131 research outputs found

    The effect of ultraviolet C radiation on stored-product pests

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    The potential of using ultraviolet C (UVC) radiation as an alternative treatment and hygiene measure in storage premises was investigated in the laboratory. The effect of UVC on development and progeny production was assessed for pest species of the storage beetles Oryzaephilus surinamensis and Tribolium castaneum, and the mites, Acarus siro and Tyrophagus putrescentiae. Photo-reactivation and the effect of indirect exposure were also investigated, as was the effect on spore germination of a mycotoxin-producing fungus Penicillium verrucosum. The ED95 values for O. surinamensis, T. castaneum, T. putrescentiae and A. siro were 96,549, 59,069, 22,014 and 3,802 μJ cm-2 respectively, when incubated in lighted conditions. There was an indication of a photo-reactivation effect with T. putrescentiae. Limited penetrative ability through substrates was observed at the doses assessed. Complete prevention of spore germination and complete spore destruction of P. verrucosum was achieved at 20,000 and 25,000 μJ cm-2 respectively. There was no significant difference in the numbers of O. surinamensis, T. castaneum and T. putrescentiae progeny produced by untreated females and females treated with a sub-lethal dose of UVC. However, there was a large degree of variation in the number of progeny produced by individual females. There was a significant reduction in the numbers of A. siro progeny produced by UVC treated females compared to untreated females; however, the majority of females died during the incubation period before any eggs had been laid. Practical applications of UVC within a storage environment may lie in the treatment of structural and equipment surfaces, such as conveyor systems. However, cleaning prior to treatment is an important consideration as UVC has limited penetrative ability. Keywords: Ultraviolet C radiation; Storage beetle, Mite and fungal pests; Structural treatment; Hygienemeasure

    Tuna Longline Fishing around West and Central Pacific Seamounts

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    BACKGROUND: Seamounts have been identified as aggregating locations for pelagic biodiversity including tuna; however the topography and prevailing oceanography differ between seamounts and not all are important for tuna. Although a relatively common feature in oceanic ecosystems, little information is available that identifies those that are biologically important. Improved knowledge offers opportunities for unique management of these areas, which may advance the sustainable management of oceanic resources. In this study, we evaluate the existence of an association between seamounts and tuna longline fisheries at the ocean basin scale, identify significant seamounts for tuna in the western and central Pacific Ocean, and quantify the seamount contribution to the tuna longline catch. METHODOLOGY/PRINCIPAL FINDINGS: We use data collected for the Western and Central Pacific Ocean for bigeye, yellowfin, and albacore tuna at the ocean basin scale. GLMs were applied to a coupled dataset of longline fisheries catch and effort, and seamount location information. The analyses show that seamounts may be associated with an annual longline combined catch of 35 thousand tonnes, with higher catch apparent for yellowfin, bigeye, and albacore tuna on 17%, 14%, and 14% of seamounts respectively. In contrast 14%, 18%, and 20% of seamounts had significantly lower catches for yellowfin, bigeye and albacore tuna respectively. Studying catch data in relation to seamount positions presents several challenges such as bias in location of seamounts, or lack of spatial resolution of fisheries data. Whilst we recognize these limitations the criteria used for detecting significant seamounts were conservative and the error in identification is likely to be low albeit unknown. CONCLUSIONS/SIGNIFICANCE: Seamounts throughout the study area were found to either enhance or reduce tuna catch. This indicates that management of seamounts is important Pacific-wide, but management approaches must take account of local conditions. Management of tuna and biodiversity resources in the region would benefit from considering such effects

    Sigma-phase in Fe-Cr and Fe-V alloy systems and its physical properties

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    A review is presented on physical properties of the sigma-phase in Fe-Cr and Fe-V alloy systems as revealed both with experimental -- mostly with the Mossbauer spectroscopy -- and theoretical methods. In particular, the following questions relevant to the issue have been addressed: identification of sigma and determination of its structural properties, kinetics of alpha-to-sigma and sigma-to-alpha phase transformations, Debye temperature and Fe-partial phonon density of states, Curie temperature and magnetization, hyperfine fields, isomer shifts and electric field gradients.Comment: 26 pages, 23 figures and 83 reference

    Integrating Multiple Data Types to Connect Ecological Theory and Data Among Levels

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    Ecological theories often encompass multiple levels of biological organization, such as genes, individuals, populations, and communities. Despite substantial progress toward ecological theory spanning multiple levels, ecological data rarely are connected in this way. This is unfortunate because different types of ecological data often emerge from the same underlying processes and, therefore, are naturally connected among levels. Here, we describe an approach to integrate data collected at multiple levels (e.g., individuals, populations) in a single statistical analysis. The resulting integrated models make full use of existing data and might strengthen links between statistical ecology and ecological models and theories that span multiple levels of organization. Integrated models are increasingly feasible due to recent advances in computational statistics, which allow fast calculations of multiple likelihoods that depend on complex mechanistic models. We discuss recently developed integrated models and outline a simple application using data on freshwater fishes in south-eastern Australia. Available data on freshwater fishes include population survey data, mark-recapture data, and individual growth trajectories. We use these data to estimate age-specific survival and reproduction from size-structured data, accounting for imperfect detection of individuals. Given that such parameter estimates would be infeasible without an integrated model, we argue that integrated models will strengthen ecological theory by connecting theoretical and mathematical models directly to empirical data. Although integrated models remain conceptually and computationally challenging, integrating ecological data among levels is likely to be an important step toward unifying ecology among levels

    Persistence of TEL-AML1 fusion gene as minimal residual disease has no additive prognostic value in CD 10 positive B-acute lymphoblastic leukemia: a FISH study

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    <p>Abstract</p> <p>Objectives </p> <p>We have analyzed t(12;21)(p13:q22) in an attempt to evaluate the frequency and prognostic significance of <it>TEL-AML1 </it>fusion gene in patients with childhood CD 10 positive B-ALL by fluorescence in situ hybridization (FISH). Also, we have monitored the prognostic value of this gene as a minimal residual disease (MRD).</p> <p>Methods</p> <p>All bone marrow samples of eighty patients diagnosed as CD 10 positive B-ALL in South Egypt Cancer Institute were evaluated by fluorescence in situ hybridization (FISH) for t(12;21) in newly diagnosed cases and after morphological complete remission as a minimal residual disease (MRD). We determined the prognostic significance of <it>TEL-AML1 </it>fusion represented by disease course and survival.</p> <p>Results</p> <p><it>TEL-AML1 </it>fusion gene was positive in (37.5%) in newly diagnosed patients. There was a significant correlation between <it>TEL-AML1 </it>fusion gene both at diagnosis (r = 0.5, P = 0.003) and as a MRD (r = 0.4, P = 0.01) with favorable course. Kaplan-Meier curve for the presence of <it>TEL-AML1 </it>fusion at the diagnosis was associated with a better probability of overall survival (OS); mean survival time was 47 ± 1 month, in contrast to 28 ± 5 month in its absence (P = 0.006). Also, the persistence at <it>TEL-AML1 </it>fusion as a MRD was not significantly associated with a better probability of OS; the mean survival time was 42 ± 2 months in the presence of MRD and it was 40 ± 1 months in its absence. So, persistence of <it>TEL-AML1 </it>fusion as a MRD had no additive prognostic value over its measurement at diagnosis in terms of predicting the probability of OS.</p> <p>Conclusion</p> <p>For most patients, the presence of <it>TEL-AML1 </it>fusion gene at diagnosis suggests a favorable prognosis. The present study suggests that persistence of <it>TEL-AML1 </it>fusion as MRD has no additive prognostic value.</p

    Characteristics of the Mesophotic Megabenthic Assemblages of the Vercelli Seamount (North Tyrrhenian Sea)

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    The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount) is described using Remotely Operated Vehicle (ROV) video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i) the top shows a dense covering of the kelp Laminaria rodriguezii; (ii) the southern side biocoenosis is mainly dominated by the octocorals Paramuricea clavata and Eunicella cavolinii; while (iii) the northern side of the seamount assemblage is colonized by active filter-feeding organisms such as sponges (sometimes covering 100% of the surface) with numerous colonies of the ascidian Diazona violacea, and the polychaete Sabella pavonina. This study highlights, also for a Mediterranean seamount, the potential role of an isolated rocky peak penetrating the euphotic zone, to work as an aggregating structure, hosting abundant benthic communities dominated by suspension feeders, whose distribution may vary in accordance to the geomorphology of the area and the different local hydrodynamic conditions

    Quantifying the Spatial Ecology of Wide-Ranging Marine Species in the Gulf of California: Implications for Marine Conservation Planning

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    There is growing interest in systematic establishment of marine protected area (MPA) networks and representative conservation sites. This movement toward networks of no-take zones requires that reserves are deliberately and adequately spaced for connectivity. Here, we test the network functionality of an ecoregional assessment configuration of marine conservation areas by evaluating the habitat protection and connectivity offered to wide-ranging fauna in the Gulf of California (GOC, Mexico). We first use expert opinion to identify representative species of wide-ranging fauna of the GOC. These include leopard grouper, hammerhead sharks, California brown pelicans and green sea turtles. Analyzing habitat models with both structural and functional connectivity indexes, our results indicate that the configuration includes large proportions of biologically important habitat for the four species considered (25–40%), particularly, the best quality habitats (46–57%). Our results also show that connectivity levels offered by the conservation area design for these four species may be similar to connectivity levels offered by the entire Gulf of California, thus indicating that connectivity offered by the areas may resemble natural connectivity. The selected focal species comprise different life histories among marine or marine-related vertebrates and are associated with those habitats holding the most biodiversity values (i.e. coastal habitats); our results thus suggest that the proposed configuration may function as a network for connectivity and may adequately represent the marine megafauna in the GOC, including the potential connectivity among habitat patches. This work highlights the range of approaches that can be used to quantify habitat protection and connectivity for wide-ranging marine species in marine reserve networks

    Science Priorities for Seamounts: Research Links to Conservation and Management

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    Seamounts shape the topography of all ocean basins and can be hotspots of biological activity in the deep sea. The Census of Marine Life on Seamounts (CenSeam) was a field program that examined seamounts as part of the global Census of Marine Life (CoML) initiative from 2005 to 2010. CenSeam progressed seamount science by collating historical data, collecting new data, undertaking regional and global analyses of seamount biodiversity, mapping species and habitat distributions, challenging established paradigms of seamount ecology, developing new hypotheses, and documenting the impacts of human activities on seamounts. However, because of the large number of seamounts globally, much about the structure, function and connectivity of seamount ecosystems remains unexplored and unknown. Continual, and potentially increasing, threats to seamount resources from fishing and seabed mining are creating a pressing demand for research to inform conservation and management strategies. To meet this need, intensive science effort in the following areas will be needed: 1) Improved physical and biological data; of particular importance is information on seamount location, physical characteristics (e.g. habitat heterogeneity and complexity), more complete and intensive biodiversity inventories, and increased understanding of seamount connectivity and faunal dispersal; 2) New human impact data; these shall encompass better studies on the effects of human activities on seamount ecosystems, as well as monitoring long-term changes in seamount assemblages following impacts (e.g. recovery); 3) Global data repositories; there is a pressing need for more comprehensive fisheries catch and effort data, especially on the high seas, and compilation or maintenance of geological and biodiversity databases that underpin regional and global analyses; 4) Application of support tools in a data-poor environment; conservation and management will have to increasingly rely on predictive modelling techniques, critical evaluation of environmental surrogates as faunal “proxies”, and ecological risk assessment

    mRNA transcripts initiating within the human immunoglobulin mu heavy chain enhancer region contain a non-translatable exon and are extremely heterogeneous at the 5' end.

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    Transcription events are thought to precede gene rearrangement in the immunoglobulin (Ig) loci and may be the mechanism by which the various gene regions are made accessible for recombination. If this is the case, identification and characterization of transcripts from the Ig loci should permit a better understanding of the gene rearrangement process. We have isolated a 2.3 kb cDNA clone from the human pre-B cell line Nalm-1 that contains enhancer-specific sequences from the Ig heavy (H) chain gene locus. The 2.3 kb transcript initiated within the enhancer region and showed extreme 5' heterogeneity, with more than 50 initiation sites mapping near the Ig-specific octamer ATTTGCGT. Sequencing of the cDNA clone demonstrated that 644 nucleotides from the Ig enhancer region were incorporated as a leader exon spliced to the mu constant (Cmu) region. This leader exon contained many translation termination codons and may function to inhibit the translation of sterile Cmu polypeptides. Using an enhancer-derived probe, we detected two low-abundancy mRNA transcripts with sizes of 2.3 and 12 kb. Northern blot analysis suggested that the 12 kb transcript was the unspliced precursor mRNA of a VDJ rearrangement. The potential role of these enhancer-containing transcripts in the opening of the IgH chain gene for rearrangement and for class switching is discussed

    Catches from world seamount fisheries

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