1,478 research outputs found
Obstetrician-assessed maternal health at pregnancy predicts offspring future health
Background:
We aimed to examine the association between obstetrician assessment of maternal physical health at the time of pregnancy and offspring cardiovascular disease risk.<p></p>
Methods and Principal Findings:
We examined this association in a birth cohort of 11,106 individuals, with 245,000 person years of follow-up. We were concerned that any associations might be explained by residual confounding, particularly by family socioeconomic position. In order to explore this we used multivariable regression models in which we adjusted for a range of indicators of socioeconomic position and we explored the specificity of the association. Specificity of association was explored by examining associations with other health related outcomes. Maternal physical health was associated with cardiovascular disease: adjusted (socioeconomic position, complications of pregnancy, birthweight and childhood growth at mean age 5) hazard ratio comparing those described as having poor or very poor health at the time of pregnancy to those with good or very good health was 1.55 (95%CI: 1.05, 2.28) for coronary heart disease, 1.91 (95%CI: 0.99, 3.67) for stroke and 1.57 (95%CI: 1.13, 2.18) for either coronary heart disease or stroke. However, this association was not specific. There were strong associations for other outcomes that are known to be related to socioeconomic position (3.61 (95%CI: 1.04, 12.55) for lung cancer and 1.28 (95%CI:1.03, 1.58) for unintentional injury), but not for breast cancer (1.10 (95%CI:0.48, 2.53)).<p></p>
Conclusions and Significance:
These findings demonstrate that a simple assessment of physical health (based on the appearance of eyes, skin, hair and teeth) of mothers at the time of pregnancy is a strong indicator of the future health risk of their offspring for common conditions that are associated with poor socioeconomic position and unhealthy behaviours. They do not support a specific biological link between maternal health across her life course and future risk of cardiovascular disease in her offspring.<p></p>
Polar Bear Conservation in Canada: Defining the Policy Problems
Conservation of polar bears (Ursus maritimus) in Canada is based on the goals and principles of the 1973 International Agreement on the Conservation of Polar Bears and Their Habitat, and has long been considered an exemplar of science-based wildlife management. However, accelerating social and ecological changes in the Arctic raise questions about the polar bear management regime’s ability to adapt successfully to new challenges. We apply the analytic framework of the policy sciences to develop a comprehensive orientation to this evolving situation, and we suggest possible ways to define and advance shared goals of stakeholders and other participants. We conclude that the decision process in polar bear management does not sufficiently foster identification and securing of common interests among participants who express multiple, competing perspectives in an arena that has been increasingly fragmented and symbolically charged by issues such as the recent listing of polar bears under the U.S. Endangered Species Act. The fundamental challenge for polar bear conservation in Canada is to design a better decision process so that it can constructively reconcile the various perspectives, demands, and expectations of stakeholders.Au Canada, la conservation des ours polaires (Ursus maritimus) respecte les objectifs et les principes de l’Accord international sur la conservation des ours blancs et leur habitat de 1973, qui est considéré depuis longtemps comme un modèle de gestion de la faune fondée sur la science. Cependant, l’évolution de plus en plus rapide des changements d’ordre social et écologique dans l’Arctique a pour effet de soulever des questions sur l’aptitude du régime de gestion de l’ours polaire à bien s’adapter aux nouveaux défis. Nous utilisons le cadre de référence analytique de la science des politiques pour aboutir à une orientation exhaustive de cette situation en pleine évolution, et nous suggérons des manières possibles de définir et de formuler des objectifs partagés par les parties prenantes et d’autres participants. Nous concluons que le processus de décision en matière de gestion de l’ours polaire n’encourage pas suffisamment l’identification et l’engagement d’intérêts communs entre les participants qui expriment des perspectives multiples et concurrentes dans un domaine de plus en plus fragmenté et symboliquement caractérisé par des enjeux tels que la liste récente d’ours polaires en vertu de la loi américaine sur les espèces en voie de disparition (U.S. Endangered Species Act). Le défi fondamental en ce qui a trait à la conservation des ours polaires au Canada consiste à concevoir un meilleur processus de décision pouvant réconcilier, de manière constructive, les diverses perspectives, exigences et attentes des parties prenantes
Other Voices, Other Ways, Better Practices: Bridging Local and Professional Environmental Knowledge
Millisecond spin-flip times of donor-bound electrons in GaAs
We observe millisecond spin-flip relaxation times of donor-bound electrons in
high-purity n-GaAs . This is three orders of magnitude larger than previously
reported lifetimes in n-GaAs . Spin-flip times are measured as a function of
magnetic field and exhibit a strong power-law dependence for fields greater
than 4 T . This result is in qualitative agreement with previously reported
theory and measurements of electrons in quantum dots.Comment: 4 pages, 4 figure
It's Not Just About Bears: A Problem-Solving Workshop on Aboriginal Peoples, Polar Bears, and Human Dignity
Why Do HIV-1 and HIV-2 Use Different Pathways to Develop AZT Resistance?
The human immunodeficiency virus type 1 (HIV-1) develops resistance to all available drugs, including the nucleoside analog reverse transcriptase inhibitors (NRTIs) such as AZT. ATP-mediated excision underlies the most common form of HIV-1 resistance to AZT. However, clinical data suggest that when HIV-2 is challenged with AZT, it usually accumulates resistance mutations that cause AZT resistance by reduced incorporation of AZTTP rather than selective excision of AZTMP. We compared the properties of HIV-1 and HIV-2 reverse transcriptase (RT) in vitro. Although both RTs have similar levels of polymerase activity, HIV-1 RT more readily incorporates, and is more susceptible to, inhibition by AZTTP than is HIV-2 RT. Differences in the region around the polymerase active site could explain why HIV-2 RT incorporates AZTTP less efficiently than HIV-1 RT. HIV-1 RT is markedly more efficient at carrying out the excision reaction with ATP as the pyrophosphate donor than is HIV-2 RT. This suggests that HIV-1 RT has a better nascent ATP binding site than HIV-2 RT, making it easier for HIV-1 RT to develop a more effective ATP binding site by mutation. A comparison of HIV-1 and HIV-2 RT shows that there are numerous differences in the putative ATP binding sites that could explain why HIV-1 RT binds ATP more effectively. HIV-1 RT incorporates AZTTP more efficiently than does HIV-2 RT. However, HIV-1 RT is more efficient at ATP-mediated excision of AZTMP than is HIV-2 RT. Mutations in HIV-1 RT conferring AZT resistance tend to increase the efficiency of the ATP-mediated excision pathway, while mutations in HIV-2 RT conferring AZT resistance tend to increase the level of AZTTP exclusion from the polymerase active site. Thus, each RT usually chooses the pathway best suited to extend the properties of the respective wild-type enzymes
Galactic and Magellanic Evolution with the SKA
As we strive to understand how galaxies evolve it is crucial that we resolve
physical processes and test emerging theories in nearby systems that we can
observe in great detail. Our own Galaxy, the Milky Way, and the nearby
Magellanic Clouds provide unique windows into the evolution of galaxies, each
with its own metallicity and star formation rate. These laboratories allow us
to study with more detail than anywhere else in the Universe how galaxies
acquire fresh gas to fuel their continuing star formation, how they exchange
gas with the surrounding intergalactic medium, and turn warm, diffuse gas into
molecular clouds and ultimately stars. The 21-cm line of atomic
hydrogen (HI) is an excellent tracer of these physical processes. With the SKA
we will finally have the combination of surface brightness sensitivity, point
source sensitivity and angular resolution to transform our understanding of the
evolution of gas in the Milky Way, all the way from the halo down to the
formation of individual molecular clouds.Comment: 25 pages, from "Advancing Astrophysics with the Square Kilometre
Array", to appear in Proceedings of Scienc
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