6,385 research outputs found
The environmental contaminant DDE fails to influence the outcome of sexual differentiation in the marine turtle Chelonia mydas.
In many turtles, the temperature experienced during the middle of egg incubation determines the sex of the offspring. The implication of steroid sex hormones as the proximate trigger for sex determination opens the possibility that endocrine-disrupting contaminants may also influence the outcome of sexual differentiation. In this study we investigate the potential effects of DDE (a common DDT metabolite) on sexual differentiation of Chelonia mydas (green sea turtle). Four clutches of eggs collected from Heron Island, Queensland, Australia, were treated with DDE at the beginning of the thermosensitive period for sexual determination. An incubation temperature of 28 degrees C or less produces male hatchlings in this species, whereas 30 degrees C or more produces female hatchlings. Dosed eggs were consequently incubated at two temperatures (27.6 degrees C and 30.4 degrees C) on the upper and lower boundaries of the sex determination threshold for this species. DDE, ranging from 3.3 to 66.5 microg, was dissolved in 5, 10, and 25 microl ethanol and applied to eggshells above the embryo. Less than 2.5 ng/g DDE was present in eggs prior to dosing. Approximately 34% of the applied DDE was absorbed in the eggs, but only approximately 8% of applied DDE was found in embryos. Thus, treated eggs, corrected for background DDE, had up to 543 ng/g DDE. The sex ratio at these doses did not differ from what would be expected on consideration of temperature alone. Incubation time, hatching success, incidence of body deformities, hatching size, and weight were also within the limits of healthy developed hatchlings. This indicates that the eggs of C. mydas in the wild with concentrations of DDE less than 543 ng/g should produce hatchlings with relatively high hatching success, survival rate, and normally differentiated gonads
Surveying the Effects of Limitations on Taxes and Expenditures: What Do/Don’t We Know?
The literature on tax and expenditure limitations (TELs) is extensive and continues to grow, as the impact of these institutional constraints on fiscal and economic outcomes continues to develop. In this survey, we review the literature of state- and local-level TELs, in an attempt to provide an overview of their theoretical, operational, and empirical contexts. The study concludes with a discussion of future TEL research needs
Mutation analysis of HIF prolyl hydroxylases (PHD/EGLN) in individuals with features of phaeochromocytoma and renal cell carcinoma susceptibility
Germline mutations in the von Hippel–Lindau disease (VHL) and succinate dehydrogenase subunit B (SDHB) genes can cause inherited phaeochromocytoma and/or renal cell carcinoma(RCC). Dysregulation of the hypoxia-inducible factor (HIF) transcription factors has been linked to VHL and SDHB-related RCC; both HIF dysregulation and disordered function of a prolyl hydroxylase domain isoform 3 (PHD3/EGLN3)-related pathway of neuronal apoptosis have been linked to the development of phaeochromocytoma. The 2-oxoglutarate-dependent prolyl hydroxylase enzymes PHD1 (EGLN2), PHD2 (EGLN1) and PHD3 (EGLN3) have a key role in regulating the stability of HIF-a subunits (and hence expression of the HIF-a transcription factors). A germline PHD2 mutation has been reported in association with congenital erythrocytosis and recurrent extra-adrenal phaeochromocytoma. We undertook mutation analysis of PHD1, PHD2 and PHD3 in two cohorts of patients with features of inherited phaeochromocytoma (nZ82) and inherited RCC (nZ64) and no evidence of germline mutations in known susceptibility genes. No confirmed pathogenic mutations were detected suggesting that mutations in these genes are not a frequent cause of inherited phaeochromocytoma or RCC
Perturbations of a Universe Filled with Dust and Radiation
A first-order perturbation approach to Friedmann cosmologies filled
with dust and radiation is developed. Adopting the coordinate gauge comoving
with the perturbed matter, and neglecting the vorticity of the radiation, a
pair of coupled equations is obtained for the trace of the metric
perturbations and for the velocity potential . A power series solution with
upwards cutoff exists such that the leading terms for large values of the
dimensionless time agree with the relatively growing terms of the dust
solution of Sachs and Wolfe.Comment: 9 pp, typeset in late
A statistical model of the international spread of wild poliovirus in Africa used to predict and prevent outbreaks
Published versio
Developing the agenda for European Union collaboration on non-communicable diseases research in Sub-Saharan Africa
<p>Abstract</p> <p>Background</p> <p>Health research is increasing in Africa, but most resources are currently chanelled towards infectious diseases and health system development. While infectious diseases remain a heavy burden for some African countries, non-communicable diseases (NCDs) account for more than half of all deaths globally and WHO predicts 27% increase in NCDs in Africa over the next decade. We present findings of a European-Africa consultation on the research agenda for NCDs.</p> <p>Methods</p> <p>A workshop was held in Yaoundé, Cameroon, organized by the Network for the Coordination and Advancement of Sub-Saharan Africa-European Union Science and Technology Cooperation (CAAST-Net). Drawing on initial presentations, a small expert group from academic, clinical, public-health and administrative positions considered research needs in Africa for cardiovascular disease, cancer and diabetes.</p> <p>Results</p> <p>Research in Africa can draw from different environmental and genetic characteristics to understand the causes of the disease, while economic and social factors are important in developing relevant strategies for prevention and treatment. The suggested research needs include better methods for description and recording, clinical studies, understanding cultural impacts, prevention strategies, and the integrated organisation of care. Specific fields proposed for research are listed.</p> <p>Conclusions</p> <p>Our paper contributes to transparency in the process of priority-setting for health research in Africa. Although the European Union Seventh Framework Research Programme prioritises biomedical and clinical research, research for Africa should also address broader social and cultural research and intervention research for greatest impact. Research policy leaders in Africa must engage national governments and international agencies as well as service providers and research communities. None can act effectively alone. Bringing together the different stakeholders, and feeding the results through to the European Union research programme is a valuable contribution of CAAST-Net.</p
Facilitating the adoption of high-throughput sequencing technologies as a plant pest diagnostic test in laboratories: A step-by- step description
High-throughput
sequencing (HTS) is a powerful tool that enables the simultaneous
detection and potential identification of any organisms present in a sample. The
growing interest in the application of HTS technologies for routine diagnostics
in plant health laboratories is triggering the development of guidelines on how to
prepare laboratories for performing HTS testing. This paper describes general and
technical recommendations to guide laboratories through the complex process of
preparing a laboratory for HTS tests within existing quality assurance systems.
From nucleic acid extractions to data analysis and interpretation, all of the steps are
covered to ensure reliable and reproducible results. These guidelines are relevant
for the detection and identification of any plant pest (e.g. arthropods, bacteria,
fungi, nematodes, invasive plants or weeds, protozoa, viroids, viruses), and from
any type of matrix (e.g. pure microbial culture, plant tissue, soil, water), regardless
of the HTS technology (e.g. amplicon sequencing, shotgun sequencing) and of the
application (e.g. surveillance programme, phytosanitary certification, quarantine,
import control). These guidelines are written in general terms to facilitate the
adoption of HTS technologies in plant pest routine diagnostics and enable broader
application in all plant health fields, including research. A glossary of relevant
terms is provided among the Supplementary Material
MUSTANG: 90 GHz Science with the Green Bank Telescope
MUSTANG is a 90 GHz bolometer camera built for use as a facility instrument
on the 100 m Robert C. Byrd Green Bank radio telescope (GBT). MUSTANG has an 8
by 8 focal plane array of transition edge sensor bolometers read out using
time-domain multiplexed SQUID electronics. As a continuum instrument on a large
single dish MUSTANG has a combination of high resolution (8") and good
sensitivity to extended emission which make it very competitive for a wide
range of galactic and extragalactic science. Commissioning finished in January
2008 and some of the first science data have been collected.Comment: 9 Pages, 5 figures, Presented at the SPIE conference on astronomical
instrumentation in 200
The Use of Gamification Techniques in a Clinical Setting for the Collection of Longitudinal Kinematic Data
'Prove me the bam!': victimization and agency in the lives of young women who commit violent offences
This article reviews the evidence regarding young women’s involvement in violent crime and, drawing on recent research carried out in HMPYOI Cornton Vale in Scotland, provides an overview of the characteristics, needs and deeds of young women sentenced to imprisonment for violent offending. Through the use of direct quotations, the article suggests that young women’s anger and aggression is often related to their experiences of family violence and abuse, and the acquisition of a negative worldview in which other people are considered as being 'out to get you' or ready to 'put one over on you'. The young women survived in these circumstances, not by adopting discourses that cast them as exploited victims, but by drawing on (sub)cultural norms and values which promote pre-emptive violence and the defence of respect. The implications of these findings for those who work with such young women are also discussed
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