3,352 research outputs found
Building capacity in waterbird and wetland monitoring in eastern Africa
The wetlands of eastern Africa support internationally important assemblages of plants and animals, and are a vital source of livelihood and water for many societies. The combined human population of Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Rwanda, Sudan, Tanzania and Uganda is estimated to be about 200 million. The region has an area of about 5.6 million km2 of which only 4.5% is open water/wetlands. Wetland conversion to agriculture often provides only short-term benefits and can pose
long-term problems. The ever-increasing human population
density coupled with the scarce water resources in Africa have put African governments under increasing pressure to allow further exploitation and drainage of wetlands. Lack of sufficient up-to-date information to guide policy and development programmes for the respective Africa governments is considered as one of the causes for the continued loss and degradation of wetlands. To fill this information gap, it was recognized that a standardized system for monitoring wetland biodiversity and making the data and information available to governments and other stakeholders was required. In 2002, a project was implemented to build and maintain capacity in the monitoring of wetland biodiversity in eastern Africa and to provide the necessary information required for wetland conservation. This paper describes the capacity building process leading to: (1) the development of a wetlands database with query tools; (2) the provision of training in the use of the wetland monitoring database; (3) the launch of the Wetland Biodiversity Monitoring Scheme
(WBMS) to provide data for use in wetland conservation and development of site management plans; and (4) training in the development of a wetland site management plan in each of the nine partner countries
Characteristics of patients with motor functional neurological disorder in a large UK mental health service:A case-control study
Hot Populations in M87 Globular Clusters
We have obtained HST/STIS far- and near-UV photometry of globular clusters in
four fields in the gE galaxy M87. To a limit of m(FUV) = 25 we detect a total
of 66 globular clusters (GCs) in common with the deep HST optical-band study of
Kundu et al. (1999). Despite strong overlap in V- and I-band properties, the
M87 GCs have UV/optical properties that are distinct from clusters in the Milky
Way and in M31. M87 clusters, especially metal-poor ones, produce larger hot HB
populations than do Milky Way analogues. Cluster mass is probably not a factor
in these distinctions. The most metal-rich M87 GCs in our sample are near Z_sun
and overlap the local E galaxy sample in estimated Mg_2 line indices.
Nonetheless, the clusters produce much more UV light at a given Mg_2, being up
to 1 mag bluer than any gE galaxy in (FUV-V) color. The M87 GCs do not appear
to represent a transition between Milky Way-type clusters and E galaxies. The
differences are in the correct sense if the clusters are significantly older
than the E galaxies. Comparisons with Galactic open clusters indicate that the
hot stars lie on the extreme horizontal branch, rather than being blue
stragglers, and that the EHB becomes well populated for ages > 5 Gyr. We find
that 43 of our UV detections have no optical-band counterparts. Most appear to
be UV-bright background galaxies, seen through M87. Eleven NUV variable sources
detected at only one epoch in the central field are probably classical novae.
[Abridged]Comment: 70 pages, 25 figures (including 4 jpgs), 7 tables. To appear in AJ.
Full resolution version available at
http://www.astro.virginia.edu/~rwo/m87/m87-hotpops.pd
The Pore Region of the Skeletal Muscle Ryanodine Receptor Is a Primary Locus for Excitation-Contraction Uncoupling in Central Core Disease
Human central core disease (CCD) is caused by mutations/deletions in the gene that encodes the skeletal muscle ryanodine receptor (RyR1). Previous studies have shown that CCD mutations in the NH2-terminal region of RyR1 lead to the formation of leaky SR Ca2+ release channels when expressed in myotubes derived from RyR1-knockout (dyspedic) mice, whereas a COOH-terminal mutant (I4897T) results in channels that are not leaky to Ca2+ but lack depolarization-induced Ca2+ release (termed excitation-contraction [EC] uncoupling). We show here that store depletion resulting from NH2-terminal (Y523S) and COOH-terminal (Y4795C) leaky CCD mutant release channels is eliminated after incorporation of the I4897T mutation into the channel (Y523S/I4897T and Y4795C/I4897T). In spite of normal SR Ca2+ content, myotubes expressing the double mutants lacked voltage-gated Ca2+ release and thus exhibited an EC uncoupling phenotype similar to that of I4897T-expressing myotubes. We also show that dyspedic myotubes expressing each of seven recently identified CCD mutations located in exon 102 of the RyR1 gene (G4890R, R4892W, I4897T, G4898E, G4898R, A4905V, R4913G) behave as EC-uncoupled release channels. Interestingly, voltage-gated Ca2+ release was nearly abolished (reduced ∼90%) while caffeine-induced Ca2+ release was only marginally reduced in R4892W-expressing myotubes, indicating that this mutation preferentially disrupts voltage-sensor activation of release. These data demonstrate that CCD mutations in exon 102 disrupt release channel permeation to Ca2+ during EC coupling and that this region represents a primary molecular locus for EC uncoupling in CCD
Aspects of slurry management on pig farms.
End of Project ReportThe objectives of manure or slurry management on intensive pig farms
are the provision of adequate slurry storage capacity and the efficient
recycling of the slurry nutrients for crop production. However, recent
surveys of pig slurry dry matter suggest there is excessive dilution of
raw pig slurry with water. This has two important implications for
management. The first is greater storage capacity will be required due
to the increased volume of slurry generated. Slurry storage is expensive.
For example, a 350 sow unit adding 10 weeks storage needs to
invest £50,000. Secondly, evidence from the literature indicates an
improved slurry nitrogen efficiency with the more dilute manure. The results of field trials showed that higher dry matter pig slurries
reduced the relative efficiency of pig slurry nitrogen for second cut
silage production. This is probably linked to reduced ammonia volatilisation
losses, consequent to the less viscous nature of dilute slurry
which permits a more rapid infiltration of the ammonium nitrogen into
the soil. The use of a band spreader or shallow injection rather than
the conventional splash plate were shown to increase the efficiency of
pig slurry nitrogen for grass silage production. Therefore, the potential
for the higher pig slurry dry matter, required for cost effective storage/
handling costs, to reduce the efficiency of its nitrogen for grass
silage production can be partially offset by using band spreaders or
shallow injection spreading systems. These have the added advantage
of reducing odour emissions from the land spreading operation.Teagasc Walsh Fellowship Programm
UV Bright Globular Clusters in M87: More Evidence for Super-helium-rich Stellar Populations?
We study the UV and optical properties of 38 massive GCs in M87, imaged using
the HST/STIS and WFPC2 instruments. The majority of these GCs appear extremely
bright in the FUV - roughly a magnitude brighter than their Galactic
counterparts with similar metallicities. The observed FUV flux is several times
larger than predictions of canonical old stellar population models. These
canonical models, which assume a fiducial helium enrichment parameter, dY/dZ=2,
are able to reproduce the observed FUV fluxes only if ages are 3--5 Gyr larger
than the WMAP age of the Universe, although the same models fit the UV
photometry of Galactic and M31 GCs for ages less than the WMAP age. A similar
discrepancy is found between the mass-weighted and UV-luminosity weighted ages
of the massive Galactic GC omega Cen, whose CMD (including peculiar features on
its well-populated horizontal branch) can be accurately reproduced by invoking
a small super-He-rich (dY/dZ ~ 90) stellar component. By comparison to omega
Cen, we propose that the majority of M87 GCs in our sample contain strong
signatures of similarly minor super-He-rich sub-components. Although we cannot
prove or disprove the extreme helium scenario at the moment, we show that the
same phenomenon that causes the extended horizontal branch of omega Cen
explains the UV brightness of our sample. If this is indeed due to the extreme
helium, this study would be the first to find its signatures in extragalactic
objects.Comment: 19 pages, 10 figures, accepted for publication in MNRA
Cold atmospheric pressure plasma jets as sources of singlet delta oxygen for biomedical applications
Far-Ultraviolet Color Gradients in Early-Type Galaxies
We discuss far-UV (1500 A) surface photometry and FUV-B color profiles for 8
E/S0 galaxies from images taken with the Ultraviolet Imaging Telescope,
primarily during the Astro-2 mission. In three cases, the FUV radial profiles
are more consistent with an exponential than a de Vaucouleurs function, but
there is no other evidence for the presence of a disk or of young, massive
stars. In all cases except M32 the FUV-B color becomes redder at larger radii.
There is a wide range of internal radial FUV-B color gradients. However, we
find no correlation between the FUV-B color gradients and internal metallicity
gradients based on Mg absorption features. We conclude that metallicity is not
the sole parameter controlling the "UV upturn component" in old populations.Comment: 11 pages; tar.gz file includes LaTeX text file, 3 PostScript figures.
Paper to be published in ApJ Letter
Integrable Deformations of Strings in Flux Backgrounds
We study d=2 0A string theory perturbed by tachyon momentum modes in
backgrounds with non-trivial tachyon condensate and Ramond-Ramond (RR) flux. In
the matrix model description, we uncover a complexified Toda lattice hierarchy
constrained by a pair of novel holomorphic string equations. We solve these
constraints in the classical limit for general RR flux and tachyon condensate.
Due to the non-holomorphic nature of the tachyon perturbations, the
transcendental equations which we derive for the string susceptibility are
manifestly non-holomorphic. We explore the phase structure and critical
behavior of the theory.Comment: 39 pages, 4 figure
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