Prise alimentaire: pas uniquement une question de volonté [Food intake: not only a question of will!]

During many years, we thought that food intake was only a question of will. Nevertheless, in the second part on the XXth century, we identified several hormones regulating food intake and energy expenditure. Furthermore, these hormones seem to be implicated in the pathogenesis of obesity and in weight loss following bariatric surgery. This short review highlights the main mechanisms implicated in food intake and energy expenditure and also their implication in obesity and bariatric surgery.

Considering a Living Will

A living will is a written declaration informing medical personnel whether certain life-sustaining procedures should be withheld or withdrawn if (1) you are in a terminal condition; and (2) you are unable to decide for yourself. You (the declarant) may execute a living will declaration as a stand-alone document or you may include a living will within a health care power of attorney document. A living will can be revoked at any time and in any way by communicating the revocation to anyone who was aware that the living will existed.

Automated segmentation of multiple red blood cells with digital holographic microscopy.

We present a method to automatically segment red blood cells (RBCs) visualized by digital holographic microscopy (DHM), which is based on the marker-controlled watershed algorithm. Quantitative phase images of RBCs can be obtained by using off-axis DHM along to provide some important information about each RBC, including size, shape, volume, hemoglobin content, etc. The most important process of segmentation based on marker-controlled watershed is to perform an accurate localization of internal and external markers. Here, we first obtain the binary image via Otsu algorithm. Then, we apply morphological operations to the binary image to get the internal markers. We then apply the distance transform algorithm combined with the watershed algorithm to generate external markers based on internal markers. Finally, combining the internal and external markers, we modify the original gradient image and apply the watershed algorithm. By appropriately identifying the internal and external markers, the problems of oversegmentation and undersegmentation are avoided. Furthermore, the internal and external parts of the RBCs phase image can also be segmented by using the marker-controlled watershed combined with our method, which can identify the internal and external markers appropriately. Our experimental results show that the proposed method achieves good performance in terms of segmenting RBCs and could thus be helpful when combined with an automated classification of RBCs.

Compliance with preoperative oral nutritional supplements in patients at nutritional risk─only a question of will?

BACKGROUND/OBJECTIVES: Preoperative nutrition has been shown to reduce morbidity after major gastrointestinal (GI) surgery in selected patients at risk. In a randomized trial performed recently (NCT00512213), almost half of the patients, however, did not consume the recommended dose of nutritional intervention. The present study aimed to identify the risk factors for noncompliance. SUBJECTS/METHODS: Demographic (n=5) and nutritional (n=21) parameters for this retrospective analysis were obtained from a prospectively maintained database. The outcome of interest was compliance with the allocated intervention (ingestion of ⩾11/15 preoperative oral nutritional supplement units). Uni- and multivariate analyses of potential risk factors for noncompliance were performed. RESULTS: The final analysis included 141 patients with complete data sets for the purpose of the study. Fifty-nine patients (42%) were considered noncompliant. Univariate analysis identified low C-reactive protein levels (P=0.015), decreased recent food intake (P=0.032) and, as a trend, low hemoglobin (P=0.065) and low pre-albumin (P=0.056) levels as risk factors for decreased compliance. However, none of them was retained as an independent risk factor after multivariate analysis. Interestingly, 17 potential explanatory parameters, such as upper GI cancer, weight loss, reduced appetite or co-morbidities, did not show any significant correlation with reduced intake of nutritional supplements. CONCLUSIONS: Reduced compliance with preoperative nutritional interventions remains a major issue because the expected benefit depends on the actual intake. Seemingly, obvious reasons could not be retained as valid explanations. Compliance seems thus to be primarily a question of will and information; the importance of nutritional supplementation needs to be emphasized by specific patients' education.

Phenomenological models of holographic superconductors and hall currents

We study general models of holographic superconductivity parametrized by four arbitrary functions of a neutral scalar field of the bulk theory. The models can accommodate several features of real superconductors, like arbitrary critical temperatures and critical exponents in a certain range, and perhaps impurities or boundary or thickness effects. We find analytical expressions for the critical exponents of the general model and show that they satisfy the Rushbrooke identity. An important subclass of models exhibit second order phase transitions. A study of the specific heat shows that general models can also describe holographic superconductors undergoing first, second and third (or higher) order phase transitions. We discuss how small deformations of the HHH model can lead to the appearance of resonance peaks in the conductivity, which increase in number and become narrower as the temperature is gradually decreased, without the need for tuning mass of the scalar to be close to the Breitenlohner-Freedman bound. Finally, we investigate the inclusion of a generalized ¿theta term¿ producing Hall effect without magnetic field.

Holographic isotropization linearized

The holographic isotropization of a highly anisotropic, homogeneous, strongly coupled, non-Abelian plasma was simplified in ref. [1] by linearizing Einstein"s equations around the final, equilibrium state. This approximation reproduces the expectation value of the boundary stress tensor with a 20% accuracy. Here we elaborate on these results and extend them to observables that are directly sensitive to the bulk interior, focusing for simplicity on the entropy production on the event horizon. We also consider next-to-leading-order corrections and show that the leading terms alone provide a better description of the isotropization process for the states that are furthest from equilibrium.

From Full stopping to transparency in a holographic model of heavy ion collisions

We numerically simulate planar shock wave collisions in anti-de Sitter space as a model for heavy ion collisions of large nuclei. We uncover a crossover between two different dynamical regimes as a function of the collision energy. At low energies the shocks first stop and then explode in a manner approximately described by hydrodynamics, in close similarity with the Landau model. At high energies the receding fragments move outwards at the speed of light, with a region of negative energy density and negative longitudinal pressure trailing behind them. The rapidity distribution of the energy density at late times around midrapidity is not approximately boost invariant but Gaussian, albeit with a width that increases with the collision energy.

Review of quantitative phase-digital holographic microscopy: promising novel imaging technique to resolve neuronal network activity and identify cellular biomarkers of psychiatric disorders.

Quantitative phase microscopy (QPM) has recently emerged as a new powerful quantitative imaging technique well suited to noninvasively explore a transparent specimen with a nanometric axial sensitivity. In this review, we expose the recent developments of quantitative phase-digital holographic microscopy (QP-DHM). Quantitative phase-digital holographic microscopy (QP-DHM) represents an important and efficient quantitative phase method to explore cell structure and dynamics. In a second part, the most relevant QPM applications in the field of cell biology are summarized. A particular emphasis is placed on the original biological information, which can be derived from the quantitative phase signal. In a third part, recent applications obtained, with QP-DHM in the field of cellular neuroscience, namely the possibility to optically resolve neuronal network activity and spine dynamics, are presented. Furthermore, potential applications of QPM related to psychiatry through the identification of new and original cell biomarkers that, when combined with a range of other biomarkers, could significantly contribute to the determination of high risk developmental trajectories for psychiatric disorders, are discussed.