The Talin Head Domain Reinforces Integrin-Mediated Adhesion by Promoting Adhesion Complex Stability and Clustering

Talin serves an essential function during integrin-mediated adhesion in linking integrins to actin via the intracellular adhesion complex. In addition, the N-terminal head domain of talin regulates the affinity of integrins for their ECM-ligands, a process known as inside-out activation. We previously showed that in Drosophila, mutating the integrin binding site in the talin head domain resulted in weakened adhesion to the ECM. Intriguingly, subsequent studies showed that canonical inside-out activation of integrin might not take place in flies. Consistent with this, a mutation in talin that specifically blocks its ability to activate mammalian integrins does not significantly impinge on talin function during fly development. Here, we describe results suggesting that the talin head domain reinforces and stabilizes the integrin adhesion complex by promoting integrin clustering distinct from its ability to support inside-out activation. Specifically, we show that an allele of talin containing a mutation that disrupts intramolecular interactions within the talin head attenuates the assembly and reinforcement of the integrin adhesion complex. Importantly, we provide evidence that this mutation blocks integrin clustering in vivo. We propose that the talin head domain is essential for regulating integrin avidity in Drosophila and that this is crucial for integrin-mediated adhesion during animal development

Prevalence and relationship of endosymbiotic Wolbachia in the butterfly genus Erebia

Wolbachia is an endosymbiont common to most invertebrates, which can have significant evolutionary implications for its host species by acting as a barrier to gene flow. Despite the importance of Wolbachia, still little is known about its prevalence and diversification pattern among closely related host species. Wolbachia strains may phylogenetically coevolve with their hosts, unless horizontal host-switches are particularly common. We address these issues in the genus Erebia, one of the most diverse Palearctic butterfly genera.; We sequenced the Wolbachia genome from a strain infecting Erebia cassioides and showed that it belongs to the Wolbachia supergroup B, capable of infecting arthropods from different taxonomic orders. The prevalence of Wolbachia across 13 closely related Erebia host species based on extensive population-level genetic data revealed that multiple Wolbachia strains jointly infect all investigated taxa, but with varying prevalence. Finally, the phylogenetic relationships of Wolbachia strains are in some cases significantly associated to that of their hosts, especially among the most closely related Erebia species, demonstrating mixed evidence for phylogenetic coevolution.; Closely related host species can be infected by closely related Wolbachia strains, evidencing some phylogenetic coevolution, but the actual pattern of infection more often reflects historical or contemporary geographic proximity among host species. Multiple processes, including survival in distinct glacial refugia, recent host shifts in sympatry, and a loss of Wolbachia during postglacial range expansion seem to have jointly shaped the complex interactions between Wolbachia evolution and the diversification of its host among our studied Erebia species

The economic role of the circular economy and its relationship to sustainable development in the Arab countries Analytical and theoretical study - Dubai as a model

إن الاقتصاد الدائري يعتبر نموذج اقتصادي يسعى وراء تقليص إهدار الطاقة، والسلع والمواد المختلفة، وتحقيق التنمية المستدامة منها أكبر قدر ممكن بالإضافة إلى التنمية المستدامة تعتبر نشاط شامل لكل قطاعات الدولة و المؤسسات العامة والخاصة، كما تساهم بتقديم الخطط المستقبلية الجيدة، وذلك من خلال استغلال الطاقات المادية و البشرية، والموارد المختلفة، وهدفت هذه الدراسة إلى إبراز الدور الاقتصادي  الذي يلعبه الاقتصاد الدائري و علاقته  بالتنمية المستدامة في البلدان العربية اخذ بعين الاعتبار دبي نموذجا ، من خلال دراسة تحليلية و نظرية  حيث أن يهدف الاقتصاد الدائري إلى الحفاظ على الاستخدام المنتجات والمعدات والبنية التحتية لفترة أطول. و توصلت هذه الدراسة إلى أهمية تطبيقات و تقنيات الاقتصاد الدائري ، و المحافظة على الموارد الطبيعية وكذلك إبراز أهمية الاستثمار في الاقتصاد الدائري لخلق قيمة اقتصادية ، اجتماعية و بيئية و بأقل التكاليف.The circular economy is an economic model that seeks to reduce the waste of energy, various commodities and materials, and achieve sustainable development of them as much as possible. In addition to sustainable development, it is a comprehensive activity for all sectors of the state and public and private institutions. Material and human resources, and various resources, and this study aimed to highlight the economic role played by the circular economy and its relationship to sustainable development in the Arab countries, taking into account Dubai as a model, through an analytical and theoretical study, as the circular economy aims to maintain the use of products, equipment and infrastructure for longer. This study concluded the importance of circular economy applications and techniques, and the preservation of natural resources, as well as highlighting the importance of investing in a circular economy to create economic, social and environmental value at the lowest costs.JELClassification

The local and filmed accountability of sensorial practices: The intersubjectivity of touch as an interactional achievement

This paper contributes to a multimodal EMCA approach to sensoriality and to a reflection about how video can support it. First, it discusses how the intersubjectivity and accountability of sensorial practices are locally and endogenously achieved by and for the participants. This accountability is implemented through various multimodal resources, which make sensorial practices accessible for the co-participants. Second, it shows how the visual, verbal and sometimes co-tactile orientations of the participants are also the very basis on which researchers and other professionals build the videographability of the activity. The paper articulates these two aspects by studying activities dealing with food, in which the participants engage in touching food as a relevant sensorial practice within their ongoing course of action

Radionescrose cerebrale a propos d\'une observation

No Abstract. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 17 2006: pp. 55-5

Novel nanomaterials for anion recognition

Abundant anions in the body, like chloride and sulphate, are the target of many studies involving anion recognition. In the past 30 years, different kinds of anion receptors have been intensively studied including small molecule receptors with the aim of facilitating anion transport in cells or treating diseases induced by anionic dysregulation. Nowadays, the use of some of these receptors in water remains a challenge for anion recognition due to the high solvability of anions in aqueous media and the low solubility of these neutral receptors (1). To overcome this problem and minimise the binding competition in aqueous media, we synthesised water-soluble crosslinked polymeric nanoparticles containing hydrophobic pockets functionalised with known anion binding motifs (2). pNIPAM (poly-N-isopropylacrylamide) soft materials are known to have tuneable properties so they can be used in-vivo. With MBA (N,N-methylanebisacrylamide) as a cross-linking agent, and pendant anion binding motifs, these nanomaterials can be used in aqueous media. We will report the results of anion binding studies using these polymeric materials with anions of interest such as phosphates and sulphates. Their selectivity will help find an application in the medical area as sensors, drug carrier or anion transporter. This novelty approach will be extended to a larger series of anions and incorporate other types of anion binding motifs with biologically active properties

Améloblastome mandibulaire place de la radiothérapie

L’améloblastome est la tumeur odontogénique la plus fréquente. il  représente 1% des tumeurs mandibulaires et maxillaires et atteint la mandibule dans 80% des cas. Son traitement se base essentiellement sur la chirurgie lorsque cela est possible. La radiothérapie est réservée aux formes inopérables localement évoluées et métastatiques. Les auteurs rapportent le cas d’un patient présentant un améloblastome mandibulaire kystique traité par radiothérapie exclusive.Mots clés: Améloblastome, mandibule, radiothérapi

FAK and talin: Who is taking whom to the integrin engagement party?

In this issue, Lawson et al. provide new insight into the relationship between FAK and talin during assembly of integrin adhesions on fibronectin. They show that FAK is upstream of talin, and that talin is not required for FAK recruitment or for integrin activation at nascent adhesions. However, FAK-talin binding is required for adhesion turnover and cell motility. The findings question the view that talin is always upstream of focal adhesion protein recruitment to clustered integrin sites

Residual stress, mechanical and microstructure properties of multilayer Mo2N/CrN coating produced by R.F Magnetron discharge

We have investigated the effect of the period thickness of the multilayer Mo2N/CrN deposited on Si substrate produced by reactive magnetron sputtering. Mo2N presents a face centered cubic structure and CrN an orthorhombic one. The residual stress of the coatings was determined by the measurement of the substrate curvature. The microstructure of the multilayer was investigated from the X-ray diffraction and scanning electron microscopy (cross section images). The residual stresses resulting from the deposition of the different bi-layer thickness were measured and correlated to the structural properties of the coating as well as the nanoindentation analysis of the coating. The stresses are compressive and tensile for the individual Mo2N and CrN layer respectively. The result shows that an increase of the multilayer coatings Mo2N/CrN thicknesses induce an increase of the hardness and the elastic modulus, in the other hand the tensile stress increases. The shift of the XRD diffraction peak (1 1 1) of Mo2N at high angle which means the reduction of the residual stress is in good agreement with the residual stresses measurements

A conserved lipid-binding loop in the kindlin FERM F1 domain is required for kindlin-mediated aIIbB3 integrin coactivation

The activation of heterodimeric integrin adhesion receptors from low to high affinity states occurs in response to intracellular signals that act on the short cytoplasmic tails of integrin beta subunits. Binding of the talin FERM (four-point-one, ezrin, radixin, moesin) domain to the integrin beta-tail provides one key activation signal, but recent data indicate that the kindlin family of FERM domain proteins also play a central role. Kindlins directly bind integrin beta subunit cytoplasmic domains at a site distinct from the talin-binding site, and target to focal adhesions in adherent cells. However, the mechanisms by which kindlins impact integrin activation remain largely unknown. A notable feature of kindlins is their similarity to the integrin-binding and activating talin FERM domain. Drawing on this similarity, here we report the identification of an unstructured insert in the kindlin F1 FERM domain, and provide evidence that a highly conserved polylysine motif in this loop supports binding to negatively charged phospholipid head groups. We further show that the F1 loop and its membrane-binding motif are required for kindlin-1 targeting to focal adhesions, and for the cooperation between kindlin-1 and -2 and the talin head in aIIbB3 integrin activation, but not for kindlin binding to integrin beta tails. These studies highlight the structural and functional similarities between kindlins and the talin head and indicate that as for talin, FERM domain interactions with acidic membrane phospholipids as well beta-integrin tails contribute to the ability of kindlins to activate integrins