mortality), and the lowest ratios were in high-income North America (0·4 for incidence) and Oceania (0·3 for mortality). For multidrug-resistant tuberculosis, eastern Europe had the highest observed-to-expected ratios (67·3 for incidence and 73·0 for mortality), and high-income North America had the lowest ratios (0·4 for incidence and 0·5 for mortality). Interpretation If current trends in tuberculosis incidence continue, few countries are likely to meet the SDG target to end the tuberculosis epidemic by 2030. Progress needs to be accelerated by improving the quality of and access to tuberculosis diagnosis and care, by developing new tools, scaling up interventions to prevent risk factors for tuberculosis, and integrating control programmes for tuberculosis and HIV