Solvent drag measurement of transcellular and basolateral membrane NaCl reflection coefficient in kidney proximal tubule.

The NaCl reflection coefficient in proximal tubule has important implications for the mechanisms of near isosmotic volume reabsorption. A new fluorescence method was developed and applied to measure the transepithelial (sigma NaClTE) and basolateral membrane (sigma NaClcl) NaCl reflection coefficients in the isolated proximal straight tubule from rabbit kidney. For sigma NaClTE measurement, tubules were perfused with buffers containing 0 Cl, the Cl-sensitive fluorescent indicator 6-methoxy-N-[3-sulfopropyl] quinolinium and a Cl-insensitive indicator fluorescein sulfonate, and bathed in buffers of differing cryoscopic osmolalities containing NaCl. The transepithelial Cl gradient along the length of the tubule was measured in the steady state by a quantitative ratio imaging technique. A mathematical model based on the Kedem-Katchalsky equations was developed to calculate the axial profile of [Cl] from tubule geometry, lumen flow, water (Pf) and NaCl (PNaCl) permeabilities, and sigma NaClTE. A fit of experimental results to the model gave PNaCl = (2.25 +/- 0.2) x 10(-5) cm/s and sigma NaClTE = 0.98 +/- 0.03 at 23 degrees C. For measurement of sigma NaClbl, tubule cells were loaded with SPQ in the absence of Cl. NaCl solvent drag was measured from the time course of NaCl influx in response to rapid (less than 1 s) Cl addition to the bath solution. With bath-to-cell cryoscopic osmotic gradients of 0, -60, and +30 mosmol, initial Cl influx was 1.23, 1.10, and 1.25 mM/s; a fit to a mathematical model gave sigma NaClbl = 0.97 +/- 0.04. These results indicate absence of NaCl solvent drag in rabbit proximal tubule. The implications of these findings for water and NaCl movement in proximal tubule are evaluated

Effect of Intensity on Prevalence of N3 Potential in Ears with Severe to Profound Hearing Loss

Objective of the study: To look for the presence of N3 potential at two different intensities in children and in adults. Method: A total of 260 ears with severe to profound hearing loss were studied from the participants in the age range of 1 to 50 years, with 170 subjects in the age group below 10 years and remaining 90 subjects of more than 10 years. Auditory brainstem response (ABR) was recorded at two intensities, 90 and 99dBnHL, to look for the presence of N3 potential. Result: N3 potential was observed in 30% of the total ears taken in the study at 90dBnHL and 38.8% at 99dBnHL. Presence of N3 potential in children was 45%, which was higher than the age group of above 10 years. When the intensity was increased there was an increase in amplitude and a reduction in latency with better wave morphology. Conclusion: It is better to use higher intensity for the identification of the N3 potential while doing ABR and thus with the single recording, auditory assessment as well as saccular assessment can be done

In situ growth regime characterization of cubic GaN using reflection high energy electron diffraction

Cubic GaN layers were grown by plasma-assisted molecular beam epitaxy on 3C-SiC (001)substrates. In situ reflection high energy electron diffraction was used to quantitatively determine the Ga coverage of the GaN surface during growth. Using the intensity of the electron beam as a probe,optimum growth conditions of c-GaN were found when a 1 ML Ga coverage is formed at the surface. 1 micrometer thick c-GaN layers had a minimum surface roughness of 2.5 nm when a Ga coverage of 1 ML was established during growth. These samples revealed also a minimum full width at half maximum of the (002)rocking curve.Comment: 3pages with 4 figure

Aquaporin-4-dependent K(+) and water transport modeled in brain extracellular space following neuroexcitation.

Potassium (K(+)) ions released into brain extracellular space (ECS) during neuroexcitation are efficiently taken up by astrocytes. Deletion of astrocyte water channel aquaporin-4 (AQP4) in mice alters neuroexcitation by reducing ECS [K(+)] accumulation and slowing K(+) reuptake. These effects could involve AQP4-dependent: (a) K(+) permeability, (b) resting ECS volume, (c) ECS contraction during K(+) reuptake, and (d) diffusion-limited water/K(+) transport coupling. To investigate the role of these mechanisms, we compared experimental data to predictions of a model of K(+) and water uptake into astrocytes after neuronal release of K(+) into the ECS. The model computed the kinetics of ECS [K(+)] and volume, with input parameters including initial ECS volume, astrocyte K(+) conductance and water permeability, and diffusion in astrocyte cytoplasm. Numerical methods were developed to compute transport and diffusion for a nonstationary astrocyte-ECS interface. The modeling showed that mechanisms b-d, together, can predict experimentally observed impairment in K(+) reuptake from the ECS in AQP4 deficiency, as well as altered K(+) accumulation in the ECS after neuroexcitation, provided that astrocyte water permeability is sufficiently reduced in AQP4 deficiency and that solute diffusion in astrocyte cytoplasm is sufficiently low. The modeling thus provides a potential explanation for AQP4-dependent K(+)/water coupling in the ECS without requiring AQP4-dependent astrocyte K(+) permeability. Our model links the physical and ion/water transport properties of brain cells with the dynamics of neuroexcitation, and supports the conclusion that reduced AQP4-dependent water transport is responsible for defective neuroexcitation in AQP4 deficiency

Warehouse commodity classification from fundamental principles. Part I: Commodity & burning rates

An experimental study was conducted to investigate the burning behavior of an individual Group A plastic commodity over time. The objective of the study was to evaluate the use of a nondimensional parameter to describe the time-varying burning rate of a fuel in complex geometries. The nondimensional approach chosen to characterize burning behavior over time involved comparison of chemical energy released during the combustion process with the energy required to vaporize the fuel, measured by a B-number. The mixed nature of the commodity and its package, involving polystyrene and corrugated cardboard, produced three distinct stages of combustion that were qualitatively repeatable. The results of four tests provided flame heights, mass-loss rates and heat fluxes that were used to develop a phenomenological description of the burning behavior of a plastic commodity. Three distinct stages of combustion were identified. Time-dependent and time-averaged B-numbers were evaluated from mass-loss rate data using assumptions including a correlation for turbulent convective heat transfer. The resultant modified B-numbers extracted from test data incorporated the burning behavior of constituent materials, and a variation in behavior was observed as materials participating in the combustion process varied. Variations between the four tests make quantitative values for each stage of burning useful only for comparison, as errors were high. Methods to extract the B-number with a higher degree of accuracy and future use of the results to improve commodity classification for better assessment of fire danger are discussed. © 2011 Elsevier Ltd. All rights reserved

Generalizations of Tucker-Fan-Shashkin lemmas

Tucker and Ky Fan's lemma are combinatorial analogs of the Borsuk-Ulam theorem (BUT). In 1996, Yu. A. Shashkin proved a version of Fan's lemma, which is a combinatorial analog of the odd mapping theorem (OMT). We consider generalizations of these lemmas for BUT-manifolds, i.e. for manifolds that satisfy BUT. Proofs rely on a generalization of the OMT and on a lemma about the doubling of manifolds with boundaries that are BUT-manifolds.Comment: 10 pages, 2 figure

Pengaruh Keselamatan Dan Kesehatan Kerja Terhadap Kepuasan Kerja Karyawan (Studi Pada Karyawan Bagian Produksi PT Indohamafish Jembrana Bali)

Basically, guarantee on Occupational safety and health are the efforts of companies to give support to every activity that employees do. Occupational safety and health guarantee existence will give safeness by itself so that employees can work well as procedure and rule defined by companies so job satisfaction can be realized. So if occupational safety and health guarantee can be maximized by companies, it can incerase job satisfaction so employees can work safetly and pleasantly and the target achievement as the final purpose that is appointed by companies can be reached maximally. This research has some purposes: 1) To find the impact of occupational safety on employee job satisfaction partialy in production division of PT. Indohamafish Jembrana Bali. 2) To find the impact of occupational health on employee job satisfaction partialy in production division of PT. Indohamafish Jembrana Bali. 3) To find the impact of occupational safety and health on job satisfaction in production division of PT. Indohamafish Jembrana Bali. This kind of research is explanatory research and the population of this research are production division of PT. Indohamafish Jembrana Bali employees, 80 as total by using total sampling technique. Multiple linear regression is used for Data Analysis technique with F test and t test. Research results shows that occupational safety has a partial impact for employees in PT. Indohamafish Jembrana Bali production division by 0,730. Occupationall health has a partial impact for employees in PT. Indohamafish Jembrana Bali production division by 0,199. Occupational safety and healthy working has a simultan impact for employees in PT. Indohamafish Jembrana Bali production division by 70,5%

The relationship between HIV seroconversion illness, HIV test interval and time to AIDS in a seroconverter cohort.

Seroconversion illness is known to be associated with more rapid HIV disease progression. However, symptoms are often subjective and prone to recall bias. We describe symptoms reported as seroconversion illness and examine the relationship between illness, HIV test interval (time between antibody-negative and anibody-positive test dates) and the effect of both on time to AIDS from seroconversion. We used a Cox model, adjusting for age, sex, exposure group and year of estimated seroconversion. Of 1820 individuals, information on seroconversion illness was available for 1244 of whom 423 (34%) reported symptomatic seroconversion. Persons with a short test interval (< or = 2 months) were significantly more likely to report an illness than people with a longer interval (OR 6.76, 95% CI 4.75-9.62). Time to AIDS was significantly faster (P = 0.01) in those with a short test interval. The HIV test interval is a useful replacement for information on seroconversion illness in studies of HIV disease progression