966 research outputs found

    Using a Bayesian modelling approach (INLA‑SPDE) to predict the occurrence of the Spinetail Devil Ray (Mobular mobular)

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    To protect the most vulnerable marine species it is essential to have an understanding of their spatiotemporal distributions. In recent decades, Bayesian statistics have been successfully used to quantify uncertainty surrounding identified areas of interest for bycatch species. However, conventional simulation-based approaches are often computationally intensive. To address this issue, in this study, an alternative Bayesian approach (Integrated Nested Laplace Approximation with Stochastic Partial Differential Equation, INLA-SPDE) is used to predict the occurrence of Mobula mobular species in the eastern Pacific Ocean (EPO). Specifically, a Generalized Additive Model is implemented to analyze data from the Inter-American Tropical Tuna Commission’s (IATTC) tropical tuna purse-seine fishery observer bycatch database (2005–2015). The INLA-SPDE approach had the potential to predict both the areas of importance in the EPO, that are already known for this species, and the more marginal hotspots, such as the Gulf of California and the Equatorial area which are not identified using other habitat models. Some drawbacks were identified with the INLA-SPDE database, including the difficulties of dealing with categorical variables and triangulating effectively to analyze spatial data. Despite these challenges, we conclude that INLA approach method is an useful complementary and/or alternative approach to traditional ones when modeling bycatch data to inform accurately management decisions.En prensa2,92

    The immune response in a dog to Encephalitozoon cuniculi infection

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    The immune response to Encephalitozoon cuniculi infection in a dog was investigated by means of the indirect fluorescent antibody test, the leucocyte migration inhibition test and the radial immunodiffusion test for serum IgG and IgM levels. Specific antibodies were detected within 7 days of infection and they persisted for 370 days. A cellmediated immune response was detected from Day 13 following infection until Day 97. Histopathological examination showed plasma cell infiltration of the kidneys, meninges, lung, bladder, smooth muscle and spleen.The immune response to Encephalitozoon cuniculi infection in a dog was investigated by means of the indirect fluorescent antibody test, the leucocyte migration inhibition test and the radial immunodiffusion test for serum IgG and IgM levels. Specific antibodies were detected within 7 days of infection and they persisted for 370 days. A cell-mediated immune response was detected from Day 13 following infection until Day 97. Histopathological examination showed plasma cell infiltration of the kidneys, meninges, lung, bladder, smooth muscle and spleen.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.University of Pretoria.mn201

    Understanding service demand for mental health among Australians aged 16 to 64 years according to their possible need for treatment

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    Background: To inform decisions about mental health resource allocation, planners require reliable estimates of people who report service demand (i.e. people who use or want mental health services) according to their level of possible need. Methods: Using data on 6915 adults aged 16-64 years in Australia's 2007 National Survey of Mental Health and Wellbeing, we examined past-year service demand among respondents grouped into four levels of possible need: (a) 12-month mental disorder; (b) lifetime but no 12-month mental disorder; (c) any other indicator of possible need (12-month symptoms or reaction to stressful event, or lifetime hospitalisation); (d) no indicator of possible need. Multivariate logistic regression analyses examined correlates of service demand, separately for respondents in each of levels 1-3. Results: Sixteen per cent of Australian adults reported service demand, of whom one-third did not meet criteria for a 12-month mental disorder (equivalent to 5.7% of the adult population). Treatment patterns tended to follow a gradient defined by level of possible need. For example, service users with a 12-month disorder received, on average, 1.6-3.9 times more consultations than their counterparts in other levels of possible need, and had 1.9-2.2 times higher rates of psychologist consultation. Service users with a lifetime but not 12-month disorder or any other indicator of need consumed a similar average number of services to people with mild 12-month mental disorders, but received relatively fewer services involving the mental health sector. Service demand was associated with increased suicidality and psychological distress in all levels of possible need examined, and with poorer clinical and functional status for those with 12-month or lifetime disorders. Conclusions: Many Australians reporting service demand do not meet criteria for a current mental disorder, but may require services to maintain recovery following a past episode or because they are experiencing symptoms and significant psychological distress

    White-light toxicity, resulting from systemically administered 5-aminolevulinic acid, under normal operating conditions

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    This study has investigated damage to the intraperitoneal organs of the rat after systemic (intraperitoneal and intravenous) administration of low doses of 5-aminolevulinic acid (ALA) and illumination with a standard white-light operating-room (o.r.) lamp. The study has been done within the framework of a larger study in which the possibility of using ALA for localization of small-volume macroscopically non-visible peritoneal metastasis of ovarian tumors is being investigated. Fluorescence diagnostics are done in addition to the standard staging and localization procedures, either through a laparoscope or during laparotomy. In these circumstances, fluorescence diagnostics involve some risk of photosensitization of critical organs since a broad-band (o.r.) light source is used during the surgical procedures for illumination of the operating area. The drug dose and the time interval between administration of ALA and illumination are varied and normal tissues are examined both macroscopically and microscopically for damage. A relationship is demonstrated between the maximum tolerable dose (MTD) of ALA (defined as the dose that does not cause any tissue damage) and the time interval between administration and illumination. The white light that is used for illumination of the operating area is sufficient to induce damage to the peritoneal organs at relatively low ALA doses. The MDTs for 2, 6 and 16 h intervals are found to be respectively 1, 10 and 100 mg kg-1. The results are similar for both intraperitoneal and intravenous administration

    Palaeoecological and genetic evidence for Neanderthal power locomotion as an adaptation to a woodland environment

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    The prevailing explanation for Neanderthal body form is the cold (glacial) adaptation hypothesis. However, palaeoecological associations appear to indicate a less cold woodland environment. Under such conditions, encounter and ambush (rather than pursuit) hunting e and thus muscular power and sprint (rather than endurance) capacity e would have been favoured. We hypothesise that the highly muscular Neanderthal body form reflects an adaptation to hunting conditions rather than cold, and here both review the palaeoecological evidence that they inhabited a mainly woodland environment, and present preliminary genetic analyses in support of this new hypothesis

    The N-methyl-d-aspartate receptor antagonist CPP alters synapse and spine structure and impairs long-term potentiation and long-term depression induced morphological plasticity in dentate gyrus of the awake rat

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    Long-term morphological synaptic changes associated with homosynaptic long-term potentiation (LTP) and heterosynaptic long-term depression (LTD) in vivo, in awake adult rats were analyzed using three-dimensional (3-D) reconstructions of electron microscope images of ultrathin serial sections from the molecular layer of the dentate gyrus. For the first time in morphological studies, the specificity of the effects of LTP and LTD on both spine and synapse ultrastructure was determined using an N-methyl-d-aspartate (NMDA) receptor antagonist CPP (3-[(R)-2-carboxypiperazin-4-yl]-propyl-1-phosphonic acid). There were no differences in synaptic density 24 h after LTP or LTD induction, and CPP alone had no effect on synaptic density. LTP increased significantly the proportion of mushroom spines, whereas LTD increased the proportion of thin spines, and both LTP and LTD decreased stubby spine number. Both LTP and LTD increased significantly spine head evaginations (spinules) into synaptic boutons and CPP blocked these changes. Synaptic boutons were smaller after LTD, indicating a pre-synaptic effect. Interestingly, CPP alone decreased bouton and mushroom spine volumes, as well as post-synaptic density (PSD) volume of mushroom spines.These data show similarities, but also some clear differences, between the effects of LTP and LTD on spine and synaptic morphology. Although CPP blocks both LTP and LTD, and impairs most morphological changes in spines and synapses, CPP alone was shown to exert effects on aspects of spine and synaptic structure

    Searching for Signatures of Cosmic Superstrings in the CMB

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    Because cosmic superstrings generically form junctions and gauge theoretic strings typically do not, junctions may provide a signature to distinguish between cosmic superstrings and gauge theoretic cosmic strings. In cosmic microwave background anisotropy maps, cosmic strings lead to distinctive line discontinuities. String junctions lead to junctions in these line discontinuities. In turn, edge detection algorithms such as the Canny algorithm can be used to search for signatures of strings in anisotropy maps. We apply the Canny algorithm to simulated maps which contain the effects of cosmic strings with and without string junctions. The Canny algorithm produces edge maps. To distinguish between edge maps from string simulations with and without junctions, we examine the density distribution of edges and pixels crossed by edges. We find that in string simulations without Gaussian noise (such as produced by the dominant inflationary fluctuations) our analysis of the output data from the Canny algorithm can clearly distinguish between simulations with and without string junctions. In the presence of Gaussian noise at the level expected from the current bounds on the contribution of cosmic strings to the total power spectrum of density fluctuations, the distinction between models with and without junctions is more difficult. However, by carefully analyzing the data the models can still be differentiated.Comment: 15 page

    Practical application of direct electron detectors to EBSD mapping in 2D and 3D

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    The use of a direct electron detector for the simple acquisition of 2D electron backscatter diffraction (EBSD) maps and 3D EBSD datasets with a static sample geometry has been demonstrated in a focused ion beam scanning electron microscope. The small size and flexible connection of the Medipix direct electron detector enabled the mounting of sample and detector on the same stage at the short working distance required for the FIB. Comparison of 3D EBSD datasets acquired by this means and with conventional phosphor based EBSD detectors requiring sample movement showed that the former method with a static sample gave improved slice registration. However, for this sample detector configuration, significant heating by the detector caused sample drift. This drift and ion beam reheating both necessitated the use of fiducial marks to maintain stability during data acquisition

    Hybrid configuration content of heavy S-wave mesons

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    We use the non-relativistic expansion of QCD (NRQCD) on the lattice to study the lowest hybrid configuration contribution to the ground state of heavy S-wave mesons. Using lowest-order lattice NRQCD to create the heavy-quark propagators, we form a basis of ``unperturbed'' S-wave and hybrid states. We then apply the lowest-order coupling of the quark spin and chromomagnetic field at an intermediate time slice to create ``mixed'' correlators between the S-wave and hybrid states. From the resulting amplitudes, we extract the off-diagonal element of our two-state Hamiltonian. Diagonalizing this Hamiltonian gives us the admixture of hybrid configuration within the meson ground state. The present effort represents a continuation of previous work: the analysis has been extended to include lattices of varying spacings, source operators having better overlap with the ground states, and the pseudoscalar (along with the vector) channel. Results are presented for bottomonium (Υ\Upsilon, ηb\eta_b^{}) using three different sets of quenched lattices. We also show results for charmonium (J/ψJ/\psi, ηc\eta_c^{}) from one lattice set, although we note that the non-relativistic approximation is not expected to be very good in this case.Comment: 9 pages, 7 figures, version to appear in Phys Rev
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