4,317 research outputs found

    Ecosystem service provision by road verges

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    This is the final version. Available on open access from Wiley via the DOI in this record.1. Roads form a vast, rapidly-growing global network that has diverse, detrimental ecological impacts. However, the habitats that border roads (‘road verges’) form a parallel network that might help mitigate these impacts and provide additional benefits (ecosystem services; ES). 2. We evaluate the capacity of road verges to provide ES by reviewing existing research and considering their relevant characteristics; area, connectivity, shape, and contextual ES supply and demand. We consider the present situation, and how this is likely to change based on future projections for growth in road extent, traffic densities and urban populations. 3. Road verges provide a wide range of ES, including biodiversity provision, regulating services (e.g. air and water filtration) and cultural services (e.g. health and aesthetic benefits by providing access to nature), but also displace other habitats and provide ecosystem disservices (e.g. allergens and damage to infrastructure). Globally, road verges may currently cover 270,000 km2 and store 0.015 Gt C year-1 , which will further increase with 70% projected growth in the global road network. 4. Road verges are well-placed to mitigate traffic pollution and address demand for ES in surrounding ES-impoverished landscapes, thereby improving human health and wellbeing in urban areas, and improving agricultural production and sustainability in farmland. Demand for ES provided by road verges will likely increase due to projected growth in traffic densities and urban populations, though traffic pollution will be reduced by technological advances (e.g. electric vehicles). Road verges form a highly-connected network, which may enhance ES provision but facilitate the dispersal of invasive species and increase vehicle-wildlife collisions. 5. Synthesis and applications. Road verges offer a significant opportunity to mitigate the negative ecological effects of roads and to address demand for ES in surrounding ES-impoverished landscapes. Their capacity to provide ES might be enhanced considerably if they were strategically designed and managed for environmental outcomes, namely by optimizing the selection, position and management of plant species and habitats. Specific opportunities include reducing mowing frequencies and planting trees in large verges. Road verge management for ES must consider safety guidelines, financial costs and ecosystem disservices, but is likely to provide long-term financial returns if environmental benefits are taken into account.Natural Environment Research Counci

    Looking for the Charged Higgs Boson

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    This review article starts with a brief introduction to the charged Higgs boson (H^\pm) in the Minimal Supersymmetric Standard Model (MSSM). It then discusses the prospects of a relatively light H^\pm boson search via top quark decay at Tevatron/LHC, and finally a heavy H^\pm boson search at LHC. The viable channels for H^\pm search are identified in both the cases, with particular emphasis on the H^\pm --> tau + nu decay channel. The effects of NLO QCD correction in the SM as well as the MSSM are discussed briefly.Comment: 17 pages with 8 eps figures, Invited review, Reference adde

    Polarization of τ\tau lepton from scalar tau decay as a probe of neutralino mixing

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    The τ\tau lepton arising from the scalar tau (\st) decay is naturally polarized. \ptau depends on the left--right mixing of the \st and the gaugino--higgsino mixing of the neutralino. The polarization \ptau could be measured from the energy distribution of the decay products of τ\tau at future \epem colliders. A measurement of \ptauand of the \st production cross section allows to determine both these mixing angles.Comment: 20 pages Latex, 5 figures(not included). compressed ps file of the figures available at ftp://ftp.kek.jp/kek/preprints/TH/TH-425/fig.ps.g

    Tracing Galaxy Formation with Stellar Halos I: Methods

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    If the favored hierarchical cosmological model is correct, then the Milky Way system should have accreted ~100-200 luminous satellite galaxies in the past \~12 Gyr. We model this process using a hybrid semi-analytic plus N-body approach which distinguishes explicitly between the evolution of light and dark matter in accreted satellites. This distinction is essential to our ability to produce a realistic stellar halo, with mass and density profile much like that of our own Galaxy, and a surviving satellite population that matches the observed number counts and structural parameter distributions of the satellite galaxies of the Milky Way. Our model stellar halos have density profiles which typically drop off with radius faster than those of the dark matter. They are assembled from the inside out, with the majority of mass (~80%) coming from the \~15 most massive accretion events. The satellites that contribute to the stellar halo have median accretion times of ~9 Gyr in the past, while surviving satellite systems have median accretion times of ~5 Gyr in the past. This implies that stars associated with the inner halo should be quite different chemically from stars in surviving satellites and also from stars in the outer halo or those liberated in recent disruption events. We briefly discuss the expected spatial structure and phase space structure for halos formed in this manner. Searches for this type of structure offer a direct test of whether cosmology is indeed hierarchical on small scales.Comment: 22 pages, 16 figures, submitted to Ap

    Visitation to Cottonseed Storage Sites by Feral Swine and Evidence of Gossypol Exposure

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    Texas ranks first in U.S. cotton production, and southern Texas is a major region of production within the state. Within Kleberg County, for example, approximately 16,147 ha are planted in cotton annually, yielding approximately 68,200 bales, or 15,467 metric tons, of cotton (U.S. Department of Agriculture [USDA] 2009). Cotton producers have discovered new uses for cotton ginned by-products, such as hydro-mulch (Holt et al. 2005) used as a protein supplement for range livestock (DelCurto et al. 2000) and white-tailed deer (Odocoileus virginianus; Cooper 2006). Because of this, much of the materials are temporarily stored for later use

    Confronting the Minimal Supersymmetric Standard Model with the Study of Scalar Leptons at Future Linear e+e- Colliders

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    Sleptons can easily be found at future linear e+e- colliders if kinematically accessible. Measurements of their masses and decay distributions would then determine MSSM parameters. This paper presents a detailed MC study of the production and decay of the lighter scalar tau lepton, stau1. We found that mstau1 and the left-right mixing angle of stau would be measured within an error of a few percent. tanbeta is determinable in some region of the parameter space through simultaneous studies of stau1-and selectron-pair production: the polarization measurement of the tau leptons from stau1 decays and the M1, mchi1 determination using selectron pair production and decay. We also point out the possibility to determine bino-selectron-e coupling through the measurement of the angular distribution of the selectron-pair production. The error on the coupling is expected to be comparable to its typical SUSY radiative correction, which is proportional to log(msquark/mslepton). The radiative correction affects M1 and tanbeta determination, necessitating the full 1-loop radiative correction to the selectron production processes. The implication of these measurements of the MSSM parameters on selecting models of the origin of supersymmetry breaking is also discussed.Comment: 35 pages. REVTEX(gzip compressed and uuencoded). Figure are not included. Text and 15 Figures are available at http://jlcux1.kek.jp/subg/susy/index-e.html#librar

    Qudit surface codes and gauge theory with finite cyclic groups

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    Surface codes describe quantum memory stored as a global property of interacting spins on a surface. The state space is fixed by a complete set of quasi-local stabilizer operators and the code dimension depends on the first homology group of the surface complex. These code states can be actively stabilized by measurements or, alternatively, can be prepared by cooling to the ground subspace of a quasi-local spin Hamiltonian. In the case of spin-1/2 (qubit) lattices, such ground states have been proposed as topologically protected memory for qubits. We extend these constructions to lattices or more generally cell complexes with qudits, either of prime level or of level dd^\ell for dd prime and 0\ell \geq 0, and therefore under tensor decomposition, to arbitrary finite levels. The Hamiltonian describes an exact ZdZ/dZ\mathbb{Z}_d\cong\mathbb{Z}/d\mathbb{Z} gauge theory whose excitations correspond to abelian anyons. We provide protocols for qudit storage and retrieval and propose an interferometric verification of topological order by measuring quasi-particle statistics.Comment: 26 pages, 5 figure

    Klein-Gordon Solutions on Non-Globally Hyperbolic Standard Static Spacetimes

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    We construct a class of solutions to the Cauchy problem of the Klein-Gordon equation on any standard static spacetime. Specifically, we have constructed solutions to the Cauchy problem based on any self-adjoint extension (satisfying a technical condition: "acceptability") of (some variant of) the Laplace-Beltrami operator defined on test functions in an L2L^2-space of the static hypersurface. The proof of the existence of this construction completes and extends work originally done by Wald. Further results include the uniqueness of these solutions, their support properties, the construction of the space of solutions and the energy and symplectic form on this space, an analysis of certain symmetries on the space of solutions and of various examples of this method, including the construction of a non-bounded below acceptable self-adjoint extension generating the dynamics

    Misogyny, racism, and Islamophobia: street harassment at the intersections

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    Veiled Muslim women are at an increased risk of street harassment in the current political and economic climate. Their visibility, combined with their popular portrayal as culturally dangerous or threatening means that they are vulnerable to receiving verbal and physical threats, which can be misogynistic and Islamophobic in nature. Drawing on 60 individual and 20 focus group interviews with Muslim women in the United Kingdom who wear the niqab (face veil) and had experienced harassment in public, this qualitative study details their lived experiences. It argues that an intersectional analysis is crucial to understanding the nuances of their lived experiences and the impact street harassment has on their lives. The findings demonstrate that street harassment can produce a hostile environment for veiled Muslim women, which can have a terrorizing effect, limiting their full participation in the public sphere

    Recurrent Clostridium difficile infection associates with distinct bile acid and microbiome profiles

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    Background: The healthy microbiome protects against the development of Clostridium difficile infection (CDI), which typically develops following antibiotics. The microbiome metabolises primary to secondary bile acids, a process if disrupted by antibiotics, may be critical for the initiation of CDI. Aim: To assess the levels of primary and secondary bile acids associated with CDI and associated microbial changes. Methods: Stool and serum were collected from patients with (i) first CDI (fCDI), (ii) recurrent CDI (rCDI) and (iii) healthy controls. 16S rRNA sequencing and bile salt metabolomics were performed. Random forest regression models were constructed to predict disease status. PICRUSt analyses were used to test for associations between predicted bacterial bile salt hydrolase (BSH) gene abundances and bile acid levels. Results: Sixty patients (20 fCDI, 19 rCDI and 21 controls) were enrolled. Secondary bile acids in stool were significantly elevated in controls compared to rCDI and fCDI (P < 0.0001 and P = 0.0007 respectively). Primary bile acids in stool were significantly elevated in rCDI compared to controls (P < 0.0001) and in rCDI compared to fCDI (P = 0.02). Using random forest regression, we distinguished rCDI and fCDI patients 84.2% of the time using bile acid ratios. Stool deoxycholate to glycoursodeoxycholate ratio was the single best predictor. PICRUSt analyses found significant differences in predicted abundances of bacterial BSH genes in stool samples across the groups. Conclusions: Primary and secondary bile acid composition in stool was different in those with rCDI, fCDI and controls. The ratio of stool deoxycholate to glycoursodeoxycholate was the single best predictor of disease state and may be a potential biomarker for recurrence.American College of Gastroenterology (Clinical Research Award ACGJR-017-2015
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