291 research outputs found
Improving Accuracy of Genomic Prediction in Holstein Friesians
Three statistical models were considered to assess the advantage of including information of known causative mutations when estimating genomic breeding values. Data included phenotypic records and 50k genotypes from 5,661 Holstein Friesian cows. This study showed that when aknown causative mutation for milk traits, DGAT1, was fit as a fixed effect in genomic prediction, an increase in accuracy was seen compared to fitting it as either a random effect or not explicitly fitting it and relying on linked markers fitted as random effects. The regression coefficients of genomic prediction on phenotype were near one for all estimates, indicating that no major bias was present in the estimates. These results suggest that, when calculatinggenomic predictions, it is beneficial to include information from known major genes in the analysis to increase the accuracy of prediction
Improved pitting corrosion resistance of S.S 316L by Pulsed Current Gas Tungsten Arc Welding
In this study, S.S 316L was welded using Direct Current Gas Tungsten Arc Welding (DGTAW) and Pulsed Current Gas Tungsten Arc Welding (PGTAW) methods. Optical observations, scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) were employed to study the effect of continuous and pulse currents on microstructure and phase transformation in weld metal (WM). In addition pits morphology were evaluated by SEM. The corrosion behaviour was analyzed using cyclic polarizaton tests and Mott-schottky measurements. The pulse current resulted in finer grain and more ferrite in WM. This can be due to the decrease in heat input and higher cooling rate encouraged by pulse current. Cyclic potentiodynamic polarization tests showed that the WM of sample produced by pulse current show higher corrosion and pitting resistances than that in sample produced by continuous current. The reason is attributed to lower segregation of solute elements such as chromium and molybdenum into the delta-ferrite and also finer grain size produced in WM due to lower heat input and higher cooling rate. Both of these factors increase the stability of passive layer formed. The results showed that the corrosion behaviour of WM in both conditions (pulse and continuous current) is higher than the base metal (BM). This fact is attributed to the presence of ferrite bands formed in BM due to the segregation of alloy elements. The Mott-schottky plots confirmed that the passive layer formed on welded samples was an n-type semiconductor. The results showed that the samples showed less pitting resistance contained more oxygen vacancies in their passive film structure. It is also concluded that the breakdown of passive layer and pitting formation obey point defect model (PDM). Keywords: S.S 316L, Pulsed Current Gas Tungsten Arc Welding (PGTAW), lacy ferrite, vermicular ferrite, Pitting corrosion, Mott- Schottky
Improving the Accuracy of Genomic Prediction of Milk Fat
Four statistical models were considered to quantify any advantage of including the genotype of known causative mutations when calculating direct genomic values. Data included 50k genotypes from 5,661 Holstein Friesian cows and 2,287 bulls. This study showed that when a known QTL for milk traits, DGAT1, was fit as a fixed class or fixed covariate in genomic prediction, an increase in accuracy was seen compared to fitting it as either a random covariate or relying on linked 50k markers fit as random covariates. The regression coefficients of genomic prediction on phenotype were near one for all estimates, indicating no major bias was in the estimates. These results suggest it is beneficial to the accuracy of prediction to include information from known major QTL in genomic analyses
Tracking 21st century anthropogenic and natural carbon fluxes through model-data integration
Monitoring the implementation of emission commitments under the Paris agreement relies on accurate estimates of terrestrial carbon fluxes. Here, we assimilate a 21st century observation-based time series of woody vegetation carbon densities into a bookkeeping model (BKM). This approach allows us to disentangle the observation-based carbon fluxes by terrestrial woody vegetation into anthropogenic and environmental contributions. Estimated emissions (from land-use and land cover changes) between 2000 and 2019 amount to 1.4 PgC yr−1, reducing the difference to other carbon cycle model estimates by up to 88% compared to previous estimates with the BKM (without the data assimilation). Our estimates suggest that the global woody vegetation carbon sink due to environmental processes (1.5 PgC yr−1) is weaker and more susceptible to interannual variations and extreme events than estimated by state-of-the-art process-based carbon cycle models. These findings highlight the need to advance model-data integration to improve estimates of the terrestrial carbon cycle under the Global Stocktake
Comparison of the effects of acupressure and touch on the headache caused by spinal anesthesia after cesarean section
Introduction: Post-Dural puncture headache (PDPH) is one of the common complications of spinal anesthesia, especially after cesarean section. It is better to treat this headache by non-pharmaceutical methods. One of the non-pharmaceutical pain control methods is the use of acupressure. But so far, its impact on headache after spinal anesthesia has not been studied. Therefore, this study was performed with aim to evaluate the effect of acupressure and touch on headache caused by spinal anesthesia after cesarean section. Methods: This randomized clinical trial with control group was conducted on 90 patients who underwent cesarean section by spinal anesthesia in Semnan Amir AlMomenin (A) Hospital in 2015. These patients were randomly divided into acupressure, touch and control groups. Pain severity was measured by Visual Analog Scale (VAS). Then, changes of pain severity pre and post intervention was measured and recorded. Data was analyzed by SPSS software (version 16) and Pearson and Spearman correlation coefficient tests, Kruskal-Wallis test, ANOVA and paired t-test. P0.05). After the intervention, there was a statistically significant decrease in mean pain score in acupressure and touch groups in comparison with control group (P<0.001). Also, after intervention, there was a statistically significant decrease in mean of headache scores in the acupressure group compared with touch group (P<0.001). Conclusion: Comparing with touch, acupressure was more effective for headache-relieving after spinal anesthesia in women undergoing cesarean section. Therefore, it is suggested that acupressure along with other conventional treatments be used to control and treat such headaches. © 2016, Mashhad University of Medical Sciences. All Rights Reserved
Scans for signatures of selection in Russian cattle breed genomes reveal new candidate genes for environmental adaptation and acclimation
Domestication and selective breeding has resulted in over 1000 extant cattle breeds. Many of these breeds do not excel in important traits but are adapted to local environments. These adaptations are a valuable source of genetic material for efforts to improve commercial breeds. As a step toward this goal we identified candidate regions to be under selection in genomes of nine Russian native cattle breeds adapted to survive in harsh climates. After comparing our data to other breeds of European and Asian origins we found known and novel candidate genes that could potentially be related to domestication, economically important traits and environmental adaptations in cattle. The Russian cattle breed genomes contained regions under putative selection with genes that may be related to adaptations to harsh environments (e.g., AQP5, RAD50, and RETREG1). We found genomic signatures of selective sweeps near key genes related to economically important traits, such as the milk production (e.g., DGAT1, ABCG2), growth (e.g., XKR4), and reproduction (e.g., CSF2). Our data point to candidate genes which should be included in future studies attempting to identify genes to improve the extant breeds and facilitate generation of commercial breeds that fit better into the environments of Russia and other countries with similar climates
Mapping evolutionary process: a multi-taxa approach to conservation prioritization
Human-induced land use changes are causing extensive habitat fragmentation. As a result, many species are not able to shift their ranges in response to climate change and will likely need to adapt in situ to changing climate conditions. Consequently, a prudent strategy to maintain the ability of populations to adapt is to focus conservation efforts on areas where levels of intraspecific variation are high. By doing so, the potential for an evolutionary response to environmental change is maximized. Here, we use modeling approaches in conjunction with environmental variables to model species distributions and patterns of genetic and morphological variation in seven Ecuadorian amphibian, bird, and mammal species. We then used reserve selection software to prioritize areas for conservation based on intraspecific variation or species-level diversity. Reserves selected using species richness and complementarity showed little overlap with those based on genetic and morphological variation. Priority areas for intraspecific variation were mainly located along the slopes of the Andes and were largely concordant among species, but were not well represented in existing reserves. Our results imply that in order to maximize representation of intraspecific variation in reserves, genetic and morphological variation should be included in conservation prioritization
Using Remote Sensing to Map the Risk of Human Monkeypox Virus in the Congo Basin
Although the incidence of human monkeypox has greatly increased in Central Africa over the last decade, resources for surveillance remain extremely limited. We conducted a geospatial analysis using existing data to better inform future surveillance efforts. Using active surveillance data collected between 2005 and 2007, we identified locations in Sankuru district, Democratic Republic of Congo (DRC) where there have been one or more cases of human monkeypox. To assess what taxa constitute the main reservoirs of monkeypox, we tested whether human cases were associated with (i) rope squirrels (Funisciurus sp.), which were implicated in monkeypox outbreaks elsewhere in the DRC in the 1980s, or (ii) terrestrial rodents in the genera Cricetomys and Graphiurus, which are believed to be monkeypox reservoirs in West Africa. Results suggest that the best predictors of human monkeypox cases are proximity to dense forests and associated habitat preferred by rope squirrels. The risk of contracting monkeypox is significantly greater near sites predicted to be habitable for squirrels (OR = 1.32; 95% CI 1.08–1.63). We recommend that semi-deciduous rainforests with oil-palm, the rope squirrel’s main food source, be prioritized for monitoring
The Importance of Consistent Global Forest Aboveground Biomass Product Validation
Several upcoming satellite missions have core science requirements to produce data for accurate forest aboveground biomass mapping. Largely because of these mission datasets, the number of available biomass products is expected to greatly increase over the coming decade. Despite the recognized importance of biomass mapping for a wide range of science, policy and management applications, there remains no community accepted standard for satellite-based biomass map validation. The Committee on Earth Observing Satellites (CEOS) is developing a protocol to fill this need in advance of the next generation of biomass-relevant satellites, and this paper presents a review of biomass validation practices from a CEOS perspective. We outline the wide range of anticipated user requirements for product accuracy assessment and provide recommendations for the validation of biomass products. These recommendations include the collection of new, high-quality in situ data and the use of airborne lidar biomass maps as tools toward transparent multi-resolution validation. Adoption of community-vetted validation standards and practices will facilitate the uptake of the next generation of biomass products
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