10,818 research outputs found
Paleoenvironmental analysis of a late Holocene deposit : Stanton site, west-central North Dakota
The Stanton Site (W1/2NE1/4 sec. 16, T. 144 N., R. 85W.), eastern Mercer County, North Dakota, contains a late Holocene organic deposit in the cutbank of an ephemeral stream on the Missouri Plateau. Strati graphic units of the 104-cm section are, in ascending order: (l) gravel; (2) silty, organic, sandy clay; (3) organic silt; (4) silty, sandy, organic clay; (5) organic silt; (6) sandy, silt, organic clay; and (7) sand. A radiocarbon date of wood from the base of unit 2 indicates initiation of deposition at 325±_115 radiocarbon years B.P.
Abundant well-preserved fossils are present in the organic sediments of the Stanton Site, A molluscan assemblage from a measured section consists of 2 species of sphaeriid bivalves, 6 species of aquatic snails, and 8 species of terrestrial snails, including Stagnicola caperata (Say), Aplexa hypnorum Haldeman, Gyraulus parvus (Say), Armiger crista (Linnaeus), Euconulus fulvus {Muller), and Hawaiia miniscula (Binney). A,;:oleopteran assemblage of 43 taxa includes 22 identified species, primarily ground beetles, including Dyschirius setosus Leconte, Elaphrus olivaceus Leconte, Pasimachus elongatus Leconte, Pterostichus leconteianus Lutshnik, and Patrobus stygicus Chaudoir. Interpretation of the fossil assemblages indicates a thickly vegetated, ephemeral, prairie stream. The similarity of faunal components throughout the section, suggests envirornnental stability, including the climatic parameters
The Natural Farming Concept: A New Economical Waste Management System for Small Family Swine Farms in Hawaiâi: Most Frequently Asked Questions on the IDLS Piggery
This fact sheet answers the most commonly asked questions about the inoculated deep litter system, which addresses the manure treatment process for swine confinement-rearing operations
Is there a single best estimator? Selection of home range estimators using area-under-the-curve
Background: Global positioning system (GPS) technology for monitoring home range and movements of wildlife has resulted in prohibitively large sample sizes of locations for traditional estimators of home range. We used areaunder- the-curve to explore the fit of 8 estimators of home range to data collected with both GPS and concurrent very high frequency (VHF) technology on a terrestrial mammal, the Florida panther Puma concolor coryi, to evaluate recently developed and traditional estimators.
Results: Area-under-the-curve was the highest for Florida panthers equipped with Global Positioning System (GPS) technology compared to VHF technology. For our study animal, estimators of home range that incorporated a temporal component to estimation performed better than traditional first- and second-generation estimators.
Conclusions: Comparisons of fit of home range contours with locations collected would suggest that use of VHF technology is not as accurate as GPS technology to estimate size of home range for large mammals. Estimators of home range collected with GPS technology performed better than those estimated with VHF technology regardless of estimator used. Furthermore, estimators that incorporate a temporal component (third-generation estimators) appeared to be the most reliable regardless of whether kernel-based or Brownian bridge-based algorithms were used and in comparison to first- and second-generation estimators. We defined third-generation estimators of home range as any estimator that incorporates time, space, animal-specific parameters, and habitat. Such estimators would include movement-based kernel density, Brownian bridge movement models, and dynamic Brownian bridge movement models among others that have yet to be evaluated
A Temperature-Dependent Positive Feedback on the Magnitude of Carbon Isotope Excursions
The decrease in the average magnitude of carbon isotope excursions in marine carbonates over Phanerozoic time is a longstanding unresolved problem. In addition, carbon isotope excursions commonly co-occur with oxygen isotope excursions of the same sign, implying the existence of a longstanding link between organic carbon burial fluxes and temperature. It was proposed that this connection was provided by the thermodynamic relationship between temperature and microbial respiration rates â changes in temperature drive changes in organic carbon remineralization rate and organic carbon burial efficiency. Such a mechanism provides the logic for a positive feedback affecting the magnitude of both climate changes and carbon isotope excursions. Here, we employ feedback analysis to quantify the strength of this mechanism with modifications to a simple carbon isotope mass balance framework. We demonstrate that the potential strength of this feedback is large (perhaps several permil) for plausible ranges of historical climate change. Furthermore, our results highlight the importance of the surface temperature boundary condition on the magnitude of the expected carbon isotope excursion. Comparisons of our model predictions with data from the terminal Eocene and Late Ordovician (Hirnantian) greenhouseâicehouse climate transitions suggest that these excursions might be substantially explained by such a thermodynamic microbial respiration feedback. Consequently, we hypothesize that the observed pattern of decreasing excursion magnitude toward the present might be explained at least, in part, by a decrease in the mean temperature of environments of organic carbon burial driven by long-term climate and paleogeographic trends. SOMMAIRELa diminution de l'amplitude moyenne des excursions des isotopes du carbone dans les carbonates marins au fil du PhanĂ©rozoĂŻque est une Ă©nigme de longue date. On note en outre que les excursions des isotopes du carbone coexistent couramment avec des excursions isotopiques de mĂȘme signe de l'oxygĂšne, ce qui implique l'existence d'un lien de longue date entre les flux dâenfouissement du carbone organique et la tempĂ©rature. On a suggĂ©rĂ© que ce lien dĂ©coulait de la relation thermodynamique entre la tempĂ©rature et les taux de respiration microbienne - les changements de tempĂ©rature dĂ©terminent le taux de reminĂ©ralisation du carbone organique et lâefficacitĂ© de lâenfouissement du carbone organique. Un tel mĂ©canisme peut expliquer la rĂ©troaction positive affectant Ă la fois l'ampleur des changements climatiques et les excursions des isotopes du carbone. Dans le cas prĂ©sent, nous utilisons l'analyse de la rĂ©troaction pour quantifier la robustesse de ce mĂ©canisme avec des modifications dâun simple bilan de masse des isotopes du carbone. Nous dĂ©montrons que la robustesse potentielle de cette rĂ©troaction est forte (peut-ĂȘtre plusieurs pour mille) dans les gammes plausibles du changement climatique historique. De plus, nos rĂ©sultats mettent en Ă©vidence l'importance de la condition aux limites de la tempĂ©rature de surface sur l'ampleur de l'excursion isotopique du carbone attendue. Les comparaisons des prĂ©dictions de notre modĂšle avec les donnĂ©es de la fin de l'ĂocĂšne et de la fin de lâOrdovicien (Hirnantien) des transitions climatiques Ă effet de serre-effet/de glaciation permettent de penser que ces excursions pourraient ĂȘtre correctement expliquĂ©es par une telle rĂ©troaction de la thermodynamique de la respiration microbienne. Par consĂ©quent, nous Ă©mettons l'hypothĂšse que la tendance observĂ©e de diminution de l'ampleur de lâamplitude des excursions du passĂ© vers le prĂ©sent peut s'expliquer, au moins en partie, par une diminution de la tempĂ©rature moyenne du milieu d'enfouissement du carbone organique engendrĂ©e par des tendances climatiques et palĂ©ogĂ©ographiques Ă long terme
What Is the Proper Method to Delineate Home Range of an Animal Using Todayâs Advanced GPS Telemetry Systems: The Initial Step
The formal concept of an animalâs home range, or derivations thereof, has been around for over half a century (Burt 1943). Within this time frame there have been countless published studies reporting home range estimators with no consensus for any single technique (Withey et al., 2001; Laver & Kelly 2008). Recent advances in global positioning system (GPS) technology for monitoring home range and movements of wildlife have resulted in locations that are numerous, more precise than very high frequency (VHF) systems, and often are auto correlated in space and time. Along with these advances, researchers are challenged with understanding the proper methods to assess size of home range or migratory movements of various species. The most acceptable method of home-range analysis with uncorrelated locations, kernel-density estimation (KDE), has been lauded by some for use with GPS technology (Kie et al., 2010) while criticized by others for errors in proper bandwidth selection (Hemson et al., 2005) and violation of independence assumptions (Swihart & Slade 1985b). The issue of autocorrelation or independence in location data has been dissected repeatedly by users of KDE for decades (Swihart & Slade 1985a; Worton 1995, but see Fieberg 2007) and can be especially problematic with data collected with GPS technology
The Transcriptional and DNA Binding Activity of Peroxisome Proliferator-activated Receptor α Is Inhibited by Ethanol Metabolism A NOVEL MECHANISM FOR THE DEVELOPMENT OF ETHANOL-INDUCED FATTY LIVER
Fatty acids are ligands for the peroxisome proliferator-activated receptor alpha (PPAR alpha). Fatty acid levels are increased in liver during the metabolism of ethanol and might be expected to activate PPAR alpha. However, ethanol inhibited PPAR alpha activation of a reporter gene in H4IIEC3 hepatoma cells expressing alcohol-metabolizing enzymes but not in CV-1 cells, which lack these enzymes. Ethanol also reduced the ability of the PPAR alpha ligand WY14,643 to activate reporter constructs in the hepatoma cells or cultured rat hepatocytes. This effect of ethanol was abolished by the alcohol dehydrogenase inhibitor 4-methylpyrazole and augmented by the aldehyde dehydrogenase inhibitor cyanamide, indicating that acetaldehyde was responsible for the action of ethanol. PPAR alpha/retinoid X receptor extracted from hepatoma cells exposed to ethanol or acetaldehyde bound poorly to an oligonucleotide containing peroxisome proliferator response elements. This effect was also blocked by 4-methylpyrazole and augmented by cyanamide. Furthermore, in vitro translated PPAR alpha exposed to acetaldehyde failed to bind DNA. Thus, ethanol metabolism blocks transcriptional activation by PPAR alpha, in part due to impairment of its ability to bind DNA. This effect of ethanol may promote the development of alcoholic fatty liver and other hepatic consequences of alcohol abuse
Supplementary data for the article: Ostafe, R.; Prodanovic, R.; Ung, W. L.; Weitz, D. A.; Fischer, R. A High-Throughput Cellulase Screening System Based on Droplet Microfluidics. Biomicrofluidics 2014, 8 (4). https://doi.org/10.1063/1.4886771
Supplementary material for: [https://doi.org/10.1063/1.4886771]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1873
Effects of simulated removal activities on movements and space use of feral swine
Abundance and distribution of feral swine (Sus scrofa) in the USA have increased dramatically during the last 30 years. Effective measures are needed to control and eradicate feral swine populations without displacing animals over wider areas. Our objective was to investigate effects of repeated simulated removal activities on feral swine movements and space use.We analyzed location data from 21 feral swine that we fitted with Global Positioning System harnesses in southern MO, USA. Various removal activities were applied over time to eight feral swine before lethal removal, including trapped-and-released, chased with dogs, chased with hunter, and chased with helicopter. We found that core space-use areas were reduced following the first removal activity, whereas overall space-use areas and diurnal movement distances increased following the second removal activity. Mean geographic centroid shifts did not differ between pre- and postperiods for either the first or second removal activities. Our information on feral swine movements and space use precipitated by human removal activities, such as hunting, trapping, and chasing with dogs, helps fill a knowledge void and will aid wildlife managers. Strategies to optimize management are needed to reduce feral swine populations while preventing enlarged home ranges and displacing individuals, which could lead to increased disease transmission risk and human-feral swine conflict in adjacent areas
Effects of simulated removal activities on movements and space use of feral swine
Abundance and distribution of feral swine (Sus scrofa) in the USA have increased dramatically during the last 30 years. Effective measures are needed to control and eradicate feral swine populations without displacing animals over wider areas. Our objective was to investigate effects of repeated simulated removal activities on feral swine movements and space use.We analyzed location data from 21 feral swine that we fitted with Global Positioning System harnesses in southern MO, USA. Various removal activities were applied over time to eight feral swine before lethal removal, including trapped-and-released, chased with dogs, chased with hunter, and chased with helicopter. We found that core space-use areas were reduced following the first removal activity, whereas overall space-use areas and diurnal movement distances increased following the second removal activity. Mean geographic centroid shifts did not differ between pre- and postperiods for either the first or second removal activities. Our information on feral swine movements and space use precipitated by human removal activities, such as hunting, trapping, and chasing with dogs, helps fill a knowledge void and will aid wildlife managers. Strategies to optimize management are needed to reduce feral swine populations while preventing enlarged home ranges and displacing individuals, which could lead to increased disease transmission risk and human-feral swine conflict in adjacent areas
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