Distribution of 5'-nucleotidase activity in the tissues of a freshwater teleost, Ophicephalus striatus Bloch

Homogenates of tissues have been analysed for the presence of 5'-nucleotidase activity. Sexes are not treated individually since no significant differences were observed. All organs showed marked activity, the highest being in the cardiac tissues, then the kidney, spleen, brain, and low values in the liver and muscles. Comparison with data from other fish studied shows a marked difference between O. striatus and O. punctatus

Adaptive dissection based subword segmentation of printed Arabic text

Numerous segmentation and recognition techniques have been proposed in literature for Arabic OCR system. Correct and efficient segmentation of Arabic text into characters is considered to be a fundamental problem. While OCR systems for other languages do not need segmentation for printed text for successful recognition, it is essential to design robust and powerful segmentation algorithms or employ segmentation free recognition schemes for printed Arabic text. Even more, in recognition of handwritten characters, segmentation is considered to be indispensable. Most of current segmentation technique suffers from over segmentation and under segmentation in addition to not being adaptive in nature. In this paper, we have proposed a new sub-word segmentation scheme, which is independent of font size and font type

Adaptive dissection based subword segmentation of printed Arabic text

Numerous segmentation and recognition techniques have been proposed in literature for Arabic OCR system. Correct and efficient segmentation of Arabic text into characters is considered to be a fundamental problem. While OCR systems for other languages do not need segmentation for printed text for successful recognition, it is essential to design robust and powerful segmentation algorithms or employ segmentation free recognition schemes for printed Arabic text. Even more, in recognition of handwritten characters, segmentation is considered to be indispensable. Most of current segmentation technique suffers from over segmentation and under segmentation in addition to not being adaptive in nature. In this paper, we have proposed a new sub-word segmentation scheme, which is independent of font size and font type

Determination of in vitro antidiabetic effects of Zingiber officinale Roscoe

Aqueous extracts of Zingiber officinale rhizomes were studied to evaluate their antidiabetic effects on protein glycation and on the diffusion of glucose in vitro in the present study. Zingiber officinale rhizome aqueous extract were examined at concentrations of 5, 10, 20 and 40 g/L. The antidiabetic effects were found to be dose-dependent. Antidiabetic potential of Zingiber officinale was mainly through inhibition of the glucose diffusion and to a limited extent by reducing the glycation. However, further studies are needed to determine in vitro effects of therapeutic potential by restraining postprandial glucose absorptions and plasma protein glycations in diabetic subjects.Extratos aquosos de rizomas Zingiber officinale foram estudados para avaliar os seus efeitos antidiabéticos em glicação de proteínas e sobre a difusão de glicose in vitro, no presente estudo. Extratos aquosos de Zingiber officinale foram examinados nas concentrações de 5, 10, 20 e 40 g extrato de planta/L. Os efeitos antidiabéticos observados eram dependentes da dose. O potencial antidiabético de Zingiber officinale se verificou, principalmente, através da inibição da difusão de glicose e, em menor extensão, através da redução da glicação. Estudos adicionais são necessários para elucidar se efeitos in vitro representam potencial terapêutico, restringindo a absorção de glicose pós-prandial e a glicação de proteínas plasmáticas em indivíduos diabéticos

A bidomain threshold model of propagating calcium waves

We present a bidomain fire-diffuse-fire model that facilitates mathematical analysis of propagating waves of elevated intracellular calcium (Ca) in living cells. Modelling Ca release as a threshold process allows the explicit construction of travelling wave solutions to probe the dependence of Ca wave speed on physiologically important parameters such as the threshold for Ca release from the endoplasmic reticulum (ER) to the cytosol, the rate of Ca resequestration from the cytosol to the ER, and the total [Ca] (cytosolic plus ER). Interestingly, linear stability analysis of the bidomain fire-diffuse-fire model predicts the onset of dynamic wave instabilities leading to the emergence of Ca waves that propagate in a back-and-forth manner. Numerical simulations are used to confirm the presence of these so-called "tango waves" and the dependence of Ca wave speed on the total [Ca]. The original publication is available at www.springerlink.com (Journal of Mathematical Biology

Calcium Dynamics in the Ventricular Myocytes of SERCA2 Knockout Mice: A Modeling Study

We describe a simulation study of Ca2+ dynamics in mice with cardiomyocyte-specific conditional excision of the sarco(endo)plasmic reticulum calcium ATPase (SERCA) gene, using an experimental data-driven biophysically-based modeling framework. Previously, we reported a moderately impaired heart function measured in mice at 4 weeks after SERCA2 gene deletion (knockout (KO)), along with a >95% reduction in the level of SERCA2 protein. We also reported enhanced Ca2+ flux through the L-type Ca2+ channels and the Na+/Ca2+ exchanger in ventricular myocytes isolated from these mice, compared to the control Serca2flox/flox mice (flox-flox (FF)). In the current study, a mathematical model-based analysis was applied to enable further quantitative investigation into changes in the Ca2+ handling mechanisms in these KO cardiomyocytes. Model parameterization based on a wide range of experimental measurements showed a 67% reduction in SERCA activity and an over threefold increase in the activity of the Na+/Ca2+ exchanger. The FF and KO models were then validated against experimentally measured [Ca2+]i transients and experimentally estimated sarco(endo)plasmic reticulum (SR) function. Simulation results were in quantitative agreement with experimental measurements, confirming that sustained [Ca2+]i transients could be maintained in the KO cardiomyocytes despite severely impaired SERCA function. In silico analysis shows that diastolic [Ca2+]i rises sharply with progressive reductions in SERCA activity at physiologically relevant pacing frequencies. Furthermore, an analysis of the roles of the compensatory mechanisms revealed that the major combined effect of the compensatory mechanisms is to lower diastolic [Ca2+]i. Finally, by using a comprehensive sensitivity analysis of the role of all cellular calcium handling mechanisms, we show that the combination of upregulation of the Na+/Ca2+ exchanger and increased L-type Ca2+ current is the most effective means to maintain diastolic and systolic calcium levels after loss of SERCA function