Hábitos alimentarios de la raya de cola corta, Bathyraja brachyurops (Chondrichthyes, Rajidae), en el Atlántico Sudoccidental

Food habits of Bathyraja brachyurops were studied based on stomach content analyses of 346 specimens collected from research cruises carried out from 2003 to 2005 on the Argentinean continental shelf (36ºS-55ºS). A total of 265 stomachs (76.6%) contained food, and thirty-five taxonomic levels of prey were identified. The most important prey were fishes followed by isopods. Trophic level analysis revealed that B. brachyurops is a tertiary consumer throughout its life history. There were no differences between sexes and regions in the diet composition, but dietary shifts with ontogeny were found. The Levins’ standardized index indicated wider niche breadth for small skates, whereas larger skate specimens showed a narrow niche breadth with a specialization in fishes.Se estudiaron los hábitos alimentarios de Bathyraja brachyurops en base al análisis de los contenidos estomacales de 346 ejemplares capturados en campañas de investigación realizadas durante el periodo 2003-2005 sobre la plataforma continental Argentina (36ºS-55ºS). Un total de 265 estómagos (76.6%) contenían alimento en los cuales se identificaron treinta y cinco ítems presa. Las presas más importantes fueron los peces, seguidos por los isópodos, ubicando a B. brachyurops como un consumidor terciario a lo largo de toda su historia de vida. No se hallaron diferencias en la composición de la dieta entre sexos y regiones, sin embargo se apreciaron cambios ontogenéticos en la alimentación. El índice de Levins’ estandarizado indicó una mayor amplitud de nicho para las rayas de menor tamaño, mientras que los ejemplares de mayor tamaño mostraron una menor amplitud de nicho trófico y una especialización ictiófaga

Non-Pharmacological Treatments

In clinical psychiatry, we dispose of different non-pharmacological approaches, such as somatic treatments, chronobiological treatments, cognitive remediation, and psychotherapy. Somatic treatments include transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS), and electroconvulsive therapy (ECT). These techniques, which exert their function through the modulation of cortical excitability, find an application in many psychiatric disorders, but mainly in resistant depression. Chronotherapies, a group of non-pharmacological therapeutic approaches to mood disorder treatment, are rooted in the hypothesis of chronobiology aetiopathogenesis of psychiatric disorders (mainly mood disorders). Chrono-biological treatments include light therapy (LT), sleep deprivation (SD), and dark therapy (DT). While LT and SD are mainly used in depression, DT finds a clinical application in mania. Cognitive remediation (CR) is a set of interventions based on behavioural training whose goal is to enhance neurocognitive abilities. This technique finds its main application in schizophrenia. Psychotherapy approaches have a proved effectiveness for the treatment of various psychiatric conditions when combined to psychopharmacological treatment. The two main approaches are cognitive-behavioural therapy and psychodynamic therapy

A comparative analysis of predictive models of morbidity in intensive care unit after cardiac surgery – Part II: an illustrative example

<p>Abstract</p> <p>Background</p> <p>Popular predictive models for estimating morbidity probability after heart surgery are compared critically in a unitary framework. The study is divided into two parts. In the first part modelling techniques and intrinsic strengths and weaknesses of different approaches were discussed from a theoretical point of view. In this second part the performances of the same models are evaluated in an illustrative example.</p> <p>Methods</p> <p>Eight models were developed: Bayes linear and quadratic models, <it>k</it>-nearest neighbour model, logistic regression model, Higgins and direct scoring systems and two feed-forward artificial neural networks with one and two layers. Cardiovascular, respiratory, neurological, renal, infectious and hemorrhagic complications were defined as morbidity. Training and testing sets each of 545 cases were used. The optimal set of predictors was chosen among a collection of 78 preoperative, intraoperative and postoperative variables by a stepwise procedure. Discrimination and calibration were evaluated by the area under the receiver operating characteristic curve and Hosmer-Lemeshow goodness-of-fit test, respectively.</p> <p>Results</p> <p>Scoring systems and the logistic regression model required the largest set of predictors, while Bayesian and <it>k</it>-nearest neighbour models were much more parsimonious. In testing data, all models showed acceptable discrimination capacities, however the Bayes quadratic model, using only three predictors, provided the best performance. All models showed satisfactory generalization ability: again the Bayes quadratic model exhibited the best generalization, while artificial neural networks and scoring systems gave the worst results. Finally, poor calibration was obtained when using scoring systems, <it>k</it>-nearest neighbour model and artificial neural networks, while Bayes (after recalibration) and logistic regression models gave adequate results.</p> <p>Conclusion</p> <p>Although all the predictive models showed acceptable discrimination performance in the example considered, the Bayes and logistic regression models seemed better than the others, because they also had good generalization and calibration. The Bayes quadratic model seemed to be a convincing alternative to the much more usual Bayes linear and logistic regression models. It showed its capacity to identify a minimum core of predictors generally recognized as essential to pragmatically evaluate the risk of developing morbidity after heart surgery.</p

The influence of the dechanneling process on the photon emission by an ultra-relativistc positron channeling in a periodically bent crystal

We investigate, both analytically and numerically, the influence of the dechanneling process on the parameters of undulator radiation generated by ultra-relativistic positron channelling along a crystal plane, which is periodically bent. The bending might be due either to the propagation of a transverse acoustic wave through the crystal, or due to the static strain as it occurs in superlattices. In either case the periodically bent crystal serves as an undulator which allows to generate X-ray and gamma-radiation. We propose the scheme for accurate quantitative treatment of the radiation in presence of the dechanneling. The scheme includes (i) the analytic expression for spectral-angular distribution which contains, as a parameter, the dechanneling length, (ii) the simulation procedure of the dechanneling process of a positron in periodically bent crystals. Using these we calculate the dechanneling lengths of 5 GeV positrons channeling in Si, Ge and W crystals, and the spectral-angular and spectral distributions of the undulator over broad ranges of the photons. The calculations are performed for various parameters of the channel bending.Comment: published in J. Phys. G: Nucl. Part. Phys. 27 (2001) 95-125, http://www.iop.or

A bootstrap approach for assessing the uncertainty of outcome probabilities when using a scoring system

Background: Scoring systems are a very attractive family of clinical predictive models, because the patient score can be calculated without using any data processing system. Their weakness lies in the difficulty of associating a reliable prognostic probability with each score. In this study a bootstrap approach for estimating confidence intervals of outcome probabilities is described and applied to design and optimize the performance of a scoring system for morbidity in intensive care units after heart surgery. Methods: The bias-corrected and accelerated bootstrap method was used to estimate the 95% confidence intervals of outcome probabilities associated with a scoring system. These confidence intervals were calculated for each score and each step of the scoring-system design by means of one thousand bootstrapped samples. 1090 consecutive adult patients who underwent coronary artery bypass graft were assigned at random to two groups of equal size, so as to define random training and testing sets with equal percentage morbidities. A collection of 78 preoperative, intraoperative and postoperative variables were considered as likely morbidity predictors. Results: Several competing scoring systems were compared on the basis of discrimination, generalization and uncertainty associated with the prognostic probabilities. The results showed that confidence intervals corresponding to different scores often overlapped, making it convenient to unite and thus reduce the score classes. After uniting two adjacent classes, a model with six score groups not only gave a satisfactory trade-off between discrimination and generalization, but also enabled patients to be allocated to classes, most of which were characterized by well separated confidence intervals of prognostic probabilities. Conclusions: Scoring systems are often designed solely on the basis of discrimination and generalization characteristics, to the detriment of prediction of a trustworthy outcome probability. The present example demonstrates that using a bootstrap method for the estimation of outcome-probability confidence intervals provides useful additional information about score-class statistics, guiding physicians towards the most convenient model for predicting morbidity outcomes in their clinical context

Posttranscriptional regulation of angiotensin II type 1 receptor expression by glyceraldehyde 3-phosphate dehydrogenase

Regulation of angiotensin II type 1 receptor (AT1R) has a pathophysiological role in hypertension, atherosclerosis and heart failure. We started from an observation that the 3′-untranslated region (3′-UTR) of AT1R mRNA suppressed AT1R translation. Using affinity purification for the separation of 3′-UTR-binding proteins and mass spectrometry for their identification, we describe glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as an AT1R 3′-UTR-binding protein. RNA electrophoretic mobility shift analysis with purified GAPDH further demonstrated a direct interaction with the 3′-UTR while GAPDH immunoprecipitation confirmed this interaction with endogenous AT1R mRNA. GAPDH-binding site was mapped to 1–100 of 3′-UTR. GAPDH-bound target mRNAs were identified by expression array hybridization. Analysis of secondary structures shared among GAPDH targets led to the identification of a RNA motif rich in adenines and uracils. Silencing of GAPDH increased the expression of both endogenous and transfected AT1R. Similarly, a decrease in GAPDH expression by H2O2 led to an increased level of AT1R expression. Consistent with GAPDH having a central role in H2O2-mediated AT1R regulation, both the deletion of GAPDH-binding site and GAPDH overexpression attenuated the effect of H2O2 on AT1R mRNA. Taken together, GAPDH is a translational suppressor of AT1R and mediates the effect of H2O2 on AT1R mRNA

A comparative analysis of predictive models of morbidity in intensive care unit after cardiac surgery – Part I: model planning

<p>Abstract</p> <p>Background</p> <p>Different methods have recently been proposed for predicting morbidity in intensive care units (ICU). The aim of the present study was to critically review a number of approaches for developing models capable of estimating the probability of morbidity in ICU after heart surgery. The study is divided into two parts. In this first part, popular models used to estimate the probability of class membership are grouped into distinct categories according to their underlying mathematical principles. Modelling techniques and intrinsic strengths and weaknesses of each model are analysed and discussed from a theoretical point of view, in consideration of clinical applications.</p> <p>Methods</p> <p>Models based on Bayes rule, <it>k-</it>nearest neighbour algorithm, logistic regression, scoring systems and artificial neural networks are investigated. Key issues for model design are described. The mathematical treatment of some aspects of model structure is also included for readers interested in developing models, though a full understanding of mathematical relationships is not necessary if the reader is only interested in perceiving the practical meaning of model assumptions, weaknesses and strengths from a user point of view.</p> <p>Results</p> <p>Scoring systems are very attractive due to their simplicity of use, although this may undermine their predictive capacity. Logistic regression models are trustworthy tools, although they suffer from the principal limitations of most regression procedures. Bayesian models seem to be a good compromise between complexity and predictive performance, but model recalibration is generally necessary. <it>k</it>-nearest neighbour may be a valid non parametric technique, though computational cost and the need for large data storage are major weaknesses of this approach. Artificial neural networks have intrinsic advantages with respect to common statistical models, though the training process may be problematical.</p> <p>Conclusion</p> <p>Knowledge of model assumptions and the theoretical strengths and weaknesses of different approaches are fundamental for designing models for estimating the probability of morbidity after heart surgery. However, a rational choice also requires evaluation and comparison of actual performances of locally-developed competitive models in the clinical scenario to obtain satisfactory agreement between local needs and model response. In the second part of this study the above predictive models will therefore be tested on real data acquired in a specialized ICU.</p

Alpine ethnobotany in Italy: traditional knowledge of gastronomic and medicinal plants among the Occitans of the upper Varaita valley, Piedmont

A gastronomic and medical ethnobotanical study was conducted among the Occitan communities living in Blins/Bellino and Chianale, in the upper Val Varaita, in the Piedmontese Alps, North-Western Italy, and the traditional uses of 88 botanical taxa were recorded. Comparisons with and analysis of other ethnobotanical studies previously carried out in other Piemontese and surrounding areas, show that approximately one fourth of the botanical taxa quoted in this survey are also known in other surrounding Occitan valleys. It is also evident that traditional knowledge in the Varaita valley has been heavily eroded. This study also examined the local legal framework for the gathering of botanical taxa, and the potential utilization of the most quoted medicinal and food wild herbs in the local market, and suggests that the continuing widespread local collection from the wild of the aerial parts of Alpine wormwood for preparing liqueurs (Artemisia genipi, A. glacialis, and A. umbelliformis) should be seriously reconsidered in terms of sustainability, given the limited availability of these species, even though their collection is culturally salient in the entire study area

Response to Therapeutic Sleep Deprivation: A Naturalistic Study of Clinical and Genetic Factors and Post-treatment Depressive Symptom Trajectory

Research has shown that therapeutic sleep deprivation (SD) has rapid antidepressant effects in the majority of depressed patients. Investigation of factors preceding and accompanying these effects may facilitate the identification of the underlying biological mechanisms. This exploratory study aimed to examine clinical and genetic factors predicting response to SD and determine the impact of SD on illness course. Mood during SD was also assessed via visual analogue scale. Depressed inpatients (n = 78) and healthy controls (n = 15) underwent ~36 h of SD. Response to SD was defined as a score of ≤ 2 on the Clinical Global Impression Scale for Global Improvement. Depressive symptom trajectories were evaluated for up to a month using self/expert ratings. Impact of genetic burden was calculated using polygenic risk scores for major depressive disorder. In total, 72% of patients responded to SD. Responders and non-responders did not differ in baseline self/expert depression symptom ratings, but mood differed. Response was associated with lower age (p = 0.007) and later age at life-time disease onset (p = 0.003). Higher genetic burden of depression was observed in non-responders than healthy controls. Up to a month post SD, depressive symptoms decreased in both patients groups, but more in responders, in whom effects were sustained. The present findings suggest that re-examining SD with a greater focus on biological mechanisms will lead to better understanding of mechanisms of depression