1,525 research outputs found
Elephant endurance in Aceh: the effects of habitat disturbance and land cover change on the conservation of Sumatran elephants in Aceh, Indonesia
The Sumatran elephant is seriously threatened by extinction throughout its range. Here, conservation issues threatening the future survival of Asian elephants in Sumatra, and Aceh in particular, are analyzed and evaluated. The impact of deforestation on the prevalence of elephants living in isolated subpopulations scattered across Sumatra was addressed by analyzing the spatial patterns of deforestation and habitat use of elephants. Deforestation data was obtained from remotely sensed imagery and elephant habitat use was assessed by means of ecological niche modelling. The Sumatra-wide impact of deforestation on elephant population survival was analyzed by comparing the historic distribution of elephants to their current distribution. The observed incidences of population extinctions were then compared to spatial pattern of land cover change and anthropogenic influences. Moreover, the occurrence of crop raiding by elephants was evaluated against the spatial configuration of the forests and forest disturbances. Finally, the effectiveness of different forest conservation strategies was assessed. Niche modelling revealed that elephants are mainly confined to closed canopy habitats located within landscape depressions and along the forest edge. Surprisingly, elephants were found over a wide range of elevations and were found at locations within rugged terrain. Since deforestation in Aceh was mainly concentrated within the same areas forming the most optimal elephant habitat, elephants are likely to become displaced from their natural ranges. Also, crop raiding incidents appeared to be most frequent in areas which recently had been cleared, but still had undisturbed or secondary forest patches in the direct vicinity. These findings, together with the observation that elephant population survival was significantly reduced in areas which had little forest cover over an extended period of time, suggest that deforestation is the main factor leading to elephant extinctions. To safeguard the survival of elephant populations into the future, conservation strategies should attempt to integrate elephant habitat requirements into land use plans while simultaneously considering human economic interests. Conserving forest by reducing access appears to be the most effective measure to reduce illegal logging. The application of buffer zones along the forest edge in which limited resource extraction is allowed is therefore more likely to reduce deforestation as compared to the investments needed to actively protect the forest
Recent Legal Literature
Abbott: Brief upon the Pleadings in Civil Actions, at Law in Equity, and under the New Procedure; McMaster: McMaster\u27s Irregular and Regular Commercial Paper; American State Reports, vols. 93 and 94
The pure non-collisional Blue Straggler population in the giant stellar system omega Centauri
We have used high spatial resolution data from the Hubble Space Telescope and
wide-field ground-based observations to search for blue straggler stars (BSS)
over the entire radial extent of the large stellar system omega Centauri. We
have detected the largest population of BSS ever observed in any stellar
system. Even though the sample is restricted to the brightest portion of the
BSS sequence, more than 300 candidates have been identified. BSS are thought to
be produced by the evolution of binary systems (either formed by stellar
collisions or mass exchange in binary stars). Since systems like Galactic
globular clusters (GGC) and omega Cen evolve dynamically on time-scales
significantly shorter than their ages, binaries should have settled toward the
center, showing a more concentrated radial distribution than the ordinary, less
massive single stars. Indeed, in all GGCs which have been surveyed for BSS, the
BSS distribution is peaked at the center. Conversely, in omega Cen we find that
the BSS share the same radial distribution as the adopted reference
populations. This is the cleanest evidence ever found that such a stellar
system is not fully relaxed even in the central region. We further argue that
the absence of central concentration in the BSS distribution rules out a
collisional origin. Thus, the omega Cen BSS are the purest and largest
population of non-collisional BSS ever observed. Our results allow the first
empirical quantitative estimate of the production rate of BSS via this channel.
BSS in omega Cen may represent the best local template for modeling the BSS
populations in distant galaxies where they cannot be individually observed.Comment: 21 pages, 6 figures, accepted for publication by Ap
Regolith production and transport at the Susquehanna Shale Hills Critical Zone Observatory, Part 2: Insights from meteoric 10Be
Regolith-mantled hillslopes are ubiquitous features of most temperate landscapes, and their morphology reflects the climatically, biologically, and tectonically mediated interplay between regolith production and downslope transport. Despite intensive research, few studies have quantified both of these mass fluxes in the same field site. Here we present an analysis of 87 meteoric 10Be measurements from regolith and bedrock within the Susquehanna Shale Hills Critical Zone Observatory (SSHO), in central Pennsylvania. Meteoric 10Be concentrations in bulk regolith samples (n=73) decrease with regolith depth. Comparison of hillslope meteoric 10Be inventories with analyses of rock chip samples (n=14) from a 24 m bedrock core confirms that >80% of the total inventory is retained in the regolith. The systematic downslope increase of meteoric 10Be inventories observed at SSHO is consistent with 10Be accumulation in slowly creeping regolith (∼ 0.2 cm yr-1). Regolith flux inferred from meteoric 10Be varies linearly with topographic gradient (determined from high-resolution light detection and ranging-based topography) along the upper portions of hillslopes at SSHO. However, regolith flux appears to depend on the product of gradient and regolith depth where regolith is thick, near the base of hillslopes. Meteoric 10Be inventories at the north and south ridgetops indicate minimum regolith residence times of 10.5 ± 3.7 and 9.1 ± 2.9 ky, respectively, similar to residence times inferred from U-series isotopes in Ma et al. (2013). The combination of our results with U-series-derived regolith production rates implies that regolith production and erosion rates are similar to within a factor of two on SSHO hillcrests. ©2013. American Geophysical Union. All Rights Reserved
The surface density profile of NGC 6388: a good candidate for harboring an intermediate-mass black hole
We have used a combination of high resolution (HST ACS-HRC, ACS-WFC, and
WFPC2) and wide-field (ESO-WFI) observations of the galactic globular cluster
NGC 6388 to derive its center of gravity, projected density profile, and
central surface brightness profile. While the overall projected profiles are
well fit by a King model with intermediate concentration (c=1.8) and sizable
core radius (rc=7"), a significant power law (with slope \alpha=-0.2) deviation
from a flat core behavior has been detected within the inner 1 arcsecond. These
properties suggest the presence of a central intermediate mass black hole. The
observed profiles are well reproduced by a multi-mass isotropic, spherical
model including a black hole with a mass of ~5.7x10^3 Msol.Comment: ApJ Letter in pres
Comparison of Bovine Mammary Involution and Intramammary Infections Following Intramammary Treatment with Casein Hydrolysate and Other Conventional Treatments at Dry-Off
Alternatives to routine antibiotic treatment of dairy cattle during the dry period before their next calving are of interest. This was a preliminary study of whether intramammary infusion of casein hydrolysate, administered alone or combined with standard dry treatment, accelerated the rate of mammary involution early in the dry period. Four treatments were studied in a split udder design. One udder half was assigned a treatment, and the contralateral half was administered dry cow treatment + internal teat sealant as a control. Treatments were casein hydrolysate, casein hydrolysate + dry cow treatment, casein hydrolysate + teat sealant and casein hydrolysate + dry cow treatment + teat sealant. Cows (n = 16) were blocked by a number of intramammary infections per udder half (0 or 1+) and randomized to treatments. Milk production was not different between control or treated udder halves post-calving. A generalized linear mixed model tested for differences between the treatment groups in the concentration of mammary involution indicators in milk: somatic cell count, bovine lactoferrin and bovine serum albumin. At 7 days, dry udder halves treated with casein hydrolysate had higher milk concentrations of lactoferrin than those treated with casein hydrolysate + dry cow treatment, casein hydrolysate + teat sealant and control. At 10 days dry, bovine serum albumin was higher in udder halves treated with casein hydrolysate than in those treated with casein hydrolysate + dry cow treatment, casein hydrolysate + dry cow treatment + teat sealant and control. Post-calving, casein hydrolysate-treated udder halves produced 51% of total milk, unchanged from before dry-off. There were seven total intramammary infections entering the dry period, all caused by coagulase-negative staphylococci. Cure rates (3/7, 43%) were not different among all treatments and control, partly because of the small sample size. Intramammary infusion of casein hydrolysate at the end of lactation may be an alternative or possible adjunct to antibiotic dry cow therapy
A Panchromatic Study of the Globular Cluster NGC 1904. I: The Blue Straggler Population
By combining high-resolution (HST-WFPC2) and wide-field ground based (2.2m
ESO-WFI) and space (GALEX) observations, we have collected a multi-wavelength
photometric data base (ranging from the far UV to the near infrared) of the
galactic globular cluster NGC1904 (M79). The sample covers the entire cluster
extension, from the very central regions up to the tidal radius. In the present
paper such a data set is used to study the BSS population and its radial
distribution. A total number of 39 bright () BSS has been
detected, and they have been found to be highly segregated in the cluster core.
No significant upturn in the BSS frequency has been observed in the outskirts
of NGC 1904, in contrast to other clusters (M 3, 47 Tuc, NGC 6752, M 5) studied
with the same technique. Such evidences, coupled with the large radius of
avoidance estimated for NGC 1904 ( core radii), indicate that
the vast majority of the cluster heavy stars (binaries) has already sunk to the
core. Accordingly, extensive dynamical simulations suggest that BSS formed by
mass transfer activity in primordial binaries evolving in isolation in the
cluster outskirts represent only a negligible (0--10%) fraction of the overall
population.Comment: ApJ accepte
The protein puzzle : the consumption and production of meat, dairy and fish in the European Union
In het rapport 'The protein puzzle. The consumption and production of meat, dairy and fish in the European Union' brengen onderzoekers van het Planbureau voor de Leefomgeving (PBL) in kaart wat de gevolgen van de productie en consumptie van dierlijke eiwitten zijn voor milieu, natuur en gezondheid. Vervolgens schetst het PBL welke opties er in Europees verband zijn om de negatieve effecten te verminderen. Met deze studie verschaft het PBL relevante feiten en cijfers ten behoeve van het debat over eiwitconsumptie, inclusief een indicatie van de onzekerheden daarbij
Discovery of Carbon/Oxygen depleted Blue Straggler Stars in 47 Tucanae: the chemical signature of a mass-transfer formation process
We use high-resolution spectra obtained with the ESO Very Large Telescope to
measure surface abundance patterns of 43 Blue Stragglers stars (BSS) in 47 Tuc.
We discovered that a sub-population of BSS shows a significant depletion of
Carbon and Oxygen with respect to the dominant population. This evidence would
suggest the presence of CNO burning products on the BSS surface coming from a
deeply peeled parent star, as expected in the case of mass-transfer process.
This is the first detection of a chemical signature clearly pointing to a
specific BSS formation process in a globular cluster.Comment: Published on 2006, August 10, in ApJ 647, L5
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