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https://www.readbyqxmd.com/read/28226767/place-field-detection-using-grid-based-clustering-in-a-large-scale-computational-model-of-the-rat-dentate-gyrus
#1
Gene J Yu, Dong Song, Theodore W Berger, Gene J Yu, Dong Song, Theodore W Berger, Dong Song, Gene J Yu, Theodore W Berger
Place cells are neurons in the hippocampus that are sensitive to location within an environment. Simulations of a large-scale, computational model of the rat dentate gyrus using grid cell input have been performed resulting in granule cells that express multiple place fields. The typical method of detecting place fields using a global threshold on this data is unreliable as the characteristics of the place fields from a single neuron can be highly variable. A grid-based implementation of DENCLUE has been developed to calculate local thresholds to identify each place field...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28199875/examining-the-impacts-of-increased-corn-production-on-groundwater-quality-using-a-coupled-modeling-system
#2
Valerie Garcia, Ellen Cooter, James Crooks, Brian Hinckley, Mark Murphy, Xiangnan Xing
This study demonstrates the value of a coupled chemical transport modeling system for investigating groundwater nitrate contamination responses associated with nitrogen (N) fertilizer application and increased corn production. The coupled Community Multiscale Air Quality Bidirectional and Environmental Policy Integrated Climate modeling system incorporates agricultural management practices and N exchange processes between the soil and atmosphere to estimate levels of N that may volatilize into the atmosphere, re-deposit, and seep or flow into surface and groundwater...
February 12, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28178279/snow-leopard-and-himalayan-wolf-food-habits-and-prey-selection-in-the-central-himalayas-nepal
#3
Madhu Chetri, Morten Odden, Per Wegge
Top carnivores play an important role in maintaining energy flow and functioning of the ecosystem, and a clear understanding of their diets and foraging strategies is essential for developing effective conservation strategies. In this paper, we compared diets and prey selection of snow leopards and wolves based on analyses of genotyped scats (snow leopards n = 182, wolves n = 57), collected within 26 sampling grid cells (5×5 km) that were distributed across a vast landscape of ca 5000 km2 in the Central Himalayas, Nepal...
2017: PloS One
https://www.readbyqxmd.com/read/28173628/designing-ecological-climate-change-impact-assessments-to-reflect-key-climatic-drivers
#4
Helen R Sofaer, Joseph J Barsugli, Catherine S Jarnevich, John T Abatzoglou, Marian K Talbert, Brian W Miller, Jeffrey T Morisette
Identifying the climatic drivers of an ecological system is a key step in assessing its vulnerability to climate change. The climatic dimensions to which a species or system is most sensitive - such as means or extremes - can guide methodological decisions for projections of ecological impacts and vulnerabilities. However, scientific workflows for combining climate projections with ecological models have received little explicit attention. We review Global Climate Model (GCM) performance along different dimensions of change and compare frameworks for integrating GCM output into ecological models...
February 7, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28161726/medial-entorhinal-cortex-and-medial-septum-contribute-to-self-motion-based-linear-distance-estimation
#5
Pierre-Yves Jacob, Marta Gordillo-Salas, Justine Facchini, Bruno Poucet, Etienne Save, Francesca Sargolini
Path integration is a navigation strategy that requires animals to integrate self-movements during exploration to determine their position in space. The medial entorhinal cortex (MEC) has been suggested to play a pivotal role in this process. Grid cells, head-direction cells, border cells as well as speed cells within the MEC collectively provide a dynamic representation of the animal position in space based on the integration of self-movements. All these cells are strongly modulated by theta oscillations, thus suggesting that theta rhythmicity in the MEC may be essential for integrating and coordinating self-movement information during navigation...
February 4, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28122050/research-on-grid-size-suitability-of-gridded-population-distribution-in-urban-area-a-case-study-in-urban-area-of-xuanzhou-district-china
#6
Nan Dong, Xiaohuan Yang, Hongyan Cai, Fengjiao Xu
The research on the grid size suitability is important to provide improvement in accuracies of gridded population distribution. It contributes to reveal the actual spatial distribution of population. However, currently little research has been done in this area. Many well-modeled gridded population dataset are basically built at a single grid scale. If the grid cell size is not appropriate, it will result in spatial information loss or data redundancy. Therefore, in order to capture the desired spatial variation of population within the area of interest, it is necessary to conduct research on grid size suitability...
2017: PloS One
https://www.readbyqxmd.com/read/28111080/tau-pathology-induces-excitatory-neuron-loss-grid-cell-dysfunction-and-spatial-memory-deficits-reminiscent-of-early-alzheimer-s-disease
#7
Hongjun Fu, Gustavo A Rodriguez, Mathieu Herman, Sheina Emrani, Eden Nahmani, Geoffrey Barrett, Helen Y Figueroa, Eliana Goldberg, S Abid Hussaini, Karen E Duff
The earliest stages of Alzheimer's disease (AD) are characterized by the formation of mature tangles in the entorhinal cortex and disorientation and confusion when navigating familiar places. The medial entorhinal cortex (MEC) contains specialized neurons called grid cells that form part of the spatial navigation system. Here we show in a transgenic mouse model expressing mutant human tau predominantly in the EC that the formation of mature tangles in old mice was associated with excitatory cell loss and deficits in grid cell function, including destabilized grid fields and reduced firing rates, as well as altered network activity...
February 8, 2017: Neuron
https://www.readbyqxmd.com/read/28067005/phosphorus-in-agricultural-soils-drivers-of-its-distribution-at-the-global-scale
#8
Bruno Ringeval, Laurent Augusto, Hervé Monod, Dirk van Apeldoorn, Lex Bouwman, Xiaojuan Yang, David L Achat, Louise P Chini, Kristof Van Oost, Bertrand Guenet, Rong Wang, Bertrand Decharme, Thomas Nesme, Sylvain Pellerin
Phosphorus (P) availability in soils limits crop yields in many regions of the world, while excess of soil P triggers aquatic eutrophication in other regions. Numerous processes drive the global spatial distribution of P in agricultural soils, but their relative roles remain unclear. Here, we combined several global datasets describing these drivers with a soil P dynamics model to simulate the distribution of P in agricultural soils and to assess the contributions of the different drivers at the global scale...
January 9, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28034697/the-representation-of-space-in-the-brain
#9
REVIEW
Roddy M Grieves, Kate J Jeffery
Animals can navigate vast distances and often display behaviours or activities that indicate a detailed, internal spatial representation of their surrounding environment or a 'cognitive map'. Over a century of behavioural research on spatial navigation in humans and animals has greatly increased our understanding of how this highly complex feat is achieved. In turn this has inspired half a century of electrophysiological spatial navigation and memory research which has further advanced our understanding of the brain...
February 2017: Behavioural Processes
https://www.readbyqxmd.com/read/28025983/grid-cells-need-for-speed
#10
Alfredo Gonzalez-Sulser, Matthew F Nolan
No abstract text is available yet for this article.
December 27, 2016: Nature Neuroscience
https://www.readbyqxmd.com/read/28024751/assessing-the-environmental-impacts-of-freshwater-thermal-pollution-from-global-power-generation-in-lca
#11
Catherine E Raptis, Justin M Boucher, Stephan Pfister
Freshwater heat emissions from power plants with once-through cooling systems constitute one of many environmental pressures related to the thermoelectric power industry. The objective of this work was to obtain high resolution, operational characterization factors (CF) for the impact of heat emissions on ecosystem quality, and carry out a comprehensive, spatially, temporally and technologically differentiated damage-based environmental assessment of global freshwater thermal pollution. The aggregation of CFs on a watershed level results in 12...
December 23, 2016: Science of the Total Environment
https://www.readbyqxmd.com/read/28001122/spatial-and-temporal-variability-in-desert-dust-and-anthropogenic-pollution-in-iraq-1997-2010
#12
A Alexandra Chudnovsky, Petros Koutrakis, Alex Kostinski, Susan P Proctor, Eric Garshick
: Satellite imaging has emerged as a method for monitoring regional air pollution and detecting areas of high dust concentrations. Unlike ground observations, continuous data monitoring is available with global coverage of terrestrial and atmospheric components. In this study we test the utility of different sources of satellite data to assess air pollution concentrations in Iraq. SeaWiFS and MODIS Deep Blue (DB) aerosol optical depth (AOD) products were evaluated and used to characterize the spatial and temporal pollution levels from the late 1990s through 2010...
2017: Journal of the Air & Waste Management Association
https://www.readbyqxmd.com/read/27996891/mapping-air-quality-zones-for-coastal-urban-centers
#13
Brian Freeman, Bahram Gharabaghi, Jesse Thé, Mohammad Munshed, Shah Faisal, Meshal Abdullah, Athari Al Aseed
This study presents a new method that incorporates modern air dispersion models allowing local terrain and land-sea breeze effects to be considered along with political and natural boundaries for more accurate mapping of air quality zones for coastal urban centers. This method uses local coastal wind patterns and key urban air pollution sources in each zone to more accurately calculate air pollutant concentration statistics. The new approach distributes virtual air pollution sources within each small grid cells of an area of interest and analyzes a puff dispersion model for a full year's worth of one-hour prognostic weather data...
December 20, 2016: Journal of the Air & Waste Management Association
https://www.readbyqxmd.com/read/27943643/the-development-of-spatial-and-memory-circuits-in-the-rat
#14
REVIEW
Hui Min Tan, Thomas Joseph Wills, Francesca Cacucci
We provide a concise review of recent studies related to the development of neural circuits supporting spatial navigation and memory in the rat. We chart the relative timeline of the emergence of the four main classes of spatially tuned neurons within the hippocampus and related limbic areas: head direction cells emerge earliest (postnatal day 12, P12), before the eyes of the rats are even open, followed by place cells and boundary responsive cells; grid cells emerge last, around the age of weaning (P21). The rate of maturation is unique to each type of neuron, with the head direction and grid cells showing rapid developmental spurts, in contrast to place cells, which show a more gradual trend of maturation...
December 12, 2016: Wiley Interdisciplinary Reviews. Cognitive Science
https://www.readbyqxmd.com/read/27941523/3-d-spatial-memory-and-navigation-functions-and-disorders
#15
Thomas Brandt, Andreas Zwergal, Stefan Glasauer
PURPOSE OF REVIEW: The aim of this review is to report on the specialized neuronal systems mediating spatial orientation and navigation discovered in animal experiments. These findings have important implications for the clinical management of patients with vestibular disorders or dementia and for translational research in these fields. RECENT FINDINGS: The following anatomically and functionally separate, but nevertheless cooperative cell types have been characterized: angular head velocity cells and head direction cells, which depend on vestibular input and interact with place cells and grid cells, which represent position and distance...
February 2017: Current Opinion in Neurology
https://www.readbyqxmd.com/read/27936209/occurrence-and-spread-of-the-invasive-asian-bush-mosquito-aedes-japonicus-japonicus-diptera-culicidae-in-west-and-north-germany-since-detection-in-2012-and-2013-respectively
#16
Helge Kampen, Cornelius Kuhlisch, Andreas Fröhlich, Dorothee E Scheuch, Doreen Walther
The invasive Asian bush mosquito Aedes japonicus japonicus was first recognised as established in Germany in 2008. In addition to the first known and quickly expanding population in the southwestern part of the country, three separate populations were discovered in West, North and southeastern Germany in 2012, 2013 and 2015, respectively, by means of the 'Mueckenatlas', a German instrument of passive mosquito surveillance. Since the first findings of mosquito specimens in West and North Germany, these regions were checked annually for continuing colonisation and spread of the species...
2016: PloS One
https://www.readbyqxmd.com/read/27932929/a-systematic-florula-of-a-disturbed-urban-habitat-pavements-of-sheffield-england
#17
Oliver L Pescott
BACKGROUND: Human settlements are of increasing interest to ecologists, a fact demonstrated by the recent cluster of book-length treatments of the topic (Forman 2008, McDonnell et al. 2009, Gaston 2010, Niemelä et al. 2011, Wilson 2011, Forman 2014). The natural world as a fascinating feature of towns and cities has a much longer history (e.g. Fitter 1945), and has also played a strong part in local biological conservation in some countries over the late 20th Century (Goode 2014​)...
2016: Biodiversity Data Journal
https://www.readbyqxmd.com/read/27919235/geographical-distribution-of-typhoid-risk-factors-in-low-and-middle-income-countries
#18
Jung-Seok Lee, Vijayalaxmi V Mogasale, Vittal Mogasale, Kangsung Lee
BACKGROUND: While the global burden of typhoid fever has been often brought up for attention, the detailed surveillance information has only been available for the limited number of countries. As more efficacious vaccines will be available in the near future, it is essential to understand the geographically diverse patterns of typhoid risk levels and to prioritize the right populations for vaccination to effectively control the disease. METHODS: A composite index called the typhoid risk factor (TRF) index was created based on data with the Global Positioning System (GPS)...
December 5, 2016: BMC Infectious Diseases
https://www.readbyqxmd.com/read/27870120/continuous-attractor-network-models-of-grid-cell-firing-based-on-excitatory-inhibitory-interactions
#19
Oliver Shipston-Sharman, Lukas Solanka, Matthew F Nolan
Neurons in the medial entorhinal cortex encode location through spatial firing fields that have a grid-like organisation. The challenge of identifying mechanisms for grid firing has been addressed through experimental and theoretical investigations of medial entorhinal circuits. Here, we discuss evidence for continuous attractor network models that account for grid firing by synaptic interactions between excitatory and inhibitory cells. These models assume that grid-like firing patterns are the result of computation of location from velocity inputs, with additional spatial input required to oppose drift in the attractor state...
November 15, 2016: Journal of Physiology
https://www.readbyqxmd.com/read/27829799/diversity-and-biogeographical-patterns-of-legumes-leguminosae-indigenous-to-southern-africa
#20
Marike Trytsman, Robert H Westfall, Philippus J J Breytenbach, Frikkie J Calitz, Abraham E van Wyk
The principal aim of this study was to establish biogeographical patterns in the legume flora of southern Africa so as to facilitate the selection of species with agricultural potential. Plant collection data from the National Herbarium, South Africa, were analysed to establish the diversity and areas covered by legumes (Leguminosae/Fabaceae) indigenous to South Africa, Lesotho and Swaziland. A total of 27,322 records from 1,619 quarter degree grid cells, representing 1,580 species, 122 genera and 24 tribes were included in the analyses...
2016: PhytoKeys
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