Homocysteine and Coronary Heart Disease: Meta-analysis of MTHFR Case-Control Studies, Avoiding Publication Bias

Robert Clarke and colleagues conduct a meta-analysis of unpublished datasets to examine the causal relationship between elevation of homocysteine levels in the blood and the risk of coronary heart disease. Their data suggest that an increase in homocysteine levels is not likely to result in an increase in risk of coronary heart disease

Warmer early instrumental measurements versus colder reconstructed temperatures : shooting at a moving target

Comparison of tree-ring-based warm-season temperature reconstructions and their instrumental target data reveals substantial divergence between (warmer) early instrumental measurements and (colder) proxy estimates. Here we detail this systematic misfit for the Northern Hemisphere before similar to 1900 and the European Alps before similar to 1850. Five hypotheses related to both proxy and target uncertainties are presented towards explaining this phenomenon. These include: (1) tree-ring detrending methods, (2) biological persistence in the proxy time-series, (3) uncertainties and instabilities in the growth response to given climatic parameters, (4) reduced instrumental station availability back in time, and (5) instrumental data homogeneity. We suggest that uncertainties in the choice of instrumental targets at the hemispheric scale, and instrumental data inhomogeneities at the Alpine and possibly also the hemispheric-scale are the most important factors in explaining this offset. Assessment of homogeneity at larger scales remains challenging. Attention is drawn to possible warm biases in early thermometer shelters and the relevance of proxy/target discrepancies for understanding and quantifying the amplitude of both recent anthropogenic and past natural forced climate fluctuations

Modeling of the plastic characteristics of AA6082 for the friction stir welding process

Focus of this paper is to model the plastic forming behavior of AA6082, in order to develop the numerical FE analysis of the friction stir welding processes and the simulation of subsequent forming processes. During the friction stir welding process, the temperatures reached can range up to 500 \ub0C and have a fundamental role for the correct performance of the process, so the material data has to show a temperature dependency. Because of the tool rotation a strain rate sensitivity of the material has to be respected as well. In this context, the general material characteristics of AA6082 were first identified for different stress states. For the uniaxial state the standard PuD-Al used in the automotive industry was applied, for the shear state the ASTM B831- 05 was used and for biaxial states the ISO 16842 was exploited. To characterize the plastic flow behavior of the AA6082 at elevated temperatures, tensile tests were performed according to DIN EN ISO 6892-2 from 25 \ub0C to 500 \ub0C with a strain rate from 0.1 s-1 up to 6.5 s-1

Multi-variable analysis of 200 years of climate variability and change in the Greater Alpine Region

HISTALP, a large multi-variable dataset consisting of monthly quality-checked and homogenised secular records for the \u201cGreater Alpine Region\u201d (GAR, 4-19 \ub0E, 43-49 \ub0N, 0-3500m asl), has been set up in the last 10 years within the frame of a number of projects coordinated by the Austrian Meteorological Central Office. It encompasses 242 sites and concerns temperature, pressure, precipitation, sunshine, cloudiness, vapour pressure and relative humidity. The climate information in HISTALP is not only stored in station-mode, but also by means of gridded data and Coarse Resolution Subregional Mean series (CRSMs), that are available at monthly, seasonal and yearly resolution. In this context, we are analysing the HISTALP database with the aim at giving a comprehensive picture of secular climate variability and change in the GAR, by means of the analysis of a wide range of relevant meteorological variables (temperature, precipitation, pressure, cloudiness, sunshine duration, vapour pressure and relative humidity). This extended abstract shows some preliminary results of our research; full details will be given in a comprehensive paper that is currently in preparation

Climate variability and change in the Greater Alpine Region over the last two centuries based on multi-variable analysis

An extensive analysis of the HISTALP database is presented with the aim of giving a comprehensive picture of secular climate variability and change in the Greater Alpine Region (GAR, 4-19 E, 43-49 N). The HISTALP database encompasses 242 sites and concerns temperature, pressure, precipitation, Cloudiness, Sunshine duration, vapour pressure and relative humidity. The analyses are based on four regional mean records representing different GAR low-level areas and on an additional mean record representing high-level locations. The first goal of the paper is to give an overview of the seasonal and annual records for the different variables, aiming to highlight both variability on decadal time scale and long-term evolution. Then it focuses on trend and correlation analysis. Trends are presented both for the period of common data availability for all regional average series and for moving windows that permit studying the trends over a wide range of timescales. Correlations among the different variables are presented both for the regional average series and for their high-pass-filtered versions. The analyses, beside highlighting a warming that is about twice as large its the global trend. also show that the different variables have responded in different ways to this warming and that the mutual interactions linking the different variables are often present only at specific temporal scales and only in parts of the GAR and in defined seasons. In spite of this complex behaviour, which may also be due to some residual inhomogeneities still affecting the data, the analyses give evidence that the HISTALP database has in excellent internal consistency and show that the availability of a multi-variable database turns out to be very useful in order to evaluate the reliability of the reconstruction of each variable and to better understand the behaviour and the mutual interactions of the different variables