4,848 research outputs found

    Non-Universal Gaugino Masses, CDMS, and the LHC

    Full text link
    We consider the possibility that the recently reported events at the CDMS-II direct dark matter detection experiment are the result of coherent scattering of supersymmetric neutralinos. In such a scenario we argue that non-universal soft supersymmetry breaking gaugino masses are favored with a resulting lightest neutralino with significant Higgsino and wino components. We discuss the accompanying signals which must be seen at liquid-xenon direct detection experiments and indirect detection experiments if such a supersymmetric interpretation is to be maintained. We illustrate the possible consequences for early discovery channels at the LHC via a set of benchmark points designed to give rise to an observed event rate comparable to the reported CDMS-II data.Comment: Typos corrected and references adde

    Seasonal and Diurnal Patterns of Temperature Inversion Formation and Breakup in a Topographically Complex Urban Environment

    Get PDF
    Measuring air temperatures and winds at several heights in a dense urban area over a nine-month period reveals important seasonal differences in patterns of atmospheric stability, boundary-layer circulation, and other important factors that affect concentrations of air pollutants. The study site in Portland, Oregon includes natural topographic variations from 5 meters above sea level at the shore of a heavily industrialized stretch of the Willamette River, up to 50 meters above sea level atop a nearby bluff where residents often complain of poor air quality. This study installed, and continues to maintain, a network of remote automated weather stations ranging in altitude from river-level to the rooftops of buildings up to eight stories high, spanning a range of 70 m in the vertical from the lowest to highest station altitude, within an area of only 0.25 square km. Prior to this study, the density of weather observations in this area was often insufficient for resolving the conditions relevant to analyzing and monitoring air pollution events, but the significantly higher resolution of meteorological data now available for the area shows promise for addressing these issues. Station measurements include air temperatures and humidities at multiple heights per station, wind direction, wind speed, gust speed, solar radiation in multiple wavelength ranges, direct-diffuse ratios of solar radiation, air pressure, precipitation rates, leaf wetness, soil moisture, thermal-infrared radiant temperatures, kinetic temperatures, and boundary layer fluxes. This study also designed new tethersonde sampling methods to complement the ground-based stations with high-resolution data on vertical profiles of air temperatures, humidity, and winds within the boundary layer. Results show strong, low-level temperature inversions that are often more diurnally-constant in winter than in other seasons, with important implications for local air pollutant concentrations. Applications include improved understanding of local atmospheric patterns, which could help to inform better policies for addressing air quality issues

    Temporal dynamics of trauma memory persistence

    Get PDF

    A model of meta-population dynamics for North Sea and West of Scotland cod - the dynamic consequences of natal fidelity

    Get PDF
    It is clear from a variety of data that cod (Gadus morhua) in the North Sea do not constitute a homogeneous population that will rapidly redistribute in response to local variability in exploitation. Hence, local exploitation has the potential to deplete local populations, perhaps to the extent that depensation occurs and recovery is impossible without recolonisation from other areas, with consequent loss of genetic diversity. The oceanographic, biological and behavioural processes which maintain the spatial population structures are only partly understood, and one of the key unknown factors is the extent to which codexhibit homing migrations to natal spawning areas. Here, we describe a model comprising 10 interlinked demes of cod in European waters, each representing groups of fish with a common natal origin. The spawning locations of fish in each deme are governed by a variety of rules concerning oceanographic dispersal, migration behaviour and straying. We describe numerical experiments with the model and comparisons with observations, which lead us to conclude that active homing is probably not necessary to explain some of the population structures of European cod. Separation of some sub-populations is possible through distance and oceanographic processes affecting the dispersal of eggs and larvae. However, other evidence suggests that homing may be a necessary behaviour to explain the structure of other sub-populations. Theconsequences for fisheries management of taking into account spatial population structuring are complicated. For example, recovery or recolonisation strategies require consideration not only of mortality rates in the target area for restoration, but also in the source areas for the recruits which may be far removed depending on the oceanography. The model has an inbuilt capability to address issues concerning the effects of climate change, including temperature change, on spatial patterns of recruitment, development and population structure in cod

    Porous silica spheres as indoor air pollutant scavengers

    Get PDF
    Porous silica spheres were investigated for their effectiveness in removing typical indoor air pollutants, such as aromatic and carbonyl-containing volatile organic compounds (VOCs), and compared to the commercially available polymer styrene-divinylbenzene (XAD-4). The silica spheres and the XAD-4 resin were coated on denuder sampling devices and their adsorption efficiencies for volatile organic compounds evaluated using an indoor air simulation chamber. Real indoor sampling was also undertaken to evaluate the affinity of the silica adsorbents for a variety of indoor VOCs. The silica sphere adsorbents were found to have a high affinity for polar carbonyls and found to be more efficient than the XAD-4 resin at adsorbing carbonyls in an indoor environment

    Predicting C-H/π\pi interactions with nonlocal density functional theory

    Full text link
    We examine the performance of a recently developed nonlocal density functional in predicting a model noncovalent interaction, the weak bond between an aromatic π\pi system and an aliphatic C-H group. The new functional is a significant improvement over traditional density functionals, providing results which compare favorably to high-level quantum-chemistry techniques but at considerably lower computational cost. Interaction energies in several model C-H/π\pi systems are in generally good agreement with coupled-cluster calculations, though equilibrium distances are consistently overpredicted when using the revPBE functional for exchange. The new functional correctly predicts changes in energy upon addition of halogen substituents.Comment: 5 pages, 4 figure

    Pengembangan UMKM sebagai Penguatan Ekonomi Kerakyatan di Kota Bukittinggi (Studi Kasus: Industri Kerupuk Sanjai)

    Get PDF
    This study aims the problems faced by home industry kerupuk Sanjai in the City of Bukittinggi to improve local economy. This study was conducted in March 2015 through a survey method (observation) with random purposive sampling technique. The sample in this study as many as twenty-six home industry Kerupuk Sanjai in Bukittinggi. This research found home industry Kerupuk Sanjai in Bukittinggi city is still traditional both in the production process, packaging and marketing system. So that the necessary cooperation with the relevant agencies in order to create innovation and creativity to improve quality and productivity as well as a broader marketing reach

    Shifting Patterns of Nitrogen Excretion and Amino Acid Catabolism Capacity during the Life Cycle of the Sea Lamprey (\u3cem\u3ePetromyzon mariunus\u3c/em\u3e)

    Get PDF
    The jawless fish, the sea lamprey (Petromyzon marinus), spends part of its life as a burrow-dwelling, suspension-feeding larva (ammocoete) before undergoing a metamorphosis into a free swimming, parasitic juvenile that feeds on the blood of fishes. We predicted that animals in this juvenile, parasitic stage have a great capacity for catabolizing amino acids when large quantities of protein-rich blood are ingested. The sixfold to 20-fold greater ammonia excretion rates (JAmm) in postmetamorphic (nonfeeding) and parasitic lampreys compared with ammocoetes suggested that basal rates of amino acid catabolism increased following metamorphosis. This was likely due to a greater basal amino acid catabolizing capacity in which there was a sixfold higher hepatic glutamate dehydrogenase (GDH) activity in parasitic lampreys compared with ammocoetes. Immunoblotting also revealed that GDH quantity was 10-fold and threefold greater in parasitic lampreys than in ammocoetes and upstream migrant lampreys, respectively. Higher hepatic alanine and aspartate aminotransferase activities in the parasitic lampreys also suggested an enhanced amino acid catabolizing capacity in this life stage. In contrast to parasitic lampreys, the twofold larger free amino acid pool in the muscle of upstream migrant lampreys confirmed that this period of natural starvation is accompanied by a prominent proteolysis. Carbamoyl phosphate synthetase III was detected at low levels in the liver of parasitic and upstream migrant lampreys, but there was no evidence of extrahepatic (muscle, intestine) urea production via the ornithine urea cycle. However, detection of arginase activity and high concentrations of arginine in the liver at all life stages examined infers that arginine hydrolysis is an important source of urea. We conclude that metamorphosis is accompanied by a metabolic reorganization that increases the capacity of parasitic sea lampreys to catabolize intermittently large amino acid loads arising from the ingestion of protein rich blood from their prey/hosts. The subsequent generation of energy-rich carbon skeletons can then be oxidized or retained for glycogen and fatty acid synthesis, which are essential fuels for the upstream migratory and spawning phases of the sea lamprey’s life cycle

    Misdiagnosis, Mistreatment, and Harm - When Medical Care Ignores Social Forces.

    Get PDF
    The Case Studies in Social Medicine demonstrate that when physicians use only biologic or individual behavioral interventions to treat diseases that stem from or are exacerbated by social factors, we risk harming the patients we seek to serve

    Kirigami Actuators

    Full text link
    Thin elastic sheets bend easily and, if they are patterned with cuts, can deform in sophisticated ways. Here we show that carefully tuning the location and arrangement of cuts within thin sheets enables the design of mechanical actuators that scale down to atomically-thin 2D materials. We first show that by understanding the mechanics of a single, non-propagating crack in a sheet we can generate four fundamental forms of linear actuation: roll, pitch, yaw, and lift. Our analytical model shows that these deformations are only weakly dependent on thickness, which we confirm with experiments at centimeter scale objects and molecular dynamics simulations of graphene and MoS2_{2} nanoscale sheets. We show how the interactions between non-propagating cracks can enable either lift or rotation, and we use a combination of experiments, theory, continuum computational analysis, and molecular dynamics simulations to provide mechanistic insights into the geometric and topological design of kirigami actuators.Comment: Soft Matter, 201
    corecore