Fourmis du Vallon de Nant - Premières données

Les auteurs ont procédé à un premier recensement de la diversité en fourmis du Vallon de Nant (Alpes vaudoises, Suisse) lors des premières Journées de la biodiversité organisées les 5 et 6 juillet 2008. Neuf espèces de fourmis ont été récoltées, entre 1240m et 1800m d'altitude. Formica lemani, Formica lugubris et Myrmica ruginodis représentent trois quarts des observations. Toutes les espèces recensées sont communes en montagne

Stressing schizotypy: The modulating role of stress-relieving behaviours and intellectual capacity on functional hemispheric asymmetry.

Relative cognitive impairments are common along the schizophrenia spectrum reflecting potential psychopathological markers. Yet stress, a vulnerability marker in schizophrenia (including its spectrum), is likewise related to cognitive impairments. We investigated whether one such cognitive marker (attenuated functional hemispheric asymmetry) during stressful life periods might be linked to individuals' schizotypal features or rather to individuals' stress-related experiences and behaviours. A total of 58 students performed a left hemisphere dominant (lateralised lexical decisions) and right hemisphere dominant (sex decisions on composite faces) task. In order to account for individual differences in stress sensitivity we separated participants into groups of high or low cognitive reserve according to their average current marks. In addition, participants filled in questionnaires on schizotypy (short O-LIFE), perceived stress, stress response, and a newly adapted questionnaire that enquired about potential stress compensation behaviour (elevated substance use). The most important finding was that enhanced substance use and cognitive disorganisation contributed to a right and left hemisphere shift in language dominance, respectively. We discuss that (i) former reports on right hemisphere shifts in language dominance with positive schizotypy might be explained by an associated higher substance use and (ii) cognitive disorganisation relates to unstable cognitive functioning that depend on individuals' life circumstances, contributing to published reports on inconsistent laterality-schizotypy relationships.

Prognostic value of serial blood S100B determinations in stage IIB-III melanoma patients: a corollary study to EORTC trial 18952.

S100B is a prognostic factor for melanoma as elevated levels correlate with disease progression and poor outcome. We determined its prognostic value based on updated information using serial determinations in stage IIb/III melanoma patients. 211 Patients who participated in the EORTC 18952 trial, evaluating efficacy of adjuvant intermediate doses of interferon α2b (IFN) versus observation, entered a corollary study. Over a period of 36 months, 918 serum samples were collected. The Cox time-dependent model was used to assess prognostic value of the latest (most recent) S100B determination. At first measurement, 178 patients had S100B values <0.2 μg/l and 33 ≥ 0.2 μg/l. Within the first group, 61 patients had, later on, an increased value of S100B (≥ 0.2 μg/l). An initial increased value of S100B, or during follow-up, was associated with worse distant metastasis-free survival (DMFS); hazard ratio (HR) of S100B ≥ 0.2 versus S100B < 0.2 was 5.57 (95% confidence interval (CI) 3.81-8.16), P < 0.0001, after adjustment for stage, number of lymph nodes and sex. In stage IIb patients, the HR adjusted for sex was 2.14 (95% CI 0.71, 6.42), whereas in stage III, the HR adjusted for stage, number of lymph nodes and sex was 6.76 (95% CI 4.50-10.16). Similar results were observed regarding overall survival (OS). Serial determination of S100B in stage IIb-III melanoma is a strong independent prognostic marker, even stronger compared to stage and number of positive lymph nodes. The prognostic impact of S100B ≥ 0.2 μg/l is more pronounced in stage III disease compared with stage IIb.

Discrepancies between office and ambulatory blood pressure: clinical implications.

BACKGROUND: Recent trials have documented no benefit from small reductions in blood pressure measured in the clinical office. However, ambulatory blood pressure is a better predictor of cardiovascular events than office-based blood pressure. We assessed control of ambulatory blood pressure in treated hypertensive patients at high cardiovascular risk. METHODS: We selected 4729 patients from the Spanish Ambulatory Blood Pressure Monitoring Registry. Patients were aged >/=55 years and presented with at least one of the following co-morbidities: coronary heart disease, stroke, and diabetes with end-organ damage. An average of 2 measures of blood pressure in the office was used for analyses. Also, 24-hour ambulatory blood pressure was recorded at 20-minute intervals with a SpaceLabs 90207 device. RESULTS: Patients had a mean age of 69.6 (+/-8.2) years, and 60.8% of them were male. Average time from the diagnosis of hypertension to recruitment into the Registry was 10.9 (+/-8.4) years. Mean blood pressure in the office was 152.3/82.3 mm Hg, and mean 24-hour ambulatory blood pressure was 133.3/72.4 mm Hg. About 60% of patients with an office-pressure of 130-139/85-89 mm Hg, 42.4% with office-pressure of 140-159/90-99 mm Hg, and 23.3% with office-pressure > or =160/100 mm Hg were actually normotensive, according to 24-hour ambulatory blood pressure criteria (<130/80 mm Hg). CONCLUSION: We suggest that the lack of benefit of antihypertensive therapy in some trials may partly be due to some patients having normal pressure at trial baseline. Ambulatory monitoring of blood pressure may allow for a better assessment of trial eligibility.

Predicting global change impacts on plant species' distributions: Future challenges

Given the rate of projected environmental change for the 21st century, urgent adaptation and mitigation measures are required to slow down the on-going erosion of biodiversity. Even though increasing evidence shows that recent human-induced environmental changes have already triggered species' range shifts, changes in phenology and species' extinctions, accurate projections of species' responses to future environmental changes are more difficult to ascertain. This is problematic, since there is a growing awareness of the need to adopt proactive conservation planning measures using forecasts of species' responses to future environmental changes. There is a substantial body of literature describing and assessing the impacts of various scenarios of climate and land-use change on species' distributions. Model predictions include a wide range of assumptions and limitations that are widely acknowledged but compromise their use for developing reliable adaptation and mitigation strategies for biodiversity. Indeed, amongst the most used models, few, if any, explicitly deal with migration processes, the dynamics of population at the "trailing edge" of shifting populations, species' interactions and the interaction between the effects of climate and land-use. In this review, we propose two main avenues to progress the understanding and prediction of the different processes A occurring on the leading and trailing edge of the species' distribution in response to any global change phenomena. Deliberately focusing on plant species, we first explore the different ways to incorporate species' migration in the existing modelling approaches, given data and knowledge limitations and the dual effects of climate and land-use factors. Secondly, we explore the mechanisms and processes happening at the trailing edge of a shifting species' distribution and how to implement them into a modelling approach. We finally conclude this review with clear guidelines on how such modelling improvements will benefit conservation strategies in a changing world. (c) 2007 Rubel Foundation, ETH Zurich. Published by Elsevier GrnbH. All rights reserved.

Quantitative distribution of parvalbumin, calretinin, and calbindin D-28k immunoreactive neurons in the visual cortex of normal and Alzheimer cases.

The distribution of parvalbumin (PV), calretinin (CR), and calbindin (CB) immunoreactive neurons was studied with the help of an image analysis system (Vidas/Zeiss) in the primary visual area 17 and associative area 18 (Brodmann) of Alzheimer and control brains. In neither of these areas was there a significant difference between Alzheimer and control groups in the mean number of PV, CR, or CB immunoreactive neuronal profiles, counted in a cortical column going from pia to white matter. Significant differences in the mean densities (numbers per square millimeter of cortex) of PV, CR, and CB immunoreactive neuronal profiles were not observed either between groups or areas, but only between superficial, middle, and deep layers within areas 17 and 18. The optical density of the immunoreactive neuropil was also similar in Alzheimer and controls, correlating with the numerical density of immunoreactive profiles in superficial, middle, and deep layers. The frequency distribution of neuronal areas indicated significant differences between PV, CR, and CB immunoreactive neuronal profiles in both areas 17 and 18, with more large PV than CR and CB positive profiles. There were also significantly more small and less large PV and CR immunoreactive neuronal profiles in Alzheimer than in controls. Our data show that, although the brain pathology is moderate to severe, there is no prominent decrease of PV, CR and CB positive neurons in the visual cortex of Alzheimer brains, but only selective changes in neuronal perikarya.

The role of territory choice mate choice and arrival date on breeding success in the Savi's warbler (Locustella luscinioides)

We investigated how territory quality, settlement date and morphometry affected several components of yearly breeding success of a Swiss population of Savi's Warblers Locustella luscinioides. Territories occupied by males differed from unoccupied sites of similar size and location by having higher and denser reeds, a more extensive straw litter, and a thicker cover of dead sedge leaves. Territories with these characteristics were the ones first chosen by males upon spring arrival. These males, however, did not differ in morphometry from those that arrived later. Availability of suitable nesting sites; rather than food availability, appears to be an important choice criterion for territories. Early arriving males had higher breeding success than late males because of a higher mating success and more successful clutches. The positive correlation between male breeding success and territory quality was thus mediated through their common dependence on occupancy date. Female breeding success decreased with the date of first-clutch laying, mainly because late-nesting females fledged fewer broods. Breeding success in either sex did not correlate with morphometry. Our results provide clear support for territory choice by males, but not for mate or territory choice by females, and show the crucial role played by individual settlement date on many aspects of the breeding cycle of both sexes. We propose a lottery model of mate choice. arriving females obtain the best available territories even without choosing mates or territories; since males occupy territories sequentially and in order of decreasing quality, the few unpaired males available at any moment also occupy the best available territories.

Alpha1-adrenoceptors are required for normal male sexual function.

BACKGROUND AND PURPOSE: Alpha(1)-adrenoceptor antagonists are extensively used in the treatment of hypertension and lower urinary tract symptoms associated with benign prostatic hyperplasia. Among the side effects, ejaculatory dysfunction occurs more frequently with drugs that are relatively selective for alpha(1A)-adrenoceptors compared with other drugs of this class. This suggests that alpha(1A)-adrenoceptors may contribute to ejaculation. However, this has not been studied at the molecular level. EXPERIMENTAL APPROACH: The physiological contribution of each alpha(1)-adrenoceptor subtype was characterized using alpha(1)-adrenoceptor subtype-selective knockout (KO) mice (alpha(1A)-, alpha(1B)- and alpha(1D)-AR KO mice) since the subtype-specific drugs available are only moderately selective. We analysed the role of alpha(1)-adrenoceptors in the blood pressure and vascular response as well as ejaculation by determining these variables in alpha(1)-adrenoceptor subtype-selective KO mice and in mice with all their alpha(1)-adrenoceptor subtypes deleted (alpha(1)-AR triple-KO mice). KEY RESULTS: The pregnancy rate was reduced by 50% in alpha(1A)-adrenoceptor KO mice, and this reduction was dramatically enhanced in alpha(1)-adrenoceptor triple-KO mice. Contractile tension of the vas deferens in response to noradrenaline was markedly decreased in alpha(1A)-adrenoceptor KO mice, and this contraction was completely abolished in alpha(1)-adrenoceptor triple-KO mice. This attenuation of contractility was also observed in the electrically stimulated vas deferens. CONCLUSIONS AND IMPLICATIONS: These results demonstrate that alpha(1)-adrenoceptors, particularly alpha(1A)-adrenoceptors, are required for normal contractility of the vas deferens and consequent sperm ejaculation as well as having a function in fertility.

Clinical relevance of cerebral autoregulation following subarachnoid haemorrhage.

Subarachnoid haemorrhage (SAH) is a form of stroke that is associated with substantial morbidity, often as a result of cerebral ischaemia that occurs in the following days. These delayed deficits in blood flow have been traditionally attributed to cerebral vasospasm (the narrowing of large arteries), which can lead to cerebral infarction and poor neurological outcome. Data from recent studies, however, show that treatment of vasospasm in patients with SAH, using targeted medication, does not translate to better neurological outcomes, and argue against vasospasm being the sole cause of the delayed ischaemic complications. Cerebral autoregulation-a mechanism that maintains stability of cerebral blood flow in response to changes in cerebral perfusion pressure-has been reported to fail after SAH, often before vasospasm becomes apparent. Failure of autoregulation, therefore, has been implicated in development of delayed cerebral ischaemia. In this Review, we summarize current knowledge about the clinical effect of disturbed cerebral autoregulation following aneurysmal SAH, with emphasis on development of delayed cerebral ischaemia and clinical outcome, and provide a critical assessment of studies of cerebral autoregulation in SAH with respect to the method of blood-flow measurement. Better understanding of cerebral autoregulation following SAH could reveal mechanisms of blood-flow regulation that could be therapeutically targeted to improve patient outcome.

Clinical management of immunocompetent hospitalized patients with community-acquired pneumonia.

Background: Clinical practices and guidelines may differ regarding the management of inpatients with community-acquired pneumonia (CAP). Methods: The management of 152 consecutive CAP inpatients (70+/-17 years) admitted to a teaching hospital was analyzed retrospectively and compared with published data and an evidence-based guideline developed at our institution. Results: Of the patients studied, 64% had a high prognostic score index (PSI), 14% were admitted to the ICU, and 4.6% died. Initially, patients received either a one-drug (47%) or a two-drug (53%) antibiotic regimen. None of the 20 PSI parameters, and neither the PSI nor admission to the ICU, was associated with the initial antibiotic regimen. Agreement between current practice and our guideline was low (kappa=0.16). Following the recommendations would have led to a decrease of 51% in the initial two-drug regimen. The duration of i.v. antibiotherapy was higher in patients following the two-drug regimen (142+/-150 vs. 102+/-60 h, P<0.05). Chest physiotherapy (CP) and bronchodilatators (BD) were prescribed in 72% and 54% of cases, respectively (median duration 10 days). Conclusions: The variations observed in the clinical management of CAP inpatients were not in agreement with published guidelines. The overuse of a two-drug regimen, CP, and BD necessitates the development and implementation of evidence-based guidelines proposing detailed steps for the management of CAP inpatients.

Littérature et contextes

Cet article présente la conception du sens impliquée par les diverses approches privilégiées par les didacticiens du FLE; après un rapide état des lieux qui met en lumière un sens un peu « figé », comme prisonnier du texte dans toutes ses dimensions possibles (générique, thématique, linguistique...), nous avons essayé d'aller au-delà de cette conception « structuraliste » du sens pour lui substituer une vision plus « herméneutique », davantage soucieuse de suivre le sens dans sa dynamique et surtout attentive à ne pas séparer le sens de ses contextes. Nous avons ensuite proposé quelques pistes pour permettre aux apprenants FLE en particulier de saisir le fonctionnement du sens - pour leur montrer qu'ils sont partie prenante du sens. Puis, à partir d'un questionnaire distribué à des apprenants de divers niveaux, nous avons tenté de réfléchir à leur manière d'appréhender le texte littéraire et ses composantes, pour comprendre où ils situent le sens, comment ils le construisent, et ainsi mesurer le chemin qu'il nous reste à parcourir pour que le texte littéraire soit plus qu'un texte parmi beaucoup d'autres.