2,735 research outputs found

    Diabetes status and post-load plasma glucose concentration in relation to site-specific cancer mortality: findings from the original Whitehall study

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    ObjectiveWhile several studies have reported on the relation of diabetes status with pancreatic cancer risk, the predictive value of this disorder for other malignancies is unclear. Methods: The Whitehall study, a 25year follow-up for mortality experience of 18,006 men with data on post-challenge blood glucose and self-reported diabetes, allowed us to address these issues. Results: There were 2158 cancer deaths at follow-up. Of the 15 cancer outcomes, diabetes status was positively associated with mortality from carcinoma of the pancreas and liver, while the relationship with lung cancer was inverse, after controlling for a range of potential covariates and mediators which included obesity and socioeconomic position. After excluding deaths occurring in the first 10years of follow-up to examine the effect of reverse causality, the magnitude of the relationships for carcinoma of the pancreas and lung was little altered, while for liver cancer it was markedly attenuated. Conclusions: In the present study, diabetes status was related to pancreatic, liver, and lung cancer risk. Cohorts with serially collected data on blood glucose and covariates are required to further examine this area

    Paleophysical Oceanography with an Emphasis on Transport Rates

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    Paleophysical oceanography is the study of the behavior of the fluid ocean of the past, with a specific emphasis on its climate implications, leading to a focus on the general circulation. Even if the circulation is not of primary concern, heavy reliance on deep-sea cores for past climate information means that knowledge of the oceanic state when the sediments were laid down is a necessity. Like the modern problem, paleoceanography depends heavily on observations, and central difficulties lie with the very limited data types and coverage that are, and perhaps ever will be, available. An approximate separation can be made into static descriptors of the circulation (e.g., its water-mass properties and volumes) and the more difficult problem of determining transport rates of mass and other properties. Determination of the circulation of the Last Glacial Maximum is used to outline some of the main challenges to progress. Apart from sampling issues, major difficulties lie with physical interpretation of the proxies, transferring core depths to an accurate timescale (the “age-model problem”), and understanding the accuracy of time-stepping oceanic or coupled-climate models when run unconstrained by observations. Despite the existence of many plausible explanatory scenarios, few features of the paleocirculation in any period are yet known with certainty.National Science Foundation (U.S.) (grant OCE-0645936

    Neutrino masses from new generations

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    We reconsider the possibility that Majorana masses for the three known neutrinos are generated radiatively by the presence of a fourth generation and one right-handed neutrino with Yukawa couplings and a Majorana mass term. We find that the observed light neutrino mass hierarchy is not compatible with low energy universality bounds in this minimal scenario, but all present data can be accommodated with five generations and two right-handed neutrinos. Within this framework, we explore the parameter space regions which are currently allowed and could lead to observable effects in neutrinoless double beta decay, μe\mu - e conversion in nuclei and μeγ\mu \rightarrow e \gamma experiments. We also discuss the detection prospects at LHC.Comment: 28 pages, 4 figures. Version to be published. Some typos corrected. Improved figures 3 and

    Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy

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    How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures

    The influence of caffeine on energy content of sugar-sweetened beverages : the caffeine–calorie effect

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    Background/Objectives: Caffeine is a mildly addictive psychoactive chemical and controversial additive to sugar-sweetened beverages (SSBs). The objective of this study is to assess if removal of caffeine from SSBs allows co-removal of sucrose (energy) without affecting flavour of SSBs, and if removal of caffeine could potentially affect population weight gain. Subjects/Methods: The research comprised of three studies; study 1 used three-alternate forced choice and paired comparison tests to establish detection thresholds for caffeine in water and sucrose solution (subjects, n ¼ 63), and to determine if caffeine suppressed sweetness. Study 2 (subjects, n ¼ 30) examined the proportion of sucrose that could be co-removed with caffeine from SSBs without affecting the flavour of the SSBs. Study 3 applied validated coefficients to estimate the impact on the weight of the United States population if there was no caffeine in SSBs. Results: Detection threshold for caffeine in water was higher (1.09±0.08 mM) than the detection threshold for caffeine in sucrose solution (0.49 ± 0.04 mM), and a paired comparison test revealed caffeine significantly reduced the sweetness of sucrose (Po0.001). Removing caffeine from SSBs allowed co-removal of 10.3% sucrose without affecting flavour of the SSBs, equating to 116 kJ per 500 ml serving. The effect of this on body weight in adults and children would be 0.600 and 0.142 kg, which are equivalent to 2.08 and 1.10 years of observed existing trends in weight gain, respectively. Conclusion: These data suggest the extra energy in SSBs as a result of caffeine's effect on sweetness may be associated with adult and child weight gain

    Fluids in cosmology

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    We review the role of fluids in cosmology by first introducing them in General Relativity and then by applying them to a FRW Universe's model. We describe how relativistic and non-relativistic components evolve in the background dynamics. We also introduce scalar fields to show that they are able to yield an inflationary dynamics at very early times (inflation) and late times (quintessence). Then, we proceed to study the thermodynamical properties of the fluids and, lastly, its perturbed kinematics. We make emphasis in the constrictions of parameters by recent cosmological probes.Comment: 34 pages, 4 figures, version accepted as invited review to the book "Computational and Experimental Fluid Mechanics with Applications to Physics, Engineering and the Environment". Version 2: typos corrected and references expande

    The detection of the imprint of filaments on cosmic microwave background lensing

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    Galaxy redshift surveys, such as 2dF, SDSS, 6df, GAMA and VIPERS, have shown that the spatial distribution of matter forms a rich web, known as the cosmic web. The majority of galaxy survey analyses measure the amplitude of galaxy clustering as a function of scale, ignoring information beyond a small number of summary statistics. Since the matter density field becomes highly non-Gaussian as structure evolves under gravity, we expect other statistical descriptions of the field to provide us with additional information. One way to study the non-Gaussianity is to study filaments, which evolve non-linearly from the initial density fluctuations produced in the primordial Universe. In our study, we report the first detection of CMB (Cosmic Microwave Background) lensing by filaments and we apply a null test to confirm our detection. Furthermore, we propose a phenomenological model to interpret the detected signal and we measure how filaments trace the matter distribution on large scales through filament bias, which we measure to be around 1.5. Our study provides a new scope to understand the environmental dependence of galaxy formation. In the future, the joint analysis of lensing and Sunyaev-Zel'dovich observations might reveal the properties of `missing baryons', the vast majority of the gas which resides in the intergalactic medium and has so far evaded most observations
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