Occupancy dynamics of South American sea-lions in Brazilian haul-outs / Dinâmica de ocupação do leão-marinho-do-sul no Brasil

Along the Brazilian coast only two haul-outs of South American sea lions (Otaria flavescens) are known: Ilha dos Lobos and Molhe Leste, both located in the southernmost state of Brazil, Rio Grande do Sul. Most sea lions observed in these haul-outs are adult and sub-adult males. It is supposed that the species' presence in these areas is due to food supply and absence of parental assistance by males. This study analysed the use of these haul-outs by O. flavescens between 1993 and 2002 based on counting data of observed individuals. Bayesian generalised linear mixed models were used to evaluate differences in abundance between areas, long term trends and seasonal patterns. Results showed that for O. flavescens abundance had a long term trend of increased average occupancy over the study period, with seasonal variation reaching the highest within-year value in August (Ilha dos Lobos) and October (Molhe Leste). The novel application of this powerful statistical modelling approach resulted in a useful tool to quantify occupancy dynamic.

Ao longo da costa do Brasil apenas duas colônias não-reprodutivas de leões-marinhos-do-sul (Otaria flavescens) são conhecidas: Ilha dos Lobos e Molhe Leste, ambas localizadas no estado do Rio Grande do Sul. A maioria dos leões-marinhos observados nestas colônias são machos adultos e sub-adultos. Supõe-se que a presença da espécie nestas áreas está relacionada ao forrageamento e a ausência de cuidado parental pelos machos. Este estudo analisou a dinâmica de ocupação e abundância de O. flavescens nas colônias não-reprodutivas entre 1993 e 2002, baseado em uma série temporal de dados de contagens de indivíduos. Modelos lineares generalizados mistos Bayesianos foram usados para avaliar diferença na abundância entre áreas, tendência de uso em longo prazo e padrões sazonais. Os resultados mostram que a abundância de O. flavescens variou sazonalmente, atingindo pico intra-anual em agosto (Ilha dos Lobos) e outubro (Molhe Leste), acompanhado de um aumento da ocupação média dos refúgios ao longo do período de estudo. A nova aplicação desta poderosa forma de modelagem estatística mostrou-se útil para quantificar a dinâmica de ocupação.

Occupancy dynamics of South American sea-lions in Brazilian haul-outs.

Along the Brazilian coast only two haul-outs of South American sea lions (Otaria flavescens) are known: Ilha dos Lobos and Molhe Leste, both located in the southernmost state of Brazil, Rio Grande do Sul. Most sea lions observed in these haul-outs are adult and sub-adult males. It is supposed that the species' presence in these areas is due to food supply and absence of parental assistance by males. This study analysed the use of these haul-outs by O. flavescens between 1993 and 2002 based on counting data of observed individuals. Bayesian generalised linear mixed models were used to evaluate differences in abundance between areas, long term trends and seasonal patterns. Results showed that for O. flavescens abundance had a long term trend of increased average occupancy over the study period, with seasonal variation reaching the highest within-year value in August (Ilha dos Lobos) and October (Molhe Leste). The novel application of this powerful statistical modelling approach resulted in a useful tool to quantify occupancy dynamic.

Stationary cuvette: a new approach to obtaining analytical curves by UV-VIS spectrophotometry.

BACKGROUND: Investigations in the field of pharmaceutical analysis and quality control of medicines require analytical procedures that achieve suitable performance. An analytical curve is one of the most important steps in the chemical analysis presenting a direct relationship to features such as linearity. OBJECTIVE: This study has the aim of developing a new methodology, the stationary cuvette, to derive analytical curves by spectroscopy for drug analysis. METHODOLOGY: The method consists basically of the use of a cuvette with a path length of 10 cm, containing a constant volume of solvent in which increasing amounts of a stock solution of the sample are added, droplet by droplet. After each addition, the cuvette is stirred and the absorbance is measured. This procedure was compared with the currently used methodology, which requires a labour-intensive dilution process, and possible sources of variation between them were evaluated. RESULTS: The results demonstrated that the proposed technique presented high sensitivity and similar reproducibility compared with the conventional methodology. In addition, a number of advantages were observed, such as user-friendliness, cost-effectiveness, accuracy, precision and robustness. CONCLUSION: The stationary cuvette approach may be considered to be an appropriate alternative to derive analytical curves for analysing drug content in raw materials and medicines through UV-VIS spectrophotometry.

A new insight about pharmaceutical dosage forms for benzathine penicillin G

O objetivo desse trabalho foi o de desenvolver e avaliar do ponto de vista físico-químico um sistema micelar de penicilina G benzatina (BPG) em desoxicolato de sódio (NaDC).Foram estudadas as características físicoquímicas da BPG quanto à solubilidade em água e em soluções tampões com diferentes pHs, além do coeficiente de partição octanol-água.Foram avaliadas as propriedades da concentração micelar crítica (CMC) das soluções micelares de Desoxicolato de sódio (NaDC) em baixa e alta força iônica provocada pela presença de cloreto de sódio.O estudo da incorporação da BPG em soluções micelares de NaDC usando várias concentrações de NaDC também foi realizado.O aumento da solubilidade da BPG provocada pela presença de micelas de NaDC foi analisada quantitativamente pelo formalismo do modelo de pseudo-fase.Houve indicação da aplicabilidade do sistema micelar estudado quanto à incorporação de penicilina e aumento se sua solubilidade aparente, com taxa de incorporação de até 90 por cento.Espera-se que a formulação micellar de BPG apresente melhor estabilidade, considerando-se que o antibiótico incorporado na região hidrofóbica das micelas está protegido do meio aquoso externo.

Real-time myocardial contrast echocardiography for the detection of stress-induced myocardial ischemia. Comparison with 99mTc-sestamibi single photon emission computed tomography.

BACKGROUND: Real-time contrast echocardiography (MCE) is a new promising technique for assessing myocardial perfusion. The purpose of this study was to test whether realtime MCE can be used to detect functionally significant coronary artery stenosis in patients with known or suspected coronary artery disease. Myocardial contrast echocardiographic studies were compared with nearly simultaneous 99mTc-sestamibi single photon emission computed tomography (SPECT) as a clinical standard reference to evaluate regional myocardial perfusion defects. METHODS: Real-time MCE based on continuous infusion of Optison (8-10 ml/h) was performed in 66 patients during standard 99mTc-SPECT dipyridamole (0.56 mg/kg x 4 min) stress testing. Images were obtained in apical 4- and 2-chamber views, each divided into 6 segments. Tracer uptake and myocardial opacification were visually analyzed for each segment by two pairs of blinded observers and graded as normal, mildly reduced, severely reduced, or absent. In 792 myocardial segments, myocardial opacification by MCE was uninterpretable in 143 (18%) segments and tracer uptake by SPECT was not clearly defined in 92 (12%) segments. Interobserver variability for MCE was good with concordance rates of 83% (kappa=0.72) for rest- and 86% (kappa=0.76) for stress images. Overall concordance between MCE and SPECT was good (83%, kappa=0.63) at a segmental level. In the diagnosis of fixed and reversible defects, and of normal perfusion, concordance rates were 73, 65 and 83%, respectively. When analysis was performed at the regional level, we found comparable levels of concordance rates for LAD (83%, kappa=0.59), LCX (86%, kappa=0.64) and RCA (80%, kappa=0.68) perfusion territories. CONCLUSIONS: These findings suggest that realtime MCE is a clinically acceptable method to evaluate myocardial perfusion defects during dipyridamole stress testing.

Contrast-enhanced doppler ultrasound for noninvasive assessment of pulmonary artery pressure during exercise in patients with chronic congestive heart failure.

Pulmonary artery pressure response to exercise was assessed using contrast enhancement of tricuspid regurgitation peak velocities in 19 patients with chronic congestive heart failure. Estimated systolic pulmonary artery pressures correlated closely with invasively measured pressures at rest (r=0.82, p <0.001) and during peak exercise (r=0.86, p <0.001) at a good level of agreement (mean difference 7.3 +/- 12 mm Hg), indicating that this method provides a reliable, noninvasive approach to evaluating functional reserve in patients with chronic congestive heart failure.