571 research outputs found

    Ecological succession of a Jurassic shallow-water ichthyosaur fall.

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    After the discovery of whale fall communities in modern oceans, it has been hypothesized that during the Mesozoic the carcasses of marine reptiles created similar habitats supporting long-lived and specialized animal communities. Here, we report a fully documented ichthyosaur fall community, from a Late Jurassic shelf setting, and reconstruct the ecological succession of its micro- and macrofauna. The early 'mobile-scavenger' and 'enrichment-opportunist' stages were not succeeded by a 'sulphophilic stage' characterized by chemosynthetic molluscs, but instead the bones were colonized by microbial mats that attracted echinoids and other mat-grazing invertebrates. Abundant cemented suspension feeders indicate a well-developed 'reef stage' with prolonged exposure and colonization of the bones prior to final burial, unlike in modern whale falls where organisms such as the ubiquitous bone-eating worm Osedax rapidly destroy the skeleton. Shallow-water ichthyosaur falls thus fulfilled similar ecological roles to shallow whale falls, and did not support specialized chemosynthetic communities

    Prevalence, characteristics, and impacts of work-related musculoskeletal disorders: a survey among physical therapists in the State of Kuwait

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    <p>Abstract</p> <p>Background</p> <p>Physical therapists working in the State of Kuwait are at risk of work-related musculoskeletal disorders (WMSDs). However, prevalence rates and risk factors are not well documented. The objective of this study was to determine the prevalence, characteristics, and impacts of WMSDs among physical therapists in the State of Kuwait.</p> <p>Methods</p> <p>A self-administered questionnaire was distributed to 350 physical therapists. The questionnaire gathered demographic data as well as information on occurrence of musculoskeletal complaints in the previous 12 months. Descriptive statistics, frequency, and Chi-square analyses were used.</p> <p>Results</p> <p>The response rate to the questionnaire was 63% (222/350). Of the 212 responders included in the study, the one-year prevalence of WMSDs was 47.6%, with lower back complaints as the most common (32%). This was followed by neck (21%), upper back (19%), shoulder (13%), hand/wrist (11%), knee (11%), ankle/foot (6%), elbow (4%), and hip/thigh (3%) complaints. The frequency of WMSDs was not gender related (except lower back, neck, and shoulder complaints) nor was it related to age (except lower back complaints), working venues (except hand/wrist), working hours, area of specialty, or exercise. WMSDs' impact on work was minor.</p> <p>Conclusions</p> <p>WMSDs among physical therapists in Kuwait were common, with lower back and neck affected most. Lower back and neck WMSDs were related to the participant's demographics. Hand/wrist WMSDs were related to work settings. Further research is needed to investigate the effect of risk factors as physical load, psychosocial load, and general health status on prevalence musculoskeletal disorders.</p

    Standards of lithium monitoring in mental health trusts in the UK

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    <p>Abstract</p> <p>Background</p> <p>Lithium is a commonly prescribed drug with a narrow therapeutic index, and recognised adverse effects on the kidneys and thyroid. Clinical guidelines for the management of bipolar affective disorder published by The National Institute for Health and Clinical Excellence (NICE) recommend checks of renal and thyroid function before lithium is prescribed. They further recommend that all patients who are prescribed lithium should have their renal and thyroid function checked every six months, and their serum lithium checked every three months. Adherence to these recommendations has not been subject to national UK audit.</p> <p>Methods</p> <p>The Prescribing Observatory for Mental Health (POMH-UK) invited all National Health Service Mental Health Trusts in the UK to participate in a benchmarking audit of lithium monitoring against recommended standards. Data were collected retrospectively from clinical records and submitted electronically.</p> <p>Results</p> <p>436 clinical teams from 38 Trusts submitted data for 3,373 patients. In patients recently starting lithium, there was a documented baseline measure of renal or thyroid function in 84% and 82% respectively. For patients prescribed lithium for a year or more, the NICE standards for monitoring lithium serum levels, and renal and thyroid function were met in 30%, 55% and 50% of cases respectively.</p> <p>Conclusions</p> <p>The quality of lithium monitoring in patients who are in contact with mental health services falls short of recognised standards and targets. Findings from this audit, along with reports of harm received by the National Patient Safety Agency, prompted a Patient Safety Alert mandating primary care, mental health and acute Trusts, and laboratory staff to work together to ensure systems are in place to support recommended lithium monitoring by December 2010.</p

    Set optimization - a rather short introduction

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    Recent developments in set optimization are surveyed and extended including various set relations as well as fundamental constructions of a convex analysis for set- and vector-valued functions, and duality for set optimization problems. Extensive sections with bibliographical comments summarize the state of the art. Applications to vector optimization and financial risk measures are discussed along with algorithmic approaches to set optimization problems

    Characterization of the Major Histocompatibility Complex Class II Genes in Miiuy Croaker

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    Major histocompatibility complex (MHC) has a central role in the adaptive immune system by presenting foreign peptide to the T-cell receptor. In order to study the molecular function and genomic characteristic of class II genes in teleost, the full lengths of MHC class IIA and IIB cDNA and genomic sequence were cloned from miiuy croaker (Miichthys miiuy). As in other teleost, four exons and three introns were identified in miiuy croaker class IIA gene; but the difference is that six exons and five introns were identified in the miiuy croaker class IIB gene. The deduced amino acid sequence of class IIA and class IIB had 26.3–85.7% and 11.0–88.8% identity with those of mammal and teleost, respectively. Real-time quantitative RT-PCR demonstrated that the MHC class IIA and IIB were ubiquitously expressed in ten normal tissues; expression levels of MHC genes were found first upregulated and then downregulated, and finally by a recovery to normal level throughout the pathogenic bacteria infection process. In addition, we report on the underlying mechanism that maintains sequences diversity among many fish species. A series of site-model tests implemented in the CODEML program revealed that positive Darwinian selection is likely the cause of the molecular evolution in the fish MHC class II genes

    Modeling acid-gas generation from boiling chloride brines

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    <p>Abstract</p> <p>Background</p> <p>This study investigates the generation of HCl and other acid gases from boiling calcium chloride dominated waters at atmospheric pressure, primarily using numerical modeling. The main focus of this investigation relates to the long-term geologic disposal of nuclear waste at Yucca Mountain, Nevada, where pore waters around waste-emplacement tunnels are expected to undergo boiling and evaporative concentration as a result of the heat released by spent nuclear fuel. Processes that are modeled include boiling of highly concentrated solutions, gas transport, and gas condensation accompanied by the dissociation of acid gases, causing low-pH condensate.</p> <p>Results</p> <p>Simple calculations are first carried out to evaluate condensate pH as a function of HCl gas fugacity and condensed water fraction for a vapor equilibrated with saturated calcium chloride brine at 50-150°C and 1 bar. The distillation of a calcium-chloride-dominated brine is then simulated with a reactive transport model using a brine composition representative of partially evaporated calcium-rich pore waters at Yucca Mountain. Results show a significant increase in boiling temperature from evaporative concentration, as well as low pH in condensates, particularly for dynamic systems where partial condensation takes place, which result in enrichment of HCl in condensates. These results are in qualitative agreement with experimental data from other studies.</p> <p>Conclusion</p> <p>The combination of reactive transport with multicomponent brine chemistry to study evaporation, boiling, and the potential for acid gas generation at the proposed Yucca Mountain repository is seen as an improvement relative to previously applied simpler batch evaporation models. This approach allows the evaluation of thermal, hydrological, and chemical (THC) processes in a coupled manner, and modeling of settings much more relevant to actual field conditions than the distillation experiment considered. The actual and modeled distillation experiments do not represent expected conditions in an emplacement drift, but nevertheless illustrate the potential for acid-gas generation at moderate temperatures (<150°C).</p

    Neural Correlates of Visual Motion Prediction

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    Predicting the trajectories of moving objects in our surroundings is important for many life scenarios, such as driving, walking, reaching, hunting and combat. We determined human subjects’ performance and task-related brain activity in a motion trajectory prediction task. The task required spatial and motion working memory as well as the ability to extrapolate motion information in time to predict future object locations. We showed that the neural circuits associated with motion prediction included frontal, parietal and insular cortex, as well as the thalamus and the visual cortex. Interestingly, deactivation of many of these regions seemed to be more closely related to task performance. The differential activity during motion prediction vs. direct observation was also correlated with task performance. The neural networks involved in our visual motion prediction task are significantly different from those that underlie visual motion memory and imagery. Our results set the stage for the examination of the effects of deficiencies in these networks, such as those caused by aging and mental disorders, on visual motion prediction and its consequences on mobility related daily activities

    Radiofrequency Treatment of Facet-related Pain: Evidence and Controversies

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    Pain originating from the lumbar facet joints is estimated to represent about 15% of all low back pain complaints. The diagnostic block is considered to be a valuable tool for confirming facetogenic pain. It was demonstrated that a block of the ramus medialis of the ramus dorsalis is preferred over an intra-articular injection. The outcome of the consequent radiofrequency treatment is not different in patients reporting over 80% pain relief after the diagnostic block than in those who have between 50% and 79% pain relief. There is one well-conducted comparative trial assessing the value of one or two controlled diagnostic blocks to none. The results of the seven randomized trials on the use of radiofrequency treatment of facet joint pain demonstrate that good patient selection is imperative for good clinical outcome. Therefore, we suggest one block of the ramus medialis of the ramus dorsalis before radiofrequency treatment
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