451 research outputs found
Evaluation of Tomato-Based Packing Material for Retention of Ammonia, Nitrous Oxide, Carbon Dioxide and Methane in Gas Phase Biofilters: A Laboratory Study
Biofilters are an effective air pollution control technology to break down gaseous contaminants
and produce innocuous end products. This laboratory study aimed to evaluate a biofilter
media, mainly composed by tomato waste, as packing material to reduce NH3, N2O, CO2 and CH4
losses from stored pig slurry. Three mixtures of packing materials, with and without oxalic acid,
were arranged in treatments, namely: mixture of tomato waste, pine bark and agricultural compost;
mixture of tomato waste and rice husk; tomato waste only. A control treatment (no biofilter) was also
included. The experiments were conducted using a system of laboratory scale biofilters connected to
jars filled with pig slurry and under a constant airflow rate. The gas concentrations were measured
for 14 days and the physicochemical of the packing materials were assessed. Results showed that
biofilter media mixtures had a potential for NH3 retention ranging from 51 to 77% and the addition
of oxalic acid to these biofilters increased NH3 retention to 72–79%. Additionally, the biofilter media
mixtures with and without oxalic acid showed a potential retention for CH4 (29–69%) but not for
N2O, yet with no impact on the global warming potential. It can be concluded that tomato based
biofilters had the potential to reduce gaseous emissions from slurry.info:eu-repo/semantics/publishedVersio
SPI-based drought category prediction using loglinear models
Loglinear modeling for three-dimensional contingency tables was used with
data from 14 rainfall stations located in Alentejo and Algarve region, southern of Portugal,
for short term prediction of drought severity classes. Loglinear models were fitted to
drought class transitions derived from Standardized Precipitation Index (SPI) time series
computed in a 12-month time scale. Quasi-association loglinear models proved to be
the most adequate in fitting all the 14 data series. Odds and respective confidence intervals
were calculated in order to understand the drought evolution and to estimate the
drought class transition probabilities. The validation of the predictions was performed
for the 2004–2006 drought, particularly for periods when the drought was initiating and
establishing, and when it was dissipating. Despite the contingency tables of drought class
transitions present a strong diagonal tendency, results of three-dimensional loglinear
modeling present good results when comparing predicted and observed drought classes
with 1 and 2 months lead for those 14 sites. Only for a few cases predictions did not fully
match the observed drought severity, mainly for 2-month lead and when the SPI values are
near the limit of the severity class. It could be concluded that loglinear prediction of
drought class transitions is a useful tool for short term drought warnin
Higher prevalence of major depressive symptoms in Brazilians aged 14 and older
Objective: Depression is a highly prevalent condition and is considered a major public health issue. The aim of the present study was to estimate the prevalence of depressive symptoms in the Brazilian population and establish their sociodemographic correlates. Method: A cross-sectional study was conducted between November 2005 and April 2006. Data were collected in face-to-face interviews using a standardized questionnaire. The sample consisted of 3,007 interviews with individuals aged 14 years and older and followed a probabilistic design covering the Brazilian national territory. Depressive symptoms were assessed according to the Center for Epidemiologic Studies Depression Scale. Results: The observed prevalence of depressive symptoms was 28.3% (13% mild/moderate; 15.3% major/severe; p < 0.01). Increased depressive symptom rates were associated with being a female, being 45 years of age and older, having lower educational attainment, being single, having family income of up to 2.5 times minimum wage, and living in the northern region of Brazil (p < 0.05). Conclusions: The prevalence of depressive symptoms in Brazil is high, with major depressive symptoms being the most frequent form of this symptomatology. Considering the biopsychosocial model of mental disorders, this survey points to the involvement of psychosocial factors in the prevalence of depressive symptoms in Brazil.Universidade Federal de São Paulo (UNIFESP) Department of PsychiatryUniversidade de São Paulo (USP) Ribeirao Preto Medical School Department of Neuroscience and BehaviorNational Science and Technology Institute for Translational Medicine (INCT-TM)USP Ribeirao Preto Medical School Department of Social MedicineUniversidade Federal de Santa Catarina (UFSC) Department of PsychiatryUniversity of Texas School of Public Health Dallas Regional CampusUNIFESP, Department of PsychiatrySciEL
Role of the chemokines CCL3/MIP-1α and CCL5/RANTES in sponge-induced inflammatory angiogenesis in mice
Barcelos, Luciola S Coelho, Amanda M Russo, Remo C Guabiraba, Rodrigo Souza, Adriano L S Bruno-Lima, Guilherme Jr Proudfoot, Amanda E I Andrade, Silvia P Teixeira, Mauro M Microvasc Res. 2009 Sep;78(2):148-54. doi: 10.1016/j.mvr.2009.04.009. Epub 2009 May 8.; International audience; OBJECTIVE: We examined the potential contribution of CCL3 and CCL5 to inflammatory angiogenesis in mice. METHODS: Polyester-polyurethane sponges were implanted in mice and blood vessel counting and hemoglobin, myeloperoxidase and N-acetylglucosaminidase measurements used as indexes for vascularization, neutrophil and macrophage accumulation, respectively. RESULTS: CCL3 and CCL5 were expressed throughout the observation period. Exogenous CCL3 enhanced angiogenesis in WT, but angiogenesis proceeded normally in CCL3(-/-) mice, suggesting that endogenous CCL3 is not critical for sponge-induced angiogenesis in mice. CCL5 expression was detected at day 1, but levels significantly increased thereafter. Exogenous CCL5 reduced angiogenesis in WT mice possible via CCR5 as CCL5 was without an effect in CCR5(-/-) mice. Treatment of WT with the CCR1/CCR5 antagonist, Met-RANTES, prevented neutrophil and macrophage accumulation, but enhanced sponge vascularization. CONCLUSION: Thus, endogenous CCL3 appears not to play a role in driving sponge-induced inflammatory angiogenesis in mice. The effects of CCL5 were anti-angiogenic and appeared to be mediated via activation of CCR5
Three-body decay of the d* dibaryon
Under certain circumstances, a three-body decay width can be approximated by
an integral involving a product of two off-shell two-body decay widths. This
``angle-average'' approximation is used to calculate the decay width
of the dibaryon in a simple model for the most
important Feynman diagrams describing pion emissions with baryon-baryon recoil
and meson retardation. The decay width is found to be about 0.006 (0.07, 0.5)
MeV at the mass of 2065 (2100, 2150) MeV for input dynamics derived from
the Full Bonn potential. The smallness of this width is qualitatively
understood as the result of the three-body decay being ``third forbidden''. The
concept of forbiddenness and the threshold behavior of a three-body
decay are further studied in connection with the decay of the dibaryon
where the idea of unfavorness has to be introduced.
The implications of these results are briefly discussed.Comment: 15 pages, RevTeX, two-column journal style, six figure
Numerical convergence of the block-maxima approach to the Generalized Extreme Value distribution
In this paper we perform an analytical and numerical study of Extreme Value
distributions in discrete dynamical systems. In this setting, recent works have
shown how to get a statistics of extremes in agreement with the classical
Extreme Value Theory. We pursue these investigations by giving analytical
expressions of Extreme Value distribution parameters for maps that have an
absolutely continuous invariant measure. We compare these analytical results
with numerical experiments in which we study the convergence to limiting
distributions using the so called block-maxima approach, pointing out in which
cases we obtain robust estimation of parameters. In regular maps for which
mixing properties do not hold, we show that the fitting procedure to the
classical Extreme Value Distribution fails, as expected. However, we obtain an
empirical distribution that can be explained starting from a different
observable function for which Nicolis et al. [2006] have found analytical
results.Comment: 34 pages, 7 figures; Journal of Statistical Physics 201
Experiência em sala de aula: evidência empírica da complexidade no ensino e aprendizagem de LE
Programa 5S's adaptado ao gerenciamento da alimentação escolar no contexto da descentralização
Modelling the heat dynamics of a residential building unit: Application to Norwegian buildings
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