1,282 research outputs found
The impact of corporate philanthropy on reputation for corporate social performance
This study seeks to examine the mechanisms by which a corporation’s use of philanthropy affects its reputation for corporate social performance (CSP), which the authors conceive of as consisting of two dimensions: CSP awareness and CSP perception. Using signal detection theory (SDT), the authors model signal amplitude (the amount contributed), dispersion (number of areas supported), and consistency (presence of a corporate foundation) on CSP awareness and perception. Overall, this study finds that characteristics of firms' portfolio of philanthropic activities are a greater predictor of CSP awareness than of CSP perception. Awareness increases with signal amplitude, dispersion, and consistency. CSP perception is driven by awareness and corporate reputation. The authors’ contention that corporate philanthropy is a complex variable is upheld, as we find that CSP signal characteristics influence CSP awareness and perception independently and asymmetrically. The authors conclude by proposing avenues for future research
Optimization of Apodized Pupil Lyot Coronagraph for ELTs
We study the optimization of the Apodized Pupil Lyot Coronagraph (APLC) in
the context of exoplanet imaging with ground-based telescopes. The APLC
combines an apodization in the pupil plane with a small Lyot mask in the focal
plane of the instrument. It has been intensively studied in the literature from
a theoretical point of view, and prototypes are currently being manufactured
for several projects. This analysis is focused on the case of Extremely Large
Telescopes, but is also relevant for other telescope designs.
We define a criterion to optimize the APLC with respect to telescope
characteristics like central obscuration, pupil shape, low order segment
aberrations and reflectivity as function of the APLC apodizer function and mask
diameter. Specifically, the method was applied to two possible designs of the
future European-Extremely Large Telescope (E-ELT).
Optimum configurations of the APLC were derived for different telescope
characteristics. We show that the optimum configuration is a stronger function
of central obscuration size than of other telescope parameters. We also show
that APLC performance is quite insensitive to the central obscuration ratio
when the APLC is operated in its optimum configuration, and demonstrate that
APLC optimization based on throughput alone is not appropriate.Comment: 9 pages, 17 figures, accepted for publication in Astronomy &
Astrophysic
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Survival of a long-lived single island endemic, the Raso lark Alauda razae, in relation to age, fluctuating population and rainfall.
Estimating and understanding variation in survival rates is crucial for the management of threatened species, especially those with limited population sizes and/or restricted ranges. Using a capture-resighting dataset covering 2004-2017, we estimate adult survival in the Raso lark Alauda razae, a Critically Endangered single-island Cape Verdean endemic, whose population varied 25-fold during the study. Average annual adult survival was similar for males (0.813 ± 0.011) and females (0.826 ± 0.011) over the period. These values are high for a temperate passerine but not unusual for an insular tropical species like the lark. The oldest bird was recorded 13 years after first ringing. There was strong evidence that survival varied among years (between 0.57 and 0.95), being generally higher in wetter years. Survival, especially of males, was lower when the population was large, but only in drier years. Survival declined with age but there was no evidence that this decline was other than linear. High survival, even in the face of dry conditions, at least when the population is depressed, has probably contributed to the persistence of the species on its 7 km2 island home over several centuries
The Dark Matter Density in the Solar Neighborhood reconsidered
Both the gas flaring and the dip in the rotation curve, which was recently
reconfirmed with precise measurements using the VERA VLBI array in Japan,
suggest doughnut-like substructure in the dark matter (DM) halo. A global fit
to all available data shows that the data are indeed best described by an NFW
DM profile complemented by two doughnut-like DM substructures with radii of 4.2
and 12.4 kpc, which coincide with the local dust ring and the Monocerus ring of
stars, respectively. Both regions have been suggested as regions with tidal
streams from "shredded" satellites. If real, the radial extensions of these
nearby ringlike structures enhance the local dark matter density by a factor of
four to about 1.3 GeV/cm.
It is shown that i) this higher DM density is perfectly consistent with the
local gravitational potential determining the surface density and the local
matter density (Oort limit), ii) previous determinations of the surface density
were biased by the assumption of a smoothly varying DM halo and iii) the
s-shaped gas flaring is explained. Such a possible enhancement of the local DM
density is of great interest for direct DM searches and would change the
directional dependence for indirect DM searches.Comment: 14 pages, 4 figures, extended version, accepted for publication in
JCA
Comparison of coronagraphs for high contrast imaging in the context of Extremely Large Telescopes
We compare coronagraph concepts and investigate their behavior and
suitability for planet finder projects with Extremely Large Telescopes (ELTs,
30-42 meters class telescopes). For this task, we analyze the impact of major
error sources that occur in a coronagraphic telescope (central obscuration,
secondary support, low-order segment aberrations, segment reflectivity
variations, pointing errors) for phase, amplitude and interferometric type
coronagraphs. This analysis is performed at two different levels of the
detection process: under residual phase left uncorrected by an eXtreme Adaptive
Optics system (XAO) for a large range of Strehl ratio and after a general and
simple model of speckle calibration, assuming common phase aberrations between
the XAO and the coronagraph (static phase aberrations of the instrument) and
non-common phase aberrations downstream of the coronagraph (differential
aberrations provided by the calibration unit). We derive critical parameters
that each concept will have to cope with by order of importance. We evidence
three coronagraph categories as function of the accessible angular separation
and proposed optimal one in each case. Most of the time amplitude concepts
appear more favorable and specifically, the Apodized Pupil Lyot Coronagraph
gathers the adequate characteristics to be a baseline design for ELTs.Comment: 12 pages, 6 figures, Accepted for publication in A&
Intentional replantation for the management of maxillary sinusitis
Aim. To present a case that emphasizes the importance of the use of intentional replantation as a technique to successfully treat a periapical lesion and an odontogenic maxillary sinusitis through the alveolus at the same time. Summary. This case report presents a patient with odontogenic maxillary sinusitis secondary to periapical disease of a maxillary molar that had previously received root canal treatment. The molar was extracted, with drainage and rinsing of the maxillary sinus. The apices were resected extra-orally, and the retrograde cavity was prepared with ultrasound and retrograde filling using silver amalgam. The tooth was then replanted. After 2 years, the patient was asymptomatic, periapical radiography showed no evidence of root resorption and computed tomography scanning demonstrated the resolution of maxillary sinusitis
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Survival of a long-lived single island endemic, the Raso lark Alauda razae, in relation to age, fluctuating population and rainfall
Abstract: Estimating and understanding variation in survival rates is crucial for the management of threatened species, especially those with limited population sizes and/or restricted ranges. Using a capture-resighting dataset covering 2004–2017, we estimate adult survival in the Raso lark Alauda razae, a Critically Endangered single-island Cape Verdean endemic, whose population varied 25-fold during the study. Average annual adult survival was similar for males (0.813 ± 0.011) and females (0.826 ± 0.011) over the period. These values are high for a temperate passerine but not unusual for an insular tropical species like the lark. The oldest bird was recorded 13 years after first ringing. There was strong evidence that survival varied among years (between 0.57 and 0.95), being generally higher in wetter years. Survival, especially of males, was lower when the population was large, but only in drier years. Survival declined with age but there was no evidence that this decline was other than linear. High survival, even in the face of dry conditions, at least when the population is depressed, has probably contributed to the persistence of the species on its 7 km2 island home over several centuries
Policy action points and approaches to promote fertility care in The Gambia: findings from a mixed-methods study
Introduction
In the Global South, (in)fertility care is scarcely recognized as a priority, yet the government of The Gambia has recently included it as one of the key priorities in its reproductive health strategic plan. This inclusion appears to be the result of years of engagement between policy actors, academic researchers, and activists in the field of reproductive health and specifically of infertility. However, the operationalization of the strategic plan may be hampered by multiple factors. The research aims to identify and analyze challenges that may impede the effective implementation of the strategic plan, thereby providing policy action points and practical guidance into the operationalization of (in)fertility care in the context of The Gambia’s health system.
Methods
This is a mixed-methods study with data from a survey and semi-structured interviews collected between 2020 and 2021 in The Gambia that were separately published. In this paper, we present the triangulation of quantitative and qualitative data using a convergence coding matrix to identify relevant policy action points.
Results
Six fertility care policy action points, driven by data, arose from the triangulation and interpretation process, specifically: (i) establishing and maintaining political commitment and national priority for fertility care; (ii) creating awareness and increasing the involvement of men in SRH and fertility; (iii) ensuring data-driven health policymaking; (iv) offering and regulating affordable IVF alternatives; (v) improving knowledge of and means for fertility care provision; and (vi) enhancing the collaboration among stakeholders and building links with the private healthcare sector.
Conclusion
This study found the implementation of the fertility care-related activities in the reproductive health strategic plan may face challenges that require careful mitigation through a holistic approach. Such an approach conceptualizes infertility not just as a biomedical issue but as a broader one that incorporates educational and socio-emotional aspects, including male and (not only) female involvement in sexual and reproductive health. Moreover, it is supported by a comprehensive health management information system that includes capturing data on the demand for, and access to, infertility services in The Gambia health system
Genetic diversity, demographic history and neo-sex chromosomes in the Critically Endangered Raso lark
Small effective population sizes could expose island species to inbreeding and loss of genetic variation. Here, we investigate factors shaping genetic diversity in the Raso lark, which has been restricted to a single islet for approximately 500 years, with a population size of a few hundred. We assembled a reference genome for the related Eurasian skylark and then assessed diversity and demographic history using RAD-seq data (75 samples from Raso larks and two related mainland species). We first identify broad tracts of suppressed recombination in females, indicating enlarged neo-sex chromosomes. We then show that genetic diversity across autosomes in the Raso lark is lower than in its mainland relatives, but inconsistent with long-term persistence at its current population size. Finally, we find that genetic signatures of the recent population contraction are overshadowed by an ancient expansion and persistence of a very large population until the human settlement of Cape Verde. Our findings show how genome-wide approaches to study endangered species can help avoid confounding effects of genome architecture on diversity estimates, and how present-day diversity can be shaped by ancient demographic events
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