2,531 research outputs found
Living on the margin: Assessing the economic impacts of Landcare in the Philippine uplands
In the Philippines, about 38 per cent of the population resides in rural areas where poverty remains a significant problem. In 2006, 47 per cent of all households in Bohol Province fell below the national poverty line, with the percentage even higher in upland communities. These households often exist in marginal landscapes that are under significant pressure from ongoing resource degradation and rising input costs. This paper first explores whether the adoption of Landcare practices in a highly degraded landscape has resulted in improved livelihood outcomes for upland farming families in Bohol. Second, it analyses the potential for the piecemeal adoption of these measures to deliver tangible benefits at the watershed scale. Finally, using a BCA approach, these outcomes are compared to the costs of the research and extension projects that have helped achieve them.Landcare, Philippines, livelihoods, poverty, watershed, ACIAR,
Neointima formation is promoted by surgical preparation and inhibited by cyclic nucleotides in human saphenous vein organ cultures
AbstractIntimal thickening is an important cause of late coronary vein graft occlusion, which no variation of surgical technique or pharmacologic intervention has been shown to reduce. We used a recently developed quantitative organ culture of human saphenous vein to investigate whether surgical preparative injury promotes neointima formation. We also investigated the effects on neointima formation of the lipid-soluble cyclic nucleotide analogs, 8-Br-cyclic adenosine monophosphate and 8-Br-cyclic guanosine monophosphate, and the phosphodiesterase inhibitor, isobutylmethylxanthine. These agents are pharmacologic mimetics of endothelium-derived prostacyclin and nitric oxide, which elevate vascular smooth muscle cyclic adenosine monophosphate and cyclic guanosine monophosphate concentrations, respectively, and may normally suppress neointima formation. Surgical preparation was found to promote intimal thickening and neointimal smooth muscle cell proliferation by 42% and 48%, respectively. 8-Br-cyclic adenosine monophosphate, 8-Br-cyclic guanosine monophosphate, or isobutylmethylxanthine (which elevated endogenous cyclic adenosine monophosphate concentrations) inhibited intimal thickening by 80%, 40%, and 72%, respectively, at a concentration of 0.1 mmol/L. The results imply that surgical techniques that avoid preparative injury and vasodilator drugs that act by elevating cyclic adenosine monophosphate or cyclic guanosine monophosphate concentrations may reduce neointima formation in vein grafts. (J Thoracic Cardiovasc Surg 1995;109:2-12
The Stellar Metallicity Distribution Function of the Galactic Halo from SDSS Photometry
We explore the stellar metallicity distribution function of the Galactic halo
based on SDSS ugriz photometry. A set of stellar isochrones is calibrated using
observations of several star clusters and validated by comparisons with
medium-resolution spectroscopic values over a wide range of metal abundance. We
estimate distances and metallicities for individual main-sequence stars in the
multiply scanned SDSS Stripe 82, at heliocentric distances in the range 5 - 8
kpc and |b| > 35 deg, and find that the in situ photometric metallicity
distribution has a shape that matches that of the kinematically-selected local
halo stars from Ryan & Norris. We also examine independent kinematic
information from proper-motion measurements for high Galactic latitude stars in
our sample. We find that stars with retrograde rotation in the rest frame of
the Galaxy are generally more metal poor than those exhibiting prograde
rotation, which is consistent with earlier arguments by Carollo et al. that the
halo system comprises at least two spatially overlapping components with
differing metallicity, kinematics, and spatial distributions. The observed
photometric metallicity distribution and that of Ryan & Norris can be described
by a simple chemical evolution model by Hartwick (or by a single Gaussian
distribution); however, the suggestive metallicity-kinematic correlation
contradicts the basic assumption in this model that the Milky Way halo consists
primarily of a single stellar population. When the observed metallicity
distribution is deconvolved using two Gaussian components with peaks at [Fe/H]
~ -1.7 and -2.3, the metal-poor component accounts for ~20% - 35% of the entire
halo population in this distance range.Comment: Accepted for publication in Ap
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