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population dynamics

M Saulnier, C Corona, M Stoffel, F Guibal, J-L Edouard
A better understanding of the respective role of key climatic variables on tree growth is crucial for an accurate assessment of how ongoing global changes may affect both dynamics and distribution of forest tree species in the future. The aim of this study was (i) to explore growth patterns of European larch (Larix decidua Mill.) through a network of tree-ring chronologies developed for the French Alps and (ii) to identify the main climatic drivers explaining radial growth. Climate-growth relationships were coupled with a hierarchical analysis...
February 5, 2019: Science of the Total Environment
Andrey N Shkoporov, Colin Hill
The human gut microbiome is a dense and taxonomically diverse consortium of microorganisms. While the bacterial components of the microbiome have received considerable attention, comparatively little is known about the composition and physiological significance of human gut-associated bacteriophage populations (phageome). By extrapolating our knowledge of phage-host interactions from other environments, one could expect that >1012 viruses reside in the human gut, and we can predict that they play important roles in regulating the complex microbial networks operating in this habitat...
February 13, 2019: Cell Host & Microbe
Maha Daghestani, Rituraj Purohit, Mazin Daghestani, Mamoon Daghistani, Arjumand Warsy
The Gln233Arg (A>G; rs1137101) polymorphism of the leptin receptor gene (LEPR) has been investigated extensively and is reported to be associated with different metabolic states. In this investigation, we aimed to study the frequency of Gln233Arg genotypes and alleles in a group of Saudi women stratified by their body mass index (BMI), to correlate the LEPR genotypes with variations in anthropometric, lipid and hormonal parameters and to investigate conformational and structural variations in the mutant LEPR using molecular dynamic (MD) investigations...
2019: PloS One
Meng Wu, Ariane M Vartanian, Gene Chong, Arun Kumar Pandiakumar, Robert J Hamers, Rigoberto Hernandez, Catherine J Murphy
We report a solution NMR-based analysis of (16-mercaptohexadecyl)trimethylammonium bromide (MTAB) self-assembled monolayers (SAMs) on colloidal gold nanospheres (AuNSs) with diameters from 1.2 nm to 25 nm, and gold nanorods (AuNRs) with aspect ratios from 1.4 to 3.9. The chemical shift analysis of the proton signals from the solvent-exposed headgroups of bound ligands suggests that the headgroups are saturated on the ligand shell as the sizes of the nanoparticles increase beyond ~10 nm. Quantitative NMR shows that the ligand density of MTAB-AuNSs is size-dependent...
February 14, 2019: Journal of the American Chemical Society
Yusong Ye, Zhuoqin Yang, Jinzhi Lei
In human tissues, the replicative potential of stem cells is limited by the shortening of telomere, limitless replicative potential is a hallmark of cancer. Telomere length changes stochastically during cell division mainly due to the competition between the end replication problem and telomerase, short telomere can lead to replicative senescence and cell apoptosis. Here, we investigate how stochastic changes of telomere length in individual cells may affect the population dynamics of clonal growth. We established a computational model that couples telomerase-regulated stochastic telomere length changes with the replicative potential of clones...
February 14, 2019: Journal of Computational Biology: a Journal of Computational Molecular Cell Biology
Ulrika Candolin
Human activities by altering environmental conditions are influencing the mate choice of animals. This is by impacts on: (i) the production and expression of traits evaluated by mate choosers; (ii) the transmission of information about potential mates to choosers; (iii) the reception and processing of the information by choosers; and (iv) the final mate choice. Here, I first discuss how these four stages of the mate-choice process can be altered by environmental change, and how these alterations, in turn, can influence individuals, populations, and communities...
February 14, 2019: Biological Reviews of the Cambridge Philosophical Society
Ana Teresa Marques, Carlos David Santos, Frank Hanssen, Antonio-Román Muñoz, Alejandro Onrubia, Martin Wikelski, Francisco Moreira, Jorge Manuel Palmeirim, João Paulo Silva
1.Wind energy production has expanded to meet climate change mitigation goals, but negative impacts of wind turbines have been reported on wildlife. Soaring birds are among the most affected groups with alarming fatality rates by collision with wind turbines and an escalating occupation of their migratory corridors. These birds have been described as changing their flight trajectories to avoid wind turbines, but this behaviour may lead to functional habitat loss, as suitable soaring areas in the proximity of wind turbines will likely be underused...
February 14, 2019: Journal of Animal Ecology
Paloma Martínez-Rodríguez, Emilio Rolán-Alvarez, M Del Mar Pérez-Ruiz, Francisca Arroyo-Yebras, Carla Carpena-Catoira, Antonio Carvajal-Rodríguez, José L Bella
Wolbachia is an intracellular endosymbiont that can produce a range of effects on host fitness, but the temporal dynamics of Wolbachia strains have rarely been experimentally evaluated. We compare interannual strain frequencies along a geographical region for understanding the forces that shape Wolbachia strain frequency in natural populations of its host, Chorthippus parallelus (Orthoptera, Acrididae). General linear models show that strain frequency changes significantly across geographical and temporal scales...
February 14, 2019: Microbial Ecology
Brian M Bonk, James W Weis, Bruce Tidor
Despite tremendous progress in understanding and engineering enzymes, knowledge of how enzyme structures and their dynamics induce observed catalytic properties is incomplete, and capabilities to engineer enzymes fall far short of industrial needs. Here we investigate the structural and dynamic drivers of enzyme catalysis for the rate-limiting step of the industrially important enzyme ketol-acid reductoisomerase (KARI) and identify a region of the conformational space of the bound enzyme-substrate complex that, when populated, leads to large increases in reactivity...
February 14, 2019: Journal of the American Chemical Society
Aanchal Mongia, Debarka Sengupta, Angshul Majumdar
Motivation: Single-cell RNA sequencing has been proved to be revolutionary for its potential of zooming into complex biological systems. Genome-wide expression analysis at single-cell resolution provides a window into dynamics of cellular phenotypes. This facilitates the characterization of transcriptional heterogeneity in normal and diseased tissues under various conditions. It also sheds light on the development or emergence of specific cell populations and phenotypes. However, owing to the paucity of input RNA, a typical single cell RNA sequencing data features a high number of dropout events where transcripts fail to get amplified...
2019: Frontiers in Genetics
Óscar López-Pérez, Alicia Otero, Hicham Filali, David Sanz-Rubio, Janne M Toivonen, Pilar Zaragoza, Juan J Badiola, Rosa Bolea, Inmaculada Martín-Burriel
Autophagy is a dynamic cellular mechanism involved in protein and organelle turnover through lysosomal degradation. Autophagy regulation modulates the pathologies associated with many neurodegenerative diseases. Using sheep naturally infected with scrapie as a natural animal model of prion diseases, we investigated the regulation of autophagy in the central nervous system (CNS) during the clinical phase of the disease. We present a gene expression and protein distribution analysis of different autophagy-related markers and investigate their relationship with prion-associated lesions in several areas of the CNS...
February 13, 2019: Scientific Reports
Verena N Buchholz, Nicole David, Malte Sengelmann, Andreas K Engel
Controlling an event through one's own action usually induces a sense of agency, a feeling that arises when an expected outcome matches the intention. The neural correlates of this feeling remain controversial however, as experimental manipulation of the action-outcome chain often introduces mismatch or prediction errors that strongly correlate with the sense of agency. Here, we took a different approach and manipulated the causal belief (self-attribution vs. computer-attribution) by external cues during matched visuo-motor tapping conditions...
February 13, 2019: Scientific Reports
Thomas Wilkop, Sivakumar Pattathil, Guangxi Ren, Destiny Jade Davis, Wenlong Bao, Dechao Duan, Angelo Gabriel Peralta, David Domozych, Michael G Hahn, Georgia Drakakaki
The plant endomembrane system facilitates transport of polysaccharides, associated enzymes and glycoproteins through its dynamic pathways. Although enzymes involved in cell wall biosynthesis have been identified, little is known about the endomembrane-based transport of glycan components. This is partially attributed to technical challenges in biochemically determining polysaccharide cargo in specific vesicles. Here we introduce a hybrid approach addressing this limitation. By combining vesicle isolation with a large-scale carbohydrate antibody arraying technique, we charted an initial large-scale map describing the glycome profile of the Syntaxin of Plants 61 (SYP61) trans-Golgi network (TGN) compartment...
February 13, 2019: Plant Cell
Yide Zhang, Evan L Nichols, Abigail M Zellmer, Ian H Guldner, Cody Kankel, Siyuan Zhang, Scott S Howard, Cody J Smith
Super-resolution microscopy is broadening our in-depth understanding of cellular structure. However, super-resolution approaches are limited, for numerous reasons, from utilization in longer-term intravital imaging. We devised a combinatorial imaging technique that combines deconvolution with stepwise optical saturation microscopy (DeSOS) to circumvent this issue and image cells in their native physiological environment. Other than a traditional confocal or two-photon microscope, this approach requires no additional hardware...
February 13, 2019: Development
Marta M Jankowska, Dorothy D Sears, Loki Natarajan, Elena Martinez, Cheryl A M Anderson, James F Sallis, Stephen A Matthews, Katie Crist, Lindsay Dillon, Eileen Johnson, Angelica Barrera-Ng, Kelsey Full, Suneeta Godbole, Jacqueline Kerr
BACKGROUND: Physical inactivity and unhealthy diet are modifiable behaviors that lead to several cancers. Biologically, these behaviors are linked to cancer through obesity-related insulin resistance, inflammation, and oxidative stress. Individual strategies to change physical activity and diet are often short lived with limited effects. Interventions are expected to be more successful when guided by multi-level frameworks that include environmental components for supporting lifestyle changes...
February 13, 2019: BMC Public Health
Markus M Knodel, Paul Targett-Adams, Alfio Grillo, Eva Herrmann, Gabriel Wittum
The hepatitis C virus (HCV) RNA replication cycle is a dynamic intracellular process occurring in three-dimensional space (3D), which is difficult both to capture experimentally and to visualize conceptually. HCV-generated replication factories are housed within virus-induced intracellular structures termed membranous webs (MW), which are derived from the Endoplasmatic Reticulum (ER). Recently, we published 3D spatiotemporal resolved diffusion⁻reaction models of the HCV RNA replication cycle by means of surface partial differential equation (sPDE) descriptions...
February 12, 2019: International Journal of Environmental Research and Public Health
Isabell Schmidt, Andreas Zimmermann
Demographic estimates are presented for the Aurignacian techno-complex (~42,000 to 33,000 y calBP) and discussed in the context of socio-spatial organization of hunter-gatherer populations. Results of the analytical approach applied estimate a mean of 1,500 persons (upper limit: 3,300; lower limit: 800) for western and central Europe. The temporal and spatial analysis indicates an increase of the population during the Aurignacian as well as marked regional differences in population size and density. Demographic increase and patterns of socio-spatial organization continue during the subsequent early Gravettian period...
2019: PloS One
Miguel Vasconcelos Almeida, António Miguel de Jesus Domingues, René F Ketting
Endogenous small RNAs (sRNAs) and Argonaute proteins are ubiquitous regulators of gene expression in germline and somatic tissues. sRNA-Argonaute complexes are often expressed in gametes and are consequently inherited by the next generation upon fertilization. In Caenorhabditis elegans, 26G-RNAs are primary endogenous sRNAs that trigger the expression of downstream secondary sRNAs. Two subpopulations of 26G-RNAs exist, each of which displaying strongly compartmentalized expression: one is expressed in the spermatogenic gonad and associates with the Argonautes ALG-3/4; plus another expressed in oocytes and in embryos, which associates with the Argonaute ERGO-1...
February 13, 2019: PLoS Genetics
Alioune Gaye, Eryu Wang, Nikos Vasilakis, Hilda Guzman, Diawo Diallo, Cheikh Talla, Yamar Ba, Ibrahima Dia, Scott C Weaver, Mawlouth Diallo
Dengue fever (DEN) is the most common arboviral disease in the world and dengue virus (DENV) causes 390 million annual infections around the world, of which 240 million are inapparent and 96 million are symptomatic. During the past decade a changing epidemiological pattern has been observed in Africa, with DEN outbreaks reported in all regions. In Senegal, all DENV serotypes have been reported. These important changes in the epidemiological profile of DEN are occurring in a context where there is no qualified vaccine against DEN...
February 2019: PLoS Neglected Tropical Diseases
T Tony Yang, Minh Nguyet Thi Tran, Weng Man Chong, Chia-En Huang, Jung-Chi Liao
Primary cilia play a vital role in cellular sensing and signaling. An essential component of ciliogenesis is intraflagellar transport (IFT) involving in IFT-protein recruitment, axonemal engagement of IFT-protein complexes, etc. The mechanistic understanding of these processes at the ciliary base was largely missing, because it is challenging to observe the motion of IFT proteins in this crowded region using conventional microscopy. Here, we report short trajectory tracking of IFT proteins at the base of mammalian primary cilia by optimizing single-particle tracking photoactivated localization microscopy (sptPALM) for IFT88-mEOS4b in live human retinal pigment epithelial cells...
February 13, 2019: Molecular Biology of the Cell
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