973 research outputs found

    Feeding value of black soldier fly larvae compared to soybean in methionine- and lysine-deficient laying hen diets

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    To increase the sustainability of egg production, alternatives to soybean in poultry nutrition are intensively searched for. Black soldier fly larvae (BSFL) could have a great potential, but the comparative protein value to soybean is not well known. The main objective of this study was to facilitate this comparison by using experimental diets clearly limited in calculated supply of sulphurous amino acids and lysine. Fifty laying hens (Lohmann Brown Classic), aged 40 weeks, were fed one of five diets for 7 weeks (n=10). Two diets were based on soybean cake and oil (SS, SS-) as protein and energy sources, and three diets contained partially defatted BSFL meal and fat from two different origins (AA-, AB-, BB-). Different from SS, all other diets were designed to be deficient in methionine and lysine in relation to requirements by >20%. The realised supply with total sulphurous amino acids and lysine was indeed superior with SS even though this diet was analysed to be more deficient in methionine than the BSFL-based diets. Despite the calculated deficiency in limiting amino acids, laying performance of the hens of all groups was similar and ranged between 93 and 97%. Similarly, egg mass, daily feed intake and feed efficiency were not influenced by the BSFL-based diets. The yolks of group BB- were more intensely coloured compared to the others indicating a difference between BSFL origins. Yolks of SS-, but not of the BSFL-based diets, had lower contents of dry matter and ether extract than those of SS. Including BSFL into the diet did not influence the odour of the eggs tested in scrambled form. The results show that soybean-based feeds for laying hens may be completely replaced by BSFL- based feeds and suggest that the recommendations for amino acid supply of laying hens might need revision

    Μελέτη και ανάπτυξη πλατφόρμας επεξεργαστή ανοικτού λογισμικού για την υλοποίηση μετεωρολογιακού δικτύου

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    This study aimed to gain insight into the microbial quality, safety and bacterial community composition of black soldier fly larvae (Hermetia illucens) reared at different facilities on a variety of organic waste streams. For seven rearing cycles, both on laboratory-scale and in large-scale facilities at several locations, the microbiota of the larvae was studied. Also samples of the substrate used and the residue (= leftover substrate after rearing, existing of non-consumed substrate, exuviae and faeces) were investigated. Depending on the sample, it was subjected to plate counting, Illumina Miseq sequencing and/or detection of specific food pathogens. The results revealed that the substrates applied at the various locations differed substantially in microbial numbers as well as in the bacterial community composition. Furthermore, little similarity was observed between the microbiota of the substrate and that of the larvae reared on that substrate. Despite substantial differences between the microbiota of larvae reared at several locations, 48 species-level operational taxonomic units (OTUs) were shared by all larvae, among which most belonged to the phyla Firmicutes and Proteobacteria. Although the substrate is assumed to be an important source of bacteria, our results suggest that a variety of supposedly interacting factors-both abiotic and biotic-are likely to affect the microbiota in the larvae. In some larvae and/or residue samples, potential foodborne pathogens such as Salmonella and Bacillus cereus were detected, emphasising that decontamination technologies are required when the larvae are used in feed, just as for other feed ingredients, or eventually in food

    Thermochemistry of Alane Complexes for Hydrogen Storage: A Theoretical and Experimental Comparison

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    Knowledge of the relative stabilities of alane (AlH3) complexes with electron donors is essential for identifying hydrogen storage materials for vehicular applications that can be regenerated by off-board methods; however, almost no thermodynamic data are available to make this assessment. To fill this gap, we employed the G4(MP2) method to determine heats of formation, entropies, and Gibbs free energies of formation for thirty-eight alane complexes with NH3-nRn (R = Me, Et; n = 0-3), pyridine, pyrazine, triethylenediamine (TEDA), quinuclidine, OH2-nRn (R = Me, Et; n = 0-2), dioxane, and tetrahydrofuran (THF). Monomer, bis, and selected dimer complex geometries were considered. Using these data, we computed the thermodynamics of the key formation and dehydrogenation reactions that would occur during hydrogen delivery and alane regeneration, from which trends in complex stability were identified. These predictions were tested by synthesizing six amine-alane complexes involving trimethylamine, triethylamine, dimethylethylamine, TEDA, quinuclidine, and hexamine, and obtaining upper limits of delta G for their formation from metallic aluminum. Combining these computational and experimental results, we establish a criterion for complex stability relevant to hydrogen storage that can be used to assess potential ligands prior to attempting synthesis of the alane complex. Based on this, we conclude that only a subset of the tertiary amine complexes considered and none of the ether complexes can be successfully formed by direct reaction with aluminum and regenerated in an alane-based hydrogen storage system.Comment: Accepted by the Journal of Physical Chemistry

    Sequentially based analysis versus image based analysis of Intima Media Thickness in common carotid arteries studies - Do major IMT studies underestimate the true relations for cardio- and cerebrovascular risk?

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    <p>Abstract</p> <p>Background</p> <p>Image-based B-mode ultrasound has gained popularity in major studies as a non-invasive method of measuring cardio- and cerebrovascular risk factors. However, none of the major studies appears to have paid sufficient attention to the variation in end diastolic wall process. By using sequentially based analyses (SBA) of Intima-Media Thickness (IMT), the general purpose of this study was to show that the current image based (ECG tracked) analysis (IBA) has some major variations and might underestimate the true relations for cardiovascular events and stroke for IMT measurement.</p> <p>Method</p> <p>The study group consisted of 2500 healthy male subjects aged between 35 to 55 years. 4 sequences (300 images) were analyzed per subject. 750,000 images were analysed throughout the course of this study.</p> <p>Results</p> <p>IBA showed significantly lower mean, maximal, and minimal values for IMT in CCA than for SBA. The correlation analysis between IBA and SBA with the cardio- and cerebrovascular risk factors showed a higher correlation of SBA for all risk factors. The Pearson coefficient was 0.81, p < 0.01, for SBA versus Framingham CHD risk level (FCRL) and 0.49, p = 0.01, for IBA versus FCRL.</p> <p>Conclusion</p> <p>IBA did not measure the true maximal values of the IMT in this study. Together with the correlation analysis, this indicates that IBA might underestimate the true relations for IMT and risk factors.</p

    Extracting clean supernova spectra

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    We use a new technique to extract the spectrum of a supernova from that of the contaminating background of its host galaxy, and apply it to the specific case of high-redshift Type Ia supernova (SN Ia) spectroscopy. The algorithm is based on a two-channel iterative technique employing the Richardson-Lucy restoration method and is implemented in the IRAF code 'specinholucy'. We run the code both on simulated (SN Ia at z=0.5 embedded in a bright host galaxy) and observed (SNe Ia at various phases up to z=0.236) data taken with VLT+FORS1 and show the advantages of using such a deconvolution technique in comparison with less elaborate methods. This paper is motivated by the need for optimal supernova spectroscopic data reduction in order to make meaningful comparisons between the low and high-redshift SN Ia samples. This may reveal subtle evolutionary and systematic effects that could depend on redshift and bias the cosmological results derived from comparisons of local and high-z SNe Ia in recent years. We describe the various aspects of the extraction in some detail as guidelines for the first-time user and present an optimal observing strategy for successful implementation of this method in future high-z SN Ia spectroscopic follow-up programmes.Comment: 15 pages, 14 figures, accepted for publication in A&

    Implementing Telemedicine in Medical Emergency Response: Concept of Operation for a Regional Telemedicine Hub

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    A regional telemedicine hub, providing linkage of a telemedicine command center with an extended network of clinical experts in the setting of a natural or intentional disaster, may facilitate future disaster response and improve patient outcomes. However, the health benefits derived from the use of telemedicine in disaster response have not been quantitatively analyzed. In this paper, we present a general model of the application of telemedicine to disaster response and evaluate a concept of operations for a regional telemedicine hub, which would create distributed surge capacity using regional telemedicine networks connecting available healthcare and telemedicine infrastructures to external expertise. Specifically, we investigate (1) the scope of potential use of telemedicine in disaster response; (2) the operational characteristics of a regional telemedicine hub using a new discrete-event simulation model of an earthquake scenario; and (3) the benefit that the affected population may gain from a coordinated regional telemedicine network

    A combined maximum-likelihood analysis of the high-energy astrophysical neutrino flux measured with IceCube

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    Evidence for an extraterrestrial flux of high-energy neutrinos has now been found in multiple searches with the IceCube detector. The first solid evidence was provided by a search for neutrino events with deposited energies 30\gtrsim30 TeV and interaction vertices inside the instrumented volume. Recent analyses suggest that the extraterrestrial flux extends to lower energies and is also visible with throughgoing, νμ\nu_\mu-induced tracks from the Northern hemisphere. Here, we combine the results from six different IceCube searches for astrophysical neutrinos in a maximum-likelihood analysis. The combined event sample features high-statistics samples of shower-like and track-like events. The data are fit in up to three observables: energy, zenith angle and event topology. Assuming the astrophysical neutrino flux to be isotropic and to consist of equal flavors at Earth, the all-flavor spectrum with neutrino energies between 25 TeV and 2.8 PeV is well described by an unbroken power law with best-fit spectral index 2.50±0.09-2.50\pm0.09 and a flux at 100 TeV of (6.71.2+1.1)1018GeV1s1sr1cm2\left(6.7_{-1.2}^{+1.1}\right)\cdot10^{-18}\,\mathrm{GeV}^{-1}\mathrm{s}^{-1}\mathrm{sr}^{-1}\mathrm{cm}^{-2}. Under the same assumptions, an unbroken power law with index 2-2 is disfavored with a significance of 3.8 σ\sigma (p=0.0066%p=0.0066\%) with respect to the best fit. This significance is reduced to 2.1 σ\sigma (p=1.7%p=1.7\%) if instead we compare the best fit to a spectrum with index 2-2 that has an exponential cut-off at high energies. Allowing the electron neutrino flux to deviate from the other two flavors, we find a νe\nu_e fraction of 0.18±0.110.18\pm0.11 at Earth. The sole production of electron neutrinos, which would be characteristic of neutron-decay dominated sources, is rejected with a significance of 3.6 σ\sigma (p=0.014%p=0.014\%).Comment: 16 pages, 10 figures; accepted for publication in The Astrophysical Journal; updated one referenc

    Measurement of the Atmospheric νe\nu_e Spectrum with IceCube

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    We present a measurement of the atmospheric νe\nu_e spectrum at energies between 0.1 TeV and 100 TeV using data from the first year of the complete IceCube detector. Atmospheric νe\nu_e originate mainly from the decays of kaons produced in cosmic-ray air showers. This analysis selects 1078 fully contained events in 332 days of livetime, then identifies those consistent with particle showers. A likelihood analysis with improved event selection extends our previous measurement of the conventional νe\nu_e fluxes to higher energies. The data constrain the conventional νe\nu_e flux to be 1.30.3+0.41.3^{+0.4}_{-0.3} times a baseline prediction from a Honda's calculation, including the knee of the cosmic-ray spectrum. A fit to the kaon contribution (ξ\xi) to the neutrino flux finds a kaon component that is ξ=1.30.4+0.5\xi =1.3^{+0.5}_{-0.4} times the baseline value. The fitted/measured prompt neutrino flux from charmed hadron decays strongly depends on the assumed astrophysical flux and shape. If the astrophysical component follows a power law, the result for the prompt flux is 0.00.0+3.00.0^{+3.0}_{-0.0} times a calculated flux based on the work by Enberg, Reno and Sarcevic.Comment: PRD accepted versio
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