Glomerular filtration rate: measure creatinine and height rather than cystatin C!

AIM: Inulin clearance (Cin) is the gold standard for assessing glomerular filtration rate (GFR). Other methods are based on the plasma creatinine concentration (Pcreat), creatinine clearance (Ccreat), the Haycock-Schwartz formula and the plasma concentration of cystatin C (PcysC), a 13 kDa basic protein produced at a constant rate by all nucleated cells. The present prospective study was thus designed to evaluate the reliability of PcysC as a marker of GFR in comparison with that of Pcreat, Ccreat and the Haycock-Schwartz formula, using Cin as the gold standard. METHODS: Ninety-nine children (51 m/48 f), with a median age of 8.3 y (1.0-17.9) were studied. Using a cut-off for Cin of 100 ml/min per 1.73 m2, 54 children (54.5%) had impaired GFR. Those with normal GFR were comparable for age, height, weight and body mass index. RESULTS: Logistic regression, ROC analysis and linear regression all showed that Ccreat was the best parameter to discriminate between impaired and normal GFR, followed by the Haycock-Schwartz formula, PcysC, and finally Pcreat, each one being significantly more predictive than the next. CONCLUSION: GFR is better assessed by the Haycock-Schwartz formula than by PcysC or Pcreat alone. It is therefore concluded that when urine collection is not possible, simply measuring the child's Pcreat and height is the best, easiest and cheapest way to assess GFR.

Parole, personnage et sujet dans les récits littéraires de Benjamin Constant

Même si Alison Fairlie, Tzvetan Todorov, Han Verhoeff et Simone Balayé ont reconnu l'importance de la parole dans les récits littéraires de Benjamin Constant (Amélie et Germaine, Cécile, Ma vie et Adolphe), dans leurs commentaires ces critiques ont surtout mis en évidence les échecs et les malentendus inhérents à toute communication verbale. Au-delà de ces constatations, il restait à montrer que les récits constantiens donnent à voir et à comprendre l'intérêt que cet écrivain nourrissait pour la parole, tout particulièrement pour la parole privée -celle qu'il a choisi de mettre en scène dans ces quatre oeuvres, qui acquièrent, grâce à cette spécificité, une manière d'unité. Cette parole intime, aux antipodes de la parole publique, s'offre comme un champ d'investigation illimité tant le locuteur est alors impliqué dans sa pratique verbale. Les introspections des narrateurs-personnages constantiens font naître la peinture d'un sujet moderne, fragilisé dans sa vie personnelle et peu engagé dans la vie sociale, mais elles offrent surtout un vaste panorama des situations d'interlocution et présentent en creux les nombreuses ressources de la parole. Ces récits, qui accordent une attention tout à fait signifiante à l'écriture de la parole, mais échappent parfois à toute classification générique, parviennent à mimer les incertitudes de leur narrateur-personnage tout en révélant que c'est par la parole, originale et singulière, que le sujet s'individualise expérience rendue souvent difficile à cause de la langue conventionnelle dont usent ceux que l'on rencontre dans les lieux de sociabilité, en ce XIXe siècle naissant.

Effect of feeding level during autumn and winter on breeding weight and result in single and pair-housed minks

Selostus: Syys- ja talviruokinnan vaikutus yksin ja pareittain kasvatettujen minkkien lisääntymistulokseen

Persuasion, binary choice, and the costs of dishonesty

We study the strategic interaction between a decision maker who needs to take a binary decision but is uncertain about relevant facts and an informed expert who can send a message to the decision maker but has a preference over the decision.We show that the probability that the expert can persuade the decision maker to take the expert's preferred decision is a hump-shaped function of his costs of sending dishonest messages.

Organic material decomposition and nutrient dynamics in a mulch system enriched with leguminous trees in the Amazon

The new techniques proposed for agriculture in the Amazon region include rotational fallow systems enriched with leguminous trees and the replacement of biomass burning by mulching. Decomposition and nutrient release from mulch were studied using fine-mesh litterbags with five different leguminous species and the natural fallow vegetation as control. Samples from each treatment were analyzed for total C, N, P, K, Ca, Mg, lignin, cellulose content and soluble polyphenol at different sampling times over the course of one year. The decomposition rate constant varied with species and time. Weight loss from the decomposed litter bag material after 96 days was 30.1 % for Acacia angustissima, 32.7 % for Sclerolobium paniculatum, 33.9 % for Iinga edulis and the Fallow vegetation, 45.2 % for Acacia mangium and 63.6 % for Clitoria racemosa. Immobilization of N and P was observed in all studied treatments. Nitrogen mineralization was negatively correlated with phenol, C-to-N ratio, lignin + phenol/N ratio, and phenol/phosphorus ratios and with N content in the litterbag material. After 362 days of field incubation, an average (of all treatments), 3.3 % K, 32.2 % Ca and 22.4 % Mg remained in the mulch. Results confirm that low quality and high amount of organic C as mulch application are limiting for the quantity of energy available for microorganisms and increase the nutrient immobilization for biomass decomposition, which results in competition for nutrients with the crop plants.

Prediction of difficult intubation with advanced face recognition techniques: a preliminary study

Introduction: Difficult tracheal intubation remains a constant and significant source of morbidity and mortality in anaesthetic practice. Insufficient airway assessment in the preoperative period continues to be a major cause of unanticipated difficult intubation. Although many risk factors have already been identified, preoperative airway evaluation is not always regarded as a standard procedure and the respective weight of each risk factor remains unclear. Moreover the predictive scores available are not sensitive, moderately specific and often operator-dependant. In order to improve the preoperative detection of patients at risk for difficult intubation, we developed a system for automated and objective evaluation of morphologic criteria of the face and neck using video recordings and advanced techniques borrowed from face recognition. Method and results: Frontal video sequences were recorded in 5 healthy volunteers. During the video recording, subjects were requested to perform maximal flexion-extension of the neck and to open wide the mouth with tongue pulled out. A robust and real-time face tracking system was then applied, allowing to automatically identify and map a grid of 55 control points on the face, which were tracked during head motion. These points located important features of the face, such as the eyebrows, the nose, the contours of the eyes and mouth, and the external contours, including the chin. Moreover, based on this face tracking, the orientation of the head could also be estimated at each frame of the video sequence. Thus, we could infer for each frame the pitch angle of the head pose (related to the vertical rotation of the head) and obtain the degree of head extension. Morphological criteria used in the most frequent cited predictive scores were also extracted, such as mouth opening, degree of visibility of the uvula or thyreo-mental distance. Discussion and conclusion: Preliminary results suggest the high feasibility of the technique. The next step will be the application of the same automated and objective evaluation to patients who will undergo tracheal intubation. The difficulties related to intubation will be then correlated to the biometric characteristics of the patients. The objective in mind is to analyze the biometrics data with artificial intelligence algorithms to build a highly sensitive and specific predictive test.

New insights on the crystalline forms in binary systems of n-alkanes: Characterization of the solid ordered phases in the phase diagram tricosane + pentacosane

X-ray diffraction analyses of the pure components n-tricosane and n-pentacosane and of their binary mixed samples have enabled us to characterize the crystalline phases observed at low temperature. On the contrary to what was announced in literature on the structural behavior of mixed samples in odd-odd binary systems with D n = 2, the three domains are not all orthorhombic. This work has enabled us to show that two of the domains are, in fact, monoclinic, (Aa, Z = 4) and the other one is orthorhombic (Pca21, Z = 4). The conclusions drawn in this work can be easily transposed to other binary systems of n-alkanes.

Increased body fat is independently and negatively related with cardiorespiratory fitness levels in children and adolescents with normal weight.

Body mass index (BMI) is related with cardiorespiratory fitness (CRF), but less is known regarding the combined relationships between BMI and body fat (BF) on CRF. Cross-sectional study included 2361 girls and 2328 boys aged 10–18 years living in the area of Lisbon, Portugal. BMI was calculated by measuring height and weight, and obesity was assessed by international criteria. BF was assessed by bioimpedance. CRF was assessed by the 20-m shuttle run and the participants were classified as normal-to-high or low-CRF level according to Fitness gram criterion-referenced standards. The prevalence of low CRF was 47 and 39% in girls and boys, respectively. The corresponding values for the prevalence of obesity were 4.8 and 5.6% (not significant) and of excess BF of 12.1 and 25.1% (P <0.001), respectively. In both sexes, BMI and BF were inversely related with CRF: r = – 0.53 and – 0.45 for BMI and % BF, respectively, in boys and the corresponding values in girls were – 0.50 and – 0.33 (all P <0.01). When compared with a participant with normal BMI and BF, the odds ratios (95% confidence interval) for low CRF were 1.94 (1.46–2.58) for a participant with normal BMI and high BF, and 6.19 (5.02–7.63) for a participant with high BMI and high BF. The prevalence of low-CRF levels is high in Portuguese youths. BF negatively influences CRF levels among children/adolescents with normal BMI.

Time of ruin in a risk model with generalized Erlang (n) interclaim times and a constant dividend barrier

In this paper we analyze the time of ruin in a risk process with the interclaim times being Erlang(n) distributed and a constant dividend barrier. We obtain an integro-differential equation for the Laplace Transform of the time of ruin. Explicit solutions for the moments of the time of ruin are presented when the individual claim amounts have a distribution with rational Laplace transform. Finally, some numerical results and a compare son with the classical risk model, with interclaim times following an exponential distribution, are given.

Non-constant discounting in finite horizon: The free terminal time case

This paper derives the HJB (Hamilton-Jacobi-Bellman) equation for sophisticated agents in a finite horizon dynamic optimization problem with non-constant discounting in a continuous setting, by using a dynamic programming approach. A simple example is used in order to illustrate the applicability of this HJB equation, by suggesting a method for constructing the subgame perfect equilibrium solution to the problem.Conditions for the observational equivalence with an associated problem with constantdiscounting are analyzed. Special attention is paid to the case of free terminal time. Strotz¿s model (an eating cake problem of a nonrenewable resource with non-constant discounting) is revisited.