7 research outputs found

    Experimental estimation of ladder dredge efficiency for capture of European flat oysters over mixed sediment

    Get PDF
    Fishing gear-based landings or survey methods are often used to make assessments of species stock abundance. In order to convert catch into abundance values, estimates or assumptions are made on the catch efficiency of the gear-based method. This is the case in areas where flat oysters, Ostrea edulis, are surveyed for fisheries and conservation objectives in a range of projects across Europe. Flat oyster dredge efficiency assumptions vary widely from 5–30% in published studies and uncertainty in what is an appropriate efficiency estimate has led some survey teams to switch to Catch-per-unit-effort (CPUE), where CPUE is also of concern should catch efficiency change with shellfish density, ground type or some other unmeasured variable such as shellfish distribution. We undertook an experimental approach to estimate dredge efficiency in a standard ladder dredge used to harvest and survey adult flat oysters in the UK and Ireland. The dredge efficiency trials assessed how efficiency was influenced by oyster density (between 1 and 2.2 oysters m2), distribution (clumped vs uniform) and ground types across a gradient of more hard to more soft surface sediments. Dredge efficiency was significantly affected by oyster distribution, but also density and ground hardness as well as their interactions. While a median value between 7 and 10% seems an appropriate universal ladder dredge efficiency to adopt, ground type and distribution had such an effect that local conditions may effect this considerably. Catch efficiency was negatively density-dependent, this makes CPUE methods challenging where oyster densities are likely to vary. Practitioners, regulators and researchers conducting surveys can improve CPUE approaches through standard techniques and knowledge of how catch efficiency varies as we have presented here

    Psychological distress and ischaemic heart disease: cause or consequence? Evidence from a large prospective cohort study

    Get PDF
    Background Ischaemic heart disease (IHD) incidence is elevated in people reporting psychological distress. The extent to which this relationship is causal or related to reverse causality—that is, undiagnosed disease causing distress—is unclear. We quantified the relationship between psychological distress and IHD, with consideration of confounding and undiagnosed disease. Methods Questionnaire data (2006–2009) from 151 811 cardiovascular disease-free and cancer-free Australian general population members aged ≥45years (45 and Up Study) were linked to hospitalisation and mortality data, to December 2013. A two-stage approach estimated HRs for incident IHD (IHD-related hospitalisation or death) for low (Kessler-10 scores: 10–<12), mild (12–<16), moderate (16–<22) and high (22–50) psychological distress, adjusting for demographic and behavioural characteristics, and then restricting to those with no/minor functioning limitations (likely free from undiagnosed disease). Results Over 859 396 person-years, 5230 incident IHD events occurred (rate: 6.09/1000person-years). IHD risk was increased for mild (age-adjusted and sex-adjusted HR: 1.18, 95%CI 1.11 to 1.26), moderate (1.36, 1.25 to 1.47), and high (1.69, 1.52 to 1.88) versus low distress. HRs attenuated to 1.15 (1.08 to 1.22), 1.26 (1.16 to 1.37) and 1.41 (1.26 to 1.57) after adjustment for demographic and behavioural characteristics and were further attenuated by 35%–41% in those with no/minor limitations, leaving a significant but relatively weak doseresponse relationship: 1.11 (1.02 to 1.20), 1.21 (1.08 to 1.37) and 1.24 (1.02 to 1.51) for mild, moderate and high versus low distress, respectively. The observed adjustment-related attenuation suggests measurement error/residual confounding likely contribute to the remaining association. Conclusion A substantial part of the distress-IHD association is explained by confounding and functional limitations, an indicator of undiagnosed disease. Emphasis should be on psychological distress as a marker of healthcare need and IHD risk, rather than a causative factorJW is supported by an Australian Government Research Training Program Scholarship.AB is supported by a Veirtel Senior Medical Research Fellowshi

    Cardiopoietic cell therapy for advanced ischemic heart failure: results at 39 weeks of the prospective, randomized, double blind, sham-controlled CHART-1 clinical trial

    Get PDF
    Cardiopoietic cells, produced through cardiogenic conditioning of patients' mesenchymal stem cells, have shown preliminary efficacy. The Congestive Heart Failure Cardiopoietic Regenerative Therapy (CHART-1) trial aimed to validate cardiopoiesis-based biotherapy in a larger heart failure cohort

    Tissue-engineered cartilage grafts for use in cartilage repair technologies [Abstract]

    No full text
    Abstract of paper from TCES (Tissue and Cell Engineering Society) meeting in 2005. The ability of the skin to extend and recoil is mediated by an elastic fibre network comprising elastin molecules deposited on a microfibrillar scaffold. Studies have demonstrated reduced tensile strength in scar tissue following cutaneous wounding, possibly due to decreased amounts of elastic fibres1. The dermal component of artificial skin substitutes also lacks an organised elastic fibre network, which may contribute to excessive contraction and scarring post-grafting. This study aimed to document the temporal and spatial distribution of elastic fibres following incisional and excisional cutaneous wounding in mice
    corecore