844 research outputs found

    The role of catch shares in Pacific halibut bycatch reduction in the U.S. West Coast bottom trawl fishery

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    Pacific halibut (Hippoglossus stenolepis) are a valuable target species in the U.S. and Canada, but are also caught as bycatch in other groundfish fisheries. In 2011, a catch shares (CS) management program was implemented in the U.S. west coast limited entry (LE) bottom trawl fishery, shifting responsibility for catch limits, including P. halibut bycatch, from the fleet to individual vessels. After CS implementation, P. halibut bycatch decreased significantly from an annual mean of 312.5 metric tons (mt) (2007-2010) to 65.6 mt (2011-2014). I hypothesized that this reduction in P. halibut bycatch resulted from changes in fishing behavior initiated by the shift to CS. I evaluated changes in variables associated with P. halibut bycatch, including fishing latitude, depth, duration, and catch of correlated species, before and after CS implementation. Comparisons of associated variables under LE versus CS management showed that significant changes to all variables occurred after CS implementation. To predict and compare relative P. halibut bycatch among LE versus CS hauls, I modeled how associated variables predicted P. halibut encounters, bycatch weight, and mortality for LE data, and re-ran these models for CS data. My results indicate that the relationship between predictor variables and P. halibut bycatch changed under CS from what was observed in the LE fleet. These changed relationships suggest that fishers altered their behavior following the management shift, likely contributing to the reduction in P. halibut bycatch under CS management. This work will help the Pacific Fishery Management Council and International Pacific Halibut Commission understand how CS has changed fishing behavior and P. halibut bycatch in bottom trawl fisheries.Bachelor of Scienc

    Bi-modal stimulation in the treatment of tinnitus: a study protocol for an exploratory trial to optimise stimulation parameters and patient subtyping

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    Introduction: Tinnitus is the perception of sound in the absence of a corresponding external acoustic stimulus. Bi-modal neuromodulation is emerging as a promising treatment for this condition. The main objectives of this study are to investigate the relevance of inter-stimuli timing and the choice of auditory stimuli for a proprietary bi-modal (auditory and somatosensory) neuromodulation device and to explore whether specific subtypes of patients are differentially responsive to this novel intervention for reducing the symptoms of chronic tinnitus. Methods and analysis: This is a two-site, randomised, triple-blind, exploratory study of a proprietary neuromodulation device with a pre-post and 12-month follow-up design. Three different bi-modal stimulation parameter sets will be examined. The study will enrol 342 patients, split 80:20 between two sites (Dublin, Ireland and Regensburg, Germany), to complete 12 weeks of treatment with the device. Patients will be allocated to one of three arms using a step-wise stratification according to four binary categories: tinnitus tonality, sound level tolerance (using Loudness Discomfort Level of <60 dB SL as an indicator for hyperacusis), hearing thresholds, and presence of a noise-induced audiometric profile. The main indicators of relative clinical efficacy for the three different parameter sets are two patient-reported outcomes measures, the Tinnitus Handicap Inventory and the Tinnitus Functional Index, after 12 weeks of intervention. Clinical efficacy will be further explored in a series of patient subtypes, split by the stratification variables and by presence of a somatic tinnitus. Evidence for sustained effects on the psychological and functional impact of tinnitus will be followed up for 12 months. Safety data will be collected and reported. A number of feasibility measures to inform future trial design include: reasons for exclusion, completeness of data collection, attrition rates, patient’s adherence to the device usage as per manufacturer’s instructions and evaluation of alternative methods for estimating tinnitus impact and tinnitus loudness. Ethics and dissemination: This study protocol is approved by the Tallaght Hospital / St. James’s Hospital Joint Research Ethics Committee in Dublin, Republic of Ireland, and by the Ethics Committee of the University Clinic Regensburg, Germany. Findings will be disseminated to relevant research, clinical, health service and patient communities through publications in peer-reviewed and popular science journals and presentations at scientific and clinical conferences. Trial registration number; the trial is registered on ClinicalTrials.gov (NCT02669069). The sponsor is Neuromod Devices, Dublin, Republic of Ireland. STRENGTHS AND LIMITATIONS OF THIS STUDY • The main strength of this study is that it is a large two-site, triple-blinded, randomised trial that will provide exploratory evidence of the relevance of stimulation parameters on the clinical efficacy of different bi-modal stimulation parameters and will inform future trial design. • The study comprehensively characterises patients for subtyping and this will refine candidature for the intervention. • Among the limitations of this study are the variability in duration between screening and enrolment and the selection of the investigated stimulation parameters. • The online recruitment process may inadvertently introduce participant selection bias

    Chemical fingerprints encode mother-offspring similarity, colony membership, relatedness and genetic quality in fur seals

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    Chemical communication underpins virtually all aspects of vertebrate social life, yet remains poorly understood because of its highly complex mechanistic basis. We therefore used chemical fingerprinting of skin swabs and genetic analysis to explore the chemical cues that may underlie mother–offspring recognition in colonially breeding Antarctic fur seals. By sampling mother–offspring pairs from two different colonies, using a variety of statistical approaches and genotyping a large panel of microsatellite loci, we show that colony membership, mother–offspring similarity, heterozygosity, and genetic relatedness are all chemically encoded. Moreover, chemical similarity between mothers and offspring reflects a combination of genetic and environmental influences, the former partly encoded by substances resembling known pheromones. Our findings reveal the diversity of information contained within chemical fingerprints and have implications for understanding mother–offspring communication, kin recognition, and mate choice

    Bimodal neuromodulation combining sound and tongue stimulation reduces tinnitus symptoms in a large randomized clinical study

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    Tinnitus is a phantom auditory perception coded in the brain that can be bothersome or debilitating for 10-15% of the population. Currently, there is no clinically recommended drug or device treatment for this major health condition. Animal research has revealed that sound paired with electrical somatosensory stimulation can drive extensive plasticity within the brain for tinnitus treatment. To investigate this bimodal neuromodulation approach in humans, we evaluated a noninvasive device that delivers sound to the ears and electrical stimulation to the tongue in a randomized, double-blinded, exploratory study that enrolled 326 adult subjects with chronic subjective tinnitus. Participants were randomized into three parallel arms with different stimulation settings. Clinical outcomes were evaluated over a 12-week treatment period and a 12-month post-treatment phase. For the primary endpoints, participants achieved a statistically significant reduction in tinnitus symptom severity at the end of treatment based on two commonly used outcome measures, Tinnitus Handicap Inventory (Cohen’s d effect size: 0.87 to 0.92 across arms; p<0.001) and Tinnitus Functional Index (0.77 to 0.87; p<0.001). Therapeutic improvements continued for 12 months post-treatment for specific bimodal stimulation settings. Long-term benefits lasting 12 months have not previously been demonstrated in a large cohort for a tinnitus intervention. The treatment also achieved high compliance and satisfaction rates with no treatment-related serious adverse events. These positive therapeutic and long-term results motivate further clinical trials towards establishing bimodal neuromodulation as the first clinically recommended device treatment for tinnitus

    fMRI evidence of ‘mirror’ responses to geometric shapes

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    Mirror neurons may be a genetic adaptation for social interaction [1]. Alternatively, the associative hypothesis [2], [3] proposes that the development of mirror neurons is driven by sensorimotor learning, and that, given suitable experience, mirror neurons will respond to any stimulus. This hypothesis was tested using fMRI adaptation to index populations of cells with mirror properties. After sensorimotor training, where geometric shapes were paired with hand actions, BOLD response was measured while human participants experienced runs of events in which shape observation alternated with action execution or observation. Adaptation from shapes to action execution, and critically, observation, occurred in ventral premotor cortex (PMv) and inferior parietal lobule (IPL). Adaptation from shapes to execution indicates that neuronal populations responding to the shapes had motor properties, while adaptation to observation demonstrates that these populations had mirror properties. These results indicate that sensorimotor training induced populations of cells with mirror properties in PMv and IPL to respond to the observation of arbitrary shapes. They suggest that the mirror system has not been shaped by evolution to respond in a mirror fashion to biological actions; instead, its development is mediated by stimulus-general processes of learning within a system adapted for visuomotor control

    Expression of Protease-Activated Receptor 1 and 2 and Anti-Tubulogenic Activity of Protease-Activated Receptor 1 in Human Endothelial Colony-Forming Cells

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    Endothelial colony-forming cells (ECFCs) are obtained from the culture of human peripheral blood mononuclear cell (hPBMNC) fractions and are characterised by high proliferative and pro-vasculogenic potential, which makes them of great interest for cell therapy. Here, we describe the detection of protease-activated receptor (PAR) 1 and 2 amongst the surface proteins expressed in ECFCs. Both receptors are functionally coupled to extracellular signal-regulated kinase (ERK) 1 and 2, which become activated and phosphorylated in response to selective PAR1- or PAR2-activating peptides. Specific stimulation of PAR1, but not PAR2, significantly inhibits capillary-like tube formation by ECFCs in vitro, suggesting that tubulogenesis is negatively regulated by proteases able to stimulate PAR1 (e.g. thrombin). The activation of ERKs is not involved in the regulation of tubulogenesis in vitro, as suggested by use of the MEK inhibitor PD98059 and by the fact that PAR2 stimulation activates ERKs without affecting capillary tube formation. Both qPCR and immunoblotting showed a significant downregulation of vascular endothelial growth factor 2 (VEGFR2) in response to PAR1 stimulation. Moreover, the addition of VEGF (50–100 ng/ml) but not basic Fibroblast Growth Factor (FGF) (25–100 ng/ml) rescued tube formation by ECFCs treated with PAR1-activating peptide. Therefore, we propose that reduction of VEGF responsiveness resulting from down-regulation of VEGFR2 is underlying the anti-tubulogenic effect of PAR1 activation. Although the role of PAR2 remains elusive, this study sheds new light on the regulation of the vasculogenic activity of ECFCs and suggests a potential link between adult vasculogenesis and the coagulation cascade

    HIF-1–dependent repression of equilibrative nucleoside transporter (ENT) in hypoxia

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    Extracellular adenosine (Ado) has been implicated as central signaling molecule during conditions of limited oxygen availability (hypoxia), regulating physiologic outcomes as diverse as vascular leak, leukocyte activation, and accumulation. Presently, the molecular mechanisms that elevate extracellular Ado during hypoxia are unclear. In the present study, we pursued the hypothesis that diminished uptake of Ado effectively enhances extracellular Ado signaling. Initial studies indicated that the half-life of Ado was increased by as much as fivefold after exposure of endothelia to hypoxia. Examination of expressional levels of the equilibrative nucleoside transporter (ENT)1 and ENT2 revealed a transcriptionally dependent decrease in mRNA, protein, and function in endothelia and epithelia. Examination of the ENT1 promoter identified a hypoxia inducible factor 1 (HIF-1)–dependent repression of ENT1 during hypoxia. Using in vitro and in vivo models of Ado signaling, we revealed that decreased Ado uptake promotes vascular barrier and dampens neutrophil tissue accumulation during hypoxia. Moreover, epithelial Hif1α mutant animals displayed increased epithelial ENT1 expression. Together, these results identify transcriptional repression of ENT as an innate mechanism to elevate extracellular Ado during hypoxia

    Delivering the WISE (Whole Systems Informing Self-Management Engagement) training package in primary care: learning from formative evaluation

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    Background: The WISE (Whole System Informing Self-management Engagement) approach encompasses creating, finding, and implementing appropriate self-care support for people with long-term conditions. A training package for primary care to introduce the approach was developed and underwent formative evaluation. This entailed exploring the acceptability of the WISE approach and its effectiveness in changing communication within consultations. The study aimed to refine the patient, practitioner, and patient level components of the WISE approach and translate the principles of WISE into an operational intervention deliverable through National Health Service training methods. Methods: Normalisation Process Theory provided a framework for development of the intervention. Practices were recruited from an inner city Primary Care Trust in NW England. All practice staff were expected to attend two afternoon training sessions. The training sessions were observed by members of the training team. Post-training audio recordings of consultations from each general practitioner and nurse in the practices were transcribed and read to provide a narrative overview of the incorporation of WISE skills and tools into consultations. Face-to-face semi-structured interviews were conducted with staff post-training. Results: Two practices out of 14 deemed eligible agreed to take part. Each practice attended two sessions, although a third session on consultation skills training was needed for one practice. Fifty-four post-training consultations were recorded from 15 clinicians. Two members of staff were interviewed at each practice. Significant elements of the training form and methods of delivery fitted contemporary practice. There were logistical problems in getting a whole practice to attend both sessions, and administrative staff founds some sections irrelevant. Clinicians reported problems incorporating some of the tools developed for WISE, and this was confirmed in the overview of consultations, with limited overt use of WISE tools and missed opportunities to address patients' self-management needs. Conclusions: The formative evaluation approach and attention to normalisation process theory allowed the training team to make adjustments to content and delivery and ensure appropriate staff attended each session. The content of the course was simplified and focussed more clearly on operationalising the WISE approach. The patient arm of the approach was strengthened by raising expectations of a change in approach to self-care support by their practice. <br/

    Identification of novel aphid-killing bacteria to protect plants

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    Aphids, including the peach-potato aphid, Myzus persicae, are major insect pests of agriculture and horticulture, and aphid control measures are limited. There is therefore an urgent need to develop alternative and more sustainable means of control. Recent studies have shown that environmental microbes have varying abilities to kill insects. We screened a range of environmental bacteria isolates for their abilities to kill target aphid species. Tests demonstrated the killing aptitude of these bacteria against six aphid genera (including Myzus persicae). No single bacterial strain was identified that was consistently toxic to insecticide-resistant aphid clones than susceptible clones, suggesting resistance to chemicals is not strongly correlated with bacterial challenge. Pseudomonas fluorescens PpR24 proved the most toxic to almost all aphid clones whilst exhibiting the ability to survive for over three weeks on three plant species at populations of 5-6 log CFU cm-2 leaf. Application of PpR24 to plants immediately prior to introducing aphids onto the plants led to a 68%, 57% and 69% reduction in aphid populations, after 21 days, on Capsicum annuum, Arabidopsis thaliana and Beta vulgaris respectively. Together, these findings provide new insights into aphid susceptibility to bacterial infection with the aim of utilizing bacteria as effective biocontrol agents
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