Complete mapping of the spin-wave spectrum in vortex state nano-disk

We report a study on the complete spin-wave spectrum inside a vortex state nano-disk. Transformation of this spectrum is continuously monitored as the nano-disk becomes gradually magnetized by a perpendicular magnetic field and encouters a second order phase transition to the uniformly magnetized state. This reveals the bijective relationship that exists between the eigen-modes in the vortex state with the ones in the saturated state. It is found that the gyrotropic mode can be continuously viewed as a uniform phase precession, which uniquely softens (its frequency vanishes) at the saturation field to transform above into the Kittel mode. By contrast the other spin-wave modes remain finite as a function of the applied field while their character is altered by level anti-crossing

Postoperative delirium is a risk factor of institutionalization after hip fracture: an observational cohort study

IntroductionHip fracture is a common clinical problem in geriatric patients often associated with poor postoperative outcomes. Postoperative delirium (POD) and postoperative neurocognitive disorders (NCDs) are particularly frequent. The consequences of these disorders on postoperative recovery and autonomy are not fully described. The aim of this study was to determine the role of POD and NCDs on the need for institutionalization at 3 months after hip fracture surgery.MethodA population-based prospective cohort study was conducted on hip fracture patients between March 2016 and March 2018. The baseline interview, which included a Mini-Mental State Examination (MMSE), was conducted in the hospital after admission for hip fracture. NCDs were appreciated by MMSE scoring evolution (difference between preoperative MMSE and MMSE at day 5 >2 points). POD was evaluated using the Confusion Assessment Method. The primary endpoint was the rate of new institutionalization at 3 months. We used a multivariate analysis to assess the risk of new institutionalization.ResultsA total of 63 patients were included. Thirteen patients (20.6%) were newly institutionalized at 3 months. Two factors were significantly associated with the risk of postoperative institutionalization at 3 months: POD (OR = 5.23; 95% CI 1.1–27.04; p = 0.04) and IADL evolution (OR = 1.8; 95% CI 1.23–2.74; p = 0.003).ConclusionOnly POD but not NCDs was associated with the risk of dependency and institutionalization after hip fracture surgery. The prevention of POD appears to be essential for improving patient outcomes and optimizing the potential for returning home

Effect of prolonged treatment with tyramine on glucose tolerance in streptozotocin-induced diabetic rats

The biogenic amine tyramine has been reported to stimulatein vitro glucose transport in adipocytes, cardiomyocytes and skeletal muscle, and to improvein vivo glucose utilization in rats. These effects were dependent on amine oxidation, since they were blocked by inhibitors of monoamine oxidase (MAO) and semicarbazide-sensitive amine oxidase (SSAO). We thus tested in this work whether a prolonged treatment with tyramine could improve glucose tolerance in streptozotocin-induced diabetic rats. First, tyramine content of standard rodent chow was determined by HPLC and daily tyramine intake of control rats was estimated to be around 26 μmol/kg body weight. Then, tyramine was administred during 3 weeks in streptozotocin-induced diabetic rats at 29 μmol/kg by daily i.p. injection alone or together with vanadate 0.02 μmol/kg. In another group of diabetic rats, tyramine was subcutaneously delivered at 116 μmol/kg/day by osmotic minipumps. All tyramine treatments resulted in a decrease of the hyperglycemic responses to an i.p. glucose load. Adipocytes isolated from either untreated or treated diabetic rats were sensitive to the stimulation of glucose uptake by tyramine. However, diabetic animals receiving tyramine for three weeks did not recover from their hyperglycemia, hypoinsulinemia and glucosuria. These results show that the improvement of glucose tolerance induced by prolonged tyramine administration occurs in an insulin-depleted model and probably results from peripheral insulin-like actions of the oxidation of MAO/SSAO substrates, such as the stimulation of glucose uptake into adipocytes

The Gut Microbiota Regulates Intestinal CD4 T Cells Expressing RORγt and Controls Metabolic Disease

SummaryA high-fat diet (HFD) induces metabolic disease and low-grade metabolic inflammation in response to changes in the intestinal microbiota through as-yet-unknown mechanisms. Here, we show that a HFD-derived ileum microbiota is responsible for a decrease in Th17 cells of the lamina propria in axenic colonized mice. The HFD also changed the expression profiles of intestinal antigen-presenting cells and their ability to generate Th17 cells in vitro. Consistent with these data, the metabolic phenotype was mimicked in RORγt-deficient mice, which lack IL17 and IL22 function, and in the adoptive transfer experiment of T cells from RORγt-deficient mice into Rag1-deficient mice. We conclude that the microbiota of the ileum regulates Th17 cell homeostasis in the small intestine and determines the outcome of metabolic disease

Importance of pre-analytical steps for transcriptome and RT-qPCR analyses in the context of the phase II randomised multicentre trial REMAGUS02 of neoadjuvant chemotherapy in breast cancer patients

<p>Abstract</p> <p>Background</p> <p>Identification of predictive markers of response to treatment is a major objective in breast cancer. A major problem in clinical sampling is the variability of RNA templates, requiring accurate management of tumour material and subsequent analyses for future translation in clinical practice. Our aim was to establish the feasibility and reliability of high throughput RNA analysis in a prospective trial.</p> <p>Methods</p> <p>This study was conducted on RNA from initial biopsies, in a prospective trial of neoadjuvant chemotherapy in 327 patients with inoperable breast cancer. Four independent centres included patients and samples. Human U133 GeneChips plus 2.0 arrays for transcriptome analysis and quantitative RT-qPCR of 45 target genes and 6 reference genes were analysed on total RNA.</p> <p>Results</p> <p>Thirty seven samples were excluded because <it>i) </it>they contained less than 30% malignant cells, or <it>ii) </it>they provided RNA Integrity Number (RIN) of poor quality. Among the 290 remaining cases, taking into account strict quality control criteria initially defined to ensure good quality of sampling, 78% and 82% samples were eligible for transcriptome and RT-qPCR analyses, respectively. For RT-qPCR, efficiency was corrected by using standard curves for each gene and each plate. It was greater than 90% for all genes. Clustering analysis highlighted relevant breast cancer phenotypes for both techniques (ER+, PR+, HER2+, triple negative). Interestingly, clustering on trancriptome data also demonstrated a "centre effect", probably due to the sampling or extraction methods used in on of the centres. Conversely, the calibration of RT-qPCR analysis led to the centre effect withdrawing, allowing multicentre analysis of gene transcripts with high accuracy.</p> <p>Conclusions</p> <p>Our data showed that strict quality criteria for RNA integrity assessment and well calibrated and standardized RT-qPCR allows multicentre analysis of genes transcripts with high accuracy in the clinical context. More stringent criteria are needed for transcriptome analysis for clinical applications.</p

Supply chain management by means of FLM-rules

International audienc

Multicomponent magnetization in paleomagnetic records of reversals from continental sediments in Bolivia

A paleomagnetic study of geomagnetic reversals has been attempted from three continental sections of the altiplano in Bolivia. The first section (Viscachani) shows a unique polarity interval with a magnetization carried by magnetite. In the two other sections (Achocalla and Irpavi) the magnetization is characterized by a complex magnetic mineralogy dominated by magnetic sulphides (mostly pyrrhotite) and magnetite. Thermal demagnetization performed under vacuum was found to be much more efficient than in air in isolating the directions of remanence carried by a low temperature (LT) component due to sulphides and a high temperature (HT) component due to magnetite. The directions of magnetization carried by the two minerals have been compared, with particular attention being paid to records of geomagnetic reversals. At Achocalla, the same polarity pattern is revealed by both components. However, the transitional directions of the LT component are located about 50 cm below the abrupt polarity change recorded by magnetite. Such observations are very similar to those from a recent study of Pliocene marine marl~ in Sicily [1]. These characteristics are compatible with the results of a simulation which assumed that a very early acquisition of the remanence was carried by the LT component and that a post-depositional reorientation of the magnetite occurred. In the last section (Irpavi), the observed LT and HT components have opposite polarities. Although the magnetic parameters indicate the presence of sulphides, we cannot rule out the hypothesis that the LT component has a secondary origin due to coarse magnetite grains. If we assume that the hypothesis of sulphides is correct, this observation emphasizes the difficulties in establishing the origin of sulphide minerals

When and why sediments fail to record the geomagnetic field during polarity reversals

We present four new records of the Matuyama–Brunhes (M–B) reversal from sediments of the Equatorial Indian Ocean, West Equatorial Pacific and North Atlantic Oceans with deposition rates between 2 cm/kyr and 4.5 cm/kyr. The magnetic measurements were performed using 8 cc cubic samples and provided well-defined reverse and normal polarity directions prior and after the last reversal. In three records stepwise demagnetization of the transitional samples revealed a succession of scattered directions instead of a well-defined characteristic component of magnetization. There is no relationship with changes in magnetic mineralogy, magnetic concentration and magnetic grain sizes. This behavior could be caused by weakly magnetized sediment. However the transitional samples of two cores have almost three orders of magnitude stronger magnetizations than the non-transitional samples that yielded unambiguous primary directions in the other two cores. Moreover a similar proportion of magnetic grains was aligned in all records. Therefore, the large amount of magnetic grains oriented by the weak transitional field did not contribute to improve the definition of the characteristic component. We infer that the weakness of the field might not be only responsible. Assuming that the transitional period is dominated by a multipolar field, it is likely that the rapidly moving non-dipole components generated different directions that were recorded over the 2 cm stratigraphic thickness of each sample. These components are carried by grains with similar magnetic properties yielding scattered directions during demagnetization. In contrast, the strongly magnetized sediments of the fourth core from the West Equatorial Pacific Ocean were exempt of problems during demagnetization. The declinations rotate smoothly between the two polarities while the inclinations remain close to zero. This scenario results from post-depositional realignment that integrated various amounts of pre- and post-transitional magnetic directions within each sample. The present results point out the impossibility of extracting reliable information on geomagnetic reversals from low-medium deposition rate sediments with the current sampling techniques. Among other features, they put in question the relationship between reversal duration and site latitude

Coherent-stable scatterers detection in SAR multi-interferograms: feature fuzzy fusion in Alpine glacier geophysical context

International audienceSAR interferometry (InSAR) performs two acquisitions (spatially separated by the baseline) of the signal back-scattered by the resolution cell which contains height and/or displacement information. Repeat pass spaceborne interferometry provides multi-interferograms which can be used to extract such information either by combining the multi-temporal results of conventional interferometry or by a different approach based on specific targets: the coherent stable scatterers (CSS). In this paper a two-step approach is proposed to obtain specific features from multi-temporal InSAR data sets. The first step consists in extracting image attributes related to the useful information. The second step consists in merging the attributes using an interactive fuzzy fusion technique. The interactive fuzzy fusion is proposed to provide end-users with a simple and easily understandable tool for tuning the detection results. The method is applied on a data set of five co-registered ERS 1/2 tandems from the French Alps (the Mont-Blanc region), including two temperate glaciers: the Argenti'ere and the Mer-de-glace. The results illustrate how the end-user can combine the proposed attributes to detect the presence of CSS or distributed stable scatterers usefull for multi-temporal analysis

Cosmogenic 10Be production records reveal dynamics of geomagnetic dipole moment (GDM) over the Laschamp excursion (20-60 ka)

International audienceDocumenting accurately amplitude and rhythms of geomagnetic variations is a prerequisite to understand the mechanisms triggering geomagnetic excursions and reversals. We present new authigenic 10Be/9Be ratio (Be ratio) results covering the 60-20 ka time interval from equatorial core MD05-2920. The most significant Be ratio peak is located 18 cm above the main relative paleointensity (RPI) minimum recorded in this sequence. These are interpreted as two independent recordings of the geomagnetic dipole moment (GDM) decrease linked to the Laschamp excursion dated at ca 41 ka. The stratigraphic offset is assignable to post-depositional magnetization lock-in processes resulting in time delay of 1.6 ka. The Be ratio and RPI records show comparable asymmetric behavior before and after the dipole low. The Be ratio record is combined with three other series to construct a global record of 10Be paleoproduction variations. This compilation demonstrates the strong coherence of low and mid latitudes data sets and its comparison with 10Be-flux records from polar regions fully supports the hypothesis of a global atmospheric 10Be production doubling during the Laschamp. The Be ratio stack is converted in terms of GDM using both a theoretical model and a reconstruction of GDM values using absolute paleointensities measured on lava flows. Both methods provide similar results. The dipole moment record derived from this approach (BeDM 20-60) shows the following characteristics: high field values (> 11 × 1022 Am2) prior to a sharp two-steps dipole decrease until reaching minimum values (1.8 ± 0.7 × 1022 Am2) between 41.6 and 40.9 ka at the time of the Laschamp excursion. The GDM partly recovers up to values of ∼ 6.3 × 1022 Am2 , and oscillates in this range, without showing any sharp decreases that could be associated with excursions reported within the 38-20 ka time interval (e.g. the Mono Lake excursion)