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Snow accumulation is an important component of the mass balance of alpine glaciers. To improve our understanding of the processes related to accumulation and their representation in state-of-the-art mass-balance models, extensive field measurements are required. We present measurements of snow accumulation distribution on Findelengletscher, Switzerland, for April 2010 using (1) in situ snow probings, (2) airborne ground-penetrating radar (GPR) and (3) differencing of two airborne light detection and ranging (lidar) digital elevation models (DEMs). Calculating high-resolution snow depth from DEM-differencing requires careful correction for vertical ice-flow velocity and densification in the accumulation area. All three methods reveal a general increase in snow depth with elevation, but also a significant small-scale spatial variability. Lidar-differencing and in situ snow probings show good agreement for the mean specific winter balance (0.72 and 0.78 m w.e., respectively). The lidar-derived distributed snow depth reveals significant zonal correlations with elevation, slope and curvature in a multiple linear regression model. Unlike lidar-differencing, GPR-derived snow depth is not affected by glacier dynamics or firn compaction, but to a smaller degree by snow density and liquid water content. It is thus a valuable independent data source for validation. The simultaneous availability of the three datasets facilitates the comparison of the methods and contributes to a better understanding of processes that govern winter accumulation distribution on alpine glaciers.
v sin i was determined by applying the Fourier transform method to the line profiles of two classical Be Stars. A variation is observed in the apparent v sin i which corresponds to the main frequencies associated to nrp modes. Rotational modulation is observed in wind sensitive UV lines of the Be star ω Ori and is associated with an oblique magnetic dipole which is discovered for the first time in a classical Be star.
High dispersion spectra in the visible range were obtained for field Be Stars in both hemispheres. As Be Stars form a class of Main Sequence fast rotators, we are intended to test how their chemical composition can be affected by rotation.
66 Oph has shown recurrent short-lived outbursts nicely detected from ground-based and space (Hipparcos) photometry.
Spectroscopic observations of He I 6678 and Hα lines were performed in June 1997 and June 1998. Search for short-term periodicities was done in He I 6678 line profiles as in equivalent width EW, radial velocity of the line centroid, and V and R components. At least two frequencies were present: ν = 4.0 c/d and ν = 2.2 c/d. The phase distribution of these frequencies over the line profile corresponds in the nrp frame to g-modes with ℓ ~ 3 − 4 and ℓ = 2 respectively.
ω Ori is a rapidly rotating B2IIIe star with known spectral variability. We applied a frequency analysis to the MuSiCoS (MUlti Site Continuous Spectroscopy) campaign 1998-dataset to search for line-profile variations (Ipv). Variability was found in all studied spectral lines and interpreted as due to non-radial pulsations (NRP).
The pole-on Be star υ Cyg (HD 202904) displayed with Hipparcos photometry a strong long-lived outburst between 1989 and 1993. High S/N spectroscopic observations were obtained in August-September 1998. The photospheric λ6678 line is strongly perturbed by variable outer V and R emission components and is itself highly variable.
All the studied quantities (profiles, EW, radial velocity of the line centroid, V and R emission components, V/R ratio) are dominated by ν = 1.5 c/d frequency. The first harmonic (ν = 3.0 c/d) is also detected in the central part of the profile. In the nrp frame, this pair of frequencies corresponds to a low degree sectorial g-mode l = |m| = 2. Moreover mid-term variations are superimposed to short ones.
The presence of norovirus in shellfish is a public health concern in Europe. Here, we report the results of an investigation into a norovirus gastroenteritis outbreak following a festive lunch which affected 84 (57%) residents and staff members of a nursing home in January 2012 in France. Individuals who had eaten oysters had a significantly higher risk of developing symptoms in the following 2·5 days than those who had not, the risk increasing with the amount eaten [relative risk 2·2 (1·0–4·6) and 3·3 (1·6–6·6) for 3–4 and 5–12 oysters, respectively]. In healthy individuals during those days, 29 (32%) subsequently became ill, most of whom were staff members performing activities in close contact with residents. Genogroup II noroviruses were detected in faecal samples, in a sample of uneaten oysters and in oysters from the production area. Identifying a norovirus's infectious dose may facilitate the health-related management of contaminated shellfish.
Mineral nitrogen (N) fertilization in cereals is commonly split into three or four applications. In order to simplify N fertilization, a single N application either broadcast or placed on the soil surface was compared to conventionally split fertilization for winter wheat (Triticum aestivum L.). The 4-year experiment (2007–2010) was performed using a participatory approach on farmers’ fields on deep loamy soils (Luvisols) in South-West Germany.
Grain yield and crude protein contents differed only slightly or not at all between treatments including different N fertilizer types (calcium ammonium nitrate, urea ammonium nitrate solution, urea) and application techniques (broadcast, placed). Furthermore, no differences were found for the yield components ears/m2 and thousand grain weight. Inorganic N in the soil profile after harvest was generally below 40 kg N/ha and did not differ between treatments. In the area where N was placed, mineral N was depleted during the vegetation period.
At the experimental sites a single N application in the period between tillering and stem elongation was sufficient to achieve high yield and quality of winter wheat without increased risk of nitrate leaching. This finding was independent of the method of application or the type of fertilizer.
Intestinal serotonin (5-hydroxytrypamine, 5-HT) metabolism is thought to play a role in gut functions by regulating motility, permeability and other functions of the intestine. In the present study, we investigated the effect of tryptophan (TRP), the precursor of 5-HT, supplementation on intestinal barrier functions and non-alcoholic fatty liver disease (NAFLD). An established mouse model of NAFLD induced by feeding a fructose-rich diet (N group) was used in the present study. TRP was administered orally for 8 weeks to C57BL/6J control or NAFLD mice. NAFLD-related liver parameters (hepatic TAG and Oil Red O staining), intestinal barrier parameters (tight-junction protein occludin and portal plasma lipopolysaccharides (LPS)) and 5-HT-related parameters (5-HT, 5-HT transporter (SERT) and motility) were measured. We observed reduced duodenal occludin protein concentrations (P= 0·0007), high portal plasma LPS concentrations (P= 0·005) and an elevated liver weight:body weight ratio (P= 0·01) in the N group compared with the parameters in the control group. TRP supplementation led to an increase in occludin concentrations (P= 0·0009) and consecutively reduced liver weight:body weight ratio (P= 0·009) as well as overall hepatic fat accumulation in the N group (P= 0·05). In addition, the N group exhibited reduced SERT protein expression (P= 0·002), which was normalised by TRP supplementation (P= 0·02). For the first time, our data indicate that oral TRP supplementation attenuates experimental NAFLD in mice. The underlying mechanisms are not clear, but probably involve stabilisation of the intestinal barrier in the upper small intestine and amelioration of the dysregulated intestinal serotonergic system.
Multi-slice computed tomography (MSCT) has proven in
several studies to have a high diagnostic accuracy for the detection
or exclusion of coronary artery disease. A major concern with coronary
MSCT, however, is the associated radiation exposure of patients.
Recent studies suggest that use of a 64-slice scanner is associated
with a non-negligible lifetime attributable risk of cancer. Several
strategies can be used to reduce patient exposure in coronary MSCT.
The purpose of this multicenter study was to investigate the effects
of the adjustment of tube voltage and current on radiation dose
and image interpretability. MSCT with retrospective ECG gating was performed
in 315 patients. The dose-length product (DLP) in the patients enrolled
with the dose reduction protocol resulted in a 36% overall reduction
in the mean radiation dose (911 ± 289 mGy.cm) compared with the
standard protocol (1427 ± 226 mGy.cm, p < 0.001).
Nevertheless, image interpretability was maintained. This study
on coronary MSCT demonstrates that the radiation dose can be significantly reduced
by parameter optimization, with maintained image interpretability.
The lattice reconstructed bec Ni (001) in Fe/Ni (001) ultrathin layers allows one to engineer films in which the in-plane 4-fold anisotropies and coercive fields can be varied and adjusted according to specific requirements. Magnetization reversals have been studied in layered structures of Fe/Ag/Fe/Ni (001). For Ag (001) interlayers thicker than 13 ML Magnetization reversal can proceed in two steps. In these samples the minor loops switch the magnetization of the Fe (001) layer from the parallel to the antiparallel configurations with respect to the magnetic moment of the Fe/Ni film. Such Minor loops exhibit a rectangular behavior with switching fields of 15–25 Oe. The lattice transformed Fe/Ni layers could be useful in spin-valve structures.
Dispersions of carbon nanotube polymer composites were characterized by Raman mapping.Single-walled nanotubes (SWNTs), double-walled nanotubes (DWNTs), multi-walled nanotubes (MWNTs), and XD-grade carbon nanotubes (XD-CNTs) were dispersed in a vinyl ester (VE) resin using an ultrasonic probe at a fixed frequency. SWNTs were functionalized with succinic acid peroxide (SAP) to enhance dispersion. Increasing ultrasonication energy was found to improve the distribution of carbon nanotubes (CNTs) and decrease the size of ropes, whereas excessive amounts of energy were found to result in damage. The quality of dispersion was verified through optical microscopy and scanning electron microscopy (SEM).
Treating cancer patients with metastatic disease remains an ultimate challenge in
clinical oncology. Because invasive cancer precludes or limits the use of surgery,
metastatic setting is often associated with (poor) survival, rather than sustained
remission, in patients with common cancers like lung, digestive or breast carcinomas.
Mathematical modeling may help us better identify non detectable metastatic status to in
turn optimize treatment for patients with metastatic disease. In this paper we present a
family of models for the metastatic growth. They are based on four principles : to be as
simple as possible, involving the least possible number of parameters, the main
informations are obtained from the primary tumor and being able to recover the variety of
phenomena observed by the clinicians. Several simulations of therapeutic strategies are
presented illustrating possible applications of modeling to the clinic.
Low-grade inflammation is a characteristic of the obese state, and adipose tissue releases many inflammatory mediators. The source of these mediators within adipose tissue is not clear, but infiltrating macrophages seem to be especially important, although adipocytes themselves play a role. Obese people have higher circulating concentrations of many inflammatory markers than lean people do, and these are believed to play a role in causing insulin resistance and other metabolic disturbances. Blood concentrations of inflammatory markers are lowered following weight loss. In the hours following the consumption of a meal, there is an elevation in the concentrations of inflammatory mediators in the bloodstream, which is exaggerated in obese subjects and in type 2 diabetics. Both high-glucose and high-fat meals may induce postprandial inflammation, and this is exaggerated by a high meal content of advanced glycation end products (AGE) and partly ablated by inclusion of certain antioxidants or antioxidant-containing foods within the meal. Healthy eating patterns are associated with lower circulating concentrations of inflammatory markers. Among the components of a healthy diet, whole grains, vegetables and fruits, and fish are all associated with lower inflammation. AGE are associated with enhanced oxidative stress and inflammation. SFA and trans-MUFA are pro-inflammatory, while PUFA, especially long-chain n-3 PUFA, are anti-inflammatory. Hyperglycaemia induces both postprandial and chronic low-grade inflammation. Vitamin C, vitamin E and carotenoids decrease the circulating concentrations of inflammatory markers. Potential mechanisms are described and research gaps, which limit our understanding of the interaction between diet and postprandial and chronic low-grade inflammation, are identified.