1,827 research outputs found

    Placental weight and mortality in premenopausal breast cancer by tumor characteristics

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    Placental weight may be regarded as an indirect marker of hormone exposures during pregnancy. There is epidemiological evidence that breast cancer mortality in premenopausal women increases with placental weight in the most recent pregnancy. We investigated if this association differs by tumor characteristics, including expression of estrogen and progesterone receptors. In a Swedish population-based cohort, we followed 1,067 women with premenopausal breast cancer diagnosed from 1992 to 2006. Using Cox regression models, we estimated hazard ratios for the association between placental weight and risk of premenopausal breast cancer mortality. In stratified analyses, we estimated mortality risks in subjects with different tumor stages, estrogen receptor (ER) or progesterone receptor (PR) status. Compared with women with placental weight less than 600 g, women with a placental weight between 600 and 699 g were at a 50 % increased risk of mortality, however, not significant change in risk was observed for women with placental weight �700 g. Mortality risks associated with higher placental weight were more pronounced among ER- and PR- breast cancer tumors, where both a placental weight 600-699 g and �700 g were associated with a more than doubled mortality risks compared with tumors among women with placental weight less than 600 g. Moreover, stratified analyses for joint receptor status revealed that a consistent increased mortality risk by placental weight was only apparent in women with ER-/PR- breast cancer. The increased mortality risk in premenopausal breast cancer associated with higher placental weight was most pronounced among ER- and PR- tumors. © 2012 Springer Science+Business Media New York

    Strain-stiffening in random packings of entangled granular chains

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    Random packings of granular chains are presented as a model polymer system to investigate the contribution of entanglements to strain-stiffening in the absence of Brownian motion. The chain packings are sheared in triaxial compression experiments. For short chain lengths, these packings yield when the shear stress exceeds a the scale of the confining pressure, similar to packings of spherical particles. In contrast, packings of chains which are long enough to form loops exhibit strain-stiffening, in which the effective stiffness of the material increases with strain, similar to many polymer materials. The latter packings can sustain stresses orders-of-magnitude greater than the confining pressure, and do not yield until the chain links break. X-ray tomography measurements reveal that the strain-stiffening packings contain system-spanning clusters of entangled chains.Comment: 4 pages, 4 figures. submitted to Physical Review Letter

    A New Disease in Iowa Corn Fields

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    It resembles maize dwarf mosaic found in Ohio, Symptoms vary widely and may include red or purple streaking of leaves or severe stunting. Research is underway and is being intensified

    Can low-carbon options change conditions for expanding energy access in Africa?

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    This discussion brief examines how low-carbon options are being used to expand energy access and electrification; the incentives and barriers to using low-carbon options; and the broader policy context

    Genome wide association studies for carcass traits measured by video image analysis in crossbred lambs

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    This is the first UK genome wide association study investigating potential links between Video Image Analysis (VIA) carcass traits and molecular polymorphisms in crossbred sheep. Phenotypic and genotypic data were collected from two crossbred lamb populations: Texel x Scotch Mule (TxSM, n = 2330) and Texel x Lleyn (TxL, n = 3816). Traits measured included live weights at birth, eight weeks and weaning (∼15 weeks). VIA-predicted traits included total weights and weights of fat, muscle and bone in the whole carcass and primal (hind leg, saddle, shoulder) regions. Within-breed heritabilities estimated for the VIA traits ranged from 0.01 to 0.70, indicating potential for inclusion of some traits in breeding programmes. The two crossbred populations differed in SNPs associated with different traits. Two SNPs on chromosomes two (s74618.1) and eight (s68536.1), respectively, reached genome-wise significance for TxSM, explaining &lt;1% of trait variance, for whole carcass fat and muscle weights, hind leg and saddle fat weights and shoulder bone weights. For TxL, four SNPs reached genome-wise significance, on chromosome two for hind leg muscle weight (OAR2_117,959,202 and OAR2_11804335), on chromosome 10 for whole carcass bone weight (OAR19_8,995,957.1), and on chromosome 19 for weaning weight (s40847.1), each explaining &lt;1% of trait genetic variation. Differences in apparent genetic control of carcass traits may be influenced by the lambs' cross-breed, but also by management decisions affecting environmental variance and trait definitions, which should be understood in order to define protocols for incorporation of carcass traits into (cross)breeding programmes. Implications: Combining VIA-measured carcass traits with conventional production traits in a breeding programme could potentially improve the production and product quality of meat sheep. Phenotypes for VIA traits could be collected relatively easily if VIA machines were present at all abattoir sites. The current study and future Genome Wide Association Studies may help to identify potentially informative molecular markers, that explain large proportions of the genetic variance observed in VIA-measured carcass traits. Including this information in the estimation of breeding values could increase the accuracy of prediction, increasing the potential rate of genetic improvement for product quality. This study confirms the polygenic architecture of the investigated carcass traits, with a small number of molecular markers that each explain a small amount of genetic variation. Further studies across breed types are recommended to further test and validate molecular markers for traits related to lamb carcass quality, as measured by video image analysis.</p

    Cognitive Behaviour Therapy for Health Anxiety:A systematic review and meta-analysis

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    Background: Health anxiety (HA), or hypochondriasis, is a psychological problem characterized by a preoccupation with the belief that one is physically unwell. A 2007 Cochrane review (Thomson and Page, 2007) found cognitive behavioural therapy (CBT) to be an effective intervention for individuals with HA. Similar findings were reported in a recent meta-analysis (Olatunji et al., 2014), which did not employ a systematic search strategy. The current review aimed to investigate the efficacy of CBT for HA, and to update the existing reviews. Method: A systematic search was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance, including randomized controlled trials that compared CBT with a control condition for people with HA. Five hundred and sixty-seven studies were found in the original search, of which 14 were included in the meta-analysis. Results: Meta-analysis was conducted on 21 comparisons and a large effect size for CBT compared with a control condition was found at post therapy d = 1.01 (95% confidence interval 0.77–1.25), as well as at 6- and 12-month follow-up. Conclusions: This systematic review and meta-analysis provides support for the hypothesis that CBT is an effective intervention for HA when compared with a variety of control conditions, e.g. treatment-as-usual, waiting list, medication, and other psychological therapies

    Birth size in the most recent pregnancy and maternal mortality in premenopausal breast cancer by tumor characteristics

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    The main aim of this study was to investigate possible associations between measures of offspring size at birth in the most recent pregnancy before premenopausal breast cancer diagnosis and the risks of maternal breast cancer mortality, taking tumor characteristics into account. We also aimed to investigate if these associations are modified by age at childbirth, time since childbirth, parity, and age at diagnosis. We followed 6,019 women from their date of premenopausal breast cancer (diagnosed from 1992 to 2008) until emigration, death or December 31st, 2009, whichever occurred first. We used Cox proportional hazard regression models, adjusted for parity, age at diagnosis, and education level, to estimate associations between women pregnancy, cancer characteristics and offspring birth characteristics, and mothers' mortality risk. In stratified analyses, mortality risks were estimated by tumor stage, ER or PR status. There was no association between offspring birth weight (HR = 1.00, 95 % CI 0.99-1.01, when used as a continuous variable), birth weight for gestational age or ponderal index, and premenopausal breast cancer mortality. Similarly, in analyses stratified by tumor stage, receptor status, and time difference between last pregnancy and date of diagnosis, we found no associations between birth size and breast cancer mortality. Our findings suggest that the hypothesis that "premenopausal breast cancer mortality is associated with offspring birth characteristics in the most recent pregnancy before the diagnosis" may not be valid. In addition, these associations are not modified by tumor characteristics. © 2014 Springer Science+Business Media New York
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