141 research outputs found

    Fish oil replacement in current aquaculture feed : is cholesterol a hidden treasure for fish nutrition?

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    Teleost fish, as with all vertebrates, are capable of synthesizing cholesterol and as such have no dietary requirement for it. Thus, limited research has addressed the potential effects of dietary cholesterol in fish, even if fish meal and fish oil are increasingly replaced by vegetable alternatives in modern aquafeeds, resulting in progressively reduced dietary cholesterol content. The objective of this study was to determine if dietary cholesterol fortification in a vegetable oil-based diet can manifest any effects on growth and feed utilization performance in the salmonid fish, the rainbow trout. In addition, given a series of studies in mammals have shown that dietary cholesterol can directly affect the fatty acid metabolism, the apparent in vivo fatty acid metabolism of fish fed the experimental diets was assessed. Triplicate groups of juvenile fish were fed one of two identical vegetable oil-based diets, with additional cholesterol fortification (high cholesterol, H-Chol) or without (low cholesterol, L-Chol), for 12 weeks. No effects were observed on growth and feed efficiency, however, in fish fed H-Col no biosynthesis of cholesterol, and a remarkably decreased apparent in vivo fatty acid b-oxidation were recorded, whilst in LChol fed fish, cholesterol was abundantly biosynthesised and an increased apparent in vivo fatty acid b-oxidation was observed. Only minor effects were observed on the activity of stearyl-CoA desaturase, but a significant increase was observed for both the transcription rate in liver and the apparent in vivo activity of the fatty acid D-6 desaturase and elongase, with increasing dietary cholesterol. This study showed that the possible effects of reduced dietary cholesterol in current aquafeeds can be significant and warrant future investigations

    Free satellite data key to conservation

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    Biodiversity is in crisis, with extinction rates orders of magnitude higher than background levels ([ 1 ][1]). Underfunded conservationists need to target their limited resources effectively. Over the past decade, satellite remote sensing has revolutionized our ability to monitor biodiversity globally, and is now used routinely, especially by nongovernmental organizations, to detect changes, set priorities, and target conservation action. The U.S. Geological Survey (USGS) unlocked high-resolution Landsat data in 2008 ([ 2 ][2]), making data available online ([ 3 ][3]), and the Copernicus program from the European Commission subsequently made their data available as well ([ 4 ][4]). These resources have been instrumental to biodiversity research. Assessments of environmental changes such as deforestation are now readily available. The current spatial and spectral resolution of Landsat data make them appropriate to many conservation applications, and although they are not always ideal, pragmatic researchers with limited resources use them regularly. Conservationists have already called for these data to remain free ([ 5 ][5]). Consequently, the news that USGS may charge for data ([ 6 ][6]) is deeply troubling. USGS has recently convened an advisory committee to determine whether users would be prepared to pay for increased spectral and spatial resolution images ([ 7 ][7]). Requiring users to pay would put these images beyond the reach of conservationists. It would halt time-series analyses that have been useful in monitoring the effects of climate change, land-cover change, and ocean surfaces, likely hindering the achievement of the Sustainable Development Goals ([ 8 ][8]). We urge the USGS to reconsider their position and continue to provide data from the Landsat program freely to all users. 1. [↡][9]1. J. DeVos et al ., Cons. Biol. 29, 452 (2015). [OpenUrl][10] 2. [↡][11]1. C. Woodcock et al . Science 320, 1011 (2008). [OpenUrl][12][CrossRef][13][PubMed][14] 3. [↡][15]USGS, Earth Explorer ([https://earthexplorer.usgs.gov/][16]). 4. [↡][17]European Commission, Copernicus (). 5. [↡][18]1. W. Turner et al ., Biol. Conserv. 182, 173 (2015). [OpenUrl][19] 6. [↡][20]1. G. Popkin , Nature 556, 417 (2018). [OpenUrl][21] 7. [↡][22]USGS, Landsat Advisory Group undertakes a Landsat Cost Recovery Study (2018); [www.usgs.gov/center-news/landsat-advisory-group-undertakes-a-landsat-cost-recovery-study][23]. 8. [↡][24]Sustainable Development Goals ([https://sustainabledevelopment.un.org/?menu=1300][25]). [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #ref-4 [5]: #ref-5 [6]: #ref-6 [7]: #ref-7 [8]: #ref-8 [9]: #xref-ref-1-1 "View reference 1 in text" [10]: {openurl}?query=rft.jtitle%253DCons.%2BBiol.%26rft.volume%253D29%26rft.spage%253D452%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [11]: #xref-ref-2-1 "View reference 2 in text" [12]: {openurl}?query=rft.jtitle%253DScience%26rft.volume%253D320%26rft.spage%253D1011%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.320.5879.1011a%26rft_id%253Dinfo%253Apmid%252F18497274%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [13]: /lookup/external-ref?access_num=10.1126/science.320.5879.1011a&link_type=DOI [14]: /lookup/external-ref?access_num=18497274&link_type=MED&atom=%2Fsci%2F361%2F6398%2F139.2.atom [15]: #xref-ref-3-1 "View reference 3 in text" [16]: http://earthexplorer.usgs.gov/ [17]: #xref-ref-4-1 "View reference 4 in text" [18]: #xref-ref-5-1 "View reference 5 in text" [19]: {openurl}?query=rft.jtitle%253DBiol.%2BConserv.%26rft.volume%253D182%26rft.spage%253D173%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [20]: #xref-ref-6-1 "View reference 6 in text" [21]: {openurl}?query=rft.jtitle%253DNature%26rft.volume%253D556%26rft.spage%253D417%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [22]: #xref-ref-7-1 "View reference 7 in text" [23]: http://www.usgs.gov/center-news/landsat-advisory-group-undertakes-a-landsat-cost-recovery-study [24]: #xref-ref-8-1 "View reference 8 in text" [25]: http://sustainabledevelopment.un.org/?menu=130

    Pharmacological Analysis of Ionotropic Glutamate Receptor Function in Neuronal Circuits of the Zebrafish Olfactory Bulb

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    Although synaptic functions of ionotropic glutamate receptors in the olfactory bulb have been studied in vitro, their roles in pattern processing in the intact system remain controversial. We therefore examined the functions of ionotropic glutamate receptors during odor processing in the intact olfactory bulb of zebrafish using pharmacological manipulations. Odor responses of mitral cells and interneurons were recorded by electrophysiology and 2-photon Ca2+ imaging. The combined blockade of AMPA/kainate and NMDA receptors abolished odor-evoked excitation of mitral cells. The blockade of AMPA/kainate receptors alone, in contrast, increased the mean response of mitral cells and decreased the mean response of interneurons. The blockade of NMDA receptors caused little or no change in the mean responses of mitral cells and interneurons. However, antagonists of both receptor types had diverse effects on the magnitude and time course of individual mitral cell and interneuron responses and, thus, changed spatio-temporal activity patterns across neuronal populations. Oscillatory synchronization was abolished or reduced by AMPA/kainate and NMDA receptor antagonists, respectively. These results indicate that (1) interneuron responses depend mainly on AMPA/kainate receptor input during an odor response, (2) interactions among mitral cells and interneurons regulate the total olfactory bulb output activity, (3) AMPA/kainate receptors participate in the synchronization of odor-dependent neuronal ensembles, and (4) ionotropic glutamate receptor-containing synaptic circuits shape odor-specific patterns of olfactory bulb output activity. These mechanisms are likely to be important for the processing of odor-encoding activity patterns in the olfactory bulb

    Economic evaluation of multiplex ligation-dependent probe amplification and karyotyping in prenatal diagnosis: a cost-minimization analysis

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    textabstractPurpose: To assess the cost-effectiveness of Multiplex Ligation-dependent Probe Amplification (MLPA, P095 kit) compared to karyotyping. Methods: A cost-minimization analysis alongside a nationwide prospective clinical study of 4,585 women undergoing amniocentesis on behalf of their age (β‰₯36Β years), an increased risk following first trimester prenatal screening or parental anxiety. Results: Diagnostic accuracy of MLPA (P095 kit) was comparable to karyotyping (1.0 95% CI 0.999-1.0). Health-related quality of life did not differ between the strategies (summary physical health: mean difference 0.31, pΒ =Β 0.82; summary mental health: mean difference 1.91, pΒ =Β 0.22). Short-term costs were lower for MLPA: mean difference €315.68 (bootstrap 95% CI €315.63-315.74; -44.4%). The long-term costs were slightly higher for MLPA: mean difference €76.42 (bootstrap 95% CI €71.32-81.52; +8.6%). Total costs were on average €240.13 (bootstrap 95% CI €235.02-245.23; -14.9%) lower in favor of MLPA. Cost differences were sensitive to proportion of terminated pregnancies, sample throughput, individual choice and performance of tests in one laboratory, but not to failure rate or the exclusion of polluted samples. Conclusion: From an economic perspective, MLPA is the preferred prenatal diagnostic strategy in women who undergo amniocentesis on behalf of their age, following prenatal screening or parental anxiety

    Elemental and configural olfactory coding by antennal lobe neurons of the honeybee (Apis mellifera)

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    When smelling an odorant mixture, olfactory systems can be analytical (i.e. extract information about the mixture elements) or synthetic (i.e. creating a configural percept of the mixture). Here, we studied elemental and configural mixture coding in olfactory neurons of the honeybee antennal lobe, local neurons in particular. We conducted intracellular recordings and stimulated with monomolecular odorants and their coherent or incoherent binary mixtures to reproduce a temporally dynamic environment. We found that about half of the neurons responded as β€˜elemental neurons’, i.e. responses evoked by mixtures reflected the underlying feature information from one of the components. The other half responded as β€˜configural neurons’, i.e. responses to mixtures were clearly different from responses to their single components. Elemental neurons divided in late responders (above 60Β ms) and early responder neurons (below 60Β ms), whereas responses of configural coding neurons concentrated in-between these divisions. Latencies of neurons with configural responses express a tendency to be faster for coherent stimuli which implies employment in different processing circuits

    The Polyamine Inhibitor Alpha-Difluoromethylornithine Modulates Hippocampus-Dependent Function after Single and Combined Injuries

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    Exposure to uncontrolled irradiation in a radiologic terrorism scenario, a natural disaster or a nuclear battlefield, will likely be concomitantly superimposed on other types of injury, such as trauma. In the central nervous system, radiation combined injury (RCI) involving irradiation and traumatic brain injury may have a multifaceted character. This may entail cellular and molecular changes that are associated with cognitive performance, including changes in neurogenesis and the expression of the plasticity-related immediate early gene Arc. Because traumatic stimuli initiate a characteristic early increase in polyamine metabolism, we hypothesized that treatment with the polyamine inhibitor alpha-difluoromethylornithine (DFMO) would reduce the adverse effects of single or combined injury on hippocampus structure and function. Hippocampal dependent cognitive impairments were quantified with the Morris water maze and showed that DFMO effectively reversed cognitive impairments after all injuries, particularly traumatic brain injury. Similar results were seen with respect to the expression of Arc protein, but not neurogenesis. Given that polyamines have been found to modulate inflammatory responses in the brain we also assessed the numbers of total and newly born activated microglia, and found reduced numbers of newly born cells. While the mechanisms responsible for the improvement in cognition after DFMO treatment are not yet clear, the present study provides new and compelling data regarding the potential use of DFMO as a potential countermeasure against the adverse effects of single or combined injury

    Progestogens to prevent preterm birth in twin pregnancies: an individual participant data meta-analysis of randomized trials

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    <p>Abstract</p> <p>Background</p> <p>Preterm birth is the principal factor contributing to adverse outcomes in multiple pregnancies. Randomized controlled trials of progestogens to prevent preterm birth in twin pregnancies have shown no clear benefits. However, individual studies have not had sufficient power to evaluate potential benefits in women at particular high risk of early delivery (for example, women with a previous preterm birth or short cervix) or to determine adverse effects for rare outcomes such as intrauterine death.</p> <p>Methods/design</p> <p>We propose an individual participant data meta-analysis of high quality randomized, double-blind, placebo-controlled trials of progestogen treatment in women with a twin pregnancy. The primary outcome will be adverse perinatal outcome (a composite measure of perinatal mortality and significant neonatal morbidity). Missing data will be imputed within each original study, before data of the individual studies are pooled. The effects of 17-hydroxyprogesterone caproate or vaginal progesterone treatment in women with twin pregnancies will be estimated by means of a random effects log-binomial model. Analyses will be adjusted for variables used in stratified randomization as appropriate. Pre-specified subgroup analysis will be performed to explore the effect of progestogen treatment in high-risk groups.</p> <p>Discussion</p> <p>Combining individual patient data from different randomized trials has potential to provide valuable, clinically useful information regarding the benefits and potential harms of progestogens in women with twin pregnancy overall and in relevant subgroups.</p

    Trends in the incidence of primary liver cancer in Central Uganda, 1960–1980 and 1991–2005

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    Primary liver cancer (PLC) incidence trends from Africa are unknown. Using Kampala Cancer Registry data from 1960 to 1980 and 1991 to 2005, we identified 771 PLCs. Although rates were stable among men, PLC incidence among women increased >50%. Investigations of viral hepatitis, aflatoxin, obesity, and human immunodeficiency virus (HIV) may help to explain the increasing incidence of hepatocellular carcinomas (HCCs)

    Rapid Host Defense against Aspergillus fumigatus Involves Alveolar Macrophages with a Predominance of Alternatively Activated Phenotype

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    The ubiquitous fungus Aspergillus fumigatus is associated with chronic diseases such as invasive pulmonary aspergillosis in immunosuppressed patients and allergic bronchopulmonary aspergillosis (ABPA) in patients with cystic fibrosis or severe asthma. Because of constant exposure to this fungus, it is critical for the host to exercise an immediate and decisive immune response to clear fungal spores to ward off disease. In this study, we observed that rapidly after infection by A. fumigatus, alveolar macrophages predominantly express Arginase 1 (Arg1), a key marker of alternatively activated macrophages (AAMs). The macrophages were also found to express Ym1 and CD206 that are also expressed by AAMs but not NOS2, which is expressed by classically activated macrophages. The expression of Arg1 was reduced in the absence of the known signaling axis, IL-4RΞ±/STAT6, for AAM development. While both Dectin-1 and TLR expressed on the cell surface have been shown to sense A. fumigatus, fungus-induced Arg1 expression in CD11c+ alveolar macrophages was not dependent on either Dectin-1 or the adaptor MyD88 that mediates intracellular signaling by most TLRs. Alveolar macrophages from WT mice efficiently phagocytosed fungal conidia, but those from mice deficient in Dectin-1 showed impaired fungal uptake. Depletion of macrophages with clodronate-filled liposomes increased fungal burden in infected mice. Collectively, our studies suggest that alveolar macrophages, which predominantly acquire an AAM phenotype following A. fumigatus infection, have a protective role in defense against this fungus
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