146 research outputs found
Effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus in the Mediterranean Sea
The effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus was investigated
in the Egadi Islands, Sicily, during spring 2005 using a fixed tuna trap set near shipping routes.
Tuna behaviour was observed when exposed to both natural ambient sound and sound generated by
hydrofoil passenger ferries, small boats and large car ferries. Acoustical and behavioural analyses
were conducted with and without extraneous sound to define a list of behavioural categories. Each
vessel produced different engine sounds with regard to their composition and bandwidth, and all
were distinctly different from ambient sound levels. In the absence of boat noise, tuna assumed a concentrated
coordinated school structure with unidirectional swimming and without a precise shape.
When a car ferry approached, tuna changed swimming direction and increased their vertical movement
toward surface or bottom; the school exhibited an unconcentrated structure and uncoordinated
swimming behaviour. Hydrofoils appeared to elicit a similar response, but for shorter periods. Agonistic
behaviour was more evident when exposed to sounds from outboard motors of small boats. This
study showed that local noise pollution generated by boats produced behavioural deviations in tuna
schools. Schooling enhances tuna homing accuracy during their spawning migration, and an alteration
in schooling behaviour can affect the accuracy of their migration to spawning and feeding
grounds
Expression of calpain-calpastatin system (CCS) member proteins in human lymphocytes of young and elderly individuals; pilot baseline data for the CALPACENT project.
Ubiquitous system of regulatory, calcium-dependent, cytoplasmic proteases – calpains – and their
endogenous inhibitor – calpastatin – is implicated in the proteolytic regulation of activation, proliferation, and
apoptosis of many cell types. However, it has not been thoroughly studied in resting and activated human
lymphocytes yet, especially in relation to the subjects’ ageing process. The CALPACENT project is an international
(Polish-Italian) project aiming at verifying the hypothesis of the role of calpains in the function of peripheral blood
immune cells of Polish (Pomeranian) and Italian (Sicilian) centenarians, apparently relatively preserved in comparison
to the general elderly population. In this preliminary report we aimed at establishing and comparing the baseline
levels of expression of μ- and m-calpain and calpastatin in various, phenotypically defined, populations of human
peripheral blood lymphocytes for healthy elderly Sicilians and Poles, as compared to these values observed in
young cohort
On stability of discretizations of the Helmholtz equation (extended version)
We review the stability properties of several discretizations of the
Helmholtz equation at large wavenumbers. For a model problem in a polygon, a
complete -explicit stability (including -explicit stability of the
continuous problem) and convergence theory for high order finite element
methods is developed. In particular, quasi-optimality is shown for a fixed
number of degrees of freedom per wavelength if the mesh size and the
approximation order are selected such that is sufficiently small and
, and, additionally, appropriate mesh refinement is used near
the vertices. We also review the stability properties of two classes of
numerical schemes that use piecewise solutions of the homogeneous Helmholtz
equation, namely, Least Squares methods and Discontinuous Galerkin (DG)
methods. The latter includes the Ultra Weak Variational Formulation
Phenotypic differentiation among native, expansive and introduced populations influences invasion success
Aim: Humans influence species distributions by modifying the environment and by dispersing species beyond their natural ranges. Populations of species that have established in disjunct regions of the world may exhibit trait differentiation from native populations due to founder effects and adaptations to selection pressures in each distributional region. We compared multiple native, expansive and introduced populations of a single species across the world, considering the influence of environmental stressors and transgenerational effects. Location: United States Gulf and Atlantic coasts, United States interior, European Atlantic and Mediterranean coasts, east coast of Australia. Taxon: Baccharis halimifolia L. (eastern baccharis). Methods: We monitored seed germination, seedling emergence, survival and early growth in a common garden experiment, conducted with over 18,200 seeds from 80 populations. We also evaluated the influence of environmental stress and maternal traits on progeny performance. Results: Introduced European Atlantic populations had faster germination and early growth than native populations. However, this was not the case for the more recently naturalized European Mediterranean populations. Introduced Australian populations grew faster than native populations in non-saline environments but had lower survival in saline conditions commonly encountered in the native range. Similarly, expansive inland US populations germinated faster than coastal native populations in non-saline environments but grew and germinated more slowly in saline environments. Maternal inflorescence and plant size were positively related with seed germination and seedling survival, whereas flower abundance was positively correlated with seedling early growth and survival. However, maternal traits explained a much lower fraction of the total variation in early demographic stages of B. halimifolia than did distributional range. Main conclusions: Phenotypic differentiation could allow B. halimifolia to adapt to different biotic and abiotic selection pressures found in each distributional range, potentially contributing to its success in introduced and expansive ranges
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Plane wave discontinuous Galerkin methods: exponential convergence of the hp-version
We consider the two-dimensional Helmholtz equation with constant coefficients on a domain with piecewise analytic boundary, modelling the scattering of acoustic waves at a sound-soft obstacle. Our discretisation relies on the Trefftz-discontinuous Galerkin approach with plane wave basis functions on meshes with very general element shapes, geometrically graded towards domain corners. We prove exponential convergence of the discrete solution in terms of number of unknowns
High activity Rhenium-186 HEDP with autologous peripheral blood stem cell rescue: a phase I study in progressive hormone refractory prostate cancer metastatic to bone
We tested the feasibility and toxicity of high activities Rhenium-186 hydroxyethylidene diphosphonate, with peripheral blood stem cell rescue in patients with progressive hormone refractory prostate cancer metastatic to bone. Twenty-five patients received between 2500 and 5000 MBq of Rhenium-186 hydroxyethylidene diphosphonate followed 14 days later by the return of peripheral blood peripheral blood stem cells. Activity limiting toxicity was defined as grade III haematological toxicity, lasting at least 7 days, or grade IV haematological toxicity of any duration or any serious unexpected toxicity. Activity limiting toxicity occurred in two of six who received activities of 5000 MBq and maximum tolerated activity was defined at this activity level. Prostate specific antigen reductions of 50% or more lasting at least 4 weeks were seen in five of the 25 patients (20%) all of whom received more than 3500 MBq of Rhenium-186 hydroxyethylidene diphosphonate. The actuarial survival at 1 year is 54%. Administered activities of 5000 MBq of Rhenium-186 hydroxyethylidene diphosphonate are feasible using autologous peripheral blood peripheral blood stem cell rescue in patients with progressive hormone refractory prostate cancer metastatic to bone. The main toxicity is thrombocytopaenia, which is short lasting. A statistically significant activity/prostate specific antigen response was seen. We have now commenced a Phase II trial to further evaluate response rates
WSB-1 regulates the metastatic potential of hormone receptor negative breast cancer
© 2018 Cancer Research UK. Background: Metastatic spread is responsible for the majority of cancer-associated deaths. The tumour microenvironment, including hypoxia, is a major driver of metastasis. The aim of this study was to investigate the role of the E3 ligase WSB-1 in breast cancer biology in the context of the hypoxic tumour microenvironment, particularly regarding metastatic spread. Methods: In this study, WSB-1 expression was evaluated in breast cancer cell lines and patient samples. In silico analyses were used to determine the impact of WSB-1 expression on distant metastasis-free survival (DMFS) in patients, and correlation between WSB1 expression and hypoxia gene expression signatures. The role of WSB-1 on metastasis promotion was evaluated in vitro and in vivo. Results: High WSB1 expression was associated with decreased DMFS in ER-breast cancer and PR-breast cancer patients. Surprisingly, WSB1 expression was not positively correlated with known hypoxic gene expression signatures in patient samples. Our study is the first to show that WSB-1 knockdown led to decreased metastatic potential in breast cancer hormone receptor-negative models in vitro and in vivo. WSB-1 knockdown was associated with decreased metalloproteinase (MMP) activity, vascular endothelial growth factor (VEGF) secretion, and angiogenic potential. Conclusions: Our data suggests that WSB-1 may be an important regulator of aggressive metastatic disease in hormone receptor-negative breast cancer. WSB-1 could therefore represent a novel regulator and therapeutic target for secondary breast cancer in these patients
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