339 research outputs found
Recommended from our members
A stated preference valuation of the non-market benefits of pollination services in the UK
Using a choice experiment survey this study examines the UK public's willingness to pay to conserve insect pollinators
in relation to the levels of two pollination service benefits: maintaining local produce supplies and the
aesthetic benefits of diverse wildflower assemblages. Willingness to pay was estimated using a Bayesian
mixed logit with two contrasting controls for attribute non-attendance, exclusion and shrinkage. The results suggest
that the UK public have an extremely strong preference to avoid a status quo scenario where pollinator populations
and pollination services decline. Total willingness to pay was high and did not significantly vary between
the two pollination service outputs, producing a conservative total of ÂŁ379M over a sample of the tax-paying
population of the UK, equivalent to ÂŁ13.4 per UK taxpayer. Using a basic production function approach, the marginal
value of pollination services to these attributes is also extrapolated. The study discusses the implications of
these findings and directions for related future research into the non-market value of pollination and other ecosystem
services
Band bending at In-rich InGaN surfaces
The band bending and carrier concentration profiles as a function of depth below the surface for oxidized InxGa1âxN alloys with a composition range of 0.39 †x †1.00 are investigated using x-ray photoelectron, infrared reflection, and optical absorption spectroscopies, and solutions of Poissonâs equation within a modified ThomasâFermi approximation. All of these InGaN samples exhibit downward band bending ranging from 0.19 to 0.66 eV and a high surface sheet charge density ranging from 5.0Ă1012 to 1.5Ă1013âcmâ2. The downward band bending is more pronounced in the most In-rich InGaN samples, resulting in larger near-surface electron concentrations
SCExAO/MEC and CHARIS Discovery of a Low Mass, 6 AU-Separation Companion to HIP 109427 using Stochastic Speckle Discrimination and High-Contrast Spectroscopy
We report the direct imaging discovery of a low-mass companion to the nearby
accelerating A star, HIP 109427, with the Subaru Coronagraphic Extreme Adaptive
Optics (SCExAO) instrument coupled with the MKID Exoplanet Camera (MEC) and
CHARIS integral field spectrograph. CHARIS data reduced with reference star PSF
subtraction yield 1.1-2.4 m spectra. MEC reveals the companion in and
band at a comparable signal-to-noise ratio using stochastic speckle
discrimination, with no PSF subtraction techniques. Combined with complementary
follow-up photometry from Keck/NIRC2, the SCExAO data favors a
spectral type, effective temperature, and luminosity of M4-M5.5, 3000-3200 ,
and , respectively.
Relative astrometry of HIP 109427 B from SCExAO/CHARIS and Keck/NIRC2, and
complementary Gaia-Hipparcos absolute astrometry of the primary favor a
semimajor axis of au, an eccentricity of
, an inclination of degrees, and a
dynamical mass of . This work shows the
potential for extreme AO systems to utilize speckle statistics in addition to
widely-used post-processing methods to directly image faint companions to
nearby stars near the telescope diffraction limit.Comment: 13 pages, 7 figures, 3 table
Adaptive Challenges, Adaptive Work, and Adaptive Leadership Among Women Living With HIV in the Southern United States: Findings From a Qualitative Study
Women living with HIV have a higher burden of non-AIDS comorbidities and prevalence of chronic conditions. The Adaptive Leadership Framework for Chronic Illness clarifies living with complex health challenges by delineating the technical work of health care providers as well as the adaptive work and leadership behaviors of patients and their providers. We conducted a descriptive, qualitative study of women residing in the Southern United States who were participating in the Women's Interagency HIV Study in North Carolina. Twenty-two participants (mean age = 52.2 years; 90.9% self-identifying as Black or African American) completed semi-structured qualitative interviews. We identified adaptive challenges (e.g., affective and disclosure challenges) and adaptive work and leadership behaviors. Women learned skills to care for their health and support their families and to work with their providers to manage their care. Findings support the importance of identifying leadership behaviors for the purpose of developing person-centered interventions
Exploring Resilience among Black Women Living with HIV in the Southern United States: Findings from a Qualitative Study
Black women living with HIV (WLWH) face individual and sociostructural challenges. Despite these challenges, many exemplify remarkable levels of resilience and coping. Yet, research on resilience and coping in this population is limited. Twenty Black WLWH in the Southern United States completed semi-structured interviews that explored challenges facing WLWH. We identified six themes related to resilience and coping: self-acceptance, disclosure, self-compassion, social support, will to live, and service. Of these, social support was a driving protective element and an essential component to building and sustaining resilience and coping. Women who experienced positive support often expressed a will to live as well as a desire to support other WLWH. Resilience and social support were characterized by patterns of reciprocity, in that they were mutually sustaining, stabilizing, and strengthening
The G0 Experiment: Apparatus for Parity-Violating Electron Scattering Measurements at Forward and Backward Angles
In the G0 experiment, performed at Jefferson Lab, the parity-violating
elastic scattering of electrons from protons and quasi-elastic scattering from
deuterons is measured in order to determine the neutral weak currents of the
nucleon. Asymmetries as small as 1 part per million in the scattering of a
polarized electron beam are determined using a dedicated apparatus. It consists
of specialized beam-monitoring and control systems, a cryogenic hydrogen (or
deuterium) target, and a superconducting, toroidal magnetic spectrometer
equipped with plastic scintillation and aerogel Cerenkov detectors, as well as
fast readout electronics for the measurement of individual events. The overall
design and performance of this experimental system is discussed.Comment: Submitted to Nuclear Instruments and Method
Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
We review HB stars in a broad astrophysical context, including both variable
and non-variable stars. A reassessment of the Oosterhoff dichotomy is
presented, which provides unprecedented detail regarding its origin and
systematics. We show that the Oosterhoff dichotomy and the distribution of
globular clusters (GCs) in the HB morphology-metallicity plane both exclude,
with high statistical significance, the possibility that the Galactic halo may
have formed from the accretion of dwarf galaxies resembling present-day Milky
Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the
second-parameter problem is presented. A technique is proposed to estimate the
HB types of extragalactic GCs on the basis of integrated far-UV photometry. The
relationship between the absolute V magnitude of the HB at the RR Lyrae level
and metallicity, as obtained on the basis of trigonometric parallax
measurements for the star RR Lyrae, is also revisited, giving a distance
modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are
studied. Finally, the conductive opacities used in evolutionary calculations of
low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and
Space Scienc
Retardadores de crescimento na produção de plantas floridas envasadas de açafrão-da-cochinchina
Recommended from our members
High Involvement Management, High Performance Work Systems and Well-being
Studies on the impact of high-performance work systems on employees' well-being are emerging but the underlying theory remains weak. This paper attempts to develop theory of the effects on well-being of four dimensions of high-performance work systems: enriched jobs, high involvement management, employee voice, and motivational supports. Hypothesized associations are tested using multilevel models and data from Britain's Workplace Employment Relations Survey of 2004 (WERS2004). Results show that enriched jobs are positively associated with both measures of well-being: job satisfaction and anxietyâcontentment. Voice is positively associated with job satisfaction, and motivational supports with neither measure. The results for high involvement management are not as predicted because it increases anxiety and is independent of job satisfaction
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
- âŠ