931 research outputs found

    Anatomy and systematics of the diplodocoid Amphicoelias altus supports high sauropod dinosaur diversity in the Upper Jurassic Morrison Formation of the USA

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    Sauropod dinosaurs were an abundant and diverse component of the Upper Jurassic Morrison Formation of the USA, with 24 currently recognized species. However, some authors consider this high diversity to have been ecologically unviable and the validity of some species has been questioned, with suggestions that they represent growth series (ontogimorphs) of other species. Under this scenario, high sauropod diversity in the Late Jurassic of North America is greatly overestimated. One putative ontogimorph is the enigmatic diplodocoid Amphicoelias altus, which has been suggested to be synonymous with Diplodocus. Given that Amphicoelias was named first, it has priority and thus Diplodocus would become its junior synonym. Here, we provide a detailed re-description of A. altus in which we restrict it to the holotype individual and support its validity, based on three autapomorphies. Constraint analyses demonstrate that its phylogenetic position within Diplodocoidea is labile, but it seems unlikely that Amphicoelias is synonymous with Diplodocus. As such, our re-evaluation also leads us to retain Diplodocus as a distinct genus. There is no evidence to support the view that any of the currently recognized Morrison sauropod species are ontogimorphs. Available data indicate that sauropod anatomy did not dramatically alter once individuals approached maturity. Furthermore, subadult sauropod individuals are not prone to stemward slippage in phylogenetic analyses, casting doubt on the possibility that their taxonomic affinities are substantially misinterpreted. An anatomical feature can have both an ontogenetic and phylogenetic signature, but the former does not outweigh the latter when other characters overwhelmingly support the affinities of a taxon. Many Morrison Formation sauropods were spatio-temporally and/or ecologically separated from one another. Combined with the biases that cloud our reading of the fossil record, we contend that the number of sauropod dinosaur species in the Morrison Formation is currently likely to be underestimated, not overestimated

    Death domain assembly mechanism revealed by crystal structure of the oligomeric PIDDosome core complex

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    Proteins of the death domain (DD) superfamily mediate assembly of oligomeric signaling complexes for the activation of caspases and kinases via unknown mechanisms. Here we report the crystal structure of the PIDD DD and RAIDD DD complex, which forms the core of the caspase-2-activating complex PIDDosome. Although RAIDD DD and PIDD DD are monomers, they assemble into a complex that comprises seven RAIDD DDs and five PIDD DDs. Despite the use of an asymmetric assembly mechanism, all DDs in the complex are in quasi-equivalent environments. The structure provided eight unique asymmetric interfaces, which can be classified into three types. These three types of interactions together cover a majority of the DD surface. Mutagenesis on almost all interfaces leads to disruption of the assembly, resulting in defective caspase-2 activation. The three types of interactions may represent most, if not all, modes of interactions in the DD superfamily for assembling complexes of different stoichiometry

    Antenatal care and skilled delivery service utilisation in Somali pastoral communities of Eastern Ethiopia

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    To assess maternal health care service utilisation and associated factors in Somali pastoral communities of eastern Ethiopia.; Community-based cross-sectional study complemented by qualitative assessments in Adadle district, Somali region, eastern Ethiopia, among 450 women in six kebeles from August to September 2016. Logistic regression was used to assess factors associated with antenatal care use and skilled delivery care use, controlling for confounders.; About 27% [95%CI 22.8-31.2%] of women used antenatal care, and 22.6% [95%CI 18.7-26.5%] received skilled delivery service. None of the respondents reported post-natal care. About 43% reported that they had no knowledge of antenatal care, and 46% did not perceive delivery at a health facility as important. Pastoral lifestyle, husband's educational status, women's attitude towards health care service and financial support from the husband were significantly associated with antenatal care utilisation. Health professionals' attitudes, perceptions of institutional delivery, antenatal care utilisation and information about exemptions from maternal health care fees were associated with skilled delivery service utilisation.; Improving community awareness of antenatal care, employing female health professionals and culturally adapted guidelines could improve skilled delivery utilisation. In a patriarchal society, involving male partners in all maternal health issues is essential to increase use of maternal health services and to decrease maternal mortality

    Effects of purified perforin and granzyme A from cytotoxic T lymphocytes on guinea pig ventricular myocytes

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    Objective: Involvement of cytotoxic T lymphocytes (CTL) in heart transplant rejection as well as in viral myocarditis is well established, but the precise mechanisms whereby infiltrating CTL damage the myocardium are unknown. The aim of the study was to investigate how CTL derived perforin, the serine protease granzyme A, and the combination of both, damage guinea pig ventricular myocytes. Methods: Action potentials and membrane currents were recorded by means of the whole cell configuration from guinea pig ventricular myocytes. Results: Resembling the effects of CTL derived lytic granules, perforin caused gradual myocyte shortening and contracture, leading to complete loss of the rod shaped morphology and to cell destruction. These changes were preceded by shortening of action potential duration and reduction of resting potential and action potential amplitude, followed by complete inexcitability. Granzyme A alone was ineffective, but accelerated the deleterious effects of perforin on the morphological and electrophysiological properties of myocytes. The effects of perforin were further evaluated by measuring membrane currents by means of the whole cell voltage clamp. Perforin induced discrete changes in membrane current, reminiscent of single ion channels, with large conductance and open time of up to several seconds. Linear regression analysis of the channel I-V relations resulted in a conductance of 890 pS and a reversal potential of −7.6 mV. These results suggest that perforin induces large non-selective channels, which can account for most of the observed adverse effects. Conclusions: As CTL participate in the immunological rejection of the transplanted heart, it is conceivable, but remains to be shown, that part of this damage is inflicted by perforin containing lytic granules. Cardiovascular Research 1994;28:643-64

    Integrated community based human and animal syndromic surveillance in Adadle district of the Somali region of Ethiopia

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    The economy of Ethiopia largely depends on agriculture and roughly 80% of the households have direct contact with domestic animals which make the community vulnerable to zoonotic diseases, especially in pastoral areas like the Somali Regional State (SRS) of Ethiopia. However, in addition to low reporting rates, especially in livestock, there is also lack of coordination between public health and animal health surveillance and there is no linkage between public health system and animal health system and mechanism or structure for sharing information on zoonotic diseases in SRS. In view of these challenges, a small scale study was conducted to evaluate the feasibility of mobile communication in the early detection of human and animal syndromes in remote pastoral areas including where there are no human and animal health facilities by engaging local communities in the diseases surveillance. Method: A small scale study, testing a community based human and animal syndromic surveillance was conducted from August 2017 to February 2018 in 20 villages in four Kebeles of Adadle district in the SRS with an estimated 1390 households and 112,850 livestock. The selected community leaders were trained on disease surveillance and detection. The communication was done by direct calls. Two dollars per month were provided to the village leaders recruited for the surveillance. Results: A total of 904 and 671 human and animal syndrome cases were reported in seven months of the study period. In addition to syndromes, suspected anthrax, sheep and goat pox (SGP), rabies, salmonellosis and mass abortion outbreaks were reported in animals. In humans, suspected cholera and chicken pox outbreaks were reported. Furthermore, tuberculosis and malaria cases were also confirmed in the study villages. In humans, gastrointestinal tract (GIT) disorder was the most common syndrome observed, which constituted (42.8%) of all syndromes, followed by respiratory disorder (37.8%) and febrile illness (15.5%). In livestock, cattle contributed (40.8%) of all cases of illness, while sheep, goats and camels contributed 24.1%, 18% and 17% of the cases respectively. Responses were organized for emergency treatment and vaccination campaigns against certain suspected disease outbreaks and emergencies such as SGP and cholera. Conclusion: This study suggests that engaging and empowering the village local leaders in disease surveillance in pastoral setting areas, including where there are no human and animal health facilities, coupled with mobile technologies (non-smart phone), would improve early detection and response to human and animal health events including zoonotic emergencies, and consequently improve the reporting rate at district, regional and national level. However, the collaboration between sectors (human health and animals health) and the capacity to respond to zoonotic diseases and etiological identification are crucial elements for effective integrated human and animals disease surveillance and response

    Lassen sich Explosivkraftmessungen auf der Kraftmessplatte durch einfache Feldtests ersetzen? Studie mit 19 Handballern des U 21-Nationalkaders

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    Die Bedeutung der Explosivkraft als Leistungsvoraussetzung fürschnelle, azyklische und zyklische Bewegungen in vielen Sportartennimmt zu. Somit steigt auch das Anspruchsniveau von Trainernund Athleten an die Messgenauigkeit und Vergleichbarkeitvon einfachen Feldtests zur Messung der Explosivkraft der unterenExtremitäten, um individuelle Trainingsfortschritte zu dokumentierenund die Trainingsplanung zu verbessern. Es bestand daherdie Absicht, einfache Feldtests mit einem Standardverfahren imLabor zu vergleichen. 19 männliche Spitzensportler des Handball-U21-Nationalkaders, Absolventen der Spitzensportler-Rekrutenschulein Magglingen, führten in einem Abstand von 2 Tagen viereinfache Feldtests (Standweitsprung, 5er-Hupf, 30-m-Sprint, Jumpand Reach) und den Sprungkrafttest auf Kraftmessplatten durch.Die Beziehung zwischen Standweitsprung, 5er-Hupf und 30-m-Sprint einschliesslich der Abschnittszeiten mit den Werten desLabortestes war im Kollektiv mit Korrelationskoeffi zienten vondurchwegs 0.6 bis 0.8 signifi kant bis hoch signifi kant. Der Jumpand Reach korreliert nicht mit den beidbeinigen Ergebnissen derKraftmessplatten. Die individuelle Voraussage aus den Feldtestsheraus, repräsentiert durch den grossen Standardfehler des Schätzers,ist allerdings ungenügend.Für einen generellen Eindruck, etwa im Sinne des mittleren Leistungsstandeseines Teams, sind die einfachen Feldtests Standweitsprung,5er-Hupf und die Sprintvarianten durchaus einsetzbar.Schon hier genügt allerdings der Jump and Reach nicht den Ansprüchen.Für eine individuell präzise Betrachtung der Explosivkraft, einschliesslichder Dokumentation individueller Änderungen, reichtdie Genauigkeit der einfachen Feldtests nicht aus, und hier ist dieAnwendung von Kraftmessplatten indiziert

    BAFF production by antigen‐presenting cells provides T cell co‐stimulation

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    The B cell‐activating factor from the tumor necrosis factor family (BAFF) is an important regulator of B cell immunity. Recently, we demonstrated that recombinant BAFF also provides a co‐stimulatory signal to T cells. Here, we studied expression of BAFF in peripheral blood leukocytes and correlated this expression with BAFF T cell co‐stimulatory function. BAFF is produced by antigen‐presenting cells (APC). Blood dendritic cells (DC) as well as DC differentiated in vitro from monocytes or CD34+ stem cells express BAFF mRNA. Exposure to bacterial products further up‐regulates BAFF production in these cells. A low level of BAFF transcription, up‐regulated upon TCR stimulation, was also detected in T cells. Functionally, blockade of endogenous BAFF produced by APC and, to a lesser extent, by T cells inhibits T cell activation. Altogether, this indicates that BAFF may regulate T cell immunity during APC-T cell interactions and as an autocrine factor once T cells have detached from the AP
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