668 research outputs found

    Relative value to surgical patients and anesthesia providers of selected anesthesia related outcomes

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    BACKGROUND: Anesthesia side effects are almost inevitable in most situations. In order to optimize the anesthetic experience from the patient's viewpoint, it makes intuitive sense to attempt to avoid the side effects that the patient fears the most. METHODS: We obtained rankings and quantitative estimates of the relative importance of nine experiences that commonly occur after anesthesia and surgery from 109 patients prior to their surgery and from 30 anesthesiologists. RESULTS: Pain was the most important thing to avoid, and subjects allocated a median of 25ofanimaginary25 of an imaginary 100 to avoiding it. Next came vomiting (20),nausea(20), nausea (10), urinary retention (5),myalgia(5), myalgia (2) and pruritus ($2). Avoiding blood transfusion, an awake anesthetic technique or postoperative somnolence was not given value by the group as a whole. Anesthesiologists valued perioperative experiences in the same way as patients. CONCLUSIONS: Our results are comparable with those of previous studies in the area, and suggest that patients can prioritize the perioperative experiences they wish to avoid during their perioperative care. Such data, if obtained in the appropriate fashion, would enable anesthetic techniques to be compared using decision analysis

    Morphological Characters of the Thickbody Skate Amblyraja frerichsi (Krefft 1968) (Rajiformes: Rajidae), with Notes on Its Biology

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    Detailed descriptions of morphological features, morphometrics, neurocranium anatomy, clasper structure and egg case descriptions are provided for the thickbody skate Amblyraja frerichsi; a rare, deep-water species from Chile, Argentina and Falkland Islands. The species diagnosis is complemented from new observations and aspects such as colour, size and distribution are described. Geographic and bathymetric distributional ranges are discussed as relevant features of this taxońs biology. Additionally, the conservation status is assessed including bycatch records from Chilean fisheries

    Morphological characteristics of motor neurons do not determine their relative susceptibility to degeneration in a mouse model of severe spinal muscular atrophy

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    Spinal muscular atrophy (SMA) is a leading genetic cause of infant mortality, resulting primarily from the degeneration and loss of lower motor neurons. Studies using mouse models of SMA have revealed widespread heterogeneity in the susceptibility of individual motor neurons to neurodegeneration, but the underlying reasons remain unclear. Data from related motor neuron diseases, such as amyotrophic lateral sclerosis (ALS), suggest that morphological properties of motor neurons may regulate susceptibility: in ALS larger motor units innervating fast-twitch muscles degenerate first. We therefore set out to determine whether intrinsic morphological characteristics of motor neurons influenced their relative vulnerability to SMA. Motor neuron vulnerability was mapped across 10 muscle groups in SMA mice. Neither the position of the muscle in the body, nor the fibre type of the muscle innervated, influenced susceptibility. Morphological properties of vulnerable and disease-resistant motor neurons were then determined from single motor units reconstructed in Thy.1-YFP-H mice. None of the parameters we investigated in healthy young adult mice - including motor unit size, motor unit arbor length, branching patterns, motor endplate size, developmental pruning and numbers of terminal Schwann cells at neuromuscular junctions - correlated with vulnerability. We conclude that morphological characteristics of motor neurons are not a major determinant of disease-susceptibility in SMA, in stark contrast to related forms of motor neuron disease such as ALS. This suggests that subtle molecular differences between motor neurons, or extrinsic factors arising from other cell types, are more likely to determine relative susceptibility in SMA

    Success of a suicidal defense strategy against infection in a structured habitat

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    Pathogen infection often leads to the expression of virulence and host death when the host-pathogen symbiosis seems more beneficial for the pathogen. Previously proposed explanations have focused on the pathogen's side. In this work, we tested a hypothesis focused on the host strategy. If a member of a host population dies immediately upon infection aborting pathogen reproduction, it can protect the host population from secondary infections. We tested this "Suicidal Defense Against Infection" (SDAI) hypothesis by developing an experimental infection system that involves a huge number of bacteria as hosts and their virus as pathogen, which is linked to modeling and simulation. Our experiments and simulations demonstrate that a population with SDAI strategy is successful in the presence of spatial structure but fails in its absence. The infection results in emergence of pathogen mutants not inducing the host suicide in addition to host mutants resistant to the pathogen

    Effect of a magnetosphere compression on Jovian radio emissions: in situ case study using Juno data

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    During its 53-day polar orbit around Jupiter, Juno often crosses the boundaries of the Jovian magnetosphere (namely the magnetopause and bow shock). From the boundary locations, the upstream solar wind dynamic pressure can be inferred, which in turn illustrates the state of compression or relaxation of the system. The aim of this study is to examine Jovian radio emissions during magnetospheric compressions, in order to determine the relationship between the solar wind and Jovian radio emissions. In this paper, we give a complete list of bow shock and magnetopause crossings (from June 2016 to August 2022), along with some extra informations (e.g. solar wind dynamic pressure and position of the standoff distances inferred from Joy et al. (2002)). We then select two compression events that occur in succession (inferred from magnetopause crossings) and we present a case study of the response of the Jovian radio emissions. We demonstrate that magnetospheric compressions lead to the activation of new radio sources. Newly activated broadband kilometric emissions are observed almost simultaneously to compression of the magnetosphere, with sources covering a large range of longitudes. Decametric emission sources are seen to be activated more than one rotation later only at specific longitudes and dusk local times. Finally, the activation of narrowband kilometric radiation is not observed during the compression phase, but when the magnetosphere is in its expansion phase

    Within- and Among-Population Variation in Chytridiomycosis-Induced Mortality in the Toad Alytes obstetricans

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    Background Chytridiomycosis is a fungal disease linked to local and global extinctions of amphibians. Susceptibility to chytridiomycosis varies greatly between amphibian species, but little is known about between- and within-population variability. However, this kind of variability is the basis for the evolution of tolerance and resistance evolution to disease. Methodology/Principal Findings In a common garden experiment, we measured mortality after metamorphosis of Alytes obstetricans naturally infected with Batrachochytrium dendrobatidis. Mortality rates differed significantly among populations and ranged from 27 to 90%. Within populations, mortality strongly depended on mass at and time through metamorphosis. Conclusions/Significance Although we cannot rule out that the differences observed resulted from differences in skin microbiota, different pathogen strains or environmental effects experienced by the host or the pathogen prior to the start of the experiment, we argue that genetic differences between populations are a likely source of at least part of this variation. To our knowledge, this is the first study showing differences in survival between and within populations under constant laboratory conditions. Assuming that some of this intraspecific variation has a genetic basis, this may suggest that there is the potential for the evolution of resistance or tolerance, which might allow population persistence

    Seasonal and Ontogenetic Changes in Movement Patterns of Sixgill Sharks

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    Understanding movement patterns is fundamental to population and conservation biology. The way an animal moves through its environment influences the dynamics of local populations and will determine how susceptible it is to natural or anthropogenic perturbations. It is of particular interest to understand the patterns of movement for species which are susceptible to human activities (e.g. fishing), or that exert a large influence on community structure, such as sharks.We monitored the patterns of movement of 34 sixgill sharks Hexanchus griseus using two large-scale acoustic arrays inside and outside Puget Sound, Washington, USA. Sixgill sharks were residents in Puget Sound for up to at least four years before making large movements out of the estuary. Within Puget Sound, sixgills inhabited sites for several weeks at a time and returned to the same sites annually. Across four years, sixgills had consistent seasonal movements in which they moved to the north from winter to spring and moved to the south from summer to fall. Just prior to leaving Puget Sound, sixgills altered their behavior and moved twice as fast among sites. Nineteen of the thirty-four sixgills were detected leaving Puget Sound for the outer coast. Three of these sharks returned to Puget Sound.For most large marine predators, we have a limited understanding of how they move through their environment, and this clouds our ability to successfully manage their populations and their communities. With detailed movement information, such as that being uncovered with acoustic monitoring, we can begin to quantify the spatial and temporal impacts of large predators within the framework of their ecosystems

    Spatial Pattern Switching Enables Cyclic Evolution in Spatial Epidemics

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    Infectious diseases often spread as spatial epidemic outbreak waves. A number of model studies have shown that such spatial pattern formation can have important consequences for the evolution of pathogens. Here, we show that such spatial patterns can cause cyclic evolutionary dynamics in selection for the length of the infectious period. The necessary reversal in the direction of selection is enabled by a qualitative change in the spatial pattern from epidemic waves to irregular local outbreaks. The spatial patterns are an emergent property of the epidemic system, and they are robust against changes in specific model assumptions. Our results indicate that emergent spatial patterns can act as a rich source for complexity in pathogen evolution
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