Frequency Distribution Profiles Research Articles

The Rural-Urban Divide: Insights from Immuno-Genetic Profiles and Implications for Health

Population disparities in health and disease have been observed and amply documented. While often attributable to genetic underpinnings, such disparities extend beyond population genetic predisposition to include environmental and geographic determinants, most pronouncedly the division between rural and urban lifestyles. Under such influences, genes and gene products may become affected by epigenetic factors, microbial modifiers including infections, and the body microbiome that ultimately shapes the outcome of a complex milieu of protein networks. Retrospective, demographic, genotype, and expression data from two rural populations in eastern Sudan were analysed for genotype, allele frequency distribution, Hardy-Weinberg equilibrium, and expression profiles using an array panel of Th1, Th2, and Th3 genes in a subset of the rural population sample against matched urban controls. Differences between urban and rural samples were observed in the departure from HWE, with an excess of heterozygosity in the rural sample. In the Th1, Th2, and Th3 array, cytokines were consistently overexpressed in the rural cohort compared to the urban cohort and were replicated in 7 selected genes that are associated with chronic diseases amongst urban dwellers in contrast to rural village inhabitants. IgE levels, as a feature of parasitic infections, are another difference to include in that dichotomy. Gene expression appears to be more exposed to the overall outcome of genetic variations, including the interaction with environmental influences within and outside the body. Here, it may be gathered from the contrast in the expression patterns between the rural and urban samples. The presence of signals of natural selection in genes that are key to certain biological functions, such as CD40L and FasL, and the sharp contrast between urban and rural populations in gene variants distribution and expression patterns, may provide important clues towards understanding the disparity between human communities in non-communicable diseases of lifestyle as well as some of the emerging infectious diseases.

Effect of two-stage crossing of right-turning vehicles on capacity of urban uncontrolled intersections under mixed traffic conditions

Occupancy time is a microscopic traffic stream parameter used for evaluating the service performance of uncontrolled or unsignalized intersections. Several studies have conducted in the past used occupancy time concept to estimate critical gaps considering single-stage crossing. However, various roadway and traffic characteristics influence the right-turning vehicles and allow them to wait at the median. The present study demonstrates a procedure to examine the critical gap behavior of minor road vehicles turning right from the approaches of uncontrolled intersections. The study analyzes the occupancy time of vehicles by developing frequency distribution profiles considering single-stage and two-stage crossings. Field data for the study was collected for eight hours at six different uncontrolled T-intersections in India. The analysis of occupancy time performed for each vehicle type observed in the field revealed that the ability of vehicles to turn through intersection-conflicting zone in single-stage crossing is 36% lower when compared to two-stage crossing. The distribution models fitted on occupancy time data pertaining to right-turning vehicles are varied under single-stage and two-stage crossings. The critical gap values are estimated using distribution model profiles for both stages of crossing at each intersection. Further, the movement capacity of the minor approach right turning calculated using estimated critical gap values is compared under both types of crossing stages. The percentage change in capacity is found to be significant with a small change in the percentage of two-stage crossings.

Thermal decomposition characterization and kinetic parameters estimation for date palm wastes and their blends using TGA

TGA has been used to evaluate the thermal degradation profiles and kinetic parameters for the pyrolysis of date leaves, date seeds, and leaf stems and their blend at various heating rates (β) in N2. Using Kissinger–Akahira–Sunose (KAS), and Ozawa-Flynn-Wall (OFW), kinetic parameters like activation energy (E) and frequency factor (A) were estimated. The diffusion, reaction order, and power law models were used to estimate the frequency factors based on the (E) values obtained from the OFW and KAS approaches. Thermal degradation profiles showed two major loss processes: volatilization of cellulose, hemicelluloses, and lignin; and slow oxidation of the residual char. The findings demonstrated that as β increased, the TG profiles shifted to higher temperature ranges. The date palm's decomposition was not favourably reflected by the high (ΔGav) values obtained. The high (ΔSav) values obtained using OFW compared to KAS confirm these materials' high reactivity. The average activation energies (Eav) for the different parts of the date palm wastes ranged between 86 and 117 kJ/mole as predicted by the KAS method, while they were between 92 and 120 kJ/mole using the OFW method. The calculated frequency factor (A) values, evaluated by the KAS and the OFW methods, ranged between 0.0 and ∼ 0.8 × 1019min-1. The difference in (Eav) values between the KAS and OFW techniques is no greater than 8 kJ/mole. For the diffusion models of DSW, DL, and Blend, the best frequency distribution profiles are essentially normal, and the blend exhibits high frequency (A) values in a relatively constrained range of (α). That denotes quick and efficient pyrolysis. The pyrolysis index (CPI) significantly increased as β increased, indicating that pyrolysis was profitable at high heating rates. The volatile release index (Ddev) increases significantly with increasing (β) value, showing that volatiles was easier to release at a high heating rate.

Single object profiles regression analysis (SOPRA): a novel method for analyzing high-content cell-based screens

BackgroundHigh-content screening (HCS) experiments generate complex data from multiple object features for each cell within a treated population. Usually, these data are analyzed by using population-averaged values of the features of interest, increasing the amount of false positives and the need for intensive follow-up validation. Therefore, there is a strong need for novel approaches with reproducible hit prediction by identifying significantly altered cell populations.ResultsHere we describe SOPRA, a workflow for analyzing image-based HCS data based on regression analysis of non-averaged object features from cell populations, which can be run on hundreds of samples using different cell features. Following plate-wise normalization, the values are counted within predetermined binning intervals, generating unique frequency distribution profiles (histograms) for each population, which are then normalized to control populations (control-based normalization). These control-normalized frequency distribution profiles are analyzed using the Bioconductor R-package maSigPro, originally developed to analyze time profiles. However, statistically significant altered frequency distributions are also identified by maSigPro when integrating it into the SOPRA workflow. Finally, significantly changed profiles can be used to generate a heatmap from which altered cell populations with similar phenotypes can be identified, enabling the detection of siRNAs and compounds with the same ‘on-target’ profile and reducing the number of false positive hits.ConclusionsSOPRA is a novel analysis workflow for the detection of statistically significant normalized frequency distribution profiles of cellular features generated in high-throughput RNAi screens. For the validation of the SOPRA software workflow, a screen for cell cycle progression was used. We were able to identify such profiles for siRNA-mediated gene perturbations and chemical inhibitors of different cell cycle stages. The SOPRA software is freely available from Github.

Techno-economic assessment of establishment of wind farms in different provinces of Saudi Arabia to mitigate future energy challenges

In the present study, the techno-economic feasibility of development of 15 MW wind power plants (wind farms) in the Kingdom of Saudi Arabia has been investigated by analyzing long-term wind speed data. To achieve this aim, two geographically distinct sites covering different non-coastal locations of the Kingdom of Saudi Arabia have been selected. Long-term data indicates that the yearly average wind speed of Kingdom of Saudi Arabia varies from 3.0-4.5 m/s at 10 m height. The wind farms simulated consist of different combinations of 600 kW commercial wind machines (50 m hub-height). The NREL?s (HOMER Energy?s) HOMER software has been employed to perform the analysis. The study presents the monthly variations of wind speed, cumulative frequency distribution profiles of wind speed, monthly and yearly amount of energy generated from the proposed 15 MW wind farms (50 m hub-height) at different non-coastal locations of Kingdom of Saudi Arabia, cost of generating energy ($/kWh), capacity factor (%), etc. The cumulative frequency distribution indicates that the wind speeds are less than 3 m/s for 48% and 59% of the time during the year at Badanah (Northern province) and Khamis-Mashayt (Southern province), respectively. This implies that wind electric conversion systems or wind farms will not produce energy for 48% of the time during the year at Badanah and for 59% at Khamis-Mashayt. The annual energy produced by 15 MW wind farms (50 m hub-height) has been found to be 18778 and 11314 MWh at Northern and Southern provinces, respectively. The cost of wind-based electricity by using 600 kW (50 m hub-height) commercial wind electric conversion systems has been found to be 0.0612 and 0.1016 US$/kWh for Badanah and Khamis-Mushayt, respectively. Also, the capacity factor of the wind-based power plant has been found to vary from 9 to 15% for the considered locations.

Total Outflow Facility in Live C57BL/6 Mice of Different Age

Purpose: To characterize total outflow facility across the live adult mouse lifespan as a reference for mouse glaucoma studies and the common C57BL/6 background strain. Methods: Microperfusion was performed by single-needle cannulation and feedback-controlled coupling of pressure and flow to maintain a constant pressure in the anterior chambers of live C57BL/6NCrl mice aged 3-4 months (n = 17), 6-9 months (n = 10), and 23-27 months (n = 12). This mouse age range represented an equivalent human age range of young adult to elderly. We characterized the following across age groups in vivo: (1) outflow facility based on constant pressure perfusion in a pressure range of 15-35 mm Hg, (2) perfusion flow rates, and (3) anterior segment tissue histology after perfusion. Thirty-nine live mice underwent perfusion. Results: Pressure-flow rate functions were consistently linear for all age groups (all R² > 0.96). Total outflow facility in mice aged 3-4, 6-9, and 23-27 months was 0.0066, 0.0064, and 0.0077 μL/min/mm Hg, respectively. Facility was not significantly different between age groups (all p > 0.4). The groups had closely overlapping frequency distribution profiles with right-sided tails. Post hoc estimates indicated that group facility differences of at least 50% would have been detectable, with this limit set mainly by inherent variability in the strain. A trend toward higher perfusion flow rates was seen in older mice aged 23-27 months, but this was not significantly different from that of mice aged 3-4 months or 6-9 months (p > 0.2). No histological disruption or difference in iridocorneal angle or drainage tissue structure was seen following perfusion in the different age groups. Conclusion: We did not find a significant difference in total outflow facility between different age groups across the live C57BL/6 mouse adult lifespan, agreeing with some human studies. The possibility that more subtle differences might exist ought to be judged with respect to the heterogeneity in facility at different ages. Our findings provide reference data for live perfusion studies pertaining to glaucoma involving the C57BL/6 strain.

Mortality in traffic accidents with older adults in Colombia.

ABSTRACTOBJECTIVE To analyze the traffic accident mortality in the Colombian older adults during the 1998-2012 period and show the loss of productive years and mortality from this cause.METHODS Quantitative study of the trend analysis of deaths in Colombia in traffic accidents, from 1998 to 2012, according to death records and population projected by the Colombian National Administrative Department of Statistics. Frequency distribution profile of the deceased, death rates per hundred thousand inhabitants, potential years of life lost and calculation of excess mortality by age in the over 60 were made.RESULTS In the study period 100,758 deaths occurred in traffic accidents, 6,717 annual average, of which 18.5% occurred in people aged 60 years and over. The predominated deaths were men; the risk of dying was 32.15 per hundred thousand people in this age range, with double risk of dying those under 60 years.CONCLUSIONS The young population has a higher proportion of deaths, but those over 60 years are at increased risk of death, leading to the need to turn our gaze to the improvement of road infrastructure and standards, to educate the population in self-care and compliance with safety measures and prepare society for an ever more adult population, more numerous and more prone to take risks.

Measurement of accommodation response of human eye to integral floating display.

The dioptric responses of human eyes to floating images at different depths reconstructed by an integral floating display are measured with an open-field autorefractor and analyzed according to observer recognition of the accommodation depth cue. Two targets are randomly presented approximately 1.75D from the observers and have a separation of 0.15D, corresponding to approximately 5cm. Two subjects participate, and over 500 responses are measured during each experimental trial. The frequency distribution profiles of the responses to targets at different locations are obtained and analyzed. The results confirm that the subjects focused on the floating targets and not on the surface of the optical component. In this paper, an analysis of the separation between the peaks of the frequency distribution profiles is presented that confirms that the integral floating display could induce the accommodation response to provide the corresponding depth stimulus.

The evaluation of potential purification of a horizontal subsurface flow constructed wetland treating greywater in semi-arid environment

The potential purification of an horizontal subsurface flow constructed wetlands (HSSFCW) treating greywater in a Moroccan primary school was investigated according to the monitoring of water quality parameters over a period of 100 days through two simultaneous stages: first, an internal three dimensional grid of sampling ports; secondly, an entry and exit. The calibration of the relaxed TIS concentration model based on tank in series hydraulic assumption with experimental data gave the frequency distribution profiles of K-rate constant values for the three parameters: BOD5, COD and TN, whose maximum values are respectively 50m/yr, 70m/yr, and 42m/yr. The HSSFCW system has higher K-rate coefficient for all the three parameters at the bottom layer compared with the surface layer, with increasing K-rates over length. The analysis of bacteriological and chemical results has shown that the HSSFCW could not completely remove all pollutants (especially TN and TP), but it could be used successfully to upgrade the quality of greywater to an acceptable level. However, we predict that there will be an increase in removal efficiencies with time bearing in mind that the system is newly implemented.

Annual variation in serum antibody concentrations against gastrointestinal nematodes in beef calves from semi-arid rangelands of western Canada

Sera from calves originating on a 17,000ha ranch in southeastern Alberta, were collected over three consecutive years (2008–2010) at weaning and analysed for the presence of anti-Ostertagia antibodies using the SVANOVIR®Ostertagia ostertagi-Ab ELISA kit. Faecal samples taken at the same time were analysed for presence of nematode eggs using the modified Wisconsin faecal flotation technique. Mean optical density ratio (ODR) values for all calves were similar in 2008 and 2010 while the 2009 values were significantly higher. Similar cumulative frequency distribution profiles were found for 2008 and 2010 while the 2009 profile had an increased number of values in the higher bin categories. This pattern indicates higher nematode transmission on pasture in 2009. There was no significant difference in ODR values between egg positive and egg-negative calves and no significant correlation was detected between individual ODR values and faecal egg output. Significantly higher ODR values in 2009 appear contradictory to general assumptions about the ecological requirements of larval development, as 2009 was a relatively dry year. However, examination of weather data identified 5–6 rainfall events that may have resulted in episodic enhanced survival of nematode larvae.

Potential of Establishment of Wind Farms in Western Province of Saudi Arabia

In the present study, the economic feasibility of development of 15 MW wind power plant (wind farm) at Taif, Western Province of the Kingdom of Saudi Arabia (K.S.A) has been investigated by analyzing long-term wind speed data. Western province has relatively better wind energy resources. Data analysis indicates that monthly average wind speeds of Taif (21 29’ N, 40 32’ E) range from 3.1 to 4.8 m/s at 10 m height. The wind farms simulated consist of different combinations of 600kW commercial wind machines (50 m hub-height). NREL's (HOMER Energy's) HOMER software has been employed to perform the techno-economic assessment.The study presents monthly variations of wind speed, cumulative frequency distribution (CFD) profiles of wind speed, monthly and yearly amount of energy generated from the 15 MW wind farm (50 m hub-height), cost of generating energy (COE, $/kWh), capacity factor (%), etc. The CFD indicates that the wind speeds are less than 3 m/s for 46% of the time during the year. This implies that wind electric conversion systems (WECS) will not produce energy for about 46% of the time during the year. The annual energy produced by 15 MW wind farm (50 m hub-height) has been found to be 19939 MWh. The cost of wind-based electricity by using 600kW (50m hub-height) commercial WECS has been found to be 0.0576 US$/kWh. With the development of 15 MW wind farm, about 453 tons/year of carbon emissions can be avoided entering into the local atmospheric. The paper also attempts to address various aspects (such as: effect of hub-height, etc.) of wind farm establishment

Retinal Nerve Fiber Layer Imaging with Spectral-Domain Optical Coherence Tomography: Pattern of RNFL Defects in Glaucoma

To characterize the distribution pattern, angular width, and area of retinal nerve fiber layer (RNFL) defects in glaucoma using spectral-domain optical coherence tomography (OCT). Prospective, cross-sectional study. We included 113 normal subjects and 116 glaucoma patients. One eye from each individual was randomly selected for Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA) RNFL imaging of the 6 × 6-mm² parapapillary region. The RNFL defects were identified in the RNFL thickness deviation map as superpixels coded in red. The angular location and the angular width of RNFL defects were measured. The proportion of area with RNFL measurements within the normal ranges in the RNFL thickness deviation map was expressed as the RNFL area index (RAI): 1 - [area of superpixels coded in red/(6 × 6 - optic disc and parapapillary atrophic area)]. The diagnostic performance between RAI and average RNFL thickness was compared with the area under the receiver operating characteristic curve after adjusting refraction, signal strength, optic disc, and parapapillary atrophic areas. Frequency distribution profiles and distribution patterns of RNFL defects, diagnostic sensitivity and specificity of RAI, and average RNFL thickness. The RNFL defects in glaucoma were most frequently found at the inferotemporal meridian at 284° (80.4%), followed by the superotemporal meridians at 73° (54.2%). The respective proportions of localized (angular width ≤ 30°) and diffuse (angular width > 30°) RNFL defects were 11.4% and 70.5% in mild glaucoma (MD ≥ 6 dB), and 4.2% and 94.5% in moderate to advanced glaucoma (MD < -6 dB). The RAI was 90.2 ± 6.4% and 83.6 ± 7.4% in the mild and moderate to advanced glaucoma groups, respectively. At a specificity of 90.0%, the respective diagnostic sensitivity of RAI and average RNFL thickness was 95.7% (95% confidence interval, 92.2-99.1%) and 94.0% (90.1-99.1%). Analysis of the pattern of RNFL defects with spectral domain OCT imaging offers important insights in understanding the characteristics of RNFL damage. As RNFL defects expand in size as the disease progresses, measurement of the angular width and area of RNFL defects can provide an additional dimension for evaluation of glaucoma.

Computer Simulations of Channeling the Coenzyme Nicotinamide Adenine Dinucleotide Between Glycolytic Enzymes

Functional protein-protein interactions are essential for many physiological processes. Some of these functional interactions have been hypothesized to play a role in substrate channeling, cofactor or coenzyme transfer, and compartmentation in glycolysis as a result of transient or dynamic interactions between glycolytic enzymes. Herein, Brownian dynamics (BD) elucidates the interactions between the glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase (LDH); the transfer of the cofactor nicotinamide adenine dinucleotide (NAD) between LDH and GAPDH. BD tests the hypotheses of whether the interaction between GAPDH and LDH produces a functional complex that can efficiently and reversibly transfer the cofactor NAD(H) between both enzymes. Preliminary results suggest favorable enzyme-enzyme complexes between GAPDH and LDH involving four different binding modes. These complexes are mainly stabilized by positively charged lysine residues and negatively charged glutamates and aspartates from both GAPDH and LDH. The efficiency of transfer determined as the relative number of BD trajectories that reached any active site of LDH or GAPDH, show higher transfer efficiencies (about an order of magnitude) when the cofactor NAD is transferred from a GAPDH active site to an LDH active site as compared to transfer efficiencies of NAD from solution to each enzyme of the complex. The average transfer time of NAD from solution to the free enzymes is 500 ns as compared to 57-200 ns when NAD is transferred between active sites of a GAPDH/LDH complex. Similarly, the frequency distribution profiles of transfer times suggest a preference for channeling NAD between GAPDH and LDH as compared to diffusing from solution. Channeling transfer is more efficient that solution transfer, due to active site proximity, favorable electrostatics and complex geometry

Role of sequence variations of the GnRH receptor and G protein-coupled receptor 54 gene in male idiopathic hypogonadotropic hypogonadism

To determine the frequency of mutations of the gonadotropin-releasing hormone receptor (GnRHR) and of the G protein-coupled receptor 54 (GPR54) genes in normosmic idiopathic hypogonadotropic hypogonadism (IHH). In a retrospective study we analyzed the GnRHR and the GPR54 genes of 45 IHH patients and 50 controls. Genomic DNA was amplified by PCR to obtain partially overlapping amplicons encompassing the exon-intron boundaries of the GnRHR and GPR54 genes and analyzed by single-stranded conformation polymorphism gel electrophoresis and/or DNA sequencing. One heterozygous R262Q mutation of the GnRHR gene was identified in one patient with familial IHH. The silent single-nucleotide polymorphism (SNP) 453C > T occurred at the same frequency in patients and controls. One patient with sporadic IHH and consanguineous parents showed a novel homozygous sequence variation of the GPR54 gene (1001_1002insC) resulting in an open reading frame shift and elongation of 43 amino acids with an increased number of proline residues in the intracellular receptor domain. This patient had delayed puberty, low testosterone (3.4 nmol/l), and low-normal LH and FSH levels responsive to GnRH. Pulsatile GnRH administration normalized testosterone levels and induced spermatogenesis sufficiently to induce a pregnancy with assisted reproduction. Two common SNPs in exon 1 and exon 5 of the GPR54 gene showed similar frequency distribution and hormonal profiles in IHH and controls. Mutations of the GnRHR and of the GPR54 gene are rare in IHH and should be investigated especially in cases with autosomal recessive transmission. Common SNPs of the GnRHR and GPR54 genes do not play any role in IHH.

La protéine MBL ( mannose-binding lectin) : intérêt de son dosage chez des enfants atteints de bronchites récidivantes

Several studies have shown that increased susceptibility to frequent and chronic infections is associated with low serum levels of mannose-binding lectin (MBL). We investigate the impact of MBL deficiency in children suffering from chronic obstructive pulmonary disease (COPD) with severity of lung disease. We measure serum MBL concentrations in 88 children with COPD (40 females and 48 males, ages 0, 25 to 20 years) and 40 healthy children (21 females and 19 males, ages 0, 6 to 18 years). MBL levels ranged from < 0.04 to 10 mg/l. The frequency distribution profile revealed a bimodal pattern, one peak around 0.3–0.6 mg/l and the other at 2.5–5 mg/l. Significantly lower concentrations of MBL (< 0.04 mg/l) were seen in 7 patients who had clinically important infections. So, it seems that MBL deficiency predisposed to severe infections and the determination of concentrations in serum may be useful as a prognostic indicator.

Detection of plastic deformation and estimation of maximum value of residual stress in low carbon steel by X-ray stress analysis using statistical techniques

Residual stress distribution on plate-type tensile specimens of low carbon steel with applied plastic strains up to 6.45% has been measured by X-ray stress analysis. Standard deviation for the frequency distribution profile of the residual stress was calculated by statistical processing to estimate the amount of macroscopic plastic strain applied on the specimen. Since adequate understanding of the maximum value of the residual stress ( σ max) has been important for the maintenance of the nuclear power reactor components, the σ max was also estimated from the limited number of the experimental data by statistics of extreme. It was found from above estimation that the X-ray stress analysis supported by the statistical techniques was a promising non-destructive evaluation (NDE) method to detect the plastic deformation and to estimate the σ max in S25C low carbon steel.

Pre-breeding manipulations for pod yield stability in a snap bean cultivar

SummaryThe objective of this study was to present pre-breeding manipulations for decreasing the magnitude of the environment-dependent performance of a climbing type snap bean (Phaseolus vulgaris L.) cultivar. The cultivar was exposed to abiotic diversity, by planting on three dates for two successive years, 1997 and 1998. In the first year, three statistical analyses were followed: i) partition of variance, which defined a significant planting date × pod measurement interaction, ii) regression analysis, which showed that temperature accumulation for each environment was highly correlated (r = 0.97) with pod yield, and iii) pod-yield frequency distributions of space-planted single plants, which showed positive skewness for all measurements, while the high coefficient of variability (CV) values quantified the genotype × environment interaction. Preliminary selection on single-plant performance for earliness and yield resulted in 12 first-generation progenies. In the second year, the frequency distribution profile for earliness and pod yield performance per se of the progenies showed improved stability of performance and resulted in 92 second-generation progenies for further exploitation. Colour abnormalities in the dry seed product of the second-generation progenies were studied in 1999 and showed a phenotypic origin of the colour variation. Conclusively, the pre-breeding manipulations resulted in gaining pod yield stability by using the isolation environment for planting, the yield performance per se for evaluating genotypes and the yield frequency distributions based on CV values for estimating stability.

Detection of Plastic Deformation and Fatigue Damage in Pressure Vessel Steel by Leakage Magnetic Flux Sensors

In order to detect material degradations in pressure vessel steel of A533B employed as a component material in light water reactors (LWRs), the leakage magnetic flux distribution on plate-type A533B specimens has been examined using a magnetic sensor of 120μm square GaAs Hall element. As reference data, the residual stress distribution has also been obtained by X-ray diffraction method where an irradiation spot was 1mm in diameter. The data of the leakage magnetic flux normal to the specimen surface (Bz) measured by the Hall sensor were converted into the form of the first derivative dBz/dx by calculating the gradient of the Bz along the axial direction of the specimen (x-axis), and the data of the axial residual stress (σx) obtained by the X-ray diffraction method were also transformed into the differential form dσx/dx. It was found that there existed a correlation between the absolute value of the dBz/dx and the dσx/dx for the tensile specimens (correlation coefficient r=0.282). Full width at half maximum (FWHM) for the frequency distribution profile of the dBz/dx was calculated. The FWHM of the tensile specimens increased remarkably at the beginning stage of the plastic deformation where the Lüder's band was generated; The FWHM of the fatigued specimens increased with stress cycling. It was suggested that the leakage magnetic flux measurement by the GaAs Hall sensor was a promising non-destructive evaluation (NDE) method to detect the amount of plastic deformation and fatigue damage.

Sodium channel protein expression enhances the invasiveness of rat and human prostate cancer cells

Expression of Na + channel protein was analysed in established cell lines of rat and human prostatic carcinoma origin by flow cytometry using a fluorescein-labelled polyclonal antibody. In many cell lines examined, the obtained frequency distribution profiles were bimodal and identified a subpopulation of cells which expressed high levels of Na + channel protein. A significant positive correlation was demonstrated between the proportion of channel-expressing cells and the functional ability of individual cell lines to invade a basement membrane matrix in vitro. In addition, two transfectant cell lines containing rat prostate cancer genomic DNA were found to express significantly elevated levels of Na + channel protein when compared with the original benign recipient cell line. Enhanced Na + channel expression by two metastatic derivatives of these transfectant cells directly correlated with increased invasiveness in vitro. These studies strongly support the hypothesis that expression of Na + channel protein and the metastatic behaviour of prostatic carcinoma cells are functionally related, either by endowing the membranes of these cells with specialised electrophysiological properties (e.g. enhancing their motility and/or secretory activities) and/or by perturbing endogenous mechanisms regulating ionic homeostasis within the cells.

Asymptotic behavior of some interactive population flow models

This paper is concerned with Markov chain models for flows of a finite population among a set of groups, where the individuals base their decisions on which group to go next partially on the current frequency distribution (profile). For a certain class of these models, the transition matrix of the profile process is analyzed algebraically, leading to surprisingly simple asymptotic results. Furthermore, in a model with after effects, the absorption probabilities are derived.