175 research outputs found

    Selected tools to visualize membrane interactions

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    In the past decade, we developed various fluorescence-based methods for monitoring membrane fusion, membrane docking, distances between membranes, and membrane curvature. These tools were mainly developed using liposomes as model systems, which allows for the dissection of specific interactions mediated by, for example, fusion proteins. Here, we provide an overview of these methods, including two-photon fluorescence cross-correlation spectroscopy and intramembrane Förster energy transfer, with asymmetric labelling of inner and outer membrane leaflets and the calibrated use of transmembrane energy transfer to determine membrane distances below 10 nm. We discuss their application range and their limitations using examples from our work on protein-mediated vesicle docking and fusion

    La Plaque Console Du Radius : Une Alternative Dans L’ostéosynthèse Des Fractures De L’extrémité Supérieure De L’humérus ?

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    The aim of this study was to report the results of our experience in the treatment of proximal fractures with distal radius plate. This prospective study was conducted between January 2010 and December 2014. It took into account patients with a body mass index (BMI) not more than 25 kg/m2 in which the indication of conservative surgical treatment was decided and who did not have enough financial means to fulfill the required implants. The Neer classification was used to characterize fracture. To assess treatment outcomes, we used UCLA (University of California in Los Angeles) slightly modified score. There were 17 patients including 10 men and 7 women with a mean age of 32 years. According to Neer classification, six patients (35,29%) had stage I lesions, 5 others (29,42%) stage II and 6 patients (35,29%), stage III. There was no open fracture. There were three cases (17, 66%) of fracture-dislocations with one posterior variety. The average time of care was 13, 7 days (with a range of 2 to 29 days). The average time of healing was 117, 4 days with extremes of 81 days and 4 months 10 days. All patients were consolidated. The results at a mean of 15.31 months revealed excellent results in 29.41% and 29.41% poor results. In young patients whose treatment should be as conservative as possible, the distal radius plate could be an alternative if patient BMI does not exceed 25 kg/m2 and the epiphyseal screws are not too long. In case of comminuted fracture, it seems more desirable to postpone the osteosynthesis of weeks. However, only other subsequent studies on larger samples and longer followup, may lead to some conclusions about the usefulness of the distal radius plate in these lesions

    Primary Malignant Musculosqueletal Tumors of Members in Adult in Togo

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    Abstract Purpose: Primary malignant musculosqueletal tumors in adult are rare affections group and its treatment is still a real challenge today. The aim of this work was to describe the epidemiologic and treatment aspects of these tumors in the national reference center of our country. Materiel and Methods: It was a retrospective review of primary malignant musculosqueletal tumors treated in orthopedics and trauma unit of Sylvanus Olympio teaching hospital of Lomé, Togo from January 2000 to December 2014. Results: During the study period, 28 cases were selected and reviewed. There were 17 men (60.71%) and 11 women (39.29%). The average age was 32.7 years. There were 20 cases (71%) of primary malignant bone tumors (PMBT) and 8 cases (29%) of primary malignant soft tissues tumors (PMSTT). There were 6 (30%) of osteosarcoma. The tumor was located in the bones of the forearm and wrist/hand in 2 (10%) patients for each anatomical site; for the lower limb, around knee in 7 (35%) patients. Eight patients had PMSTT (28, 57%). There were three cases of rhabdomyosarcoma, 2 cases of fibrosarcoma. Tumors were located around knee in 4 cases and around ankle/foot in 3 cases. In the two groups of tumor, tumor resection was performed in 5 patients (17.86%) and limb amputation indicated in 23 patients (82.14%), was performed in 15 (53.57%) and 8 patients (37.78%), rejected it and left hospital against medical advice. Conclusion: Malignant musculoskeletal tumors are relatively rare in Togo. Their treatment is based on radical surgery which is often not supervised by adjuvant therapies. Ignorance, poverty of the population and embryonic state of diagnostic and treatment infrastructures are the obstacles to their care. Education and awareness must be integrated to care and fight against this group of diseases

    The Early Stages and Natural History of Antirrhea Adoptive Porphyrosticta (Watkins, 1928) in Eastern Ecuador (Lepidoptera: Nymphalidae: Morphinae)

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    Here we describe the immature stages and ecological associations of Antirrhea adoptiva porphyrosticta Watkins, 1928 (Lepidoptera:Nymphalidae:Morphinae). The cloud forest bamboo, Chusquea scandens Kunth (Bambusoidea: Poaceae), serves as the larval food plant for this butterfly in eastern Ecuador, the first hostplant record for Antirrhea outside the family Arecaceae. The larvae of A. adoptiva porphyrosticta are superficially similar to those of other Antirrhea species. We also provide observations on adult and larval behavior. Caterpillars of this butterfly species are parasitized by tachinid flies, as well as by Ichneumonidae and a newly described braconid wasp

    Risk-shifting Through Issuer Liability and Corporate Monitoring

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    This article explores how issuer liability re-allocates fraud risk and how risk allocation may reduce the incidence of fraud. In the US, the apparent absence of individual liability of officeholders and insufficient monitoring by insurers under-mine the potential deterrent effect of securities litigation. The underlying reasons why both mechanisms remain ineffective are collective action problems under the prevailing dispersed ownership structure, which eliminates the incentives to moni-tor set by issuer liability. This article suggests that issuer liability could potentially have a stronger deterrent effect when it shifts risk to individuals or entities holding a larger financial stake. Thus, it would enlist large shareholders in monitoring in much of Europe. The same risk-shifting effect also has implications for the debate about the relationship between securities litigation and creditor interests. Credi-tors’ claims should not be given precedence over claims of defrauded investors (e.g., because of the capital maintenance principle), since bearing some of the fraud risk will more strongly incentivise large creditors, such as banks, to monitor the firm in jurisdictions where corporate debt is relatively concentrated

    Ultrafast transient absorption spectroscopy: principles and application to photosynthetic systems

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    The photophysical and photochemical reactions, after light absorption by a photosynthetic pigment–protein complex, are among the fastest events in biology, taking place on timescales ranging from tens of femtoseconds to a few nanoseconds. The advent of ultrafast laser systems that produce pulses with femtosecond duration opened up a new area of research and enabled investigation of these photophysical and photochemical reactions in real time. Here, we provide a basic description of the ultrafast transient absorption technique, the laser and wavelength-conversion equipment, the transient absorption setup, and the collection of transient absorption data. Recent applications of ultrafast transient absorption spectroscopy on systems with increasing degree of complexity, from biomimetic light-harvesting systems to natural light-harvesting antennas, are presented. In particular, we will discuss, in this educational review, how a molecular understanding of the light-harvesting and photoprotective functions of carotenoids in photosynthesis is accomplished through the application of ultrafast transient absorption spectroscopy

    Health Care for Mitochondrial Disorders in Canada: A Survey of Physicians

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    Background: An improved understanding of diagnostic and treatment practices for patients with rare primary mitochondrial disorders can support benchmarking against guidelines and establish priorities for evaluative research. We aimed to describe physician care for patients with mitochondrial diseases in Canada, including variation in care. Methods: We conducted a cross-sectional survey of Canadian physicians involved in the diagnosis and/or ongoing care of patients with mitochondrial diseases. We used snowball sampling to identify potentially eligible participants, who were contacted by mail up to five times and invited to complete a questionnaire by mail or internet. The questionnaire addressed: personal experience in providing care for mitochondrial disorders; diagnostic and treatment practices; challenges in accessing tests or treatments; and views regarding research priorities. Results: We received 58 survey responses (52% response rate). Most respondents (83%) reported spending 20% or less of their clinical practice time caring for patients with mitochondrial disorders. We identified important variation in diagnostic care, although assessments frequently reported as diagnostically helpful (e.g., brain magnetic resonance imaging, MRI/MR spectroscopy) were also recommended in published guidelines. Approximately half (49%) of participants would recommend mitochondrial cocktails for all or most patients, but we identified variation in responses regarding specific vitamins and cofactors. A majority of physicians recommended studies on the development of effective therapies as the top research priority. Conclusions: While Canadian physicians\u27 views about diagnostic care and disease management are aligned with published recommendations, important variations in care reflect persistent areas of uncertainty and a need for empirical evidence to support and update standard protocols

    Effects of aversive odour presentation on inhibitory control in the Stroop colour-word interference task

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    <p>Abstract</p> <p>Background</p> <p>Due to the unique neural projections of the olfactory system, odours have the ability to directly influence affective processes. Furthermore, it has been shown that emotional states can influence various non-emotional cognitive tasks, such as memory and planning. However, the link between emotional and cognitive processes is still not fully understood. The present study used the olfactory pathway to induce a negative emotional state in humans to investigate its effect on inhibitory control performance in a standard, single-trial manual Stroop colour-word interference task. An unpleasant (H<sub>2</sub>S) and an emotionally neutral (Eugenol) odorant were presented in two separate experimental runs, both in blocks alternating with ambient air, to 25 healthy volunteers, while they performed the cognitive task.</p> <p>Results</p> <p>Presentation of the unpleasant odorant reduced Stroop interference by reducing the reaction times for incongruent stimuli, while the presentation of the neutral odorant had no effect on task performance.</p> <p>Conclusions</p> <p>The odour-induced negative emotional state appears to facilitate cognitive processing in the task used in the present study, possibly by increasing the amount of cognitive control that is being exerted. This stands in contrast to other findings that showed impaired cognitive performance under odour-induced negative emotional states, but is consistent with models of mood-congruent processing.</p
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