2,100 research outputs found
SUSTAINABILITY OF POULTRY PRODUCTION USING THE EMERGY APPROACH: COMPARISON OF CONVENTIONAL AND ORGANIC REARING SYSTEMS
The organic production system is an important strategy, compatible with sustainable agriculture, avoiding the use of chemical compounds,limiting the intensity of production and providing controls along the entire chain of production. The aim of this study is to compare conventional and organic poultry production in terms of emergy analysis. The main differences in the two systems were the emergy cost for poultry feed and for cleaning/sanitization of the buildings between successive productive cycles. In both production systems the poultry feed represented more than 50% of the emergy flow. Regarding the agronomic phase, it was shown that almost all the organic crops, avoiding
chemical fertilizers and pesticides, saved around 60% emergy. The emergetic costs for housing of the birds were very similar in both systems. Relating the emergy results with productive performance it is possible to show that, although the annual productive performance was much lower in organic than in conventional (206%), transformity of organic poultry was around 10% lower. Comparison of the organic poultry system with a conventional one from the viewpoint of sustainability showed that all the emergy-based indicators are in favour of the organic farming system with a higher efficiency in transforming the available inputs in the final product, a higher level of renewable inputs, a higher level of local inputs and a lower density of energy and matter flows
Quantum Plasmonics with multi-emitters: Application to adiabatic control
We construct mode-selective effective models describing the interaction of N
quantum emitters (QEs) with the localised surface plasmon polaritons (LSPs)
supported by a spherical metal nanoparticle (MNP) in an arbitrary geometric
arrangement of the QEs. We develop a general formulation in which the field
response in the presence of the nanosystem can be decomposed into orthogonal
modes with the spherical symmetry as an example. We apply the model in the
context of quantum information, investigating on the possibility of using the
LSPs as mediators of an efficient control of population transfer between two
QEs. We show that a Stimulated Raman Adiabatic Passage configuration allows
such a transfer via a decoherence-free dark state when the QEs are located on
the same side of the MNP and very closed to it, whereas the transfer is blocked
when the emitters are positioned at the opposite sides of the MNP. We explain
this blockade by the destructive superposition of all the interacting plasmonic
modes
Characteristics of academic publications, preprints, and registered clinical trials on the COVID-19 pandemic
The COVID-19 pandemic has unleashed a deluge of publications. For this cross-sectional study we compared the amount and reporting characteristics of COVID-19-related academic articles and preprints and the number of ongoing clinical trials and systematic reviews. To do this, we searched the PubMed database of citations and abstracts for published life science journals by using appropriate combinations of medical subject headings (MeSH terms), and the COVID-19 section of the MedRxiv and BioRxiv archives up to 20 May 2020 (21 weeks). In addition, we searched Clinicaltrial.gov, Chinese Clinical Trial Registry, EU Clinical Trials Register, and 15 other trial registers, as well as PROSPERO, the international prospective register of systematic reviews. The characteristics of each publication were extracted. Regression analyses and Z tests were used to detect publication trends and their relative proportions. A total of 3635 academic publications and 3805 preprints were retrieved. Only 8.6% (n = 329) of the preprints were already published in indexed journals. The number of academic and preprint publications increased significantly over time (p<0.001). Case reports (6% academic vs 0.9% preprints; p<0.001) and letters (17.4% academic vs 0.5% preprints; p<0.001) accounted for a greater share of academic compared to preprint publications. Differently, randomized controlled trials (0.22% vs 0.63%; p<0.001) and systematic reviews (0.08% vs 5%) made up a greater share of the preprints. The relative proportion of clinical studies registered at Clinicaltrials.gov, Chinese Clinical Trial Registry, and EU Clinical Trials Register was 57.9%, 49.5%, and 98.9%, respectively, most of which were still "recruiting". PROSPERO listed 962 systematic review protocols. Preprints were slightly more prevalent than academic articles but both were increasing in number. The void left by the lack of primary studies was filled by an outpour of immediate opinions (i.e., letters to the editor) published in PubMed-indexed journals. Summarizing, preprints have gained traction as a publishing response to the demand for prompt access to empirical, albeit not peer-reviewed, findings during the present pandemic.publishersversionpublishe
Convolutional Neural Network and Stochastic Variational Gaussian Process for Heating Load Forecasting
Heating load forecasting is a key task for operational planning in district heating networks. In this work we present two advanced models for this purpose, namely a Convolutional Neural Network (CNN) and a Stochastic Variational Gaussian Process (SVGP). Both models are extensions of an autoregressive linear model available in the literature. The CNN outperforms the linear model in terms of 48-h prediction accuracy and its parameters are interpretable. The SVGP has performance comparable to the linear model but it intrinsically deals with prediction uncertainty, hence it provides both load estimations and confidence intervals. Models and performance are analyzed and compared on a real dataset of heating load collected in an Italian network
European green policy announcements and sectoral stock returns
To fulfill the Paris Agreement commitments and stimulated by an unprecedented amount of public resources put in place to recover from the COVID-induced recession, European governments have recently announced sizable green policy plans. In this paper, we examine the behavior of green and brown portfolios around green policy-related announcements (GPAs) made by major European governments in 2020 via a standard event study analysis and the use of returns of stocks listed in the “STOXX 100 All Europe”. Our main empirical findings indicate the presence of positive cumulative abnormal returns (CARs) both in the green and brown sectors following GPAs. However, the estimated positive sentiment effect is stronger in the former sector. A size effect in terms of the amount of resources announced to be allocated for a specific category of policy is also observed. We find that the observed positive sentiment is mainly driven by announcements on climate change mitigation-related policies, which account for 70% of the total allocated funds. At the sector level, positive and significant CARs due to GPAs are found in the (i) energy, (ii) financial and (iii) industrial sectors. At the country level, GPAs are found to drive a significant positive sentiment effect in the following European countries: Switzerland, Spain, UK, Ireland and Italy. Sector- and country-level analyses confirm the presence of larger benefits from GPAs among more sustainable portfolios
Transfer of bioactive compounds from pasture to meat in organic free-range chickens
Abstract The aim of this study was to analyze the transfer of bioactive compounds from the pasture to the body and meat of organic free-range chickens and to verify the effect of these compounds on the oxidative processes of the meat. Starting at 21 d of age, 100 male naked-neck birds were divided into two homogeneous groups: an indoor group (0.12 m2/bird) and an outdoor group (0.12 m2/bird indoor and 10 m2/bird of forage paddock). At slaughter (81 d of age), blood samples were collected, and the carcasses were stored for 24 h at 4°C (20 birds/group). The grass samples had higher values of carotenoids, tocopherols, and flavonoids respect to standard feed (based on dry matter comparison). The polyunsaturated fatty acid (PUFA) content was also greater in grass, especially the n-3 series (so named because its first double bond occurs after the third carbon atom counting from the methyl at the end of the molecule). The antioxidant profile of the grass improved the antioxidant status of the crop and gizzard contents in the outdoor chickens. The higher antioxidant intake resulted in a higher plasma concentration of antioxidants in outdoor birds; thiobarbituric acid reactive substances (TBARs) and the antioxidant capacity of the plasma were also better in the outdoor than the indoor group. The meat of the outdoor birds had higher levels of antioxidants, mainly due to the higher amount of tocopherols and tocotrienols. Despite the higher antioxidant protection in the drumstick of the outdoor group, the TBARs value was greater, probably due to the kinetic activity of birds, the higher percentage of PUFAs, and the peroxidability index. In conclusion, grazing improved the nutritional value of the meat (PUFA n-3 and the ratio between n-6 and n-3 PUFA) with a minor negative effect on the oxidative stability. Suitable strategies to reduce such negative effects (e.g., reduction of kinetic activity in the last days of rearing) should be studied
Does cemented or cementless single-stage exchange arthroplasty of chronic periprosthetic hip infections provide similar infection rates to a two-stage? A systematic review
BACKGROUND: The best surgical modality for treating chronic periprosthetic hip infections remains controversial, with a lack of randomised controlled studies. The aim of this systematic review is to compare the infection recurrence rate after a single-stage versus a two-stage exchange arthroplasty, and the rate of cemented versus cementless single-stage exchange arthroplasty for chronic periprosthetic hip infections. METHODS: We searched for eligible studies published up to December 2015. Full text or abstract in English were reviewed. We included studies reporting the infection recurrence rate as the outcome of interest following single- or two-stage exchange arthroplasty, or both, with a minimum follow-up of 12 months. Two reviewers independently abstracted data and appraised quality assessment. RESULTS: After study selection, 90 observational studies were included. The majority of studies were focused on a two-stage hip exchange arthroplasty (65 %), 18 % on a single-stage exchange, and only a 17 % were comparative studies. There was no statistically significant difference between a single-stage versus a two-stage exchange in terms of recurrence of infection in controlled studies (pooled odds ratio of 1.37 [95 % CI = 0.68-2.74, I(2) = 45.5 %]). Similarly, the recurrence infection rate in cementless versus cemented single-stage hip exchanges failed to demonstrate a significant difference, due to the substantial heterogeneity among the studies. CONCLUSION: Despite the methodological limitations and the heterogeneity between single cohorts studies, if we considered only the available controlled studies no superiority was demonstrated between a single- and two-stage exchange at a minimum of 12 months follow-up. The overalapping of confidence intervals related to single-stage cementless and cemented hip exchanges, showed no superiority of either technique
consumer preference for chicken breast may be more affected by information on organic production than by product sensory properties
ABSTRACT Conventional chicken from a fast-growing strain (CC), organic chicken from a slow-growing strain (OSG), and organic chicken from a fast-growing strain (OFG) were used to assess descriptive sensory differences between organic and conventional breasts, to verify whether differences were perceived by consumers and to evaluate the effect of information about organic production on liking. A conventional quantitative–descriptive analysis was performed by a trained panel of 10 members on breast slices (1 cm thick) grilled at 300°C. A 150-member consumer panel (from southern, central, and northern Italy) rated CC, OSG, and OFG breasts according to 3 types of evaluation: tasting without information (perceived liking), information without tasting (expected liking), and tasting with information (actual liking). Breasts from different sources were clearly discriminated by the trained panel as meat from CC was perceived more tender than OFG (
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