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Water absorption and diffusion characteristics of nanohydroxyapatite (nHA) and poly(hydroxybutyrate-co-hydroxyvalerate-) based composite tissue engineering scaffolds and nonporous thin films
No full textWater uptake characteristics of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV-) based composite tissue engineering (TE) scaffolds incorporating nanosized hydroxyapatite (nHA) have been investigated. The water absorption of these composite scaffolds obeyed the classical diffusion theory for the initial period of time. The diffusion coefficients of the composite scaffolds during the water absorption were much faster than those for the nonporous thin films, suggesting that the water uptake process depends on the presence of porosity and porous microstructure of the composite scaffolds. The incorporation of nHA increased the water uptake of both the composite scaffolds and thin films. It was also observed that the equilibrium uptake increased with the incorporation of nHA. This increase in the water uptake was largely due to the nHA particle aggregates in the microstructure of both composite scaffolds and thin films. The activation energy for diffusion was also determined using the Arrhenius equation for both porous scaffolds and thin films and the results suggested that the activation energy for scaffolds was lower than that for thin films. © 2013 Naznin Sultana and Tareef Hayat Khan
Assessing the Effectiveness of the Violence Free Zone in Milwaukee Public Schools: A Research Note
Get PDFInterrelationships between apoptosis and fertility in bull sperm
No full textMale fertility, the ability of sperm to fertilize and activate the egg and support early embryogenesis, is vital for mammalian reproduction. Despite producing adequate numbers of sperm with normal motility and morphology, some males suffer from low fertility whose molecular mechanisms are not known. The objective was to determine apoptosis in sperm from high and low fertility bulls and its relationship with male fertility. DNA damage, phosphatidylserine (PS) translocation, and expression of proand anti-apoptotic proteins (BAX and BCL-2) in the sperm were determined using TUNEL, Annexin V, and immunoblotting approaches, respectively. Amounts of apoptotic spermatozoa were 2.86 (± 1.31) and 3.00 (± 0.96) in high and low fertility bulls, respectively (P=0.548), and were not correlated with fertility. There was a negative correlation between early necrotic spermatozoa and viable spermatozoa (r = -0.99, P\u3c0.0001). Fertility scores were correlated with live spermatozoa detected by eosin-nigrosin test and necrotic spermatozoa determined via fow cytometry (r = -0.49, P\u3c0.006 and r = -0.266, P\u3c0.0113, respectively). BAX level was higher in low fertile group than high fertile group; however, this difference was not statistically significant due to the variations of bull samples (Bull 1-3 vs. Bull 4-5) in low fertile group (P\u3c0.283). BCL-2 was not detectable in any of the sperm samples. The results shed light onto molecular and cellular underpinnings of male fertility. © 2013 by the Society for Reproduction and Development
Hydro-thermal convective solutions for an aquifer system heated from below
Get PDFWe investigate the effect of hydro-thermal convection in an aquifer system. It is assumed that the aquifer is bounded below and above by impermeable boundaries and it is heated from below. The solution of the governing system is expressed in terms of the basic steady state solution and perturbed solution. We obtain the critical Rayleigh number and critical wavenumber using Runge-Kutta method in combination of shooting method and present the marginal stability curve. The amplitude equation is derived by introducing the adjoint system. After amplitude is obtained, we compute the linear solutions for super-critical and sub-critical cases. Numerical results for various spatial and time values are presented in graphical forms
Solutions of System of Fractional Partial Differential Equations
Get PDFIn this paper, system of fractional partial differential equation which has numerous applications in many fields of science is considered. Adomian decomposition method, a novel method is used to solve these type of equations. The solutions are derived in convergent series form which shows the effectiveness of the method for solving wide variety of fractional differential equations
Analysis of Mixed Correlated Bivariate Negative Binomial and Continuous Responses
Get PDFA general model for the mixed correlated negative binomial and continuous responses is proposed. It is shown how to construct parameter of the models, using the maximization of the full likelihood. Influence of a small perturbation of correlation parameter of the model on the likelihood displacement is also studied. The model is applied to a medical data, obtained from an observational study on women, where the correlated responses are the negative binomial response of joint damage and continuous responses of body mass index. Simultaneous effects of some covariates on both responses are investigated
Numerical Solution of Fuzzy Arbitrary Order Predator-Prey Equations
Get PDFThis paper seeks to investigate the numerical solution of fuzzy arbitrary order predator-prey equations using the Homotopy Perturbation Method (HPM). Fuzziness in the initial conditions is taken to mean convex normalised fuzzy sets viz. triangular fuzzy number. Comparisons are made between crisp solution given by others and fuzzy solution in special cases. The results obtained are depicted in plots and tables to demonstrate the efficacy and powerfulness of the methodology
Using Fuzzy Linear Regression to Estimate Relationship between Forest Fires and Meteorological Conditions
Get PDFEach year, millions of hectares of forest land are destroyed by fires causing great financial loss and ecological damage. In this paper, our aim is to study the effect of the variation of meteorological conditions on the total burned area in hectares, by using fuzzy linear regression analysis based on Tanaka’s approaches. The total burned area is considered a dependent variable. Air temperature (in ºC), relative humidity (in %), wind speed (in km/h) and rainfall (in mm/m2 ) are considered to be independent variables. The relationship between input and output data is estimated using data provided in data mining literature. In our study, we apply fuzzy regression, using crisp/fuzzy input data and fuzzy output data expressed in linguistic terms
Some Geometric Properties of a New Type Metric Space
Get PDFIn this paper, we define a metric on our new space and then show that this linear metric space is k-nearly uniform convex and has property beta where p = pk is a bounded sequence of positive real numbers. Finally, we give a result about property (H) by using k-nearly uniform convexity
