Distribution of Testudo graeca in the western Mediterranean according to climatic factors

Despite being one of the most charismatic elements of the Mediterranean Basin fauna and its threatened status, the western Mediterranean range of Testudo graeca is at present very poorly known. The present work provides the most detailed geographical and ecological description for the North African clade of T. graeca so far. We gathered 283 occurrence data of T. graeca in North Africa and modelled the distribution by means of presence-only distribution modelling tools. The obtained model was then projected to southern Europe in order to explore whether the environmental characteristics of European populations fall into the predicted niche of the species in North Africa. T. graeca showed a wide environmental range in North Africa. Presence localities ranged from the sea level to 2090 m of altitude and from 116 to 1093 mm of annual precipitation. The presence-only model indicates that distribution in North Africa is mainly related to rainfall, specifically rainfall values in the wettest and coldest quarter of the year. The distribution model showed a range of ca. 1∈000∈000 km 2. The projection of the model to southern Europe showed that the southern Iberian and Balkan Peninsulas, as well as most Mediterranean islands, present climatic conditions within those found in the range of the species in North Africa. © Koninklijke Brill NV, Leiden, 2012.Peer Reviewe

Supercritical CO2 extraction of Rosmarinus eriocalyx growing in Algeria: chemical composition and antioxidant activity of extracts and their solid plant materials

Supercritical fluid extraction using carbon dioxide (SFE-CO2) is an eco-friendly, safe and effective extraction technique used on an industrial level to obtain flavour and fragrances as well as bioactive compounds from aromatic plants. In the present work, we investigated the SFE-CO2 extracts obtained from leaves and flowers of Rosmarinus eriocalyx, an aromatic shrub growing in Algeria and used similarly to R. officinalis. The SFE-CO2 extracts were obtained from R. eriocalyx using the following parameters: extraction time 180 min (including 30 min of static extraction), pressure 45 MPa; temperature 70°C. The chemical profiles of SFE-CO2 extracts were determined by gas chromatography-mass spectrometry (GC–MS). β-Amyrin and camphor were major compounds in the leaf extract, whereas tetradecenoic and linolenic acids were abundant in the flower extract. The amounts of tocopherols in the SFE-CO2 extracts were determined by high performance liquid chromatography (HPLC) analysis. Here, α-tocopherol attained noteworthy concentrations (8839 μg/g dw). The antioxidant activity of SFE-CO2 extract, plant powder and residue after SFE-CO2 extraction was assessed using three different methods, namely ABTS, FRAP and DPPH assays. The overall activity was as follows: plant powder > residue after SFE-CO2 extraction > SFE-CO2 extracts. Findings showed that R. eriocalyx is a rich source of antioxidant compounds, especially the plant material, and that considerable part of polar bioactive components still remain in the solid residue after SFE-CO2 extraction. Consequently, both lipophilic SFE-CO2 extract and antioxidant-rich extraction residues may be of interest for various industrial applications

Occupational Noise Exposure and Diabetes Risk

Introduction. Noise is one of the most common worldwide environmental pollutants, especially in occupational fields. As a stressor, it affects not only the ear but also the entire body. Its physiological and psychological impacts have been well established in many conditions such as cardiovascular diseases. However, there is a dearth of evidence regarding diabetes risk related to noises. Aim. To evaluate the relationship between occupational exposure to noise and the risk of developing diabetes. Methods. This is a cross-sectional analytical study enrolling two groups of 151 workers each. The first group (noise exposed group: EG) included the employees of a Tunisian power plant, who worked during the day shift and had a permanent position. The second group (unexposed to noise group: NEG) included workers assigned to two academic institutions, who were randomly selected in the Occupational Medicine Department of the Farhat Hached University Hospital in Sousse, during periodical fitness to work visits. Both populations (exposed and unexposed) were matched by age and gender. Data collection was based on a preestablished questionnaire, a physical examination, a biological assessment, and a sonometric study. Results. The mean equivalent continuous sound level was 89 dB for the EG and 44.6 dB for the NEG. Diabetes was diagnosed in 24 workers from EG (15.9%) and 14 workers from NEG (9.3%), with no statistically significant difference (p=0.08). After multiple binary logistic regression, including variables of interest, noise did not appear to be associated with diabetes. Conclusion. Our results did not reveal a higher risk of developing diabetes in workers exposed to noise. Further studies assessing both level and duration of noise exposure are needed before any definitive conclusion

Tangency property and prior-saturation points in minimal time problems in the plane

International audienceIn this paper, we consider minimal time problems governed by control-affine-systems in the plane, and we focus on the synthesis problem in presence of a singular locus that involves a saturation point for the singular control. After giving sufficient conditions on the data ensuring occurence of a prior-saturation point and a switching curve, we show that the bridge, the optimal bang arc issued from the singular locus at this point) is tangent to the switching curve at the prior-saturation point. This property is proved using the Pontryagin Maximum Principle that also provides a set of non-linear equations that can be used to compute the prior-saturation point. These issues are illustrated on a fed-batch model in bioprocesses and on a Magnetic Resonance Imaging (MRI) model for which minimal time syntheses for the point-to-point problem are discussed