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https://www.readbyqxmd.com/read/28342549/stream-aquifer-and-in-stream-processes-affecting-nitrogen-along-a-major-river-and-contributing-tributary
#1
Alexander Huizenga, Ryan T Bailey, Timothy K Gates
This study assesses the spatio-temporal patterns of water and nutrient mass exchange in a stream-riparian system of a major river and a contributing tributary in an irrigated semi-arid region. Field monitoring is performed along reaches of the Arkansas River (4.7km) and Timpas Creek (2.0km) in southeastern Colorado during the 2014 growing season, with water quantity and water quality data collected using a network of in-stream sampling sites and groundwater monitoring wells. Mass balance approaches were used to identify temporal and spatial trends in flow, nitrogen (N), and salinity in stream-aquifer exchange...
March 8, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28342324/short-bursts-of-cyclic-mechanical-compression-modulate-tissue-formation-in-a-3d-hybrid-scaffold
#2
M Brunelli, C M Perrault, D Lacroix
Among the cues affecting cells behaviour, mechanical stimuli are known to have a key role in tissue formation and mineralization of bone cells. While soft scaffolds are better at mimicking the extracellular environment, they cannot withstand the high loads required to be efficient substitutes for bone in vivo. We propose a 3D hybrid scaffold combining the load-bearing capabilities of polycaprolactone (PCL) and the ECM-like chemistry of collagen gel to support the dynamic mechanical differentiation of human embryonic mesodermal progenitor cells (hES-MPs)...
March 18, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28339252/helical-floquet-channels-in-1d-lattices
#3
Jan Carl Budich, Ying Hu, Peter Zoller
We show how dispersionless channels exhibiting perfect spin-momentum locking can arise in a 1D lattice model. While such spectra are forbidden by fermion doubling in static 1D systems, here we demonstrate their appearance in the stroboscopic dynamics of a periodically driven system. Remarkably, this phenomenon does not rely on any adiabatic assumptions, in contrast to the well known Thouless pump and related models of adiabatic spin pumps. The proposed setup is shown to be experimentally feasible with state-of-the-art techniques used to control ultracold alkaline earth atoms in optical lattices...
March 10, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28339071/direct-interaction-between-caffeic-acid-phenethyl-ester-and-human-neutrophil-elastase-inhibits-the-growth-and-migration-of-panc-1-cells
#4
Jianhui Duan, Yilixiati Xiaokaiti, Shengjun Fan, Yan Pan, Xin Li, Xuejun Li
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignant tumors of the digestive system, but the mechanisms of its development and progression are unclear. Inflammation is thought to be fundamental to pancreatic cancer development and caffeic acid phenethyl ester (CAPE) is an active component of honey bee resin or propolis with anti-inflammatory and anticancer activities. We investigated the inhibitory effects of CAPE on cell growth and migration induced by human neutrophil elastase (HNE) and report that HNE induced cancer cell migration at low doses and growth at higher doses...
March 21, 2017: Oncology Reports
https://www.readbyqxmd.com/read/28337282/chronic-intermittent-hypoxia-affects-endogenous-serotonergic-inputs-and-expression-of-synaptic-proteins-in-rat-hypoglossal-nucleus
#5
Xu Wu, Huan Lu, Lijuan Hu, Wankun Gong, Juan Wang, Cuiping Fu, Zilong Liu, Shanqun Li
Evidence has shown that hypoxic episodes elicit hypoglossal neuroplasticity which depends on elevated serotonin (5-HT), in contrast to the rationale of obstructive sleep apnea (OSA) that deficient serotonergic input to HMs fails to keep airway patency. Therefore, understanding of the 5-HT dynamic changes at hypoglossal nucleus (HN) during chronic intermittent hypoxia (CIH) will be essential to central pathogenic mechanism and pharmacological therapy of OSA. Moreover, the effect of CIH on BDNF-TrkB signaling proteins was quantified in an attempt to elucidate cellular cascades/synaptic mechanisms following 5-HT alteration...
2017: American Journal of Translational Research
https://www.readbyqxmd.com/read/28336395/human-immune-compartment-comparisons-optimization-of-proliferative-assays-for-blood-and-gut-t-lymphocytes
#6
Jeffrey Dock, Lance Hultin, Patricia Hultin, Julie Elliot, Otto O Yang, Peter A Anton, Beth D Jamieson, Rita B Effros
The accumulation of peripheral blood late-differentiated memory CD8 T cells with features of replicative (cellular) senescence, including inability to proliferate in vitro, has been extensively studied. Importantly, the abundance of these cells is directly correlated with increased morbidity and mortality in older persons. Of note, peripheral blood contains only 2% of the total body lymphocyte population. By contrast, the gut-associated lymphoid tissue (GALT) is the most extensive lymphoid organ, housing up to 60% of total body lymphocytes, but has never been assessed with respect to senescence profiles...
March 20, 2017: Journal of Immunological Methods
https://www.readbyqxmd.com/read/28335715/cytotype-coexistence-in-the-field-cannot-be-explained-by-inter-cytotype-hybridization-alone-linking-experiments-and-computer-simulations-in-the-sexual-species-pilosella-echioides-asteraceae
#7
Jindřich Chrtek, Tomáš Herben, Radka Rosenbaumová, Zuzana Münzbergová, Zuzana Dočkalová, Jaroslav Zahradníček, Jana Krejčíková, Pavel Trávníček
BACKGROUND: Processes driving ploidal diversity at the population level are virtually unknown. Their identification should use a combination of large-scale screening of ploidy levels in the field, pairwise crossing experiments and mathematical modelling linking these two types of data. We applied this approach to determine the drivers of frequencies of coexisting cytotypes in mixed-ploidy field populations of the fully sexual plant species Pilosella echioides. We examined fecundity and ploidal diversity in seeds from all possible pairwise crosses among 2x, 3x and 4x plants...
March 23, 2017: BMC Evolutionary Biology
https://www.readbyqxmd.com/read/28335603/molecular-dynamics-simulation-of-water-transport-mechanisms-through-nanoporous-boron-nitride-and-graphene-multilayers
#8
Majid Shahbabaei, Daejoong Kim
In this study, molecular dynamics simulations are used to investigate water transport mechanisms through hourglass-shaped pore structure in nanoporous boron nitride (BN) and graphene multilayers. An increase in water flux is evidenced as the gap between the layers increases, reaching a maximum of 41 and 43 at d=6 Å in BN and graphene multilayers, respectively. Moreover, the BN multilayer exhibits less flux compared to graphene due to large friction force and energy barrier. In BN, the friction force dramatically increases when the layers are strongly stacked (d=3...
March 23, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28335193/facile-synthesis-of-gd-functionalized-gold-nanoclusters-as-potential-mri-ct-contrast-agents
#9
Wenjun Le, Shaobin Cui, Xin Chen, Huanhuan Zhu, Bingdi Chen, Zheng Cui
Multi-modal imaging plays a key role in the earlier detection of disease. In this work, a facile bioinspired method was developed to synthesize Gd-functionalized gold nanoclusters (Gd-Au NCs). The Gd-Au NCs exhibit a uniform size, with an average size of 5.6 nm in dynamic light scattering (DLS), which is a bit bigger than gold clusters (3.74 nm, DLS), while the fluorescent properties of Gd-Au NCs are almost the same as that of Au NCs. Moreover, the Gd-Au NCs exhibit a high longitudinal relaxivity value (r1) of 22...
April 9, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28334271/a-temperature-dependent-phenology-model-for-liriomyza-huidobrensis-diptera-agromyzidae
#10
Norma Mujica, Marc Sporleder, Pablo Carhuapoma, Jürgen Kroschel
Liriomyza huidobrensis (Blanchard) is an economically important and highly polyphagous worldwide pest. To establish a temperature-dependent phenology model, essential for understanding the development and growth of the pest population under a variety of climates and as part of a pest risk analysis, L. huidobrensis life-table data were collected under laboratory conditions at seven constant temperatures on its host faba bean (Vicia faba L.). Several nonlinear equations were fitted to each life stage to model the temperature-dependent population growth and species life history and finally compile an overall temperature-dependent pest phenology model using the Insect Life Cycle Modeling (ILCYM) software...
March 8, 2017: Journal of Economic Entomology
https://www.readbyqxmd.com/read/28334079/how-do-cold-adapted-plants-respond-to-climatic-cycles-interglacial-expansion-explains-current-distribution-and-genomic-diversity-in-primula-farinosa-l
#11
Spyros Theodoridis, Christophe Randin, Peter Szövényi, Florian C Boucher, Theofania S Patsiou, Elena Conti
Understanding the effects of past climatic fluctuations on the distribution and population-size dynamics of cold-adapted species is essential for predicting their responses to ongoing global climate change. In spite of the heterogeneity of cold-adapted species, two main contrasting hypotheses have been proposed to explain their responses to Late Quaternary glacial cycles, namely, the interglacial contraction versus the interglacial expansion hypotheses. Here, we use the cold-adapted plant Primula farinosa to test two demographic models under each of the two alternative hypotheses and a fifth, null model...
December 21, 2016: Systematic Biology
https://www.readbyqxmd.com/read/28334037/ang1-treatment-reduces-muscle-pathology-and-prevents-a-decline-in-perfusion-in-dmd-mice
#12
Kelly M Gutpell, Nikola Tasevski, Boaz Wong, William Thomas Hrinivich, Feng Su, Jennifer Hadway, Lise Desjardins, Ting-Yim Lee, Lisa Marie Hoffman
Vascular endothelial growth factor (VEGF) and other pro-angiogenic growth factors have been investigated to enhance muscle tissue perfusion and repair in Duchenne muscular dystrophy (DMD). Current understanding is limited by a lack of functional data following in vivo delivery of these growth factors. We previously used dynamic contrast-enhanced computed tomography to monitor disease progression in murine models of DMD, but no study to date has utilized this imaging technique to assess vascular therapy in a preclinical model of DMD...
2017: PloS One
https://www.readbyqxmd.com/read/28333893/magnetic-resonance-imaging-characteristics-of-a-baerveldt-glaucoma-implant
#13
Daniel M Anderson, Ryan B Schwope, Michael J Reiter, Abraham W Suhr
PURPOSE: Evaluate for normative postoperative magnetic resonance imaging (MRI) characteristics of a Baerveldt Glaucoma Implant (BGI). DESIGN: Prospective case series. PARTICIPANTS: Seven subjects with uncontrolled glaucoma requiring a primary superotemporal BGI. METHODS: Subjects prospectively underwent sequential MRI orbital scans without contrast at 0 to 2 weeks, 6 to 8 weeks, and 4 to 6 months after implantation of a BGI model 103-250...
March 22, 2017: Journal of Glaucoma
https://www.readbyqxmd.com/read/28333590/mean-first-passage-memory-lifetimes-by-reducing-complex-synapses-to-simple-synapses
#14
Terry Elliott
Memory models that store new memories by forgetting old ones have memory lifetimes that are rather short and grow only logarithmically in the number of synapses. Attempts to overcome these deficits include "complex" models of synaptic plasticity in which synapses possess internal states governing the expression of synaptic plasticity. Integrate-and-express, filter-based models of synaptic plasticity propose that synapses act as low-pass filters, integrating plasticity induction signals before expressing synaptic plasticity...
March 23, 2017: Neural Computation
https://www.readbyqxmd.com/read/28333248/the-evolutionary-dynamics-of-orthologs-that-shift-in-gene-body-methylation-between-arabidopsis-species
#15
Shohei Takuno, Danelle K Seymour, Brandon S Gaut
DNA methylation labels a specific subset of genes in plant genomes. Recent work has shown that this gene-body methylation (gbM) is a conserved feature of orthologs, because highly methylated genes in one species tend to be highly methylated in another. In this study, we examined the exceptions to that rule by identifying genes that differ in gbM status between two plant species - Arabidopsis thaliana and Arabidopsis lyrata. Using Capsella grandiflora as an outgroup, we polarized the loss and gain of gbM for orthologs in Arabidopsis lineages...
March 2, 2017: Molecular Biology and Evolution
https://www.readbyqxmd.com/read/28333164/the-theory-of-parallel-climate-realizations-as-a-new-framework-for-teleconnection-analysis
#16
Mátyás Herein, Gábor Drótos, Tímea Haszpra, János Márfy, Tamás Tél
Teleconnections are striking features of the Earth climate system which appear as statistically correlated climate-related patterns between remote geographical regions of the globe. In a changing climate, however, the strength of teleconnections might change, and an appropriate characterization of these correlations and their change (more appropriate than detrending the time series) is lacking in the literature. Here we present a novel approach, based on the theory of snapshot attractors, corresponding in our context to studying parallel climate realizations...
March 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28332980/a-receptor-and-neuron-that-activate-a-circuit-limiting-sucrose-consumption
#17
Ryan M Joseph, Jennifer S Sun, Edric Tam, John R Carlson
The neural control of sugar consumption is critical for normal metabolism. In contrast to sugar-sensing taste neurons that promote consumption, we identify a taste neuron that limits sucrose consumption in Drosophila. Silencing of the neuron increases sucrose feeding; optogenetic activation decreases it. The feeding inhibition depends on the IR60b receptor, as shown by behavioral analysis and Ca2+ imaging of an IR60b mutant. The IR60b phenotype shows a high degree of chemical specificity when tested with a broad panel of tastants...
March 23, 2017: ELife
https://www.readbyqxmd.com/read/28331741/pet-mri-findings-of-two-patients-with-breast-carcinoma-before-treatment
#18
Filiz Çelebi, Ülkühan Köksal, Kezban Nur Pilancı, Çetin Ordu, Dauren Sarsenov, Serkan İlgün, Fatmagül Kuşku Çabuk, Gül Alço, Güzide Özdil, Zeynep Erdoğan, Vahit Özmen
Integrated positron-emission tomography-magnetic resonance imaging (PET-MRI) is a new hybrid simultaneous imaging modality with higher soft tissue contrast and lower radiation doses compared with PET-CT. Two patients who were referred to our hospital with left breast masses that were pathologically diagnosed as invasive ductal carcinoma. The women were then scanned using the first PET-MRI system in Turkey, which was established in our department. In this case report, we aimed to determine the advantages of PET-MRI in staging, follow-up, neoadjuvant chemotherapy response, and to compare the usefulness of this modality with PET-CT and dynamic contrast-enhanced breast MRI...
April 2016: J Breast Health (2013)
https://www.readbyqxmd.com/read/28331597/pollinator-population-size-and-pollination-ecosystem-service-responses-to-enhancing-floral-and-nesting-resources
#19
Johanna Häussler, Ullrika Sahlin, Charlotte Baey, Henrik G Smith, Yann Clough
Modeling pollination ecosystem services requires a spatially explicit, process-based approach because they depend on both the behavioral responses of pollinators to the amount and spatial arrangement of habitat and on the within- and between-season dynamics of pollinator populations in response to land use. We describe a novel pollinator model predicting flower visitation rates by wild central-place foragers (e.g., nesting bees) in spatially explicit landscapes. The model goes beyond existing approaches by: (1) integrating preferential use of more rewarding floral and nesting resources; (2) considering population growth over time; (3) allowing different dispersal distances for workers and reproductives; (4) providing visitation rates for use in crop pollination models...
March 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28330878/linear-summation-of-repulsive-and-attractive-serial-dependencies-orientation-and-motion-dependencies-sum-in-motion-perception
#20
David Alais, Johahn Leung, Erik Van der Burg
Recent work from several groups has shown that perception of various visual attributes in human observers at a given moment is biased towards what was recently seen. This positive serial dependency is a kind of temporal averaging which exploits short-term correlations in visual scenes to reduce noise and stabilise perception. To date this stabilising 'continuity field' has been demonstrated on stable visual attributes such as orientation and face identity, yet it would be counterproductive to apply it to dynamic attributes where change sensitivity is needed...
March 22, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
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