14 research outputs found

    The ichthyofauna in a small temporarily open/closed Eastern Cape estuary, South Africa

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    The ichthyofaunal community structure, population dynamics and movement patterns in the small temporarily open/closed (TOCE) Grantā€™s Valley estuary, situated along the Eastern Cape coastline, were investigated over the period May 2004 to April 2005. Community structure in the littoral zone was assessed, while growth of selected ichthyofaunal species was investigated using the MULTIFAN model. Population size was assessed using mark recapture models and movement within the estuary using the Hilborn (1990) model. Total ichthyofaunal densities and biomass within the littoral zone ranged between 0.31 to 21.45 fish mā»Ā² and 0.20 to 4.67 g wwt mā»Ā², with the highest values typically recorded during the summer. Results of the study indicated that the ichthyofaunal community structure within the estuary was closely linked to the mouth phase and the establishment of a link to the marine environment via overtopping events. In the absence of any link to the sea, the ichthyofaunal community was numerically dominated by estuarine resident species, mainly Gilchristella aestuaria and to a lesser extent, by the river goby, Glossogobius callidus which collectively comprised ca. 88% of all fish sampled. The establishment of the link to the marine environment contributed to an increased contribution of marine breeding species (e.g. Rhabdosargus holubi, Myxus capensis and Atherina breviceps) to the total ichthyofaunal abundances. In contrast, total ichthyofaunal biomass was almost always dominated by marine breeding species by virtue of their larger sizes. Results of hierarchical cluster analyses did not identify any spatial patterns in the ichthyofaunal community within the littoral zone. Results of MULTIFAN analysis indicated estuarine resident fish species bred over an extended period with peaks occurring in the summer months. Conversely, marine breeding fish were shown to recruit into the estuary following overtopping and breaching events. Results of the mark-recapture experiment indicated a population of ca. 12 000 (11 219 ā€“ 13 311) individuals greater than 50mm SL. Marine-breeding species (R. holubi, Monodactylus falciformis, and two mullet species) numerically dominated the ichthyofauna, possibly as a result of their effective use of overtopping events. The two mullet species, M. capensis and Liza richardsonii, and the Cape stumpnose, R. holubi moved extensively throughout the estuary, while the remaining species exhibited restricted movement patterns possibly due to the preference for refuge and foraging areas associated with reed beds. The observed movement patterns of individual fish species appeared to be associated with both foraging behaviour and habitat selection

    Re-engineering a NiFe hydrogenase to increase the H2 production bias while maintaining native levels of O2 tolerance

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    Naturally occurring oxygen tolerant NiFe membrane bound hydrogenases have a conserved catalytic bias towards hydrogen oxidation which limits their technological value. We present an Escherichia coli Hyd-1 amino acid exchange that apparently causes the catalytic rate of H2 production to double but does not impact the O2 tolerance

    Research and Analysis of Fisheries in Illinois

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    Reports on progress and results for the following project objectives: sport fish population and sport fishing metrics; enhanced field sampling of sport fish populations; determination of factors affecting fishing quality; coordination with ongoing fisheries research projects; support for and enhance of web interface; fishes of Champaign County; recovery of urban stream sport fisheries.Illinois Department of Natural Resources, Division of Fisheries, Federal Aid Project F-69-R Segment 28unpublishednot peer reviewedOpe

    Clinical quantification of the integrin Ī±vĪ²6 by [18F]FB-A20FMDV2 positron emission tomography in healthy and fibrotic human lung (PETAL Study)

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    Ā© 2019, The Author(s). Purpose: The RGD-integrin, Ī±vĪ²6, plays a role in the pathogenesis of pulmonary fibrosis through activation of transforming growth factor beta (TGFĪ²). This study sought to quantify expression of Ī±vĪ²6 in the lungs of healthy humans and subjects with pulmonary fibrosis using the Ī±vĪ²6-selective [18F]FB-A20FMDV2 PET ligand. Methods: [18F]FB-A20FMDV2 PET/CT scans were performed in healthy subjects and those with fibrotic lung disease. Standard uptake values (SUV) and volume of distribution (VT) were used to quantify Ī±vĪ²6 expression. In subjects with fibrotic lung disease, qualitative assessment of the relationship between Ī±vĪ²6 expression and the distribution of fibrosis on high resolution computed tomography was conducted. Results: A total of 15 participants (6 healthy, 7 with idiopathic pulmonary fibrosis (IPF) and 2 with connective tissue disease (CTD) associated PF) were enrolled. VT and SUV of [18F]FB-A20FMDV2 were increased in the lungs of subjects with pulmonary fibrosis (PF) compared with healthy subjects. Geometric mean VT (95% CI) was 0.88 (0.60, 1.29) mL/cm3 for healthy subjects, and 1.40 (1.22, 1.61) mL/cm3 for subjects with IPF; and SUV was 0.54 (0.36, 0.81) g/mL for healthy subjects and 1.03 (0.86, 1.22) g/mL for subjects with IPF. The IPF/healthy VT ratio (geometric mean, (95% CI of ratio)) was 1.59 (1.09, 2.32) (probability ratio > 1 = 0.988)) and the SUV ratio was 1.91 (1.27, 2.87) (probability ratio > 1 = 0.996). Increased uptake of [18F]FB-A20FMDV2 in PF was predominantly confined to fibrotic areas. [18F]FB-A20FMDV2 measurements were reproducible at an interval of 2 weeks. [18F]FB-A20FMDV2 was safe and well tolerated. Conclusions: Lung uptake of [18F]FB-A20FMDV2, a measure of expression of the integrin Ī±vĪ²6, was markedly increased in subjects with PF compared with healthy subjects

    Translational pharmacology of an inhaled small molecule Ī±vĪ²6 integrin inhibitor for idiopathic pulmonary fibrosis

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    The Ī±vĪ²6 integrin plays a key role in the activation of transforming growth factor-Ī² (TGFĪ²), a pro-fibrotic mediator that is pivotal to the development of idiopathic pulmonary fibrosis (IPF). We identified a selective small molecule Ī±vĪ²6 RGD-mimetic, GSK3008348, and profiled it in a range of disease relevant pre-clinical systems. To understand the relationship between target engagement and inhibition of fibrosis, we measured pharmacodynamic and diseaserelated end points. Here we report, GSK3008348 binds to Ī±vĪ²6 with high affinity in human IPF lung and reduces downstream pro-fibrotic TGFĪ² signaling to normal levels. In human lung epithelial cells, GSK3008348 induces rapid internalization and lysosomal degradation of the Ī±vĪ²6 integrin. In the murine bleomycin-induced lung fibrosis model, GSK3008348 engages Ī±vĪ²6, induces prolonged inhibition of TGFĪ² signaling and reduces lung collagen deposition and serum C3M, a marker of IPF disease progression. These studies highlight the potential of inhaled GSK3008348 as an anti-fibrotic therapy

    Army Research Needs for Automated Neuropsychological Tests: Monitoring Soldier Health and Performance Status

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    Information on the mental status of soldiers operating at the limits of human tolerance will be vital to their management in future deployments; it may also allow earlier intervention for conditions such as undiagnosed Gulf War illnesses and Parkinsonā€™s Disease. The Army needs a parsimonious set of neuropsychological tests that reliably identify subtle changes for: (1) early detection of individual health and military performance impairments and (2) management of occupational and deployment health risks. Testing must characterize cognitive lapses in healthy individuals faced with relevant operational stressors (i.e., anxiety, information overload, thermal strain, hypoxia, fatigue, head impact, chemical or radiation exposures, metabolic challenges). This effort must also explore the neuropsychological methods in militarily relevant conditions to extend our understanding of relevant functional domains and how well they correspond to modes of testing. The ultimate objective is unobtrusive real-time mental status monitoring

    Modelling badlands erosion with SHETRAN at Draix, southeast France

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    The physically-based, distributed flow and sediment transport modelling system SHETRAN was applied to the Draix basins to test its ability to represent badlands flow and erosion response, to quantify characteristic parameter values and to investigate spatial scale effects in badlands modelling. A unit gully, area 0.133 ha, was simulated using a 5-m grid resolution model and a single cell model, with comparable results. Application of the models to a badlands basin, area 86 ha, suggests that transfer of parameter sets from the gully scale to a larger scale may be feasible but, given uncertainty in parameter evaluation, a separate calibration still yields improved results. Considering the flashy basin responses, satisfactory flow simulations were achieved using physically realistic parameter values, and sediment yields were well simulated within the bounds of uncertainty. Any scale effects which may distinguish the gully and basin simulations are masked by the uncertainty in parameter evaluation.</p
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