256 research outputs found

    Flow amplitude or up‐ramping rate? : quantifying single and combined effects on macroinvertebrate drift during hydropeaking simulations, considering sensitive traits

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    The hydrological regime of many alpine rivers is heavily altered due hydroelectric power generation. Hydropeaking operation produces frequent and irregular discharge fluctuations. Depending on the operational changes of flow amplitude and/or upramping rate as well as on river morphology, hydropeaking can lead to quick and strong variations in hydraulic stress affecting stream invertebrates and causing increased drift. In the present flume experimental study, we analyzed trait-specific drift reactions to single and combined effects of increased flow amplitude and upramping rate. We analyzed taxa according to their hydraulic habitat preference and flow exposure, as these traits seem to be indicative toward hydropeaking. The results show that the sudden increase in discharge and related flow velocity led to increased macroinvertebrate drift proportions in hydropeaking treatments, which differed significantly to parallel control runs (mean drift proportion in all hydropeaking setups: 13% compared to 5% in controls). Increasing flow amplitudes led to an increase in drift for most taxa and traits. This was particularly significant for taxa associated with lentic areas. The effect of the up-ramping rate on macroinvertebrate drift was nonsignificant but showed strong interactive effects with the flow amplitude, especially for taxa dwelling on the substrate surface. Our results therefore indicate that dischargerelated parameters, such as flow velocity, primarily affect macroinvertebrate drift and the importance of the up-ramping rate increases, if certain discharge-related thresholds are exceeded. Vice versa, a reduction of the up-ramping rate at hydropeaking events with high flow amplitudes may reduce the effect on macroinvertebrate drift. Flow-exposed (surface) and flow-sensitive (lentic) taxa showed distinct drift reactions following hydropeaking treatments, which were significantly higher compared to effects on taxa associated to lotic and interstital habitats. Therefore, we conclude that both traits (hydraulic and vertical habitat preference) have proven as promising for analyzing hydropeaking effects. The trait classifications should be extended to a higher number of taxa and to different life stages as these may show different drift patterns

    Rheumatoid Arthritis Naive T Cells Share Hypermethylation Sites With Synoviocytes.

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    ObjectiveTo determine whether differentially methylated CpGs in synovium-derived fibroblast-like synoviocytes (FLS) of patients with rheumatoid arthritis (RA) were also differentially methylated in RA peripheral blood (PB) samples.MethodsFor this study, 371 genome-wide DNA methylation profiles were measured using Illumina HumanMethylation450 BeadChips in PB samples from 63 patients with RA and 31 unaffected control subjects, specifically in the cell subsets of CD14+ monocytes, CD19+ B cells, CD4+ memory T cells, and CD4+ naive T cells.ResultsOf 5,532 hypermethylated FLS candidate CpGs, 1,056 were hypermethylated in CD4+ naive T cells from RA PB compared to control PB. In analyses of a second set of CpG candidates based on single-nucleotide polymorphisms from a genome-wide association study of RA, 1 significantly hypermethylated CpG in CD4+ memory T cells and 18 significant CpGs (6 hypomethylated, 12 hypermethylated) in CD4+ naive T cells were found. A prediction score based on the hypermethylated FLS candidates had an area under the curve of 0.73 for association with RA case status, which compared favorably to the association of RA with the HLA-DRB1 shared epitope risk allele and with a validated RA genetic risk score.ConclusionFLS-representative DNA methylation signatures derived from the PB may prove to be valuable biomarkers for the risk of RA or for disease status

    Effect of NASA Light-emitting Diode Irradiation on Wound Healing

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    Objective: The purpose of this study was to assess the effects of hyperbaric oxygen (HBO) and near-infrared light therapy on wound healing. Background Data: Light-emitting diodes (LED), originally developed for NASA plant growth experiments in space show promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. In this paper, we review and present our new data of LED treatment on cells grown in culture, on ischemic and diabetic wounds in rat models, and on acute and chronic wounds in humans. Materials and Methods: In vitro and in vivo (animal and human) studies utilized a variety of LED wavelength, power intensity, and energy density parameters to begin to identify conditions for each biological tissue that are optimal for biostimulation. Results: LED produced in vitro increases of cell growth of 140–200% in mouse-derived fibroblasts, rat-derived osteoblasts, and rat-derived skeletal muscle cells, and increases in growth of 155–171% of normal human epithelial cells. Wound size decreased up to 36% in conjunction with HBO in ischemic rat models. LED produced improvement of greater than 40% in musculoskeletal training injuries in Navy SEAL team members, and decreased wound healing time in crew members aboard a U.S. Naval submarine. LED produced a 47% reduction in pain of children suffering from oral mucositis. Conclusion: We believe that the use of NASA LED for light therapy alone, and in conjunction with hyperbaric oxygen, will greatly enhance the natural wound healing process, and more quickly return the patient to a preinjury/ illness level of activity. This work is supported and managed through the NASA Marshall Space Flight Center–SBIR Program

    Évaluation du programme de prĂ©vention du tabagisme du canton de NeuchĂątel 2016-2020

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    Antisense Oligonucleotide- and CRISPR-Cas9-Mediated Rescue of mRNA Splicing for a Deep Intronic CLRN1 Mutation

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    Mutations in CLRN1 cause Usher syndrome (USH) type III (USH3A), a disease characterized by progressive hearing impairment, retinitis pigmentosa, and vestibular dysfunction. Due to the lack of appropriate disease models, no efficient therapy for retinitis pigmentosa in USH patients exists so far. In addition, given the yet undefined functional role and expression of the different CLRN1 splice isoforms in the retina, non-causative therapies such as gene supplementation are unsuitable at this stage. In this study, we focused on the recently identified deep intronic c.254-649T>G CLRN1 splicing mutation and aimed to establish two causative treatment approaches: CRISPR-Cas9-mediated excision of the mutated intronic region and antisense oligonucleotide (AON)-mediated correction of mRNA splicing. The therapeutic potential of these approaches was validated in different cell types transiently or stably expressing CLRN1 minigenes. Both approaches led to substantial correction of the splice defect. Surprisingly, however, no synergistic effect was detected when combining both methods. Finally, the injection of naked AONs into mice expressing the mutant CLRN1 minigene in the retina also led to a significant splice rescue. We propose that both AONs and CRISPR-Cas9 are suitable strategies to initiate advanced preclinical studies for treatment of USH3A patients

    Sound design for exergames : a design research pilot project

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    Effects of hydropeaking on drift, stranding and community composition of macroinvertebrates : a field experimental approach in three regulated Swiss rivers

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    Hydropeaking operation leads to fluctuations in wetted area between base and peak flow and increases discharge-related hydraulic forces (e.g. flow velocity). These processes promote macroinvertebrate drift and stranding, often affecting benthic abundance and biomass. Our field experimental study—conducted in three hydropeakingregulated Swiss rivers—aimed to quantify (a) the short-term effects of the combined increase in flow amplitude and up-ramping rate based on macroinvertebrate drift and stranding, as well as (b) long-term effects based on the established community composition. Hydropeaking led to increased macroinvertebrate drift compared to base flow and to unaffected residual flow reaches. Moreover, stranding of macroinvertebrates was positively related to drift, especially during the up-ramping phase. Flow velocity and up-ramping rate were identified as major determinants for macroinvertebrate drift, while flow ratio and down-ramping rate for stranding. Particularly high sensitivity towards hydropeaking was found for Limnephilidae, whereas Heptageniidae seemed to be resistant in respect to short- and long-term hydropeaking effects. In the longterm, hydropeaking did not considerably reduce benthic density of most taxa, especially of some highly resistant and resilient taxa such as Chironomidae and Baetidae, which dominated the community composition even though they showed comparably high drift and stranding responses. Therefore, we argue that high drift and/or stranding, especially of individual-rich taxa, does not necessarily indicate strong hydropeaking sensitivity. Finally, our results demonstrate the necessity to consider the differences in river-specific morphological complexity and hydropeaking intensity, since these factors strongly influence the community composition and short-term drift and stranding response of macroinvertebrates to hydropower pressure
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