Analysis of bioavailable arsenic in rice with whole cell living bioreporter bacteria.

A multiwell plate bioassay was developed using genetically modified bacteria (bioreporter cells) to detect inorganic arsenic extracted from rice. The bacterial cells expressed luciferase upon exposure to arsenite, the activity of which was detected by measurement of cellular bioluminescence. The bioreporter cells detected arsenic in all rice varieties tested, with averages of 0.02-0.15 microg of arsenite equivalent per gram of dry weight and a method detection limit of 6 ng of arsenite per gram of dry rice. This amounted to between approximately 20 and 90% of the total As content reported by chemical methods for the same sample and suggested that a major proportion of arsenic in rice is in the inorganic form. Calibrations of the bioassay with pure inorganic and organic arsenic forms showed that the bacterial cells react to arsenite with highest affinity, followed by arsenate (with 25% response relative to an equivalent arsenite concentration) and trimethylarsine oxide (at 10% relative response). A method for biocompatible arsenic extraction was elaborated, which most optimally consisted of (i) grinding rice to powder, (ii) mixing with an aqueous solution containing pancreatic enzymes, (iii) mechanical shearing, (iv) extraction in mild acid conditions and moderate heat, and (v) centrifugation and pH neutralization. Detection of mainly inorganic arsenic by the bacterial cells may have important advantages for toxicity assessment of rice consumption and would form a good complement to total chemical arsenic determination.

Quantifying the weight of fingerprint evidence through the spatial relationship, directions and types of minutiae observed on fingermarks

This paper presents a statistical model for the quantification of the weight of fingerprint evidence. Contrarily to previous models (generative and score-based models), our model proposes to estimate the probability distributions of spatial relationships, directions and types of minutiae observed on fingerprints for any given fingermark. Our model is relying on an AFIS algorithm provided by 3M Cogent and on a dataset of more than 4,000,000 fingerprints to represent a sample from a relevant population of potential sources. The performance of our model was tested using several hundreds of minutiae configurations observed on a set of 565 fingermarks. In particular, the effects of various sub-populations of fingers (i.e., finger number, finger general pattern) on the expected evidential value of our test configurations were investigated. The performance of our model indicates that the spatial relationship between minutiae carries more evidential weight than their type or direction. Our results also indicate that the AFIS component of our model directly enables us to assign weight to fingerprint evidence without the need for the additional layer of complex statistical modeling involved by the estimation of the probability distributions of fingerprint features. In fact, it seems that the AFIS component is more sensitive to the sub-population effects than the other components of the model. Overall, the data generated during this research project contributes to support the idea that fingerprint evidence is a valuable forensic tool for the identification of individuals.

Void Ratio and Shear Strength of Two Compacted Crushed Stones, Progress Report, HR-99

Triaxial compression tests of two crushed limestones of differing highway service records indicate a fundamental difference in their shear strength -- void ratio relationship. Analyses were based on stress parameters at minimum sample volume, i.e., before there was significant sample dilation due to shear. The better service record sample compacted to higher density, and had a high effective angle of internal friction and zero effective cohesion. The other sample compacted to lower density and had a lower friction angle, but gained significant stability from effective cohesion. Repeated loading-unloading cycles reduced the cohesion, apparently due to modification of the sample structure. Extrapolations of the results to zero void ratio agree with sliding friction data reported on calcite, or with triaxial parameters reported on carbonate rocks.

Prevalence, awareness and control of diabetes in the Seychelles and relationship with excess body weight.

BACKGROUND: The evidence for a "diabesity" epidemic is accumulating worldwide but population-based data are still scarce in the African region. We assessed the prevalence, awareness and control of diabetes (DM) in the Seychelles, a rapidly developing country in the African region. We also examined the relationship between body mass index, fasting serum insulin and DM. METHODS: Examination survey in a sample representative of the entire population aged 25-64 of the Seychelles, attended by 1255 persons (participation rate of 80.2%). An oral glucose tolerance test (OGTT) was performed in individuals with fasting blood glucose between 5.6 and 6.9 mmol/l. Diabetes mellitus (DM), impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were defined along criteria of the ADA. Prevalence estimates were standardized for age. RESULTS: The prevalence of DM was 11.5% and 54% of persons with DM were aware of having DM. Less than a quarter of all diabetic persons under treatment were well controlled for glycemia (HbA1c), blood pressure or LDL-cholesterol. The prevalence of IGT and IFG were respectively 10.4% and 24.2%. The prevalence of excess weight (BMI > or = 25 kg/m2) and obesity (BMI > or = 30 kg/m2) was respectively 60.1% and 25.0%. Half of all DM cases in the population could be attributed to excess weight. CONCLUSION: We found a high prevalence of DM and pre-diabetes in a rapidly developing country in the African region. The strong association between overweight and DM emphasizes the importance of weight control measures to reduce the incidence of DM in the population. High rates of diabetic persons not aware of having DM in the population and insufficient cardiometabolic control among persons treated for DM stress the need for intensifying health care for diabetes.

Differing trends in the association between obesity and self-reported health in Portugal and Switzerland: data from national health surveys 1992-2007.

BACKGROUND: The escalating prevalence of obesity might prompt obese subjects to consider themselves as normal, as this condition is gradually becoming as frequent as normal weight. In this study, we aimed to assess the trends in the associations between obesity and self-rated health in two countries. METHODS: Data from the Portuguese (years 1995-6, 1998-6 and 2005-6) and Swiss (1992-3, 1997, 2002 and 2007) National Health Surveys were used, corresponding to more than 130,000 adults (64,793 for Portugal and 65,829 for Switzerland). Body mass index and self-rated health were derived from self-reported data. RESULTS: Obesity levels were higher in Portugal (17.5% in 2005-6 vs. 8.9% in 2007 in Switzerland, p < 0.001) and increased in both countries. The prevalence of participants rating their health as "bad" or "very bad" was higher in Portugal than in Switzerland (21.8% in 2005-6 vs 3.9% in 2007, p < 0.001). In both countries, obese participants rated more frequently their health as "bad" or "very bad" than participants with regular weight. In Switzerland, the prevalence of "bad" or "very bad" rates among obese participants, increased from 6.5% in 1992-3 to 9.8% in 2007, while in Portugal it decreased from 41.3% to 32.3%. After multivariate adjustment, the odds ratio (OR) of stating one self's health as "bad" or "very bad" among obese relative to normal weight participants, almost doubled in Switzerland: from 1.38 (95% confidence interval, CI: 1.01-1.87) in 1992-3 to 2.64 (95% CI: 2.14-3.26) in 2007, and similar findings were obtained after sample weighting. Conversely, no such trend was found in Portugal: 1.35 (95% CI: 1.23-1.48) in 1995-6 and 1.52 (95% CI: 1.37-1.70) in 2005-6. CONCLUSION: Obesity is increasing in Switzerland and Portugal. Obesity is increasingly associated with poorer self-health ratings in Switzerland but not in Portugal.

Expectation to improve cardiovascular risk factors control in participants to a health promotion program.

BACKGROUND: We assessed expectations to improve cardiovascular disease risk factors (CVD-RF) in participants to a health promotion program. PARTICIPANTS AND METHODS: Blood pressure (BP), blood glucose (BG), blood total cholesterol (TC), body mass index (BMI), and self-reported smoking were assessed in 1,598 volunteers from the general public (men: 40%; mean age: 56.7 +/- 12.7 years) participating in a mobile health promotion program in the Vaud canton, Switzerland. Participants were asked about their expectation to have their CVD-RF improved at a next visit scheduled 2-3 years later. RESULTS: Expectation for improved control was found in 90% of participants with elevated BP, 91% with elevated BG, 45% with elevated TC, 44% who were overweight, and 35% who were smoking. Expectation for TC improvement was reported more often by men, persons with high level of TC, and persons who had consulted a doctor in the past 12 months. Expectations to lose weight and to quit smoking were found more often in younger persons than the older ones. CONCLUSION: Volunteers from the general population participating in a health promotion program expected improved control more often for hypertension and dysglycemia than for dyslipidemia, overweight and smoking.

Transgenic reexpression of GLUT1 or GLUT2 in pancreatic beta cells rescues GLUT2-null mice from early death and restores normal glucose-stimulated insulin secretion.

GLUT2-null mice are hyperglycemic, hypoinsulinemic, hyperglucagonemic, and glycosuric and die within the first 3 weeks of life. Their endocrine pancreas shows a loss of first phase glucose-stimulated insulin secretion (GSIS) and inverse alpha to beta cell ratio. Here we show that reexpression by transgenesis of either GLUT1 or GLUT2 in the pancreatic beta cells of these mice allowed mouse survival and breeding. The rescued mice had normal-fed glycemia but fasted hypoglycemia, glycosuria, and an elevated glucagon to insulin ratio. Glucose tolerance was, however, normal. In vivo, insulin secretion assessed following hyperglycemic clamps was normal. In vitro, islet perifusion studies revealed that first phase of insulin secretion was restored as well by GLUT1 or GLUT2, and this was accompanied by normalization of the glucose utilization rate. The ratio of pancreatic insulin to glucagon and volume densities of alpha to beta cells were, however, not corrected. These data demonstrate that 1) reexpression of GLUT1 or GLUT2 in beta cells is sufficient to rescue GLUT2-null mice from lethality, 2) GLUT1 as well as GLUT2 can restore normal GSIS, 3) restoration of GSIS does not correct the abnormal composition of the endocrine pancreas. Thus, normal GSIS does not depend on transporter affinity but on the rate of uptake at stimulatory glucose concentrations.

Proinflammatory activity of cell-wall constituents from gram-positive bacteria.

Innate immunity reacts to conserved bacterial molecules. The outermost lipopolysaccharide (LPS) of Gram-negative organisms is highly inflammatory. It activates responsive cells via specific CD14 and toll-like receptor-4 (TLR4) surface receptor and co-receptors. Gram-positive bacteria do not contain LPS, but carry surface teichoic acids, lipoteichoic acids and peptidoglycan instead. Among these, the thick peptidoglycan is the most conserved. It also triggers cytokine release via CD14, but uses the TLR2 co-receptor instead of TLR4 used by LPS. Moreover, whole peptidoglycan is 1000-fold less active than LPS in a weight-to-weight ratio. This suggests either that it is not important for inflammation, or that only part of it is reactive while the rest acts as ballast. Biochemical dissection of Staphylococcus aureus and Streptococcus pneumoniae cell walls indicates that the second assumption is correct. Long, soluble peptidoglycan chains (approximately 125 kDa) are poorly active. Hydrolysing these chains to their minimal unit (2 sugars and a stem peptide) completely abrogates inflammation. Enzymatic dissection of the pneumococcal wall generated a mixture of highly active fragments, constituted of trimeric stem peptides, and poorly active fragments, constituted of simple monomers and dimers or highly polymerized structures. Hence, the optimal constraint for activation might be 3 cross-linked stem peptides. The importance of structural constraint was demonstrated in additional studies. For example, replacing the first L-alanine in the stem peptide with a D-alanine totally abrogated inflammation in experimental meningitis. Likewise, modifying the D-alanine decorations of lipoteichoic acids with L-alanine, or deacylating them from their diacylglycerol lipid anchor also decreased the inflammatory response. Thus, although considered as a broad-spectrum pattern-recognizing system, innate immunity can detect very subtle differences in Gram-positive walls. This high specificity underlines the importance of using well-characterized microbial material in investigating the system.

Hypoxia: unique myocardial morphology?

OBJECTIVE: The objective of this study was to investigate the effects of chronic and intermittent hypoxia on myocardial morphology. METHODS: Rats randomly divided into 3 groups (n = 14 per group) were exposed to room air (Fio(2) = 0.21), chronic hypoxia (Fio(2) = 0.10), and intermittent hypoxia (chronic hypoxia with 1 hour per day of room air) for 2 weeks. Weight, blood gas analysis, hematocrit, hemoglobin, red cells, and right and left ventricular pressures were measured. Hearts excised for morphologic examination were randomly divided into 2 groups (9 per group for gross morphologic measurements and 5 per group for histologic and morphometric analysis). The weight ratio of right to left ventricles plus interventricular septum, myocyte diameter, cross-sectional area, and free wall thickness in right and left ventricles were measured. RESULTS: Despite the same polycythemia, the right ventricle pressure (P <.05) and ratio of right to left ventricle pressures (P <.02) were higher after chronic hypoxia than intermittent hypoxia. The ratio of heart weight to total body weight and the ratio of right to left ventricles plus interventricular septum was higher (P <.01) in chronic and intermittent hypoxia than in normoxia. Myocyte diameter was not different between the right and left ventricles in normoxia, whereas right ventricle myocytes were larger than left ventricle myocytes in chronic hypoxia (P <.05) and intermittent hypoxia (P <.0005). There was marked dilatation of right ventricle size (P <.001) and marked reduction of left ventricle (P <.001) size in chronic and intermittent hypoxia compared with normoxia. The total ventricular area (right ventricle plus left ventricle area) remained the same in all groups. The wall thickness ratio in chronic hypoxia and intermittent hypoxia was increased (P <.001) compared with normoxia in the right ventricle but not in the left ventricle. CONCLUSIONS: Intermittent reoxygenation episodes do not induce a lesser ventricular hypertrophic response than observed with chronic hypoxia. The functional myocardial preconditioning consequence of intermittent reoxygenation is not supported by structural differences evident with the available techniques.

ML approaches to channel estimation for pilot-aided multi-rate DS/CDMA systems

This paper analyzes the asymptotic performance of maximum likelihood (ML) channel estimation algorithms in wideband code division multiple access (WCDMA) scenarios. We concentrate on systems with periodic spreading sequences (period larger than or equal to the symbol span) where the transmitted signal contains a code division multiplexed pilot for channel estimation purposes. First, the asymptotic covariances of the training-only, semi-blind conditional maximum likelihood (CML) and semi-blind Gaussian maximum likelihood (GML) channelestimators are derived. Then, these formulas are further simplified assuming randomized spreading and training sequences under the approximation of high spreading factors and high number of codes. The results provide a useful tool to describe the performance of the channel estimators as a function of basicsystem parameters such as number of codes, spreading factors, or traffic to training power ratio.

Body image perception and weight-related behaviour among adolescents of the Seychelles

Background: We examined one's own body image perception and its association with reported weight-related behavior among adolescents of a rapidly developing country in the African region. Methods: We conducted a school-based survey of 1432 students aged 11-17 years in the Seychelles. Weight and height were measured, and thinness, normal weight and overweight were assessed along standard criteria. A self-administered and anonymous questionnaire was administered. Perception of body image was assessed using both a closed-ended question (CEQ) and the Stunkard's pictorial silhouettes (SPS). Finally, a question assessed voluntary attempts to change weight. Results: Overall, 14.1% of the students were thin, 63.9% were normal-weight, and 22.0% were overweight or obese. There was fair agreement between actual weight status and self-perceived body image based on either CEQ or SPS. However, a substantial proportion of the overweight students did not consider themselves as overweight (SPS: 24%, CEQ: 34%) and, inversely, a substantial proportion of the normal-weight students considered themselves as too thin (SPS: 29%, CEQ: 15%). Among the overweight students, an adequate attempt to lose weight was reported more often by boys and girls who perceived themselves as overweight vs. not overweight (72-88% vs. 40-71%, p <0.05 for most comparisons). Among the normal-weight students, an inadequate attempt to gain weight was reported more often by boys and girls who perceived themselves as thin vs. not thin (27-68% vs. 11-19%, p <0.05). Girls had leaner own body ideals than boys. Conclusions: We found that substantial proportions of overweight students did not perceive themselves as overweight and/or did not want to lose weight and, inversely, that many normalweight students perceived themselves as too thin and/or wanted to gain weight: this points to forces that can drive the upwards overweight trends. Appropriate perception of one's weight was associated with adequate weight-control behavior, although not strongly, emphasizing that appropriate weight perception is only one of several factors driving adequate weight-related behavior. These findings emphasize the need to address appropriate perception of one's own weight and adequate weight-related behavior in adolescents for both individual and community weight-related interventions.

Obesity-related phenotypes are associated to parental longevity in a Swiss population-based study

METHODS. We analyzed data from a population-based sample of 2561 participants (1163 men and 1398 women) aged 55-75 years from the city of Lausanne, Switzerland (CoLaus study). Participants were stratified by the number of parents (0, 1, 2) who survived to 85 years or more. Trend across these strata was assessed using a non-parametric kmean test. The associations of parental age (independent covariate used as a proxy for longevity) with fasting blood glucose, blood pressures, blood lipids, body mass index (BMI), weight, height or liver enzymes (continuous dependent variables) were analyzed using multiple linear regressions. Models were adjusted for age, sex, alcohol consumption, smoking and educational level, and BMI for liver enzymes. RESULTS. For subjects with 0 (N = 1298), 1 (N = 991) and 2 (N = 272) long-lived parents, median BMI (interquartile range) was 25.4 (6.5), 24.9 (6.1) and 23.7 (4.8) kg/m2 in women (P <0.001), and 27.3 (4.8), 27.0 (4.5) and 25.9 (4.9) kg/m2 in men (P = 0.04), respectively; median weight was 66.5 (16.1), 65.0 (16.4) and 63.4 (13.7) kg in women (P = 0.003), and 81.5 (17.0), 81.4 (16.4) and 80.3 (17.1) kg in men (P = 0.36). Median height was 161 (8), 162 (9) and 163 (8) cm in women (P = 0.005) and 173 (9), 174 (9) and 174 (11) cm in men (P = 0.09). The corresponding medians for AST (Aspartate Aminotransferase) were 31 (13), 29 (11) and 28 (10) U/L (P = 0.002), and 28 (17), 27 (14) and 26 (19) U/L for ALT (Alanin Aminotransferase, P = 0.053) in men. In multivariable analyses, greater parental longevity was associated with lower BMI, lower weight and taller stature in women (P < 0.01) and lower AST in men (P = 0.011). No significant associations were observed for the other variables analyzed. Sensitivity analyses restricted to subjects whose parents were dead (N = 1844) led to similar results, with even stronger associations of parental longevity with liver enzymes in men. CONCLUSIONS. In women, increased parental longevity was associated with smaller BMI, attributable to lower weight and taller stature. In men, the association of increased parental longevity with lower liver enzymes, independently of BMI, suggests that parental longevity may be associated with decreased nonalcoholic fatty liver disease.

Body size and early growth in appropriate- and large-for-gestational-age infants.

AIMS: To study weight, length, body composition, sleeping energy expenditure (SEE), and respiratory quotient (RQ) at birth and at 5 mo of age in both adequate-for-gestational-age (AGA) and large-for-gestational-age (LGA) subjects; to compare the changes in body weight and body composition adjusting for gender, age, SEE, RQ and several maternal factors; to investigate the contribution of initial SEE and RQ to changes in body weight and body composition. METHODS: Sixty-nine neonates were recruited among term infants in the University Hospital of Verona, Italy. Forty-nine subjects participated until follow-up. At birth and follow-up, weight and length were measured and arm-fat area and arm-muscle area were calculated from triceps and subscapular skinfolds. SEE and RQ were measured by indirect calorimetry. RESULTS: At birth, weight, length, arm-muscle and arm-fat areas were significantly higher in LGA subjects than in AGA subjects. Weight status, SEE and RQ at birth did not explain the relative weight change after adjusting for gestational weight, placental weight, age at follow-up and gender. Arm-fat area and weight/length ratio at birth were negatively associated with relative changes in body weight after adjusting for the above variables (p < 0.05). CONCLUSION: Early growth from birth to 5 mo of life is significantly affected by body size and adiposity at birth. Fatter newborns had a slower growth rate than thinner newborns.

Two distinct plant respiratory physiotypes might exist which correspond to fast-growing and slow-growing species

The origin of the carbon atoms in CO2 respired by leaves in the dark of several plant species has been studied using 13C/12C stable isotopes. This study was conducted using an open gas exchange system for isotope labeling that was coupled to an elemental analyser and further linked to an isotope ratio mass spectrometer (EA-IRMS) or coupled to a gas chromatography-combustion-isotope ratio mass spectrometer (GC-C-IRMS). We demonstrate here that the carbon, which is recently assimilated during photosynthesis, accounts for nearly ca. 50% of the carbon in the CO2 lost through dark respiration after illumination in fast-growing and cultivated plants and trees and, accounts for only ca. 10% in slow-growing plants. Moreover, our study shows that fast- growing plants, which had the largest percentages of newly fixed carbon of leaf-respired CO2 , were also those with the largest shoot/root ratios, whereas slow-growing plants showed the lowest shoot/root values.

Mortality risk associated with underweight : a census-linked cohort of 31,578 individuals with up to 32 years of follow-up

BACKGROUND: In contrast to obesity, information on the health risks of underweight is sparse. We examined the long-term association between underweight and mortality by considering factors possibly influencing this relationship. METHODS: We included 31,578 individuals aged 25-74 years, who participated in population based health studies between 1977 and 1993 and were followed-up for survival until 2008 by record linkage with the Swiss National Cohort (SNC). Body Mass Index (BMI) was calculated from measured (53% of study population) or self-reported height and weight. Underweight was defined as BMI < 18.5 kg/m2. Cox regression models were used to determine mortality Hazard Ratios (HR) of underweight vs. normal weight (BMI 18.5- < 25.0 kg/m2). Covariates were study, sex, smoking, healthy eating proxy, sports frequency, and educational level. RESULTS: Underweight individuals represented 3.0% of the total study population (n = 945), and were mostly women (89.9%). Compared to normal weight, underweight was associated with increased all-cause mortality (HR: 1.37; 95% CI: 1.14-1.65). Increased risk was apparent in both sexes, regardless of smoking status, and mainly driven by excess death from external causes (HR: 3.18; 1.96-5.17), but not cancer, cardiovascular or respiratory diseases. The HR were 1.16 (0.88-1.53) in studies with measured BMI and 1.59 (1.24-2.05) with self-reported BMI. CONCLUSIONS: The increased risk of dying of underweight people was mainly due to an increased mortality risk from external causes. Using self-reported BMI may lead to an overestimation of mortality risk associated with underweight.