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https://www.readbyqxmd.com/read/29684709/the-role-of-natural-selection-in-shaping-genetic-variation-in-a-promising-chagas-disease-drug-target-trypanosoma-cruzi-trans-sialidase
#1
Joseph P Gallant, Raquel Asunción Lima-Cordón, Silvia Justi, Maria Carlota Monroy, Toni Viola, Lori Stevens
Rational drug design creates innovative therapeutics based on knowledge of the biological target to provide more effective and responsible therapeutics. Chagas disease, endemic throughout Latin America, is caused by Trypanosoma cruzi, a protozoan parasite. Current therapeutics are problematic with widespread calls for new approaches. Researchers are using rational drug design for Chagas disease and one target receiving considerable attention is the T. cruzi trans-sialidase protein (TcTS). In T. cruzi, trans-sialidase catalyzes the transfer of sialic acid from a mammalian host to coat the parasite surface membrane and avoid immuno-detection...
April 20, 2018: Infection, Genetics and Evolution
https://www.readbyqxmd.com/read/29684183/neutral-theory-microbial-practice-challenges-in-bacterial-population-genetics
#2
Eduardo P C Rocha
Kimura's outstanding contributions to population genetics included many elegant theoretical results on the vagaries of alleles in populations. Once polymorphism data showed extensive variation in natural populations, these results led naturally to the Neutral Theory. In this article, I'll depart from some of these results to focus on four major open problems in microbial population genetics with direct implications to the study of molecular evolution: the lack of neutral polymorphism, the modeling of genetic exchanges, the population genetics of ill-defined populations, and the difficulty of untangling selection and demography in the light of the previous issues...
April 19, 2018: Molecular Biology and Evolution
https://www.readbyqxmd.com/read/29683032/applicability-of-api-zym-to-capture-seasonal-and-spatial-variabilities-in-lake-and-river-sediments
#3
Drashti Patel, Renee Gismondi, Ali Alsaffar, Sonia M Tiquia-Arashiro
Waters draining into a lake carry with them much of the suspended sediment that is transported by rivers and streams from the local drainage basin. The organic matter processing in the sediments is executed by heterotrophic microbial communities, whose activities may vary spatially and temporally. Thus, to capture and evaluate some of these variabilities in the sediments, we sampled six sites: three from St. Clair River (SC1, SC2, and SC3) and three from Lake St. Clair in spring, summer, fall and winter of 2016...
April 21, 2018: Environmental Technology
https://www.readbyqxmd.com/read/29683000/re-examining-the-early-history-of-the-leiden-jar-stabilization-and-variation-in-transforming-a-phenomenon-into-a-fact
#4
Cibelle Celestino Silva, Peter Heering
In this paper, we examine the period that immediately followed the invention of the Leiden jar. Historians of science have developed narrations that emphasize the role of grounding during the process of charging the jar. In this respect, this episode shows significant aspects that can be used to characterize science, scientific knowledge production, and the nature of science. From our own experimentation, we learned that grounding was not necessary in order to produce the effect. These experiences inspired us to go back to primary sources...
April 1, 2018: History of Science; An Annual Review of Literature, Research and Teaching
https://www.readbyqxmd.com/read/29682858/natural-biological-variation-of-white-matter-microstructure-is-accentuated-in-huntington-s-disease
#5
Sarah Gregory, Helen Crawford, Kiran Seunarine, Blair Leavitt, Alexandra Durr, Raymund A C Roos, Rachael I Scahill, Sarah J Tabrizi, Geraint Rees, Douglas Langbehn, Michael Orth
Huntington's disease (HD) is a monogenic neurodegenerative disorder caused by a CAG-repeat expansion in the Huntingtin gene. Presence of this expansion signifies certainty of disease onset, but only partly explains age at which onset occurs. Genome-wide association studies have shown that naturally occurring genetic variability influences HD pathogenesis and disease onset. Investigating the influence of biological traits in the normal population, such as variability in white matter properties, on HD pathogenesis could provide a complementary approach to understanding disease modification...
April 22, 2018: Human Brain Mapping
https://www.readbyqxmd.com/read/29681058/the-physcomitrella-patens-gene-atlas-project-large-scale-rna-seq-based-expression-data
#6
Pierre-François Perroud, Fabian B Haas, Manuel Hiss, Kristian K Ullrich, Alessandro Alboresi, Mojgan Amirebrahimi, Kerrie Barry, Roberto Bassi, Sandrine Bonhomme, Haodong Chen, Juliet Coates, Tomomichi Fujita, Anouchka Guyon-Debast, Daniel Lang, Junyan Lin, Anna Lipzen, Fabien Nogué, Melvin J Oliver, Inés Ponce de León, Ralph S Quatrano, Catherine Rameau, Bernd Reiss, Ralf Reski, Mariana Ricca, Younousse Saidi, Ning Sun, Peter Szövényi, Avinash Sreedasyam, Jane Grimwood, Gary Stacey, Jeremy Schmutz, Stefan A Rensing
High throughput RNA sequencing (RNA-seq) has recently become the method of choice to define and analyse transcriptomes. For the model moss Physcomitrella patens, although this method has been used to help the analysis of specific perturbations, no overall reference dataset has been established yet. In the framework of its Gene Atlas project, the Joint Genome Institute selected P. patens as a flagship genome, opening the way to generate the first comprehensive transcriptome dataset for this moss. The first round of sequencing described here is composed of 99 independent libraries spanning 34 different developmental stages and conditions...
April 22, 2018: Plant Journal: for Cell and Molecular Biology
https://www.readbyqxmd.com/read/29679777/integrating-microbial-biomass-composition-and-function-to-discern-the-level-of-anthropogenic-activity-in-a-river-ecosystem
#7
Kailingli Liao, Yaohui Bai, Yang Huo, Zhiyu Jian, Wanchao Hu, Chen Zhao, Jiuhui Qu
Anthropogenic activities (e.g., wastewater discharge and pesticide and fertilizer use) have considerable impact on the biotic properties of natural aquatic ecosystems, especially the microbial community and function. Microbes can respond to anthropogenic activities and are thus potential indicators of activity levels. Several reports have documented the impacts of anthropogenic activities on the variations in the microbial community, but the direct use of microbial community indices to discern anthropogenic activity levels remains limited...
April 18, 2018: Environment International
https://www.readbyqxmd.com/read/29678862/natural-variation-within-a-species-for-traits-underpinning-c4-photosynthesis
#8
Gregory Reeves, Pallavi Singh, Timo A Rossberg, Deedi Sogbohossou, M Eric Schranz, Julian M Hibberd
Engineering C4 photosynthesis into C3 crops could substantially increase their yield by alleviating photorespiratory losses. This objective is challenging because the C4 pathway involves complex modifications to the biochemistry, cell biology and anatomy of leaves. Forward genetics has provided limited insight into the mechanistic basis of these properties, and there have been no reports of significant quantitative intra-specific variation of C4 attributes that would allow trait mapping. Here, we show that accessions of the C4 species Gynandropsis gynandra collected from locations across Africa and Asia exhibit natural variation in key characteristics of C4 photosynthesis...
April 20, 2018: Plant Physiology
https://www.readbyqxmd.com/read/29678630/characterization-and-simulation-of-noise-in-pet-images-reconstructed-with-osem-development-of-a-method-for-the-generation-of-synthetic-images
#9
P Castro, C Huerga, P Chamorro, J Garayoa, M Roch, L Pérez
INTRODUCTION: The goals of the study are to characterize imaging properties in 2D PET images reconstructed with the iterative algorithm ordered-subset expectation maximization (OSEM) and to propose a new method for the generation of synthetic images. MATERIAL AND METHODS: The noise is analyzed in terms of its magnitude, spatial correlation, and spectral distribution through standard deviation, autocorrelation function, and noise power spectrum (NPS), respectively...
April 17, 2018: Revista Española de Medicina Nuclear e Imagen Molecular
https://www.readbyqxmd.com/read/29677830/hydrogen-production-by-steam-reforming-of-natural-gas-over-vanadium-nickel-alumina-catalysts
#10
Jaekyeong Yoo, Seungwon Park, Ji Hwan Song, In Kyu Song
A series of vanadium-nickel-alumina (xVNA) catalysts were prepared by a single-step sol-gel method with a variation of vanadium content (x, wt%) for use in the hydrogen production by steam reforming of natural gas. The effect of vanadium content on the physicochemical properties and catalytic activities of xVNA catalysts in the steam reforming of natural gas was investigated. It was found that natural gas conversion and hydrogen yield showed volcano-shaped trends with respect to vanadium content. It was also revealed that natural gas conversion and hydrogen yield increased with decreasing nickel crystallite size...
September 1, 2018: Journal of Nanoscience and Nanotechnology
https://www.readbyqxmd.com/read/29677702/is-the-pelvis-sexually-dimorphic-in-turtles
#11
Gerardo A Cordero
Variation in the pelvis is intrinsically linked to life history evolution. This is perhaps best exemplified by sexually dimorphic pelvic variation in bipedal primates. Yet, whether this trend is applicable to other taxa is unclear. Using turtle anatomy as a model, I tested the hypothesis that the pelvis is also sexually dimorphic in egg-laying tetrapods. I sampled a natural turtle population with female-biased sexual size dimorphism (i.e. larger females). I show that the area of the egg canal (pelvic aperture) is greater in females...
April 20, 2018: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
https://www.readbyqxmd.com/read/29677668/widespread-asymmetric-response-of-soil-heterotrophic-respiration-to-warming-and-cooling
#12
Yuan Liu, Xuefa Wen, Yunhai Zhang, Jing Tian, Yang Gao, Nichloas J Ostle, Shuli Niu, Shiping Chen, Xiaomin Sun, Nianpeng He
Soil is the largest organic carbon (C) pool in terrestrial ecosystems. Periodic changes in environmental temperature occur diurnally and seasonally; yet, the response of soil organic matter (SOM) decomposition to varying temperatures remains unclear. In this study, we conducted a modified incubation experiment using soils from 16 forest ecosystems in China with periodically and continuously varying incubation temperature to investigate how heterotrophic respiration (Rh ) responds to different temperature patterns (both warming and cooling temperature ranging between 5 and 30°C)...
April 17, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/29677477/systems-immunology-learning-the-rules-of-the-immune-system
#13
Alexandra-Chloé Villani, Siranush Sarkizova, Nir Hacohen
Given the many cell types and molecular components of the human immune system, along with vast variations across individuals, how should we go about developing causal and predictive explanations of immunity? A central strategy in human studies is to leverage natural variation to find relationships among variables, including DNA variants, epigenetic states, immune phenotypes, clinical descriptors, and others. Here, we focus on how natural variation is used to find patterns, infer principles, and develop predictive models for two areas: (a) immune cell activation-how single-cell profiling boosts our ability to discover immune cell types and states-and (b) antigen presentation and recognition-how models can be generated to predict presentation of antigens on MHC molecules and their detection by T cell receptors...
April 26, 2018: Annual Review of Immunology
https://www.readbyqxmd.com/read/29677204/estimating-plant-distance-in-maize-using-unmanned-aerial-vehicle-uav
#14
Jinshui Zhang, Bruno Basso, Richard F Price, Gregory Putman, Guanyuan Shuai
Distance between rows and plants are essential parameters that affect the final grain yield in row crops. This paper presents the results of research intended to develop a novel method to quantify the distance between maize plants at field scale using an Unmanned Aerial Vehicle (UAV). Using this method, we can recognize maize plants as objects and calculate the distance between plants. We initially developed our method by training an algorithm in an indoor facility with plastic corn plants. Then, the method was scaled up and tested in a farmer's field with maize plant spacing that exhibited natural variation...
2018: PloS One
https://www.readbyqxmd.com/read/29676911/oniom-investigation-of-the-second-order-nonlinear-optical-responses-of-fluorescent-proteins
#15
Marc de Wergifosse, Edith Botek, Evelien De Meulenaere, Koen Clays, Benoît Champagne
The first hyperpolarizability ( ) of six fluorescent proteins (FPs), namely eGFP, eYFP, SHardonnay, ZsYellow, DsRed, and mCherry, has been calculated to unravel structure-property relationships on their second-order nonlinear optical properties, owing to their potential for multidimensional biomedical imaging. The ONIOM scheme has been employed and several of its refinements have been addressed to incorporate efficiently the effects of the microenvironment on the nonlinear optical responses of the FP chromophore that is embedded in a protective -barrel protein cage...
April 20, 2018: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29676059/among-year-variation-in-selection-during-early-life-stages-and-the-genetic-basis-of-fitness-in-arabidopsis-thaliana
#16
Froukje M Postma, Jon Ågren
Incomplete information regarding both selection regimes and the genetic basis of fitness limits our understanding of adaptive evolution. Among-year variation in the genetic basis of fitness is rarely quantified, and estimates of selection are typically based on single components of fitness, thus potentially missing conflicting selection acting during other life-history stages. Here, we examined among-year variation in selection on a key life-history trait and the genetic basis of fitness covering the whole life cycle in the annual plant Arabidopsis thaliana...
April 19, 2018: Molecular Ecology
https://www.readbyqxmd.com/read/29676042/meta-analysis-of-chromosome-scale-crossover-rate-variation-in-eukaryotes-and-its-significance-to-evolutionary-genomics
#17
Quiterie Haenel, Telma G Laurentino, Marius Roesti, Daniel Berner
Understanding the distribution of crossovers along chromosomes is crucial to evolutionary genomics because the crossover rate determines how strongly a genome region is influenced by natural selection on linked sites. Nevertheless, generalities in the chromosome-scale distribution of crossovers have not been investigated formally. We fill this gap by synthesizing joint information on genetic and physical maps across 62 animal, plant, and fungal species. Our quantitative analysis reveals a strong and taxonomically wide-spread reduction of the crossover rate in the center of chromosomes relative to their peripheries...
April 19, 2018: Molecular Ecology
https://www.readbyqxmd.com/read/29675018/contribution-to-tumor-angiogenesis-from-innate-immune-cells-within-the-tumor-microenvironment-implications-for-immunotherapy
#18
REVIEW
Adriana Albini, Antonino Bruno, Douglas M Noonan, Lorenzo Mortara
The critical role of angiogenesis in promoting tumor growth and metastasis is strongly established. However, tumors show considerable variation in angiogenic characteristics and in their sensitivity to antiangiogenic therapy. Tumor angiogenesis involves not only cancer cells but also various tumor-associated leukocytes (TALs) and stromal cells. TALs produce chemokines, cytokines, proteases, structural proteins, and microvescicles. Vascular endothelial growth factor (VEGF) and inflammatory chemokines are not only major proangiogenic factors but are also immune modulators, which increase angiogenesis and lead to immune suppression...
2018: Frontiers in Immunology
https://www.readbyqxmd.com/read/29673977/epizootics-of-pseudomonas-anguilliseptica-among-cultured-seabream-sparus-aurata-populations-control-and-treatment-strategies
#19
Amr Fadel, Mahmoud Mabrok, Salah Aly
The present study was investigating the clinical pictures, prevalence, as well as the ecological conditions associated with Pseudomonas anguilliseptica outbreaks in four cultured seabream (Sparus aurata) farms at different localities in Egypt during the winter season of 2016. The phenotypic and genotypic patterns of pseudomonas isolates were investigated. The existence of intraspecific heterogeneity among different isolates was analyzed using Restriction fragment length polymorphism (RFLP) technique. Attempts on disease control using antibiogram or dietary supplement were also considered...
April 16, 2018: Microbial Pathogenesis
https://www.readbyqxmd.com/read/29673899/it-s-about-time-cesarean-sections-and-neonatal-health
#20
Ana María Costa-Ramón, Ana Rodríguez-González, Miquel Serra-Burriel, Carlos Campillo-Artero
Cesarean sections have been associated in the literature with poorer newborn health, particularly with a higher incidence of respiratory morbidity. Most studies suffer, however, from potential omitted variable bias, as they are based on simple comparisons of mothers who give birth vaginally and those who give birth by cesarean section. We try to overcome this limitation and provide credible causal evidence by using variation in the probability of having a c-section that is arguably unrelated to maternal and fetal characteristics: variation by time of day...
March 27, 2018: Journal of Health Economics
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