1,356 research outputs found
Diet of the Common Warthog (Phacochoerus africanus) on Former Cattle Grounds in a Tanzanian Savanna
In otherwise nutrient-poor savannas, fertile vegetation patches are particularly attractive to ungulates because of the higher-quality food they provide. We investigated forage plants and diet of the common warthog (Phacochoerus africanus) on an abandoned cattle ranch in coastal Tanzania. The forage grasses of highest nutritional quality occurred in former paddock enclosures (bomas) where cattle had been herded at night. In the dry season, grass samples from bomas contained approximately 4 times as much nitrogen and phosphorus as those of the surrounding vegetation. δ15N values of soil and plants also were highest in bomas and decreased significantly with distance, and high δ15N values in feces suggest that warthogs preferentially fed in the vicinity of the former bomas. δ13C values of warthog feces indicate that warthogs ingested on average 83% (77-98%) C4 grasses, with this proportion varying regionally but not seasonally. We conclude that, for medium-sized selective grazers such as warthogs, bomas represent attractive feeding grounds. We also hypothesize that by promoting nutrient turnover in these patchily distributed areas, grazing animals help to maintain them as sources of high-quality forag
Comment on ``Evidence Against Instanton Dominance of Topological Charge Fluctuations in QCD''
We comment on the recent paper (hep-lat/0102003) by Horvath, Isgur, McCune,
and Thacker, which concludes that the local chiral structure of fermionic
eigenmodes is not consistent with instanton dominance. Our calculations, done
with an overlap action, suggest the opposite conclusion.Comment: 5 pages, Revtex, 4 postscript figures. COLO-HEP-45
Integrating tobacco dependence treatment and tobacco-free standards into addiction treatment: New Jersey\u27s experience
New Jersey was the first State to require that all residential addiction treatment programs assess and treat patients for tobacco dependence and maintain tobacco-free facilities (including grounds). An evaluation of this policy change found that tobacco dependence treatment can be successfully integrated into residential substance abuse treatment programs through policy regulation, training, and the provision of nicotine replacement therapy (NRT) (Williams et al. 2005). Many other addiction treatment agencies (both residential and outpatient) around the country now have implemented or are planning to implement similar policies to ensure that their patients receive appropriate assessment and treatment of their tobacco dependence while receiving treatment for addiction to other substances. This paper aims to summarize the lessons learned from the experience in New Jersey
Low-lying fermion modes, topology and light hadrons in quenched QCD
We explore the properties of low lying eigenmodes of fermions in the quenched
approximation of lattice QCD. The fermion action is a recently proposed overlap
action and has exact chiral symmetry. We find that chiral zero-eigenvalue modes
are localized in space and their positions correlate strongly with the
locations (as defined through the density of pure gauge observables) of
instantons of the appropriate charge. Nonchiral modes are also localized with
peaks which are strongly correlated with the positions of both charges of
instantons. These correlations slowly die away as the fermion eigenvalue rises.
Correlators made of quark propagators restricted to these modes closely
reproduce ordinary hadron correlators at small quark mass in many channels. Our
results are in qualitative agreement with the expectations of instanton liquid
models.Comment: 21 pages, Revtex, 21 postscript figures. COLO-HEP-45
Binding-Folding Induced Regulation of AF1 Transactivation Domain of the Glucocorticoid Receptor by a Cofactor That Binds to Its DNA Binding Domain
Intrinsically disordered (ID) regions of proteins commonly exist within transcription factors, including the N-terminal domain (NTD) of steroid hormone receptors (SHRs) that possesses a powerful activation function, AF1 region. The mechanisms by which SHRs pass signals from a steroid hormone to control gene expression remain a central unresolved problem. The role of N-terminal activation function AF1, which exists in an intrinsically disordered (ID) conformation, in this process is of immense importance. It is hypothesized that under physiological conditions, ID AF1 undergoes disorder/order transition via inter- and intra-molecular communications, which allows AF1 surfaces to interact with specific co-regulatory proteins, critical for the final outcome of target gene expression regulated by SHRs. However, the means by which AF1 acquires functionally folded conformations is not well understood. In this study, we tested whether binding of jun dimerization protein 2 (JDP2) within the DNA binding domain (DBD) of the glucocorticoid receptor (GR) leads to acquisition of functionally active structure in its AF1/NTD. Our results show that signals mediated from GR DBD:JDP2 interactions in a two domain GR fragment, consisting of the entire NTD and little beyond DBD, significantly increased secondary/tertiary structure formation in the NTD/AF1. This increased structure formation facilitated AF1’s interaction with specific co-regulatory proteins and subsequent glucocorticoid response element-mediated AF1 promoter:reporter activity. These results support the hypothesis that inter- and intra-molecular signals give a functionally active structure(s) to the GR AF1, which is important for its transcriptional activity
Scaling and Eigenmode Tests of the Improved Fat Clover Action
We test a recently proposed improved lattice-fermion action, the fat link
clover action, examining indicators of pathological small-quark-mass lattice
artifacts ("exceptional configurations") on quenched lattices of spacing 0.12
fm and studying scaling properties of the light hadron spectrum for lattice
spacing a=0.09 and 0.16 fm. We show that the action apparently has fewer
problems with pathological lattice artifacts than the conventional
nonperturbatively improved clover action and its spectrum scales just as well.Comment: 15 pp RevTeX, 5 Postscript figures, submitted to Phys. Rev.
Rearranged section order and added an analysis of fluctuations of the pion
correlato
Non-Universal Stellar Initial Mass Functions: Large Uncertainties in Star Formation Rates at and Other Astrophysical Probes
We explore the assumption, widely used in many astrophysical calculations,
that the stellar initial mass function (IMF) is universal across all galaxies.
By considering both a canonical Salpeter-like IMF and a non-universal IMF, we
are able to compare the effect of different IMFs on multiple observables and
derived quantities in astrophysics. Specifically, we consider a non-universal
IMF which varies as a function of the local star formation rate, and explore
the effects on the star formation rate density (SFRD), the extragalactic
background light, the supernova (both core-collapse and thermonuclear) rates,
and the diffuse supernova neutrino background. Our most interesting result is
that our adopted varying IMF leads to much greater uncertainty on the SFRD at
than is usually assumed. Indeed, we find a SFRD (inferred using
observed galaxy luminosity distributions) that is a factor of lower
than canonical results obtained using a universal Salpeter-like IMF. Secondly,
the non-universal IMF we explore implies a reduction in the supernova
core-collapse rate of a factor of , compared against a universal IMF.
The other potential tracers are only slightly affected by changes to the
properties of the IMF. We find that currently available data do not provide a
clear preference for universal or non-universal IMF. However, improvements to
measurements of the star formation rate and core-collapse supernova rate at
redshifts may offer the best prospects for discernment.Comment: 15 pages, 11 figures, 1 appendi
Dwarf koa (Desmanthus virgatus)
This is the final version. It was first published by BioMed Central at http://www.biomedcentral.com/1471-2164/16/473.Background: Mobile elements are active in the human genome, both in the germline and cancers, where they can\ud
mutate driver genes.\ud
Results: While analysing whole genome paired-end sequencing of oesophageal adenocarcinomas to find genomic\ud
rearrangements, we identified three ways in which new mobile element insertions appear in the data, resembling\ud
translocation or insertion junctions: inserts where unique sequence has been transduced by an L1 (Long interspersed\ud
element 1) mobile element; novel inserts that are confidently, but often incorrectly, mapped by alignment software to\ud
L1s or polyA tracts in the reference sequence; and a combination of these two ways, where different sequences within\ud
one insert are mapped to different loci. We identified nine unique sequences that were transduced by neighbouring\ud
L1s, both L1s in the reference genome and L1s not present in the reference. Many of the resulting inserts were small\ud
fragments that include little or no recognisable mobile element sequence. We found 6 loci in the reference genome to\ud
which sequence reads from inserts were frequently mapped, probably erroneously, by alignment software: these were\ud
either L1 sequence or particularly long polyA runs. Inserts identified from such apparent rearrangement junctions\ud
averaged 16 inserts/tumour, range 0?153 insertions in 43 tumours. However, many inserts would not be detected by\ud
mapping the sequences to the reference genome, because they do not include sufficient mappable sequence. To\ud
estimate total somatic inserts we searched for polyA sequences that were not present in the matched normal or other\ud
normals from the same tumour batch, and were not associated with known polymorphisms. Samples of these candidate\ud
inserts were verified by sequencing across them or manual inspection of surrounding reads: at least 85 % were somatic\ud
and resembled L1-mediated events, most including L1Hs sequence. Approximately 100 such inserts were detected per\ud
tumour on average (range zero to approximately 700).\ud
Conclusions: Somatic mobile elements insertions are abundant in these tumours, with over 75 % of cases having a\ud
number of novel inserts detected. The inserts create a variety of problems for the interpretation of paired-end\ud
sequencing data.Funding\ud
was primarily from Cancer Research UK program grants to RCF and ST\ud
(C14478/A15874 and C14303/A17197), with additional support awarded to\ud
RCF from UK Medical Research Council, NHS National Institute for Health\ud
Research (NIHR), the Experimental Cancer Medicine Centre Network and\ud
the NIHR Cambridge Biomedical Research Centre, and Cancer Research UK\ud
Project grant C1023/A14545 to PAWE. JMJW was funded by a Wellcome\ud
Trust Translational Medicine and Therapeutics grant
Styrene-Associated Health Outcomes at a Windblade Manufacturing Plant
Background: Health risks of using styrene to manufacture windblades for the green energy sector are unknown.
Methods: Using data collected from 355 (73%) current windblade workers and regression analysis, we investigated associations between health outcomes and styrene exposure estimates derived from urinary styrene metabolites.
Results: The median current styrene exposure was 53.6 mg/g creatinine (interquartile range: 19.5–94.4). Color blindness in men and women (standardized morbidity ratios 2.3 and 16.6, respectively) was not associated with exposure estimates, but was the type previously reported with styrene. Visual contrast sensitivity decreased and chest tightness increased (odds ratio 2.9) with increasing current exposure. Decreases in spirometric parameters and FeNO, and increases in the odds of wheeze and asthma-like symptoms (odds ratios 1.3 and 1.2, respectively) occurred with increasing cumulative exposure.
Conclusions: Despite styrene exposures below the recommended 400 mg/g creatinine, visual and respiratory effects indicate the need for additional preventative measures in this industry
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