Factores sociales y lumínicos que afectan al desencadenamiento de la pubertad del morueco

Se ha estudiado el efecto los factores sociales y lumínicos que afectan al desencadenamiento de la pubertad en cuarenta corderos nacidos en otoño, así como en su actividad sexual y en su fertilidad cuando alcanzan los 8 meses de edad. Los animales fueron asignados a cuatro grupos (n=10): FA, expuestos a 2 meses de días largos (15 de enero a 15 de marzo); SAR, alojados con tres machos adultos sexualmente activados desde el 15 de marzo al 20 de junio; NAR, alojados con tres machos adultos no activados; y Control (C), aislados de los de los moruecos adultos durante todo el experimento. A mediado de junio se realizan pruebas de comportamiento sexual tanto individuales como grupales. Los niveles medios de testosterona plasmática (ng/ml) a lo largo del experimento fueron mayores (P <0,001) en los grupos C (4,4±0,2) y SAR (4,3±0,2) que en los grupos FA (3,4±0,2) y NAR (3,4±0,2). En los test comportamentales, los corderos del grupo C mostraron un mayor número de manifestaciones sexuales (P <0,05). Las tasas de fertilidad de las ovejas cubiertas con corderos de los grupos SAR (90%) o C (100%) son más altas (P <0,01) que las de las ovejas cubiertas con FA (50%) y NAR (40%). En conclusión, los corderos nacidos en otoño y criados en aislamiento de sus congéneres adultos tuvieron una mayor actividad sexual y fertilidad a los 8 meses de edad, lo que sugiere que no es necesaria una estrategia de cría especial para inducir la pubertad en estos corderos.<br /

Assembly and structural analysis of a covalently closed nano-scale DNA cage

The inherent properties of DNA as a stable polymer with unique affinity for partner molecules determined by the specific Watson–Crick base pairing makes it an ideal component in self-assembling structures. This has been exploited for decades in the design of a variety of artificial substrates for investigations of DNA-interacting enzymes. More recently, strategies for synthesis of more complex two-dimensional (2D) and 3D DNA structures have emerged. However, the building of such structures is still in progress and more experiences from different research groups and different fields of expertise are necessary before complex DNA structures can be routinely designed for the use in basal science and/or biotechnology. Here we present the design, construction and structural analysis of a covalently closed and stable 3D DNA structure with the connectivity of an octahedron, as defined by the double-stranded DNA helices that assembles from eight oligonucleotides with a yield of ∼30%. As demonstrated by Small Angle X-ray Scattering and cryo-Transmission Electron Microscopy analyses the eight-stranded DNA structure has a central cavity larger than the apertures in the surrounding DNA lattice and can be described as a nano-scale DNA cage, Hence, in theory it could hold proteins or other bio-molecules to enable their investigation in certain harmful environments or even allow their organization into higher order structures

Does the Methacholine Test Reproduce Symptoms?

BACKGROUND: The interpretation of methacholine test results do not usually consider the symptoms for which the subject was referred and those that occur during the test

Activité de conception du formateur et formation professionnelle

Parmi la diversité des activités menées par les formateurs, celle relative à la conception des situations et/ou dispositifs de formation, est peu étudiée et, de fait, reste à ce jour encore assez méconnue. La préoccupation première de ce dossier thématique est de permettre au lecteur d’avoir accès à des contributions qui, à partir d’ancrages théoriques et de méthodologies différents mais aussi de terrains d’étude singuliers (agriculture, enseignement, etc.), étudient l’activité de conception. Les contributions retenues au sein de ce dossier permettent de couvrir trois types d’enjeux en matière de conception des situations et/ou dispositifs de formation. Certaines étudient comment et dans quelle mesure l’activité de conception du formateur parvient à prendre en considération les contraintes et les aménagements nécessaires au passage de la transmission/acquisition des savoirs au développement de compétences singulières chez les formés. D’autres contributions interrogent plutôt la place du métier, objet de formation plus ou moins objectivisé et formalisé, au coeur de l’activité de conception. À ce titre, elles posent des problématiques connexes telles que par exemple celle relative au statut des formateurs et à la nature de leur expertise. Enfin, certaines contributions étudient plus spécifiquement comment concevoir des situations et/ou dispositifs de formation dont l’objectif serait de participer à la construction de compétences plus générales (par exemple les « soft skills » relatives au travail en équipe, à la pensée critique, etc.) de plus en plus attendues dans de nombreux domaines professionnels

Clinical manifestations of intermediate allele carriers in Huntington disease

Objective: There is controversy about the clinical consequences of intermediate alleles (IAs) in Huntington disease (HD). The main objective of this study was to establish the clinical manifestations of IA carriers for a prospective, international, European HD registry. Methods: We assessed a cohort of participants at risk with <36 CAG repeats of the huntingtin (HTT) gene. Outcome measures were the Unified Huntington's Disease Rating Scale (UHDRS) motor, cognitive, and behavior domains, Total Functional Capacity (TFC), and quality of life (Short Form-36 [SF-36]). This cohort was subdivided into IA carriers (27-35 CAG) and controls (<27 CAG) and younger vs older participants. IA carriers and controls were compared for sociodemographic, environmental, and outcome measures. We used regression analysis to estimate the association of age and CAG repeats on the UHDRS scores. Results: Of 12,190 participants, 657 (5.38%) with <36 CAG repeats were identified: 76 IA carriers (11.56%) and 581 controls (88.44%). After correcting for multiple comparisons, at baseline, we found no significant differences between IA carriers and controls for total UHDRS motor, SF-36, behavioral, cognitive, or TFC scores. However, older participants with IAs had higher chorea scores compared to controls (p 0.001). Linear regression analysis showed that aging was the most contributing factor to increased UHDRS motor scores (p 0.002). On the other hand, 1-year follow-up data analysis showed IA carriers had greater cognitive decline compared to controls (p 0.002). Conclusions: Although aging worsened the UHDRS scores independently of the genetic status, IAs might confer a late-onset abnormal motor and cognitive phenotype. These results might have important implications for genetic counseling. ClinicalTrials.gov identifier: NCT01590589