1,388 research outputs found
COLONIZATION OF NORTHERN LOUISIANA BY THE MEDITERRANEAN GECKO, HEMIDACTYLUS TURCICUS
The Mediterranean Gecko, Hemidactylus turcicus, is known to have colonized nearly every state in the southern United States. In Louisiana, the Mediterranean Gecko has been documented in many of the southern parishes, but records for the northern portion of the state are limited. We sampled northern Louisiana parishes to document the presence of the Mediterranean Gecko. We sampled a total of 21 parishes in northern Louisiana and found geckos in 17 of those parishes, 16 of which represent new distribution records for the species. This indicates a significant range expansion of this introduced species throughout northern Louisiana. Geckos were found across a temperature range of 14.0–28.0°C and had a strong association with buildings. The species’ affinity for anthropogenic association and the continual nature of anthropogenic expansion facilitate the high vagility of this species. The result is a successful colonization throughout much of Louisiana and likely continued range expansion throughout the southern United States
Accuracy Assessment of the 2006 National Land Cover Database Percent Impervious Dataset
An impervious surface is any surface that prevents water from infiltrating the ground. As impervious surface area increases within watersheds, stream networks and water quality are negatively impacted. The Multi-Resolution Land Characteristic Consortium developed a percent impervious dataset using Landsat imagery as part of the 2006 National Land Cover Database. This percent impervious dataset estimates imperviousness for each 30-meter cell in the land cover database. The percent impervious dataset permits study of impervious surfaces, can be used to identify impacted or critical areas, and allows for development of impact mitigation plans; however, the accuracy of this dataset is unknown. To determine the accuracy of the 2006 percent impervious dataset, reference data were digitized from one-foot digital aerial imagery for three study areas in Arkansas, USA. Digitized reference data were compared to percent impervious dataset estimates of imperviousness at multiple 900m2 , 8,100m2 , and 22,500m2 sample grids to determine if accuracy varied by ground area. Analyses showed percent impervious estimates and digitized reference data differ modestly; however, as ground area increases, percent impervious estimates and reference data match more closely. These findings suggest that the percent impervious dataset is useful for planning purposes for ground areas of at least 2.25ha
Energy landscapes of a hairpin peptide including NMR chemical shift restraints.
Methods recently introduced to improve the efficiency of protein structure prediction simulations by adding a restraint potential to a molecular mechanics force field introduce additional input parameters that can affect the performance. Here we investigate the changes in the energy landscape as the relative weight of the two contributions, force field and restraint potential, is systematically altered, for restraint functions constructed from calculated nuclear magnetic resonance chemical shifts. Benchmarking calculations were performed on a 12-residue peptide, tryptophan zipper 1, which features both secondary structure (a β-hairpin) and specific packing of tryptophan sidechains. Basin-hopping global optimization was performed to assess the efficiency with which lowest-energy structures are located, and the discrete path sampling approach was employed to survey the energy landscapes between unfolded and folded structures. We find that inclusion of the chemical shift restraints improves the efficiency of structure prediction because the energy landscape becomes more funnelled and the proportion of local minima classified as native increases. However, the funnelling nature of the landscape is reduced as the relative contribution of the chemical shift restraint potential is increased past an optimal value.This research was supported by the EPSRC and the ERC.This is the final version of the article. It first appeared from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C5CP01259
Improving spatial predictability of petroleum resources within the Central Tertiary Basin, Spitsbergen: a geochemical and petrographic study of coals from the eastern and western coalfields
Central Tertiary Basin (CTB) coals from a variety of palaeogeographic conditions within the Longyear and Verkhnij seams, were sampled to assess the relationship between the petroleum present, the remaining generation potential and coal geochemistry in order to improve the spatial predictability of petroleum resources within the basin. Vitrinite reflectance (VR) values from the CTB coals have been shown to be suppressed (Marshall et al., 2015a). This study attempts to quantify and correct for this suppression effect by applying the Lo (1993) method (LoVR), which uses Hydrogen Index (HI) values to modify VR data, and the coal Rank(Sr) scale of Suggate (2000, 2002), a technique not affected by suppression. In addition, the oil generation and expulsion thresholds for the CTB coals were investigated
Internet-of-Things Devices, Intellectual Property, Venture Capital, China Manufacturing, and the Art of a Clean Deal: Who Owns What?
Internet-of-Things Devices, Intellectual Property, Venture Capital, China Manufacturing, and the Art of a Clean Deal: Who Owns What
Initial lists of AMMA-2050 user-relevant climate metrics
AMMA-2050 (African Monsoon Multi-disciplinary Analysis 2050) will improve understanding of how the West African monsoon will be affected by climate change in the coming decades – and help West African societies prepare and adapt
- …
