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Rate Values (rate + value)
Kinds of Rate Values Selected AbstractsPolymorphisms in innate immunity genes and lung cancer risk in Xuanwei, China,ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 4 2009Min Shen Abstract The high incidence of lung cancer in Xuanwei County, China has been attributed to exposure to indoor smoky coal emissions that contain polycyclic aromatic hydrocarbons (PAHs). The inflammatory response induced by coal smoke components may promote lung tumor development. We studied the association between single nucleotide polymorphisms (SNPs) in genes involved in innate immunity and lung cancer risk in a population-based case,control study (122 cases and 122 controls) in Xuanwei. A total of 1,360 tag SNPs in 149 gene regions were included in the analysis. FCER2 rs7249320 was the most significant SNP (OR: 0.30; 95% CI: 0.16,0.55; P: 0.0001; false discovery rate value, 0.13) for variant carriers. The gene regions ALOX12B/ALOX15B and KLK2 were associated with increased lung cancer risk globally (false discovery rate value <0.15). In addition, there were positive interactions between KLK15 rs3745523 and smoky coal use (OR: 9.40; Pinteraction = 0.07) and between FCER2 rs7249320 and KLK2 rs2739476 (OR: 10.77; Pinteraction = 0.003). Our results suggest that genetic polymorphisms in innate immunity genes may play a role in the genesis of lung cancer caused by PAH-containing coal smoke. Integrin/receptor and complement pathways as well as IgE regulation are particularly noteworthy. Environ. Mol. Mutagen., 2009. Published 2009 Wiley-Liss, Inc. [source] Blends of triazine-based hyperbranched polyether with LDPE and plasticized PVCJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007Jyotishmoy Borah Abstract Triazine-based hyperbranched polyether was obtained by earlier reported method and blended with low density polyethylene (LDPE) and plasticized poly(vinyl chloride) (PVC) separately to improve some desirable properties of those linear polymers. The properties like processability, mechanical properties, flammability, etc. of those linear polymers were studied by blending with 1,7.5 phr of hyperbranched polyether. The mechanical properties were also measured after thermal aging and leaching in different chemical media. SEM study indicates that both polymers exhibit homogenous morphology at all dose levels. The mechanical properties like tensile strength, elongation at break, hardness, etc. of LDPE and PVC increase with the increase of dose level of hyperbranched polyether. The flame retardant behavior as measured by limiting oxygen index (LOI) for all blends indicates an enhanced LOI value compared to the polymer without hyperbranched polyether. The processing behavior of both types of blends as measured by solution viscosity and melt flow rate value indicates that hyperbranched polyether acts as a process aid for those base polymers. The effect of leaching and heat aging of these linear polymers on the mechanical properties showed that hyperbranched polyether is a superior antidegradant compared to the commercially used N -isopropyl- N -phenyl p -phenylene diamine. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 648,654, 2007 [source] Value at risk from econometric models and implied from currency optionsJOURNAL OF FORECASTING, Issue 8 2004James ChongArticle first published online: 3 DEC 200 Abstract This paper compares daily exchange rate value at risk estimates derived from econometric models with those implied by the prices of traded options. Univariate and multivariate GARCH models are employed in parallel with the simple historical and exponentially weighted moving average methods. Overall, we find that during periods of stability, the implied model tends to overestimate value at risk, hence over-allocating capital. However, during turbulent periods, it is less responsive than the GARCH-type models, resulting in an under-allocation of capital and a greater number of failures. Hence our main conclusion, which has important implications for risk management, is that market expectations of future volatility and correlation, as determined from the prices of traded options, may not be optimal tools for determining value at risk. Therefore, alternative models for estimating volatility should be sought. Copyright © 2004 John Wiley & Sons, Ltd. [source] Causes of shear sensitivity of the toxic dinoflagellate Protoceratium reticulatumBIOTECHNOLOGY PROGRESS, Issue 3 2009J. J. Gallardo Rodríguez Abstract Dinoflagellates have proven extremely difficult to culture because they are inhibited by low-level shear forces. Specific growth rate of the toxic dinoflagellate Protoceratium reticulatum was greatly decreased compared with static control culture by intermittent exposure to a turbulent hydrodynamic environment with a bulk average shear rate that was as low as 0.3 s,1. Hydrodynamic forces appeared to induce the production of reactive oxygen species (ROS) within the cells and this caused peroxidation of cellular lipids and ultimately cell damage. Exposure to damaging levels of shear rate correlated with the elevated level of lipoperoxides in the cells, but ROS levels measured directly by flow cytometry did not correlate with shear induced cell damage. This was apparently because the measured level of ROS could not distinguish between the ROS that are normally generated by photosynthesis and the additional ROS produced as a consequence of hydrodynamic shear forces. Continuously subjecting the cells to a bulk average shear rate value of about 0.3 s,1 for 24-h caused an elevation in the levels of chlorophyll a, peridinin and dinoxanthin, as the cells apparently attempted to counter the damaging effects of shear fields by producing pigments that are potential antioxidants. In static culture, limitation of carbon dioxide produced a small but measureable increase in ROS. The addition of ascorbic acid (0.1 mM) to the culture medium resulted in a significant protective effect on lipid peroxidation, allowing cells to grow under damaging levels of shear rates. This confirmed the use of antioxidant additives as an efficient strategy to counter the damaging effects of turbulence in photobioreactors where shear sensitive dinoflagellates are cultivated. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] The use of fire-retardant intumescent mats for fire and heat protection of glass fibre-reinforced polyester composites: Thermal barrier propertiesFIRE AND MATERIALS, Issue 1 2010Everson Kandare Abstract This study investigates the use of integral, hybrid intumescent thermal barriers (mats) to provide surface protection to the core fibre-reinforced polyester composite structural integrity when exposed to a fire or heat source. Glass fibre-reinforced composites protected by intumescent mats/fabrics containing silicate fibres, expandable graphite and in some cases borosilicate glass bounded together by an organic matrix have been evaluated for fire performance under a constant heat flux of 50kW/m2. The effect of insulative fabric thickness as well as chemical composition on the flammability of the resultant hybrid composites is evaluated. Glass fibre-reinforced polyester (GRP) composites without any surface protection have a relatively higher time-to-ignition and peak heat release rate values when compared with core composites protected by insulative fabrics. Thermograms representing the variation of temperature on the reverse side of the hybrid composites with time when exposed to a constant heat flux show that the inclusion of intumescent surface barriers results in retarded temperature increments within the core GRP composites. Copyright © 2009 John Wiley & Sons, Ltd. [source] Response Surface Model for the Estimation of Escherichia coli O 157:H7 Growth under Different Experimental ConditionsJOURNAL OF FOOD SCIENCE, Issue 1 2005Rose Maria García-Gimeno ABSTRACT: In this study, a Response Surface Model (RSM) of Escherichia coli O157:H7 as affected by pH levels, sodium chloride and nitrite concentrations, temperature, and aerobic/anaerobic conditions is presented. The standard error of prediction (%SEP) obtained was acceptable for the growth rate prediction (33%SEP), although a bit high for lag time (53.01 %SEP). Mathematical validation demonstrated that the RSM predicts growth rate values on the fail-safe side in aerobic conditions and within the acceptable range (bias factor [Bf] = 0.99) with acceptable accuracy (accuracy factor [Af] = 1.15), as well as for lag time (Bf = 1.05; Af = 1.25). Temperature was found to have the greatest effect on the kinetic parameters, followed by NaCl concentration and pH. In the experimental range considered here (0 to 200 ppm), NaNO2 concentration was found to have a significant effect on growth rate but not on lag time. [source] Rheological Investigation of Shear Induced-Mixing and Shear Induced-Demixing for Polystyrene/Poly(vinyl methyl ether) BlendMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 9 2004Samy A. Madbouly Abstract Full Paper: The phase behavior of polystyrene (PS) and poly(vinyl methyl ether) (PVME) blend has been investigated rheologically as a function of temperature, composition and oscillating shear rate as well as different heating rates. An LCST (lower critical solution temperature)-type phase diagram was detected rheologically from the sudden changes in the slopes of the dynamic temperature ramps of G, at given heating and shear rate values. The rheological cloud points were dependent on the heating rate, , and oscillating shear rate, . The cloud points shifted a few degrees to higher temperatures with increasing and reached an equilibrium value (heating rate independent) at ,°C/min. The phase diagrams of the blends detected at ,=,0.1 and 1 rad/s were located in lower temperature ranges than the quiescent phase diagram, i.e., oscillating shear rate induced-demixing at these two values for the shear rate. On the other hand, at ,=,10 rad/s, the phase diagram shifted to higher temperatures, higher than the corresponding values found under quiescent conditions, i.e., shear induced-mixing took place. Based on these two observations, shear induced-demixing and shear induced-mixing can be detected rheologically within a single composition at low and high shear rate values, respectively, and this is in good agreement with the previous investigation using simple shear flow techniques. In addition, the William, Landel and Ferry (WLF)-superposition principle was found to be applicable only in the single-phase regime; however, the principle broke-down at a temperature higher than or equal to the cloud point. Furthermore, different spinodal phase diagrams were estimated at different oscillating shear rates based on the theoretical approach of Ajji and Choplin. Spinodal phase diagrams at different oscillating shear rates. [source] Development of UHMWPE modified PP/PET blends and their mechanical and abrasive wear behaviorPOLYMER COMPOSITES, Issue 2 2007Navin Chand In this study, polypropylene and polyethylene terephthalate blend were modified by incorporating different percentages of ultrahigh molecular weight polyethylene (UHMWPE) ranging from 1 to 5 phr. Modified blends were prepared by melt mixing the PP/PET blend and UHMWPE. Ultimate tensile strength of UHMWPE filled blend was determined at 10, 20, 50, and 100 mm/min cross head speeds of testing. It was found that increase of cross head speed from 10 to 100 mm/min increases the tensile strength of PP/PET/UHMWPE blends. Maximum ultimate tensile strength is exhibited by the blend containing 2 phr UHMWPE. Breaking strain of the UHMWPE modified and unmodified PP/PET blend increased with the increase of cross head speed due to the highly entangled chain structure of UHMWPE. Shore A hardness of the filled blends also increased from 341 to 356, which is highest for 2 phr UHMWPE. High stress abrasive wear of UHMWPE modified blend was determined by using Suga abrasion tester, model NUS-1 Japan. Wear rate of the PP/PET(90/10) blends having 1, 2, and 5 phr of UHMWPE was determined at different loads such as 1, 3, 5, and 7 N and sliding distances from 6.4 m to 25.6 m. Wear rate values show that UHMWPE has prominent effect on abrasive wear of PP/PET blends. Addition of 2 and 5 phr UHMWPE improved the wear resistance of PP/PET blends at different loads, which has been explained on the basis of improved bonding as compared with pure PP/PET blend and increased hardness. Maximum abrasive wear rate reduction was achieved by adding 2 phr UHMWPE in PP/PET(90/10) blend. POLYM. COMPOS. 28:267,272, 2007. © 2007 Society of Plastics Engineers [source] Rheological characterization of HDPE/sisal fiber compositesPOLYMER ENGINEERING & SCIENCE, Issue 10 2007Smita Mohanty The present paper summarizes an experimental study on the molten viscoelastic behavior of HDPE/sisal composites under steady and dynamic mode. Variations of the melt viscosity and die swell of the composites with an increase in shear rate, fiber loading, and coupling agent concentration have been investigated using capillary rheometer. The shear rate , at the wall was calculated using Rabinowitsch correction applied to the apparent shear rate values. It was observed that the melt viscosity of the composites increased with the addition of fibers and maleic anhydride-grafted PE (MAPE). Die swell of HDPE also decreased with the addition of sisal fibers and MAPE. Further, the dynamic viscoelastic behavior of the composites was measured employing parallel plate rheometer. Time,temperature superposition was applied to generate various viscoelastic master curves. Temperature sweeps were also carried out to study the flow activation energy determined from Arrhenius equation. The fiber,matrix morphology of the extrudates was also examined using scanning electron microscopy. POLYM. ENG. SCI., 47:1634,1642, 2007. © 2007 Society of Plastics Engineers [source] Substituting fish meal with poultry by-product meal in diets for black Sea turbot Psetta maeoticaAQUACULTURE NUTRITION, Issue 5 2006M. YIGIT Abstract A 60 days feeding experiment was carried out with Black Sea turbot Psetta maeotica to determine the amount of poultry by-product meal (PBM) that could replace fish meal (FM) in formulated diets without reducing growth performance. Juvenile Black Sea turbot (initial average weight, 30 g) were fed five isoenergetic (gross energy, 20.5 ± 0.21 kJ g,1 diet) and isonitrogenous diets (protein content, 550 ±,0.35 g kg,1). The control diet used white FM as the sole protein source, the other four diets were prepared to replace FM protein at levels of 25%, 50%, 75% and 100% with PBM. The fish readily accepted all experimental diets and no mortality were recorded during the trial. There were no significant differences in growth performance of turbot (P < 0.05) fed the diets with 25% and 50% replacement levels compared with fish offered the control diet (100% FM), however, final body weight and specific growth rate values in the 50% replacement diet were about 8% lower than those of the control. Total nitrogen excretion in fish fed 50% replacement diet were about 10% higher than the control group, even though these parameters were not found to be statistically different. At the levels of 750 and 1000 g kg,1 of the protein, PBM inclusion caused a severe decrease in growth performance, feed utilization, protein efficiency ratio and per cent nitrogen retention. The results in the present study indicate that up to 25% of FM protein can be replaced by PBM protein without causing reduction in growth performance, nutrient utilization and nitrogen retention. [source] Reference values for change in body mass index from birth to 18 years of ageACTA PAEDIATRICA, Issue 6 2003J Karlberg Body mass index (BMI) has become the measure of choice for determination of nutritional status during the paediatric years, as in adults. Recently, several cross-sectional BMI childhood reference values standards have been published. In order precisely to evaluate childhood nutritional interventions, reference values allowing for the evaluation of changes in BMI values are also needed. For the first time, such reference values can be presented based on 3650 longitudinally followed healthy Swedish children born full term. The reference values for the change in BMI are given as the change in BMI standard deviation scores. The reference values are given as means of mathematical functions adjusting for gender, age of the child and the length of the interval between two measurements for interval lengths of 0.25 to 1.0 y before 2y of age and of 1 to 5 y between birth and 18 y. The usefulness of the reference values is proved by a graph that forms a part of a clinical computer program; the -2 to +2 standard deviation range of the predicted change in BMI can be computed for an individual child and drawn in the graph as an extended support for clinical decision-making. Conclusion: For the first time this communication gives access to BMI growth rate values that can be used both in research and in the clinic to evaluate various interventions, be they nutritional, surgical or therapeutic. [source] A prospective pilot study of curative-intent stereotactic body radiation therapy in patients with 5 or fewer oligometastatic lesions,CANCER, Issue 3 2008Michael T. Milano MD Abstract BACKGROUND. It is hypothesized that oligometastatic disease represents a state of potentially curable, limited metastases. Stereotactic body radiation therapy (SBRT) is an option for patients who are not amenable to or do not want resection. METHODS. From 2001 to 2006, 121 patients with ,5 detectable metastases were enrolled in 2 prospective studies that used curative-intent SBRT. Most patients were treated with 10 fractions of 5 Gray. Stereotactic radiosurgery was offered to patients with brain metastases. RESULTS. The 2-year overall survival (OS), progression-free survival (PFS), local control (LC), and distant control (DC) rates were 50%, 26%, 67%, and 34%, respectively; and the respective 4-year rates values were 28%, 20%, 60%, and 25%. A greater net tumor volume predicted significantly worse OS, PFS, LC, and DC. Patients with breast cancer fared significantly better with respect to OS, PFS, LC, and DC; and patients with adrenal metastases had significantly worse OS, PFS, and DC despite the small number of such patients enrolled. Neither the number of metastatic lesions nor the number of organs involved was a significant predictor of outcome. Among 45 patients who remained alive at the last follow-up, 29 patients had no evidence of disease, including 23 patients with ,2 years of follow-up. CONCLUSIONS. Oligometastatic disease is a potentially curable state of distant cancer spread. In this hypothesis-generating analysis, patients with less volume burden of their metastatic disease and those with primary breast cancer fared better. SBRT delivered with curative intent in patients with limited metastases should be investigated further. The Southwest Oncology Group is developing a prospective protocol to treat women who have limited breast cancer metastases with SBRT. Cancer 2008. © 2007 American Cancer Society. [source] | ||||||||||||||||