2,323 research outputs found

    Magnetotelluric study in the Moine Thrust region of Northern Scotland

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    Ceremony at a Boundary fire: a story of Indigenist Knowledge

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    National Science Foundation (United States of America

    Ocular Pathology Relevant to Glaucoma in a Gja1(Jrt) Mouse Model of Human Oculodentodigital Dysplasia

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    PURPOSE. Oculodentodigital dysplasia (ODDD) is a human disorder caused by mutations in the gap junction alpha 1 (GJA1) gene encoding the connexin43 (Cx43) gap junction protein. Causal links between GJA1 mutations and glaucoma are not understood. The purpose in this study was to examine the ocular phenotype for Gja1(Jrt/+) mice harboring a Cx43 G60S mutation. METHODS. In young Gja1(Jrt/+) mice, Cx43 abundance was assessed with a Western blot, and Cx43 localization was visualized using immunohistochemistry and confocal microscopy. Intraocular pressure (IOP) was measured by rebound tonometry, and eye anatomy was imaged using ocular coherence tomography (OCT). Hematoxylin and eosin (H&E)-stained eye sections were examined for ocular histopathology related to the development of glaucoma. RESULTS. Decreased Cx43 protein levels were evident in whole eyes from Gja1(Jrt/+) mice compared with those of wild-type mice at postnatal day 1 (P = 0.005). Cx43 immunofluorescence in ciliary bodies of Gja1(Jrt/+) mice was diffuse and intracellular, unlike the gap junction plaques prevalent in wildtype mice. IOP in Gja1(Jrt/+) mice changed during postnatal development, with significantly lower IOP at 21 weeks of age in comparison to the IOP of wild-type eyes. Microphthalmia, enophthalmia, anterior angle closure, and reduced pupil diameter were observed in Gja1(Jrt/+) mice at all ages examined. Ocular histology showed prominent separations between the pigmented and nonpigmented ciliary epithelium of Gja1(Jrt/+) mice, split irides, and alterations in the number and distribution of nuclei in the retina. CONCLUSIONS. Detailed phenotyping of Gja1(Jrt/+) eyes offers a framework for elucidating human ODDD ocular disease mechanisms and evaluating new treatments designed to protect ocular synaptic network integrity

    Risk assessment of war wrecks – a comprehensive approach investigating four wrecks containing munitions in the German Bight/North Sea

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    Shipwrecks and dumped munition continue to be a major hazard, both in the North Sea but also on a global scale. Research within the EU Interreg project North Sea Wrecks (NSW), in cooperation with the German Aerospace Centre, Institute for the Protection of Maritime Infrastructures (DLR), is generating new insights into the status of wrecks, the potential leakage of pollutants from remaining munitions loads and the effects of contamination on exposed marine organisms in the North Sea environment. Further, historical documents are generated from archives to describe ship’s history and sinking scenario. These historical findings were compared to models and images of the visual inspections of the wrecks. Further, samples of water, sediment and organisms are being analysed for traces of explosives. Combining the results of these different fields of research allows for a better understanding of the environmental risks deriving from these wrecks. This process is shown below by focusing on the wreck of the German light cruiser SMS MAINZ, which sank in 1914. Data were compared to three additional wrecks situated also within the southern German Bight. Available data about the wrecks were preliminary assessed using a wreck risk model. Finally, wrecks were ranked according to their potential environmental risk

    Efficiency of primary saliva secretion: an analysis of parameter dependence in dynamic single-cell and acinus models, with application to aquaporin knockout studies

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    Secretion from the salivary glands is driven by osmosis following the establishment of osmotic gradients between the lumen, the cell and the interstitium by active ion transport. We consider a dynamic model of osmotically driven primary saliva secretion and use singular perturbation approaches and scaling assumptions to reduce the model. Our analysis shows that isosmotic secretion is the most efficient secretion regime and that this holds for single isolated cells and for multiple cells assembled into an acinus. For typical parameter variations, we rule out any significant synergistic effect on total water secretion of an acinar arrangement of cells about a single shared lumen. Conditions for the attainment of isosmotic secretion are considered, and we derive an expression for how the concentration gradient between the interstitium and the lumen scales with water- and chloride-transport parameters. Aquaporin knockout studies are interpreted in the context of our analysis and further investigated using simulations of transport efficiency with different membrane water permeabilities. We conclude that recent claims that aquaporin knockout studies can be interpreted as evidence against a simple osmotic mechanism are not supported by our work. Many of the results that we obtain are independent of specific transporter details, and our analysis can be easily extended to apply to models that use other proposed ionic mechanisms of saliva secretion

    What do aquaporin knockout studies tell us about fluid transport in epithelia?

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    The investigation of near-isosmotic water transport in epithelia goes back over 100 years; however, debates over mechanism and pathway remain. Aquaporin (AQP) knockouts have been used by various research groups to test the hypothesis of an osmotic mechanism as well as to explore the paracellular versus transcellular pathway debate. Nonproportional reductions in the water permeability of a water-transporting epithelial cell (e.g., a reduction of around 80–90 %) compared to the reduction in overall water transport rate in the knockout animal (e.g., a reduction of 50–60 %) are commonly found. This nonproportionality has led to controversy over whether AQP knockout studies support or contradict the osmotic mechanism. Arguments raised for and against an interpretation supporting the osmotic mechanism typically have partially specified, implicit, or incorrect assumptions. We present a simple mathematical model of the osmotic mechanism with clear assumptions and, for models based on this mechanism, establish a baseline prediction of AQP knockout studies. We allow for deviations from isotonic/isosmotic conditions and utilize dimensional analysis to reduce the number of parameters that must be considered independently. This enables a single prediction curve to be used for multiple epithelial systems. We find that a simple, transcellular-only osmotic mechanism sufficiently predicts the results of knockout studies and find criticisms of this mechanism to be overstated. We note, however, that AQP knockout studies do not give sufficient information to definitively rule out an additional paracellular pathway

    A summary of pain and pain-related variables in the Avon Longitudinal Study of Parents and Children

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    To study pain, data on pain characteristics, possible triggers and consequences - such as the impact of pain on people's lives - need to be available. When not collated, described and/or organised in a systematic manner, it can be difficult to assess how useful an existing dataset may be for one's project. This data note describes and categorises the complex and multi-modal indices of pain available in the Avon Longitudinal Study of Parents and Children (ALSPAC). Data from two generations of the ALSPAC cohort; index child participants (Generation 1, G1), their mothers and fathers/mothers' partners (Generation 0, G0) were used. Search terms such as 'pain', 'ache', 'hurt', 'sore', specific pain conditions, labour pain and methods of pain relief were used to identify pain and pain-related variables. These data were extracted from all waves of data collection. We developed pain categories and subsequently categorised variables in an iterative process. Repeated measurements of the same variables over waves of data collection were also identified. We identified 21 categories of pain variables, which were subsequently grouped into themes: pain characteristics, extended pain characteristics and causes, treatment for pain, pain interference and pain-related to specific events. Pain and pain-related data have been collected from G1 participants, G0 mothers, and G0 partners, although there are fewer data for the partners. There were some repeated measurements, most commonly, of pain location. As is typical with longitudinal birth cohort studies, maternal proxy-reports were used during participants' younger years and self-reports were utilised from adolescence onwards. Researchers interested in studying pain can feasibly do so in two generations of a regional UK population who have been followed up over 30 years. ALSPAC can be used to study pain from the early years through to young adulthood and in mothers from the perinatal period onwards. [Abstract copyright: Copyright: © 2024 Ly A et al.
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