Etude de la variation de la végétation en milieux salé et acide au Sénégal

L’objectif de l’étude était de comprendre la variation de la végétation en milieux acide et salé. Larépartition de la végétation des sols sulfatés acides salés en fonction  de certains paramètres (pH, conductivité électrique ou CE, humidité du sol et texture des sols) a ainsi été étudiée dans les secteurs situés au Sud et au Nord du fleuve Saloum (Sénégal). Des relevés ont été effectués sur les différentes unités géomorphologiques (terrasses et dunes) suivant la méthode des grappes de superficies  graduelles. Au niveau de chaque surface de collecte, des échantillons de sol ont été prélevés à 6 cm de profondeur pour déterminer leur CE, pH, teneur en eau et texture. L’étude a mis en évidence la distribution de la végétation en fonction des unités géomorphologiques et des types de faciès ainsi que les changements des faciès écologiques à travers les distributions aires-espèces. L’analyse en composantes principales a montré le rôle important de la texture du sol sur le regroupement de la végétation en fonction des gammes de salinité, d’acidité et du taux d’humidité. La connaissance du mode de regroupement de la végétation en milieux acide et salé pourrait aider dans le choix du type d’aménagement pour régénérer les potentialités agronomiques de ces sols et leur  réintégration dans le système productif national.Mots clés: Acidité des sols, diversité biologique, humidité, salinité des sols, texture

Board review course effect on resident in-training examination

Background The in-training examination is a national and yearly exam administered by the American Board of Emergency Medicine to all emergency medicine residents in the USA. The purpose of the examination is to evaluate a resident’s progress toward obtaining the fundamental knowledge to practice independent emergency medicine. Aims The purpose of this study was to determine the effects of a 40 hour board review lecture course on the resident in-training examination in emergency medicine. Methods A 40 hour board review lecture course was designed and implemented during the weekly 5 hour long resident conferences during the 8 weeks preceding the in-training examination date in 2006. Attendance was manda-tory at the Accreditation Council for Graduate Medical Education (ACGME) standard of 70 % or greater. A positive result was considered to be a 10 % increase or greater in the resident’s individual national class percentile ranking among their national peers for their class year for the emergency medicine in-training examination. A resident was excluded from the study if there was no 2005 in-training examination score for self-comparison. The 95% confidence intervals (CI) were used to analyze the results. Results Of 16 residents, 1 (6.25%; 95 % CI: 0–18%) showed a positive result of increasing their national class percentile ranking by 10 % or greater. For the PGY2, one of the eight had a positive result (12.5%; 95 % CI: 0–35.4%). For PGY3, no resident (0%; 95 % CI: 0–35.4%) had a positive result. Conclusions A 40 hour board review lecture course has no positive effect on improving a resident’s in-training examination score

Diffusion Tensor Imaging for Diagnosing Root Avulsions in Traumatic Adult Brachial Plexus Injuries: A Proof-of-Concept Study

Cross-sectional MRI has modest diagnostic accuracy for diagnosing traumatic brachial plexus root avulsions. Consequently, patients either undergo major exploratory surgery or months of surveillance to determine if and what nerve reconstruction is needed. This study aimed to develop a diffusion tensor imaging (DTI) protocol at 3 Tesla to visualize normal roots and identify traumatic root avulsions of the brachial plexus. Seven healthy adults and 12 adults with known (operatively explored) unilateral traumatic brachial plexus root avulsions were scanned. DTI was acquired using a single-shot echo-planar imaging sequence at 3 Tesla. The brachial plexus was visualized by deterministic tractography. Fractional anisotropy (FA) and mean diffusivity (MD) were calculated for injured and avulsed roots in the lateral recesses of the vertebral foramen. Compared to healthy nerves roots, the FA of avulsed nerve roots was lower (mean difference 0.1 [95% CI 0.07, 0.13]; p < 0.001) and the MD was greater (mean difference 0.32 × 10−3 mm2/s [95% CI 0.11, 0.53]; p < 0.001). Deterministic tractography reconstructed both normal roots and root avulsions of the brachial plexus; the negative-predictive value for at least one root avulsion was 100% (95% CI 78, 100). Therefore, DTI might help visualize both normal and injured roots of the brachial plexus aided by tractography. The precision of this technique and how it relates to neural microstructure will be further investigated in a prospective diagnostic accuracy study of patients with acute brachial plexus injuries

Major milestones in translational oncology.

Translational oncology represents a bridge between basic research and clinical practice in cancer medicine. Today, translational research in oncology benefits from an abundance of knowledge resulting from genome-scale studies regarding the molecular pathways involved in tumorigenesis. In this Forum article, we highlight the state of the art of translational oncology in five major cancer types. We illustrate the use of molecular profiling to subtype colorectal cancer for both diagnosis and treatment, and summarize the results of a nationwide screening program for ovarian cancer based on detection of a tumor biomarker in serum. Additionally, we discuss how circulating tumor DNA can be assayed to safely monitor breast cancer over the course of treatment, and report on how therapy with immune checkpoint inhibitors is proving effective in advanced lung cancer. Finally, we summarize efforts to use molecular profiling of prostate cancer biopsy specimens to support treatment decisions. Despite encouraging early successes, we cannot disregard the complex genetics of individual susceptibility to cancer nor the enormous complexity of the somatic changes observed in tumors, which urge particular attention to the development of personalized therapies

Whole plant cannabis extracts in the treatment of spasticity in multiple sclerosis: a systematic review

<p>Abstract</p> <p>Background</p> <p>Cannabis therapy has been considered an effective treatment for spasticity, although clinical reports of symptom reduction in multiple sclerosis (MS) describe mixed outcomes. Recently introduced therapies of combined Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD) extracts have potential for symptom relief with the possibility of reducing intoxication and other side effects. Although several past reviews have suggested that cannabinoid therapy provides a therapeutic benefit for symptoms of MS, none have presented a methodical investigation of newer cannabinoid treatments in MS-related spasticity. The purpose of the present review was to systematically evaluate the effectiveness of combined THC and CBD extracts on MS-related spasticity in order to increase understanding of the treatment's potential effectiveness, safety and limitations.</p> <p>Methods</p> <p>We reviewed MEDLINE/PubMed, Ovid, and CENTRAL electronic databases for relevant studies using randomized controlled trials. Studies were included only if a combination of THC and CBD extracts was used, and if pre- and post-treatment assessments of spasticity were reported.</p> <p>Results</p> <p>Six studies were systematically reviewed for treatment dosage and duration, objective and subjective measures of spasticity, and reports of adverse events. Although there was variation in the outcome measures reported in these studies, a trend of reduced spasticity in treated patients was noted. Adverse events were reported in each study, however combined TCH and CBD extracts were generally considered to be well-tolerated.</p> <p>Conclusion</p> <p>We found evidence that combined THC and CBD extracts may provide therapeutic benefit for MS spasticity symptoms. Although some objective measures of spasticity noted improvement trends, there were no changes found to be significant in post-treatment assessments. However, subjective assessment of symptom relief did often show significant improvement post-treatment. Differences in assessment measures, reports of adverse events, and dosage levels are discussed.</p

Hypermethylation of CpG islands in the mouse asparagine synthetase gene: relationship to asparaginase sensitivity in lymphoma cells. Partial methylation in normal cells

We have sequenced the promoter region of the murine asparagine synthetase gene and examined its methylation profile in the CpG islands of L-asparaginase-sensitive 6C3HED cells (asparagine auxotrophs) and resistant variants (prototrophs). In the former, complete methylation of the CpG island is correlated with failure of expression of mRNA: cells of the latter possess both methylated and unmethylated alleles, as do cells of the intrinsically asparagine-independent lines L1210 and EL4. A similar phenomenon was seen in normal splenic cells of adult mice. This was age related: no methylation was found in weanlings, but up to 45% of gene copies in animals 18 weeks or older were methylated. It was also tissue related, with methylation occurring rarely in liver cells. The relationship of these changes to oncogenesis is considered. http://www.bjcancer.com © 2001 Cancer Research Campaignhttp://www.bjcancer.co

Genetic Architecture of Hybrid Male Sterility in Drosophila: Analysis of Intraspecies Variation for Interspecies Isolation

Background: The genetic basis of postzygotic isolation is a central puzzle in evolutionary biology. Evolutionary forces causing hybrid sterility or inviability act on the responsible genes while they still are polymorphic, thus we have to study these traits as they arise, before isolation is complete. Methodology/Principal Findings: Isofemale strains of D. mojavensis vary significantly in their production of sterile F 1 sons when females are crossed to D. arizonae males. We took advantage of the intraspecific polymorphism, in a novel design, to perform quantitative trait locus (QTL) mapping analyses directly on F1 hybrid male sterility itself. We found that the genetic architecture of the polymorphism for hybrid male sterility (HMS) in the F1 is complex, involving multiple QTL, epistasis, and cytoplasmic effects. Conclusions/Significance: The role of extensive intraspecific polymorphism, multiple QTL, and epistatic interactions in HMS in this young species pair shows that HMS is arising as a complex trait in this system. Directional selection alone would be unlikely to maintain polymorphism at multiple loci, thus we hypothesize that directional selection is unlikely to be the only evolutionary force influencing postzygotic isolation

Proprioceptive Movement Illusions Due to Prolonged Stimulation: Reversals and Aftereffects

Background. Adaptation to constant stimulation has often been used to investigate the mechanisms of perceptual coding, but the adaptive processes within the proprioceptive channels that encode body movement have not been well described. We investigated them using vibration as a stimulus because vibration of muscle tendons results in a powerful illusion of movement. Methodology/Principal Findings. We applied sustained 90 Hz vibratory stimulation to biceps brachii, an elbow flexor and induced the expected illusion of elbow extension (in 12 participants). There was clear evidence of adaptation to the movement signal both during the 6-min long vibration and on its cessation. During vibration, the strong initial illusion of extension waxed and waned, with diminishing duration of periods of illusory movement and occasional reversals in the direction of the illusion. After vibration there was an aftereffect in which the stationary elbow seemed to move into flexion. Muscle activity shows no consistent relationship with the variations in perceived movement. Conclusion. We interpret the observed effects as adaptive changes in the central mechanisms that code movement in direction-selective opponent channels