A model for the conformational activation of the structurally quiescent metalloprotease ADAMTS13 by Von Willebrand factor

Blood loss is prevented by the multi-domain glycoprotein von Willebrand factor (VWF), which binds exposed collagen at damaged vessels and captures platelets. VWF is regulated by the metalloprotease ADAMTS13, which, in turn, is conformationally activated by VWF. To delineate the structural requirements for VWF-mediated conformational activation of ADAMTS13, we performed binding and functional studies with a panel of truncated ADAMTS13 variants. We demonstrate that both the isolated CUB1 and CUB2 domains in ADAMTS13 bind to the spacer domain exosite of a truncated ADAMTS13 variant, MDTCS (KD of 135 ± 10.1 nM and 86.9 ± 9.0 nM, respectively). However, only the CUB1 domain inhibited proteolytic activity of MDTCS. Moreover, ADAMTS13∆CUB2, unlike ADAMTS13∆CUB1-2, exhibited activity similar to wild-type ADAMTS13 and could be activated by VWF D4-CK. The CUB2 domain is therefore not essential for maintaining the inactive conformation of ADAMTS13. Both CUB domains could bind to the VWF D4-CK domain fragment (KD of 53.7± 2.1 nM and 84.3 ± 2.0 nM, respectively). However, deletion of both CUB domains did not prevent VWF D4-CK binding, suggesting that competition for CUB-domain binding to the spacer domain is not the dominant mechanism behind the conformational activation. ADAMTS13∆TSP8-CUB2 could no longer bind to VWF D4-CK, and deletion of TSP8 abrogated ADAMTS13 conformational activation. These findings support an ADAMTS13-activation model in which VWF D4-CK engages the TSP8-CUB2 domains, inducing the conformational change that disrupts the CUB1-spacer domain interaction and thereby activates ADAMTS13

Signatures of quantum phase transitions in parallel quantum dots: Crossover from local-moment to underscreened spin-1 Kondo physics

We study a strongly interacting "quantum dot 1" and a weakly interacting "dot 2" connected in parallel to metallic leads. Gate voltages can drive the system between Kondo-quenched and non-Kondo free-moment phases separated by Kosterlitz-Thouless quantum phase transitions. Away from the immediate vicinity of the quantum phase transitions, the physical properties retain signatures of first-order transitions found previously to arise when dot 2 is strictly noninteracting. As interactions in dot 2 become stronger relative to the dot-lead coupling, the free moment in the non-Kondo phase evolves smoothly from an isolated spin-one-half in dot 1 to a many-body doublet arising from the incomplete Kondo compensation by the leads of a combined dot spin-one. These limits, which feature very different spin correlations between dot and lead electrons, can be distinguished by weak-bias conductance measurements performed at finite temperatures.Comment: 7 pages, 7 figures. Accepted for publication in Phys. Rev.

Clinical reasoning in canine spinal disease: what combination of clinical information is useful?

Spinal disease in dogs is commonly encountered in veterinary practice. Numerous diseases may cause similar clinical signs and presenting histories. The study objective was to use statistical models to identify combinations of discrete parameters from the patient signalment, history and neurological examination that could suggest the most likely diagnoses with statistical significance. A retrospective study of 500 dogs referred to the Queen Mother Hospital for Animals before June 2012 for the investigation of spinal disease was performed. Details regarding signalment, history, physical and neurological examinations, neuroanatomical localisation and imaging data were obtained. Univariate analyses of variables (breed, age, weight, onset, deterioration, pain, asymmetry, neuroanatomical localisation) were performed, and variables were retained in a multivariate logistic regression model if P<0.05. Leading diagnoses were intervertebral disc extrusion (IVDE, n=149), intervertebral disc protrusion (n=149), ischaemic myelopathy (IM, n=48) and neoplasms (n=44). Multivariate logistic regression characterised IM and acute non-compressive nucleus pulposus extrusions as the only peracute onset, non-progressive, non-painful and asymmetrical T3-L3 myelopathies. IVDE was most commonly characterised as acute onset, often deteriorating, painful and largely symmetrical T3-L3 myelopathy. This study suggests that most spinal diseases cause distinctive combinations of presenting clinical parameters (signalment, onset, deterioration, pain, asymmetry, neuroanatomical localisation). Taking particular account of these parameters may aid decision making in a clinical setting

SymGRASS: a database of sugarcane orthologous genes involved in arbuscular mycorrhiza and root nodule symbiosis : from Seventh International Meeting on Computational Intelligence Methods for Bioinformatics and Biostatistics, (CIBB 2010), Palermo, Italy, 16 - 18 September 2010

Background: The rationale for gathering information from plants procuring nitrogen through symbiotic interactions controlled by a common genetic program for a sustainable biofuel production is the high energy demanding application of synthetic nitrogen fertilizers. We curated sequence information publicly available for the biofuel plant sugarcane, performed an analysis of the common SYM pathway known to control symbiosis in other plants, and provide results, sequences and literature links as an online database. Methods: Sugarcane sequences and informations were downloaded from the nucEST database, cleaned and trimmed with seqclean, assembled with TGICL plus translating mapping method, and annotated. The annotation is based on BLAST searches against a local formatted plant Uniprot90 generated with CD-HIT for functional assignment, rpsBLAST to CDD database for conserved domain analysis, and BLAST search to sorghum's for Gene Ontology (GO) assignment. Gene expression was normalized according the Unigene standard, presented as ESTs/100 kb. Protein sequences known in the SYM pathway were used as queries to search the SymGRASS sequence database. Additionally, antimicrobial peptides described in the PhytAMP database served as queries to retrieve and generate expression profiles of these defense genes in the libraries compared to the libraries obtained under symbiotic interactions. Results: We describe the SymGRASS, a database of sugarcane orthologous genes involved in arbuscular mycorrhiza (AM) and root nodule (RN) symbiosis. The database aggregates knowledge about sequences, tissues, organ, developmental stages and experimental conditions, and provides annotation and level of gene expression for sugarcane transcripts and SYM orthologous genes in sugarcane through a web interface. Several candidate genes were found for all nodes in the pathway, and interestingly a set of symbiosis specific genes was found. Conclusions: The knowledge integrated in SymGRASS may guide studies on molecular, cellular and physiological mechanisms by which sugarcane controls the establishment and efficiency of endophytic associations. We believe that the candidate sequences for the SYM pathway together with the pool of exclusively expressed tentative consensus (TC) sequences are crucial for the design of molecular studies to unravel the mechanisms controlling the establishment of symbioses in sugarcane, ultimately serving as a basis for the improvement of grass crops

Maternidade e cadeia : um estudo de caso sobre a prisão domiciliar

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Faculdade de Direito, 2017.A presente pesquisa tem por objetivo analisar, com uma perspectiva feminista e a partir de um estudo de caso, como o exercício do direito à prisão albergue domiciliar (PAD) de uma mulher encarcerada foi negado. Minha tese é de que há casos em que a prisão albergue domiciliar não é concedida, ainda que a mulher atenda às hipóteses da lei, devido a uma ordem moral - a patriarcal - que não admite que determinadas mulheres recebam o referido benefício sob um ideal de gênero feminino e maternidade. Para tanto, foi feita revisão de literatura sobre o tema e o material empírico utilizado foram processos judiciais originários da Justiça Federal de São Paulo, do STJ e do STF. Apoiado no material empírico houve análise de um recorte da história jurídica-processual da Adriana da Conceição, uma mulher cabo-verdiana, preta, pouco escolarizada, doméstica, solteira, pobre, presa por tráfico transnacional de drogas enquanto estava grávida e que teve o filho na prisão. Durante o processo penal, enquanto persistia a prisão preventiva, houve o pedido de prisão albergue domiciliar, demanda essa que foi negada sob vários argumentos - “ausência de comprovação da imprescindibilidade de cuidados”, “inexistência na legislação de obrigatoriedade para a concessão do instituto”, “irresponsabilidade da mãe”, “direitos da criança” - em todas as instâncias em que percorreu. Quanto à questão da prisão, lembrou-se que, atualmente 80% das mulheres têm filhos (ITTC, 2012) e em cada 10 mulheres presas 3 estão sob esta condição de forma provisória (BRASIL, 2014). Diante deste cenário, uma das premissas que se tem neste trabalho é o potencial desencarcerador que a prisão albergue domiciliar substitutiva da prisão preventiva possui para grande parte das mulheres presas nos presídios brasileiros, seja estrangeira ou nacional. Concluo que os discursos jurídico-penais se movimentaram para punir Adriana da Conceição duas vezes: não somente pelo julgamento de direito sobre desvio da norma penal, mas pelo julgamento de uma mulher que se desviou do imaginário construído pelo regime de gênero de mãe cuidadora.The present research aims to analyze, with a feminist perspective and from a case study, how the exercise of the right to the home detention (PAD) of an imprisoned woman was denied. My thesis is that there are cases where home detention right is not granted, even if the woman meets the hypotheses of the law, due to a moral order - the patriarchal one - that does not allow certain women to receive the benefit under an ideal of gender and maternity. For that, a review of the literature on the subject was done and the empirical material used was judicial proceedings originating from the Federal Court of São Paulo, STJ and STF. Based on the empirical material, there was made an analysis of the micronarrative of Adriana da Conceição, a black, poorly educated, domestic, single, poor Cape Verdean woman arrested for transnational drug trafficking, while pregnant, and who had her child in prison. During the criminal proceedings, while pre-trial detention persisted, the request for a residential shelter was denied under several arguments - "lack of proof of the indispensability of care", "lack of mandatory legislation for the grant of the institute" , "Irresponsibility of the mother", "child rights" - in all the instances in which it has gone. Regarding the issue of imprisonment, it was recalled that currently 80% of the women have children (ITTC, 2012) and in every 10 women arrested, 3 are under this condition on a provisional basis (BRAZIL, 2014). In view of this scenario, one of the premises that we have in this work is the potential disincarnating that the house arrest substitute of the preventive prison has for a great part of the women prisoners in the Brazilian prisons, be it foreign or national. I conclude that the juridical-penal discourses moved to punish Adriana da Conceição twice: not only for the judgment of law on deviation from the penal norm, but for the judgment of a woman who has deviated from the imaginary constructed by the gender regime of caretaker mother

Collisionless dynamics in Globular Clusters

Since globular clusters (GCs) are old, low-N systems their dynamics is widely believed to be fully dominated by collisional two-body processes, and their surface brightness profiles are fit by King models. However, for many GCs, especially those with HST-resolved central regions, and `extra-tidal' features, King models provide poor fits. We suggest that this is partly because collisionless dynamics is also important and contribute to shaping the cluster properties. We show using time-scale and length-scale arguments that except for the very centers of clusters, collisionless dynamics should be more important than collisional. We then fit 38 GCs analyzed by Noyola and Gebhardt (2006) with (collisional) King and (collisionless) DARKexp models over the full available radial range, and find that the latter provide a better fit to 29 GCs; for six of these the fit is at least ~5x better in term of rms. DARKexp models are theoretically derived maximum entropy equilibrium states of self-gravitating collisionless systems and have already been shown to fit the results of dark matter N-body simulations. (We do not attempt fits with ad hoc fitting functions.)Comment: 27 pages, 18 figures; accepted to MNRA