Diversité spécifique de la macrofaune benthique dans la côte ouest de la baie de Tunis et la côte de l'île de Djerba (sud-ouest de la Méditerranée)

In this study, 21 stations were sampled, 11 in the Djerba island coast and 10 in the western coast of Tunis bay. Then, samples were sifted on a square mesh of 1 mm a side, and the animals collected were identified and counted. Lacking an efficient single index suitable for application in all situations, several traditional nonparametric indices of biodiversity were selected, calculated and discussed. Results show that the community composition is totally different in the two studied sites, and, within each site, several species are common, butthey exchange the leader ranks from one station to another. For biodiversity measurement and since results show varying values depending on indices at several stations, an arithmetic mean index was calculated at each station on the basis of the most similar indices. It shows that, overall, the biodiversity is significantly higher in Tunis bay coast than in Djerba coast. These results are more reliable considering the real environmental /anthropogenic constraints imposed on both sites. Indeed, Djerba coast is subject, these last decades, to strong industrial, urban and fishing activities, causing significant regression of benthic habitats, which can led to a reduction of the biodiversity.Dans cette étude, 21 stations ont été échantillonnées, 11 dans la côte de l'île de Djerba et 10 dans la côte ouest de la baie de Tunis. Ensuite, les échantillons ont été tamisés sur une maille carrée de 1 mm de côté, et les animaux capturés ont été identifiés et comptés. Faute d'un indice unique efficace et adapté à toutes les situations, plusieurs indices traditionnels de biodiversité ont été choisis, calculés et discutés. Les résultats montrent que la composition de la communauté est totalement différente dans les deux sites étudiés, et, à chaque site, plusieurs espèces sont communes, mais ils se substituent aux places des leaders d'une station à l’autre. Pour la mesure de la biodiversité et étant donné la grande différence dans les valeurs enregistrées par les indices retenus, une moyenne arithmétique a été calculée à chaque station sur la base des indices les plus cohérents. Elle montre que, globalement, la biodiversité est nettement plus élevée dans la baie de Tunis par rapport à la côte de Djerba. Ces résultats semblent être plus fiables tenant en compte les contraintes réelles environnementales et anthropiques imposées aux deux sites. En effet, la côte de Djerba est l'objet, ces dernières décennies, à de fortes activités urbaines et de pêche industrielle, entraînant une régression significative des habitats benthiques, ce qui peut conduire à la réduction de la biodiversité

Le mal de pott sous occipital révélé par un abcès rétro pharyngien a propos d’un cas

Introduction : Pott's disease is the most frequent localisation of osteo-articular tuberculosis. The suboccipital localisation remains rare. Case report : A 12-years old boy, admitted for cervicalgy and dysphagia. His clinical exam revealed a swelling of posterior pharyngeal wall associated with a basicervical tumefaction fistulased to the skin. Cervical spine MRI and cervico-thoracic tomodensitometry show a retro-pharyngeal collection associated with necrosed mediastinal adenopathies and apical pulmonar retractile lesion. The patient underwent, in emergency, an incision of the retro-pharyngeal abscess. The biological assessment revealed an inflommatory syndrom. A tuberculine intra dermo-reaction was negative whereas the BK research were positive. The diagnosis of suboccipital Pott's disease associated with pulmonar tuberculosis was done. The anti-tuberculosis drug was mentained for 11 months with a good recovery. The follow-up was 6 years. Discussion : The sub occipital pain Pott localisation was rare. The cervicalgy was the important clinical sign of consultation. Whearas, the dysphagia and retro-pharyngeal abscess could be revealing. The MRI was necessary for an early diagnosis. The diagnosis confirmation was made by the presence of Mycobacterium Koch in the pottic lesion. The treatment was based on the anti-tuberculosis drugs for a period of 11 months completed with an orthopedic or surgical stabilisation of cervical occipital jonction.Keywords : Pott’s disease, tuberculosis, cervical spine, MRI, Mycobacterium Koch

GPI-anchor signal sequence influences PrPC sorting, shedding and signalling, and impacts on different pathomechanistic aspects of prion disease in mice

The cellular prion protein (PrPC) is a cell surface glycoprotein attached to the membrane by a glycosylphosphatidylinositol (GPI)-anchor and plays a critical role in transmissible, neurodegenerative and fatal prion diseases. Alterations in membrane attachment influence PrPC-associated signaling, and the development of prion disease, yet our knowledge of the role of the GPI-anchor in localization, processing, and function of PrPC in vivo is limited We exchanged the PrPC GPI-anchor signal sequence of for that of Thy-1 (PrPCGPIThy-1) in cells and mice. We show that this modifies the GPI-anchor composition, which then lacks sialic acid, and that PrPCGPIThy-1 is preferentially localized in axons and is less prone to proteolytic shedding when compared to PrPC. Interestingly, after prion infection, mice expressing PrPCGPIThy-1 show a significant delay to terminal disease, a decrease of microglia/astrocyte activation, and altered MAPK signaling when compared to wild-type mice. Our results are the first to demonstrate in vivo, that the GPI-anchor signal sequence plays a fundamental role in the GPI-anchor composition, dictating the subcellular localization of a given protein and, in the case of PrPC, influencing the development of prion disease

Artificial Intelligence for Sustainable Development: Synthesis Report, Mobile Learning Week 2019

(First paragraph) 2019’s Mobile Learning Week (MLW), UNESCO’s flagship event for information and communication technology (ICT) in education, focused on the theme ‘Artificial Intelligence for Sustainable Development’. Held over five days in Paris, it comprised a sequence of high-profile events (a global conference, a policy forum and workshops, a symposium and strategy labs), and involved more than 1,500 participants from 140 countries (including Ministers of Education and ICT, other representatives from Member States, the private sector, academia and international organizations)

Disentangling the heterogeneous income elasticity and dynamics of health expenditure.

In this article, we empirically study the impact of per capita income on health-care expenditure and its dynamics over time in a sample of 14 OECD countries for the period 1971 to 2009. A simple model, built upon one developed by Newhouse (1977), suggests that health care is a necessity in the short run but it cannot be rejected to be a luxury good in the long run. Our findings provide strong empirical evidence that a year’s health expenditure is conditioned by the previous one. Interestingly, our results reveal increasing income inelasticity over time along with huge heterogeneity across countries. Finally, this article supports the hypothesis of conditional convergence in health-care spending among countries. In designing policies which facilitate the sustainability of national health systems, we emphasize that ceteris paribus the greater the participation of public health, the lower the growth rate of health spending. High share of children and elderly over working age population opposite influences. We also provide evidence that technological progress could reduce the long-run income elasticity for health care, which in turn threaten the sustainability of health-care systems

Simulating heterogeneous behaviours in complex systems on GPUs

Agent Based Modelling (ABM) is an approach for modelling dynamic systems and studying complex and emergent behaviour. ABMs have been widely applied in diverse disciplines including biology, economics, and social sciences. The scalability of ABM simulations is typically limited due to the computationally expensive nature of simulating a large number of individuals. As such, large scale ABM simulations are excellent candidates to apply parallel computing approaches such as Graphics Processing Units (GPUs). In this paper, we present an extension to the FLAME GPU 1 [1] framework which addresses the divergence problem, i.e. the challenge of executing the behaviour of non-homogeneous individuals on vectorised GPU processors. We do this by describing a modelling methodology which exposes inherent parallelism within the model which is exploited by novel additions to the software permitting higher levels of concurrent simulation execution. Moreover, we demonstrate how this extension can be applied to realistic cellular level tissue model by benchmarking the model to demonstrate a measured speedup of over 4x

Molecular architecture and activation of the insecticidal protein Vip3Aa from Bacillus thuringiensis

Bacillus thuringiensis Vip3 (Vegetative Insecticidal Protein 3) toxins are widely used in biotech crops to control Lepidopteran pests. These proteins are produced as inactive protoxins that need to be activated by midgut proteases to trigger cell death. However, little is known about their three-dimensional organization and activation mechanism at the molecular level. Here, we have determined the structures of the protoxin and the protease-activated state of Vip3Aa at 2.9 Å using cryo-electron microscopy. The reconstructions show that the protoxin assembles into a pyramid-shaped tetramer with the C-terminal domains exposed to the solvent and the N-terminal region folded into a spring-loaded apex that, after protease activation, drastically remodels into an extended needle by a mechanism akin to that of influenza haemagglutinin. These results provide the molecular basis for Vip3 activation and function, and serves as a strong foundation for the development of more efficient insecticidal proteins

A study of patent thickets

Report analysing whether entry of UK enterprises into patenting in a technology area is affected by patent thickets in the technology area

Genome wide analysis of gene expression changes in skin from patients with type 2 diabetes

Non-healing chronic ulcers are a serious complication of diabetes and are a major healthcare problem. While a host of treatments have been explored to heal or prevent these ulcers from forming, these treatments have not been found to be consistently effective in clinical trials. An understanding of the changes in gene expression in the skin of diabetic patients may provide insight into the processes and mechanisms that precede the formation of non-healing ulcers. In this study, we investigated genome wide changes in gene expression in skin between patients with type 2 diabetes and non-diabetic patients using next generation sequencing. We compared the gene expression in skin samples taken from 27 patients (13 with type 2 diabetes and 14 non-diabetic). This information may be useful in identifying the causal factors and potential therapeutic targets for the prevention and treatment of diabetic related diseases