NUMERICAL APPROACHES FOR A MATHEMATICAL MODEL OF AN FCCU REGENERATOR

This work discusses a mathematical model of an FCCU (Fluid Catalytic Cracking Unit) regenerator. The model assumes that the regenerator is divided into two regions: the freeboard and the dense bed. The latter is composed of a bubble phase and an emulsion phase. Both phases are modeled as a CSTR (Continuously Stirred Tank Reactor) in which ordinary differential equations are employed to represent the conservation of mass, energy and species. In the freeboard, the flow is considered to be onedimensional, and the conservation principles are represented by partial differential equations to describe space and time changes. The main aim ofthis work is to compare two numerical approaches for solving the set of partial and ordinary differential equations, namely, the fourth-order Runge-Kutta and implicit finite-difference methods. Although both methods give very similar results, the implicit finite-difference method can be much faster. Steady-state results were corroborated by experimental data, and the dynamic results were compared with those in the literature (Han and Chung, 2001b). Finally, an analysis of the model’s sensitivity to the boundary conditions was conducted

Exercise training prevents the deterioration in the arterial baroreflex control of sympathetic nerve activity in chronic heart failure patients

Arterial baroreflex control of muscle sympathetic nerve activity (ABRMSNA) is impaired in chronic systolic heart failure (CHF). the purpose of the study was to test the hypothesis that exercise training would improve the gain and reduce the time delay of ABRMSNA in CHF patients. Twenty-six CHF patients, New York Heart Association Functional Class II-III, EF <= 40%, peak (V) over dot O-2 <= 20 ml.kg(-1).min(-1) were divided into two groups: untrained (UT, n = 13, 57 +/- 3 years) and exercise trained (ET, n = 13, 49 +/- 3 years). Muscle sympathetic nerve activity (MSNA) was directly recorded by microneurography technique. Arterial pressure was measured on a beat-to-beat basis. Time series of MSNA and systolic arterial pressure were analyzed by autoregressive spectral analysis. the gain and time delay of ABRMSNA was obtained by bivariate autoregressive analysis. Exercise training was performed on a cycle ergometer at moderate intensity, three 60-min sessions per week for 16 wk. Baseline MSNA, gain and time delay of ABRMSNA, and low frequency of MSNA (LFMSNA) to high-frequency ratio (HFMSNA) (LFMSNA/HFMSNA) were similar between groups. ET significantly decreased MSNA. MSNA was unchanged in the UT patients. the gain and time delay of ABRMSNA were unchanged in the ET patients. in contrast, the gain of ABRMSNA was significantly reduced [3.5 +/- 0.7 vs. 1.8 +/- 0.2, arbitrary units (au)/mmHg, P = 0.04] and the time delay of ABRMSNA was significantly increased (4.6 +/- 0.8 vs. 7.9 +/- 1.0 s, P = 0.05) in the UT patients. LFMSNA-to-HFMSNA ratio tended to be lower in the ET patients (P < 0.08). Exercise training prevents the deterioration of ABRMSNA in CHF patients.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao ZerbiniCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)National Heart, Lung, and Blood InstituteUniv São Paulo, Sch Med, Heart Inst InCor, São Paulo, BrazilUniv São Paulo, Sch Phys Educ & Sport, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Cardiol, São Paulo, BrazilUniv Calif Los Angeles, David Geffen Sch Med, Dept Med Cardiol & Physiol, Los Angeles, CA 90095 USAUniversidade Federal de São Paulo, Dept Med, Div Cardiol, São Paulo, BrazilFAPESP: 2010/50048-1FAPESP: 140643/2009-5FAPESP: 2013/07651-7CNPq: 142366/2009-9CNPq: 301867/2010-0CNPq: 308068/2011-4FAPESP: 2013/15651-7National Heart, Lung, and Blood Institute: RO1-HL084525Web of Scienc

Transect walks : method sensitivity for on-farm welfare evaluation in turkeys

There is increasing consumer demands for livestock and poultry products that meet minimum animal welfare standards during their production cycle. Additionally, a growing number of farmers are aware about full compliance with the animal welfare standards that could play an important economic role in commercial intensive productions. Indeed, animal welfare assessment protocols have meaningful effects to promote and guarantee the on-farm safeguard animal standards. Transect walks method appeared to provide a practical approach to welfare assessment in broilers farms. Because of the similarities of meat poultry production, this method could be considered a reasonable approach for turkey welfare evaluation in terms of time demands, within costs and feasibility. The aim of this study was to determine the sensitivity of this method at 3 commercial turkey farms with similar facilities (Animal Welfare Indicators project, FP7-KBBE-2010-4). In this study, 10 commercial female-turkey flocks (6 houses with identical management), ranging from 3,212 to 6,000 birds and belonging to the same company were evaluated one week before slaughter. On turkey farms, walking through the house is a routine daily procedure to check the health status of the birds. Two previously trained assessors in performing the transect methodology and properly assessing the selected indicators, evaluated each paired house sequentially and independently within the same day by walking through predefined transect bands (1 to 4) in random order. The animal-based indicators considered were: immobility, lameness, wounds and featherless. The statistical model used was GLM in the GENMOD procedure (SAS V9). The results showed that this welfare assessment method highlights even small variation among houses for the considered variables. In fact, there were significant difference across houses (P=0.0021, P=0.0006, P=0.0081 and P=0.0003) for all the evaluated indicators respectively. Differences across observers were detected for wounds and featherless (P<0.0001). These results may be due to the difficulties in assessing equally these parameters while walking. On the contrary, lameness, probably the most important welfare problem in meat poultry, showed a good concordance between observers (P= 0.361). These preliminary findings suggest that this new approach has potential as a tool for on-farm welfare evaluation, which may be worthwhile to be further developed

Integrative Effect of Carvedilol and Aerobic Exercise Training Therapies on Improving Cardiac Contractility and Remodeling in Heart Failure Mice

The use of b-blockers is mandatory for counteracting heart failure (HF)-induced chronic sympathetic hyperactivity, cardiac dysfunction and remodeling. Importantly, aerobic exercise training, an efficient nonpharmacological therapy to HF, also counteracts sympathetic hyperactivity in HF and improves exercise tolerance and cardiac contractility; the latter associated with changes in cardiac Ca2+ handling. This study was undertaken to test whether combined b-blocker and aerobic exercise training would integrate the beneficial effects of isolated therapies on cardiac structure, contractility and cardiomyocyte Ca2+ handling in a genetic model of sympathetic hyperactivity-induced HF (alpha(2A)/alpha 2C(-)adrenergic receptor knockout mice, KO). We used a cohort of 5-7 mo male wild-type (WT) and congenic mice (KO) with C57Bl6/J genetic background randomly assigned into 5 groups: control (WT), saline-treated KO (KOS), exercise trained KO (KOT), carvedilol-treated KO (KOC) and, combined carvedilol-treated and exercise-trained KO (KOCT). Isolated and combined therapies reduced mortality compared with KOS mice. Both KOT and KOCT groups had increased exercise tolerance, while groups receiving carvedilol had increased left ventricular fractional shortening and reduced cardiac collagen volume fraction compared with KOS group. Cellular data confirmed that cardiomyocytes from KOS mice displayed abnormal Ca2+ handling. KOT group had increased intracellular peak of Ca2+ transient and reduced diastolic Ca2+ decay compared with KOS group, while KOC had increased Ca2+ decay compared with KOS group. Notably, combined therapies re-established cardiomyocyte Ca2+ transient paralleled by increased SERCA2 expression and SERCA2: PLN ratio toward WT levels. Aerobic exercise trained increased the phosphorylation of PLN at Ser16 and Thr17 residues in both KOT and KOCT groups, but carvedilol treatment reduced lipid peroxidation in KOC and KOCT groups compared with KOS group. the present findings provide evidence that the combination of carvedilol and aerobic exercise training therapies lead to a better integrative outcome than carvedilol or exercise training used in isolation.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Pesquisa e DesenvolvimentoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ São Paulo, Sch Phys Educ & Sport, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, Santos, BrazilDept Circulat & Med Imaging, Trondheim, NorwayKG Jebsen Ctr Exercise Med, Trondheim, NorwayUniv Fed Minas Gerais, Dept Physiol & Biophys, Belo Horizonte, MG, BrazilUniv São Paulo, Heart Inst InCor, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, Santos, BrazilFAPESP: FAPESP:2010/50048-1FAPESP: 06/56123-0CNPq: 302201/2011-4Web of Scienc