1,524 research outputs found

    Modeling the trade-off between diet costs and methane emissions: A goal programming approach

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    AbstractEnteric methane emission is a major greenhouse gas from livestock production systems worldwide. Dietary manipulation may be an effective emission-reduction tool; however, the associated costs may preclude its use as a mitigation strategy. Several studies have identified dietary manipulation strategies for the mitigation of emissions, but studies examining the costs of reducing methane by manipulating diets are scarce. Furthermore, the trade-off between increase in dietary costs and reduction in methane emissions has only been determined for a limited number of production scenarios. The objective of this study was to develop an optimization framework for the joint minimization of dietary costs and methane emissions based on the identification of a set of feasible solutions for various levels of trade-off between emissions and costs. Such a set of solutions was created by the specification of a systematic grid of goal programming weights, enabling the decision maker to choose the solution that achieves the desired trade-off level. Moreover, the model enables the calculation of emission-mitigation costs imputing a trading value for methane emissions. Emission imputed costs can be used in emission-unit trading schemes, such as cap-and-trade policy designs. An application of the model using data from lactating cows from dairies in the California Central Valley is presented to illustrate the use of model-generated results in the identification of optimal diets when reducing emissions. The optimization framework is flexible and can be adapted to jointly minimize diet costs and other potential environmental impacts (e.g., nitrogen excretion). It is also flexible so that dietary costs, feed nutrient composition, and animal nutrient requirements can be altered to accommodate various production systems

    Use Of Autologous Fibrin Glue In Dermatologic Surgery: Application Of Skin Graft And Second Intention Healing.

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    OBJECTIVE: To evaluate the efficiency of biological sealant, an autologous fibrin glue, in dermatological surgery. DESIGN: Randomized clinical trial. SETTING: The Dermatology Service of Hospital das Clinicas, Universidade de Campinas (UNICAMP), referral center. PATIENTS: 14 patients with malign epithelial cutaneous tumors participated in the evaluation, each having two tumors, generally facial and symmetrical, in order to perform a comparative evaluation on the same individual. PROCEDURES: The glue was prepared beforehand with a sample of autologous blood. Surgical extirpation of the tumor was followed by grafts or second intention healing. OUTCOMES: The efficiency of the sealant was then evaluated in relation to hemostasis, adhesion, surgical time and evolution of the granulation tissue, clinically and histologically. RESULTS: Immediate hemostasis and graft adhesion, with a significant reduction of surgical time, and in the open wounds there was immediate hemostasis and a clinical increase in granulation tissue, but with no histological differences among the groups on the 7th day. CONCLUSION: It is an adjuvant resource in skin cancer surgery.11641747175

    Assessment of rubber tree panels under crowns resistant to South American leaf blight

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    The objective of this work was to assess the performance of panel clones under crowns resistant to South American leaf blight (Microcyclus ulei). The experiment was carried out with 18 panel clones crown-budded with Hevea pauciflora x H. guianensis, in a Xanthic Ferralsol (Oxisol) in Manaus, AM, Brazil. The following parameters were evaluated: dry rubber yield, plant nutritional status, and anatomical and physiological characteristics of the latex vessels. In the first three years of evaluation, the panel clones IAN 2878, IAN 2903, CNS AM 7905, CNS AM 7905 P1, and PB 28/59 showed the highest dry rubber yield potential, while the clones IAN 6158, IAN 6590, and IAN 6515 should not be recommended for crown budding. Higher potassium and copper foliar content in panel clones were associated to an increase in dry rubber yield. The simultaneous evaluation of anatomical and physiological characteristics of latex is fundamental for the selection of panel clones in the Amazon region. Crown budding is an efficient technology for South American leaf blight management in endemic regions

    Advertisement call of species of the genus Frostius Cannatella 1986 (Anura: Bufonidae)

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    Frostius pernambucensis and F. erythrophthalmus are cryptic bufonid species recognized mainly by the iris color: yellow in F. permambucensis and red in F. erythrophthalmus. However, field studies showed that the iris color of F. erythrophthalmus could vary between yellow and red. To improve the recognition of these species we described the advertisement call of Frostius pernambucensis and Frostius erythrophthalmus and we tested if call characteristics are influenced by temperature, male size and perch height. We also report on a physical interaction between two males of F. pernambucensis and the associated vocalization, suggesting that F. pernambucensis has not a territorial call or encounter call. Comparing the advertisement calls, the call of F. pernambucensis was lower, shorter and with a smaller number of notes than the call of F. erythrophthalmus. Dominant frequency and fundamental frequency variation of the F. pernambucensis advertisement call were related to the male’s size, while the call emission rate was related to air temperature. However, we could not find relationship among the acoustic characteristic of F. erythrophthalmus and male size or temperature

    Multiple Interactions and the Structure of Beam Remnants

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    Recent experimental data have established some of the basic features of multiple interactions in hadron-hadron collisions. The emphasis is therefore now shifting, to one of exploring more detailed aspects. Starting from a brief review of the current situation, a next-generation model is developed, wherein a detailed account is given of correlated flavour, colour, longitudinal and transverse momentum distributions, encompassing both the partons initiating perturbative interactions and the partons left in the beam remnants. Some of the main features are illustrated for the Tevatron and the LHC.Comment: 69pp, 33 figure

    Study of Tau-pair Production in Photon-Photon Collisions at LEP and Limits on the Anomalous Electromagnetic Moments of the Tau Lepton

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    Tau-pair production in the process e+e- -> e+e-tau+tau- was studied using data collected by the DELPHI experiment at LEP2 during the years 1997 - 2000. The corresponding integrated luminosity is 650 pb^{-1}. The values of the cross-section obtained are found to be in agreement with QED predictions. Limits on the anomalous magnetic and electric dipole moments of the tau lepton are deduced.Comment: 20 pages, 9 figures, Accepted by Eur. Phys. J.

    Evidence for an Excess of Soft Photons in Hadronic Decays of Z^0

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    Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qqbar disintegrations of the Z^0 were studied in the kinematic range 0.2 < E_gamma < 1 GeV and transverse momentum with respect to the closest jet direction p_T < 80 MeV/c. A clear excess of photons in the experimental data as compared to the Monte Carlo predictions is observed. This excess (uncorrected for the photon detection efficiency) is (1.17 +/- 0.06 +/- 0.27) x 10^{-3} gamma/jet in the specified kinematic region, while the expected level of the inner hadronic bremsstrahlung (which is not included in the Monte Carlo) is (0.340 +/- 0.001 +/- 0.038) x 10^{-3} gamma/jet. The ratio of the excess to the predicted bremsstrahlung rate is then (3.4 +/- 0.2 +/- 0.8), which is similar in strength to the anomalous soft photon signal observed in fixed target experiments with hadronic beams.Comment: 37 pages, 9 figures, Accepted by Eur. Phys. J.

    Fibrosis assessment using FibroMeter combined to first generation tests in hepatitis C

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    AIM: To evaluate the performance of FibroMeter combined to the first generation tests aspartate aminotransferase-to-platelet ratio index (APRI) or Forns index to assess significant fibrosis in chronic hepatitis C (CHC). METHODS: First generation tests APRI or Forns were initially applied in a derivation population from Rio de Janeiro in Brazil considering cut-offs previously reported in the literature to evaluate significant fibrosis. FibroMeter was sequentially applied to unclassified cases from APRI or Forns. Accuracy of non-invasive combination of tests, APRI plus FibroMeter and Forns plus FibroMeter was evaluated in the Brazilian derivation population. APRI plus FibroMeter combination was validated in a population of CHC patients from Angers in France. All patients were submitted to liver biopsy staged according to METAVIR score by experienced hepatopathologists. Significant fibrosis was considered as METAVIR F ≥ 2. The fibrosis stage classification was used as the reference for accuracy evaluation of non-invasive combination of tests. Blood samples for the calculation of serum tests were collected on the same day of biopsy procedure or within a maximum 3 mo interval and stored at -70 °C. RESULTS: Seven hundred and sixty CHC patients were included (222 in the derivation population and 538 in the validation group). In the derivation population, the FibroMeter AUROC was similar to APRI AUROC (0.855 0.815, = 0.06) but higher than Forns AUROC (0.769, &lt; 0.001). The best FibroMeter cut-off to discriminate significant fibrosis was 0.61 (80% diagnostic accuracy; 75% in the validation population, = 0.134). The sequential combination of APRI or Forns with FibroMeter in derivation population presented similar performance compared to FibroMeter used alone (79% 78% 80%, respectively, = 0.791). Unclassified cases of significant fibrosis after applying APRI and Forns corresponded to 49% and 54%, respectively, of the total sample. However, the combination of APRI or Forns with FibroMeter allowed 73% and 77%, respectively, of these unclassified cases to be correctly evaluated. Moreover, this combination resulted in a reduction of FibroMeter requirement in approximately 50% of the entire sample. The stepwise combination of APRI and FibroMeter applied to the validation population correctly identified 74% of patients with severe fibrosis (F ≥ 3). CONCLUSION: The stepwise combination of APRI or Forns with FibroMeter may represent an accurate lower cost alternative when evaluating significant fibrosis, with no need for liver biopsy
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