Impacts of land leveling on lowland soil physical properties

The practice of land leveling alters the soil surface to create a uniform slope to improve land conditions for the application of all agricultural practices. The aims of this study were to evaluate the impacts of land leveling through the magnitudes, variances and spatial distributions of selected soil physical properties of a lowland area in the State of Rio Grande do Sul, Brazil; the relationships between the magnitude of cuts and/or fills and soil physical properties after the leveling process; and evaluation of the effect of leveling on the spatial distribution of the top of the B horizon in relation to the soil surface. In the 0-0.20 m layer, a 100-point geo-referenced grid covering two taxonomic soil classes was used in assessment of the following soil properties: soil particle density (Pd) and bulk density (Bd); total porosity (Tp), macroporosity (Macro) and microporosity (Micro); available water capacity (AWC); sand, silt, clay, and dispersed clay in water (Disp clay) contents; electrical conductivity (EC); and weighted average diameter of aggregates (WAD). Soil depth to the top of the B horizon was also measured before leveling. The overall effect of leveling on selected soil physical properties was evaluated by paired "t" tests. The effect on the variability of each property was evaluated through the homogeneity of variance test. The thematic maps constructed by kriging or by the inverse of the square of the distances were visually analyzed to evaluate the effect of leveling on the spatial distribution of the properties and of the top of the B horizon in relation to the soil surface. Linear regression models were fitted with the aim of evaluating the relationship between soil properties and the magnitude of cuts and fills. Leveling altered the mean value of several soil properties and the agronomic effect was negative. The mean values of Bd and Disp clay increased and Tp, Macro and Micro, WAD, AWC and EC decreased. Spatial distributions of all soil physical properties changed as a result of leveling and its effect on all soil physical properties occurred in the whole area and not specifically in the cutting or filling areas. In future designs of leveling, we recommend overlaying a cut/fill map on the map of soil depth to the top of the B horizon in order to minimize areas with shallow surface soil after leveling.

Relation entre glucose cérébral et systémique chez le sujet neurolésé: une étude par microdialyse cérébrale

Introduction: Le glucose est le principal substrat énergétique cérébral. Sa concentration dans le cerveau est étroitement liée à la glycémie. Chez le patient neurolésé, du fait de l'augmentation des besoins énergétiques, les réserves cérébrales de glucose sont limitées. Une glycémie suffisamment élevée paraît nécessaire pour assurer un apport adéquat de glucose au cerveau. Objectifs : Le but de cette étude est de mieux comprendre la relation entre glucose cérébral et glycémie lors de lésion cérébrale en analysant la physiologie cérébrale chez des patients neurolésés. Plus précisément nous investiguerons: La relation entre le glucose cérébral et le glucose systémique et son association avec le pronostic vital, l'association entre la neuroglucopénie et différents paramètres cérébraux tel que l'hypertension intracrânienne (HTIC) ou la dysfonction énergétique et finalement l'effet d'une perfusion de glucose 10% sur le glucose cérébral lors d'état de neuroglucopénie. Méthodologie : Analyse d'une base de données prospective comportant des patients souffrant d'un traumatisme crânio-cérébral (TCC) ou une hémorragie sous- arachnoïdienne (HSA) sévères. Les patients comateux sont monitorés par un dispositif intra-parenchymateux avancé, comprenant un cathéter de microdialyse cérébrale et un capteur de PbO2. Résultats : 34 patients consécutifs (moyenne d'âge 42 ans, moyenne de temps jusqu'au début du monitoring : 1.5 jours ± 1 ; moyenne de la durée maximale du monitoring : 6 jours ± 3) ont été étudiés, 25 patients souffrant d'un TCC et 9 patients avec une HSA. Nous avons obtenu une corrélation individuelle entre le glucose cérébral et la glycémie chez 52.9 % des patients. Lorsque la glycémie est inférieure à 5 mmol/l, on observe plus fréquemment des épisodes de neuroglucopénie en comparaison aux valeurs intermédiaires de glycémie (5 - 9.9 mmol/l). Les épisodes d'HTIC (pression intracrânienne (PIC) > 20 mmHg) sont plus fréquemment associés à des épisodes de neuroglucopénie que lorsque la pression intracrânienne est normale 75 % vs. 35%. La dysfonction énergétique est plus souvent associés à des épisodes de neuroglucopénie que lorsque le LPR est normal: 55% contre 36%. Un coefficient de corrélation entre glucose cérébral et glycémie significativement plus élevé a été obtenu chez les survivants que chez les non-survivants (0.1 [interquartile range 0.02- 0.3] contre 0.32 [0.17-0.61]). Chez les patients neuroglucopéniques ayant une corrélation entre glucose cérébral et glycémie, la perfusion de glucose i.v. fait monter le glucose cérébral jusqu'à l'arrêt de la perfusion. Conclusion : Malgré une étroite relation entre glycémie et glucose cérébral en conditions stables, cette relation peut être altérée par des causes cérébrales chez les patients neurolésés montrant que la diminution de la disponibilité du glucose extracellulaire ne résulte pas uniquement d'une hypoglycémie relative mais également de causes cérébrales tel que l'hypoperfusion, l'HTIC ou la dysfonction énergétique.

La relation entre les acteurs politiques et les gestionnaires publics: complémentarité ou séparation? Le constat dans trois cantons suisses

La recherche, faisant l'objet de la présente communication, interroge cette nouvelle répartition des rôles telle qu'elle a été théorisée dans les écrits gestionnaires portant sur la NGP. Nous investiguons donc la véracité de l'affirmation selon laquelle une gestion moderne, efficiente et efficace des affaires publiques implique une séparation plus stricte des sphères politiques et administratives. Autrement dit, est-ce que la mise en oeuvre des réformes managériales au sein des administrations cantonales de Suisse romande change effectivement la nature de la relation entre les hauts fonctionnaires et leurs ministres de tutelle ? Pour apporter un début de réponse à cette question, nous avons décidé de nous approcher de trois cantons romands qui se trouvent dans des dynamiques de réforme administrative d'ampleur différentes. Aussi, notre choix de terrain s'est porté sur le canton du Valais, qui est l'un des plus avancés en matière de NGP, sur le canton de Neuchâtel, qui se trouve dans une dynamique hybride puisque certains services administratifs ont adopté les principes de la contractualisation sur base volontaire et d'autres non, ansi que le canton du Jura qui n'a pas, pour l'instant, opté pour les nouveaux principes et outils de la NGP. La comparaison de ces trois entités, dont les trajectoires de modernisation diffèrent, nous permettra de constater ou non des différences d'appréciation dans la nature des relations politico-administratives des trois cantons. Si l'on se réfère à la description idéale-typique proposée par les tenants de la NGP, nous devrions constater d'importantes divergences. Enfin, il est à relever que cette recherche est pionnière en Suisse puisqu'aucune autre étude à ce jour ne s'est attelée à décrire ces changements relationnels, comme cela a été le cas dans la plupart des pays de l'OCDE.

Relation for the nonequilibrium population of the interface states: effects on the bias dependence of the ideality factors

By an analysis of the exchange of carriers through a semiconductor junction, a general relationship for the nonequilibrium population of the interface states in Schottky barrier diodes has been derived. Based on this relationship, an analytical expression for the ideality factor valid in the whole range of applied bias has been given. This quantity exhibits two different behaviours depending on the value of the applied bias with respect to a critical voltage. This voltage, which depends on the properties of the interfacial layer, constitutes a new parameter to complete the characterization of these junctions. A simple interpretation of the different behaviours of the ideality factor has been given in terms of the nonequilibrium charging properties of interface states, which in turn explains why apparently different approaches have given rise to similar results. Finally, the relevance of our results has been considered on the determination of the density of interface states from nonideal current-voltage characteristics and in the evaluation of the effects of the interfacial layer thickness in metal-insulator-semiconductor tunnelling diodes.

Assessment of driving capability through the use of clinical and psychomotor tests in relation to blood cannabinoids levels following oral administration of 20 mg dronabinol or of a cannabis decoction made with 20 or 60 mg Delta9-THC.

Delta(9)-Tetrahydrocannabinol (THC) is frequently found in the blood of drivers suspected of driving under the influence of cannabis or involved in traffic crashes. The present study used a double-blind crossover design to compare the effects of medium (16.5 mg THC) and high doses (45.7 mg THC) of hemp milk decoctions or of a medium dose of dronabinol (20 mg synthetic THC, Marinol on several skills required for safe driving. Forensic interpretation of cannabinoids blood concentrations were attempted using the models proposed by Daldrup (cannabis influencing factor or CIF) and Huestis and coworkers. First, the time concentration-profiles of THC, 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC) (active metabolite of THC), and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THCCOOH) in whole blood were determined by gas chromatography-mass spectrometry-negative ion chemical ionization. Compared to smoking studies, relatively low concentrations were measured in blood. The highest mean THC concentration (8.4 ng/mL) was achieved 1 h after ingestion of the strongest decoction. Mean maximum 11-OH-THC level (12.3 ng/mL) slightly exceeded that of THC. THCCOOH reached its highest mean concentration (66.2 ng/mL) 2.5-5.5 h after intake. Individual blood levels showed considerable intersubject variability. The willingness to drive was influenced by the importance of the requested task. Under significant cannabinoids influence, the participants refused to drive when they were asked whether they would agree to accomplish several unimportant tasks, (e.g., driving a friend to a party). Most of the participants reported a significant feeling of intoxication and did not appreciate the effects, notably those felt after drinking the strongest decoction. Road sign and tracking testing revealed obvious and statistically significant differences between placebo and treatments. A marked impairment was detected after ingestion of the strongest decoction. A CIF value, which relies on the molar ratio of main active to inactive cannabinoids, greater than 10 was found to correlate with a strong feeling of intoxication. It also matched with a significant decrease in the willingness to drive, and it matched also with a significant impairment in tracking performances. The mathematic model II proposed by Huestis et al. (1992) provided at best a rough estimate of the time of oral administration with 27% of actual values being out of range of the 95% confidence interval. The sum of THC and 11-OH-THC blood concentrations provided a better estimate of impairment than THC alone. This controlled clinical study points out the negative influence on fitness to drive after medium or high dose oral THC or dronabinol.

SOIL QUALITY IN RELATION TO FOREST CONVERSION TO PERENNIAL OR ANNUAL CROPPING IN SOUTHERN BRAZIL

Many forested areas have been converted to intensive agricultural use to satisfy food, fiber, and forage production for a growing world population. There is great interest in evaluating forest conversion to cultivated land because this conversion adversely affects several soil properties. We examined soil microbial, physical, and chemical properties in an Oxisol (Latossolo Vermelho distrófico) of southern Brazil 24 years after forest conversion to a perennial crop with coffee or annual grain crops (maize and soybeans) in conventional tillage or no-tillage. One goal was to determine which soil quality parameters seemed most sensitive to change. A second goal was to test the hypothesis that no-tillage optimized preservation of soil quality indicators in annual cropping systems on converted land. Land use significantly affected microbial biomass and its activity, C and N mineralization, and aggregate stability by depth. Cultivated sites had lower microbial biomass and mineralizable C and N than a forest used as control. The forest and no-tillage sites had higher microbial biomass and mineralizable C and N than the conventional tillage site, and the metabolic quotient was 65 and 43 % lower, respectively. Multivariate analysis of soil microbial properties showed a clear separation among treatments, displaying a gradient from conventional tillage to forest. Although the soil at the coffee site was less disturbed and had a high organic C content, the microbial activity was low, probably due to greater soil acidity and Al toxicity. Under annual cropping, microbial activity in no-tillage was double that of the conventional tillage management. The greater microbial activity in forest and no-tillage sites may be attributed, at least partially, to lower soil disturbance. Reducing soil disturbance is important for soil C sequestration and microbial activity, although control of soil pH and Al toxicity are also essential to maintain the soil microbial activity high.

Inhibition of Na(+)-K(+)-ATPase by digoxin and its relation with energy expenditure and nutrient oxidation rate.

This study investigates the effects of digoxin, an inhibitor of the Na+ pump (Na(+)-K(+)-ATPase), on resting metabolic rate (RMR), respiratory quotient (RQ), and nutrient oxidation rate. Twelve healthy male subjects followed a double-blind protocol design and received either 1 mg/day digoxin or a placebo 2 days before indirect calorimetry measurements. Digoxin induced a 0.22 +/- 0.07 kJ/min or 3.8 +/- 1.5% (mean +/- SE, P = 0.01) decrease in RMR and a 0.40 +/- 0.13 kJ/min (P = 0.01) decrease in fat oxidation rate, whereas carbohydrate and protein oxidation rates did not change significantly. A dose-response relationship between serum digoxin and RQ was observed. These results suggest that digoxin reduces not only RMR but also fat oxidation rate by mechanisms that remain to be elucidated. Because a linkage and an association between genes coding the Na(+)-K(+)-ATPase and the RQ have been previously observed, the present demonstration of an effect of Na(+)-K(+)-ATPase inhibition on fat oxidation rate strengthens the concept that the activity of this enzyme may play a role in body weight regulation.

Magnitude of CD8 T-cell responses against hepatitis C virus and severity of hepatitis do not necessarily determine outcomes in acute hepatitis C virus infection.

Aim: We investigated the relationship between the magnitude of comprehensive hepatitis C virus (HCV)-specific CD8(+) T-cell responses and the clinical course of acute HCV infection. Methods: Six consecutive patients with acute HCV infection were studied. Analysis of HCV-specific CD8(+) T-cell responses was performed using an interferon-gamma-based enzyme-linked immunospot assay using peripheral CD8(+) T-cells, monocytes and 297 20-mer synthetic peptides overlapping by 10 residues and spanning the entire HCV sequence of genotype 1b. Results: Five patients presented detectable HCV-specific CD8(+) T-cell responses against a single and different peptide, whereas 1 patient showed responses against three different peptides. Neither the magnitude of HCV-specific CD8(+) T-cell responses nor the severity of hepatitis predicts the outcome of acute hepatitis. The maximum number of HCV-specific CD8(+) T-cells correlated with maximum serum alanine aminotransferase level during the course (r = 0.841, P = 0.036). Conclusions: HCV-specific CD8(+) T-cell responses were detectable in all 6 patients with acute HCV infection, and 6 novel HCV-specific CTL epitopes were identified. Acute HCV infection can resolve with detectable HCV-specific CD8(+) T-cell responses, but without development of antibody against HCV.

Cancer du sein et obésité, une liaison dangereuse [Breast cancer and obesity, a dangerous relation].

Obesity is associated with different cancers including breast cancer, whose incidence is increased in postmenopausal women. It has an adverse impact on the prognosis of the patients, regardless of their menopausal status. The fact of receiving a systemic adjuvant therapy does not neutralize the prognostic role of obesity. Moderate weight loss after cancer diagnosis could improve the outcome of the patients, while a weight gain during treatment seems without significant effect. Currently available data are still too incomplete to justify systematic programs to lose weight with an oncologic therapeutic aim. However, it is worth to encourage and support our patients to have an optimal diet, physical activity, and to lose weight as promotion of general health.