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Geometric Mean (geometric + mean)
Terms modified by Geometric Mean Selected AbstractsLarge differences in serum leptin levels between nonwesternized and westernized populations: the Kitava studyJOURNAL OF INTERNAL MEDICINE, Issue 6 2001S. Lindeberg Abstract.,Lindeberg S, Söderberg S, Ahrén B, Olsson T (Lund University; and Umeå University, Malmö, Sweden). Large differences in serum leptin levels between nonwesternized and westernized populations: the Kitava study. J Intern Med 2001; 249: 553,558. Objectives.,To compare serum leptin between nonwesternized and westernized populations. Setting., (i) The tropical island of Kitava, Trobriand Islands, Papua New Guinea and (ii) the Northern Sweden MONICA study population. Design.,Cross-sectional survey. Methods.,Fasting levels of serum leptin were analysed in 163 randomly selected Kitavans aged 20,86 years and in 224 Swedes aged 25,74. Main outcome measures.,Mean and determinants of serum leptin. Results.,Geometric mean of serum leptin in Kitavan males and females were 1.5 and 4.0 vs. 4.9 and 13.8 ng mL,1 in Swedish male and females (P < 0.0001 for both sexes). In Kitavans, observed geometric mean were close to predicted levels (1.8 ng mL,1 for males and 4.5 ng mL,1 for females) based on multiple linear regression equations including body mass index (BMI), triceps skinfolds (TSF) and age from the Swedish population-based sample. In Kitavans serum leptin was positively related to TSF amongst both sexes and, amongst females, to BMI. In Kitavans leptin was not related to fasting serum insulin. TSF explained 55% of the variation of leptin amongst females. There was a slight age-related increase of leptin amongst males. In Kitava leptin was not related to fasting serum insulin which was substantially lower than in Sweden. Conclusion.,The low concentrations of serum leptin amongst Kitavans probably relates to the absence of overweight and hyperinsulinaemia. At a population level serum leptin can apparently be predicted from simple measures of adiposity. [source] High levels of grass pollen inside European dairy farms: a role for the allergy-protective effects of environment?ALLERGY, Issue 7 2009B. Sudre Background:, There is evidence of an allergy protective effect in children raised on farm. It has been assumed that microbial exposure may confer this protection. However in farm, little attention has been given to the pollen level and to concomitant microbiological exposure, and indoor pollen concentrations have never been precisely quantified. Methods:, The kinetics of pollen in dairy farms have been studied in a pilot study (n = 9), and exposure in a sub-sample of the ongoing European birth cohort PASTURE (n = 106). Measurements of viable microorganisms and pollen were performed in air samples. To identify factors that modulate the pollen concentration multivariate regression analyses were run. Results:, Indoor pollen (95% of Poaceae fragments and grains) were significantly higher in winter than in summer (P = 0.001) and ranged between 858 to 11 265 counts/m3 during feeding in winter, thus exceeding typical outdoor levels during the pollen season. Geometric mean in French farms was significantly higher than in German and Swiss farms (7 534, 992 and 1 079 count/m3, respectively). The presence of a ventilation system and loose housing systems significantly reduced indoor pollen levels. This pollen concentration rise after feeding was accompanied by an increase in fungal and actinomycetal levels, whereas the concentration of bacteria was not associated with feeding. Conclusions:, Farmers and their children who attend cowsheds during the feeding sessions are exposed perennially to high pollen concentrations. It might be speculated that the combined permanent exposure to microbes from livestock and grass pollen may initiate tolerance in children living on a farm. [source] Concentrations of domestic mite and pet allergens and endotoxin in PalestineALLERGY, Issue 6 2004N. El Sharif Background:, A few studies have compared indoor allergens and endotoxin levels between urban and rural settings as important determinants for asthma and atopy in children. However, no study was done in the Middle East or investigated refugee camps. Methods:, As part of a nested case,control study in Ramallah in 2001, we measured house dust mite and pet allergens, as well as endotoxin in dust collected from 110 children's mattresses and living room floors. Results:, Geometric mean (GM) concentrations of Dermatophagoides pteronyssinus (Der p1) antigen were 4.48 ,g/g in mattress dust and 1.23 ,g/g floor dust. The highest Der p1 levels were seen in refugee camps. Concentrations of Dermatophagoides farinae antigen (Der f1) were much lower (<0.08 ,g/g dust). Concentrations of cat allergen (Fel d1) were highest in villages, and those of dog allergen (Can f1) were highest in mattresses from cities and in floor dust from refugee camps. GM of endotoxin levels were 25.7 EU/mg in mattress dust and 49 EU/mg dust in floor dust. Conclusions:, Concentrations of Der p1 were high compared to Western European countries, but were lower compared to UK and Australia. Levels of pet allergens were lower than in Western Europe. Endotoxin levels were higher compared to developed countries. Indoor environmental factors such as dampness seemed to be important determinants for allergen and endotoxin, but living habits such as lack of mattress cover appeared unimportant. [source] Life course weight gain and C-reactive protein levels in young adults: Findings from a Brazilian birth cohort,AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 2 2009Aydin Nazmi Rapid weight gain in childhood is associated with increased risk of chronic diseases in adults. C-reactive protein (CRP) is a mediator of atherosclerosis and chronically elevated levels predict cardiovascular outcomes. The effects of life course weight gain on CRP levels are not clear. The 1982 Pelotas (Brazil) birth cohort study (n = 5,914) has prospectively collected weight and health data at several follow-ups since birth. The most recent was in 2004,05, when 77.4% of the cohort was traced and CRP levels were measured in 89% of those interviewed (n = 3827). Geometric mean (SE) C-reactive protein levels were 0.89 mg/l (0.03) and 1.66 mg/l (0.04) in men and women, respectively. In analyses adjusted for confounding variables, weight gain in infancy showed a weak negative association among males, but from the second year onwards, weight gain was positively associated with CRP levels. In females, weight gain was associated with higher CRP at every period tested. The strongest associations were observed in the most recent (18,23 years) period; CRP ratios (95% CI) per z score increase in weight gain were 1.78 (1.57,2.00) and 1.52 (1.30,1.78) for men and women, respectively. Males who were stunted at 2 years and centrally obese at 23 years had the highest CRP levels (P = 0.002 for interaction). In summary, rapid weight gain throughout life predicted higher CRP levels. Public health efforts need to tackle chronic under-nutrition in infancy, together with rapid weight gain in later childhood and adolescence, especially in countries undergoing the nutritional transition. Am. J. Hum. Biol. 2009. © 2008 Wiley-Liss, Inc. [source] Occurrence and distribution of culturable enteroviruses in wastewater and surface waters of north-eastern SpainJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2008A. Costįn-Longares Abstract Aims:, Update information regarding occurrence and levels of culturable enteroviruses in several types of surface polluted waters in north-eastern Spain and determine the proportion of the different species and serotypes. Methods and Results:, The best procedures on hand in our laboratory for concentrating and quantifying culturable enteroviruses from different water sample types were used. Sequencing was used for typing the virus isolates. Geometric means of enteroviruses densities expressed in plaque forming units per litre were 968 in raw sewage, 12·51 in secondary effluents, 0·017 in tertiary effluents, 0·4 in river water and 0·36 in seawater. Enterovirus densities in wastewater revealed certain seasonality with a maximum at the end of spring , beginning of the summer. Coxsackievirus B, and amid them serotype CB4, were the most abundant species and serotypes detected. Conclusions:, Densities of enteroviruses in different north-eastern Spain surface waters are similar to those present in industrialized countries with temperate climate. No wild polioviruses were detected. Distribution of species showed a clear prevalence of coxsackieviruses. Significance and Impact of the Study:, Information regarding enteroviruses in this geographical area provides valuable information to estimate the risk of enteroviruses transmission through water and for complementing clinical epidemiological data. [source] Antimicrobial and anti-inflammatory activity of five Taxandria fragrans oils in vitroMICROBIOLOGY AND IMMUNOLOGY, Issue 11 2008Katherine A. Hammer ABSTRACT The antimicrobial activity of five samples of Taxandria fragrans essential oil was evaluated against a range of Gram-positive (n= 26) and Gram-negative bacteria (n= 39) and yeasts (n= 10). The majority of organisms were inhibited and/or killed at concentrations ranging from 0.06,4.0% v/v. Geometric means of MIC were lowest for oil Z (0.77% v/v), followed by oils X (0.86%), C (1.12%), A (1.23%) and B (1.24%). Despite differences in susceptibility data between oils, oils A and X did not differ when tested at 2% v/v in a time kill assay against Staphylococcus aureus. Cytotoxicity assays using peripheral blood mononuclear cells demonstrated that T. fragrans oil was cytotoxic at 0.004% v/v but not at 0.002%. Exposure to one or more of the oils at concentrations of ,0.002% v/v resulted in a dose responsive reduction in the production of proinflammatory cytokines IL-6 and TNF-,, regulatory cytokine IL-10, Th1 cytokine IFN-, and Th2 cytokines IL-5 and IL-13 by PHA stimulated mononuclear cells. Oil B inhibited the production of all cytokines except IL-10, oil X inhibited TNF-,, IL-6 and IL-10, oil A inhibited TNF-, and IL-6, oil C inhibited IL-5 and IL-6 and oil Z inhibited IL-13 only. IL-6 production was significantly inhibited by the most oils (A, B, C and X), followed by TNF-, (oils A, B and X). In conclusion, T. fragrans oil showed both antimicrobial and anti-inflammatory activity in vitro, however, the clinical relevance of this remains to be determined. [source] Equilibrium and growth shapes of crystals: how do they differ and why should we care?CRYSTAL RESEARCH AND TECHNOLOGY, Issue 4-5 2005Robert F. SekerkaArticle first published online: 15 MAR 200 Abstract Since the death of Prof. Dr. Jan Czochralski nearly 50 years ago, crystals grown by the Czochralski method have increased remarkably in size and perfection, resulting today in the industrial production of silicon crystals about 30 cm in diameter and two meters in length. The Czochralski method is of great technological and economic importance for semiconductors and optical crystals. Over this same time period, there have been equally dramatic improvements in our theoretical understanding of crystal growth morphology. Today we can compute complex crystal growth shapes from robust models that reproduce most of the features and phenomena observed experimentally. We should care about this because it is likely to result in the development of powerful and economical design tools to enable future progress. Crystal growth morphology results from an interplay of crystallographic anisotropy and growth kinetics by means of interfacial processes and long-range transport. The equilibrium shape of a crystal results from minimizing its anisotropic surface free energy under the constraint of constant volume; it is given by the classical Wulff construction but can also be represented by an analytical formula based on the ,-vector formalism of Hoffman and Cahn. We now have analytic criteria for missing orientations (sharp corners or edges) on the equilibrium shape, both in two (classical) and three (new) dimensions. Crystals that grow under the control of interfacial kinetic processes tend asymptotically toward a "kinetic Wulff shape", the analogue of the Wulff shape, except it is based on the anisotropic interfacial kinetic coefficient. If it were not for long range transport, crystals would presumably nucleate with their equilibrium shape and then evolve toward their "kinetic Wulff shape". Allowing for long range transport leads to morphological instabilities on the scale of the geometric mean of a transport length (typically a diffusivity divided by the growth speed) and a capillary length (of the order of atomic dimensions). Resulting crystal growth shapes can be cellular or dendritic, but can also exhibit corners and facets related to the underlying crystallographic anisotropy. Within the last decade, powerful phase field models, based on a diffuse interface, have been used to treat simultaneously all of the above phenomena. Computed morphologies can exhibit cells, dendrites and facets, and the geometry of isotherms and isoconcentrates can also be determined. Results of such computations are illustrated in both two and three dimensions. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Multiple mealtime administration of biphasic insulin aspart 30 versus traditional basal-bolus human insulin treatment in patients with type 1 diabetesDIABETES OBESITY & METABOLISM, Issue 6 2006J. -W. Aim:, The aim of this study was to compare the effect of multiple mealtime injections of biphasic insulin aspart 30 (30% fast-acting insulin aspart in the formulation, BIAsp30) to traditional basal-bolus human insulin regimen (HI) on glycaemic control in patients with type 1 diabetes. Methods:, Twenty-three patients (eight women and 15 men) aged 44.8 (20.6,62.5) years (median and range) with a diabetes duration of 19.5 (1.6,44.6) years completed the study. All eligible patients were randomly assigned to BIAsp30 thrice daily supplied with bedtime NPH insulin when necessary, or basal-bolus HI for 12 weeks and then switched to the alternative regimen for another 12 weeks. The insulin dose adjustments were made by patients on the basis of advice from a diabetes nurse. At end of each treatment period, the patients attended two profile days, 1 week apart for pharmacodynamic and pharmacokinetic assessments. HbA1C was measured at baseline and at the end of each treatment period. A seven-point self-monitored blood glucose (SMBG) was obtained twice weekly. Results:, In comparison with HI, multiple mealtime injections of BIAsp30 resulted in a significant reduction in HbA1C[HI vs. BIAsp30 (%, geometric mean and range): 8.6 (7.4,11.4) vs. 8.3 (6.7,9.8), p = 0.013]. During treatment with BIAsp30, nighttime glycaemic control was significantly improved. Day-to-day variation in pharmacodynamics and pharmacokinetics and the rate of hypoglycaemia were not increased with BIAsp30 compared with HI. Conclusions:, In type 1 diabetics, multiple mealtime administration of BIAsp30 compared with traditional basal-bolus human insulin treatment significantly improves long-term glycaemic control without increasing the risk of hypoglycaemia. Despite a higher proportion of intermediate-acting insulin, thrice-daily injections with BIAsp30 do not increase the day-to-day variations in insulin pharmacokinetics and pharmacodynamics. [source] Treatment of symptomatic diabetic polyneuropathy with the antioxidant ,-lipoic acid: a meta-analysisDIABETIC MEDICINE, Issue 2 2004D. Ziegler Abstract Aims To determine the efficacy and safety of 600 mg of ,-lipoic acid given intravenously over 3 weeks in diabetic patients with symptomatic polyneuropathy. Methods We searched the database of VIATRIS GmbH, Frankfurt, Germany, for clinical trials of ,-lipoic acid according to the following prerequisites: randomized, double-masked, placebo-controlled, parallel-group trial using ,-lipoic acid infusions of 600 mg i.v. per day for 3 weeks, except for weekends, in diabetic patients with positive sensory symptoms of polyneuropathy which were scored by the Total Symptom Score (TSS) in the feet on a daily basis. Four trials (ALADIN I, ALADIN III, SYDNEY, NATHAN II) comprised n = 1258 patients (,-lipoic acid n = 716; placebo n = 542) met these eligibility criteria and were included in a meta-analysis based on the intention-to-treat principle. Primary analysis involved a comparison of the differences in TSS from baseline to the end of i.v. Treatment between the groups treated with ,-lipoic acid or placebo. Secondary analyses included daily changes in TSS, responder rates (, 50% improvement in TSS), individual TSS components, Neuropathy Impairment Score (NIS), NIS of the lower limbs (NIS-LL), individual NIS-LL components, and the rates of adverse events. Results After 3 weeks the relative difference in favour of ,-lipoic acid vs. placebo was 24.1% (13.5, 33.4) (geometric mean with 95% confidence interval) for TSS and 16.0% (5.7, 25.2) for NIS-LL. The responder rates were 52.7% in patients treated with ,-lipoic acid and 36.9% in those on placebo (P < 0.05). On a daily basis there was a continuous increase in the magnitude of TSS improvement in favour of ,-lipoic acid vs. placebo which was noted first after 8 days of treatment. Among the individual components of the TSS, pain, burning, and numbness decreased in favour of ,-lipoic acid compared with placebo, while among the NIS-LL components pin-prick and touch-pressure sensation as well as ankle reflexes were improved in favour of ,-lipoic acid after 3 weeks. The rates of adverse events did not differ between the groups. Conclusions The results of this meta-analysis provide evidence that treatment with ,-lipoic acid (600 mg/day i.v.) over 3 weeks is safe and significantly improves both positive neuropathic symptoms and neuropathic deficits to a clinically meaningful degree in diabetic patients with symptomatic polyneuropathy. Diabet. Med. 21, 114,121 (2004) [source] Relationship of lipoprotein(a) with intimal medial thickness of the carotid artery in Type 2 diabetic patients in south IndiaDIABETIC MEDICINE, Issue 6 2003K. Velmurugan Abstract Objective The objective of this study was to investigate the association of lipoprotein(a) [Lp(a)] levels with intimal medial thickness (IMT) in Type 2 diabetic patients in south India. Study design We studied 587 consecutive Type 2 diabetic patients at the M.V. Diabetes Specialities Centre, Chennai. The mean age of the study group was 55 ± 10 years and 71.2% were males. IMT of the right common carotid artery was determined using high-resolution B mode ultrasonography. Lp(a) levels were measured using ELISA. Since the frequency distribution of Lp(a) was skewed, Lp(a) values were log transformed and the geometric mean was used for statistical analysis. The tertiles of IMT were determined to analyse the association of Lp(a) and other factors with IMT. Result The mean Lp(a) level in the study patients was 18.9 ± 3.1 mg/dl (geometric mean ± sd) and the mean IMT of the study subjects was 0.93 ± 0.19 mm (mean ± sd). The prevalence of carotid atherosclerosis (defined as IMT > 1.1 mm) among subjects with elevated Lp(a) levels > 20 mg/dl was significantly higher compared with those with Lp(a) levels , 20 mg/dl (26.9% vs. 16.3%, P = 0.003). Lp(a) levels increased with increase in tertiles of IMT (anova, P < 0.05). Pearson correlation analysis of carotid IMT with other cardiovascular risk factors revealed strong correlation of IMT with age (P < 0.0001), duration of diabetes (P < 0.0001), systolic blood pressure (P < 0.0001), diastolic blood pressure (P = 0.006), LDL-cholesterol (P = 0.023), HbA1c (P = 0.017) and Lp(a) (P < 0.0001). Multiple logistic regression analysis showed age (P = 0.010), LDL-cholesterol (P = 0.032) and Lp(a) (P = 0.021) to be associated with carotid atherosclerosis. Conclusion The results suggest that Lp(a) has a strong association with IMT of carotid arteries in Type 2 diabetic subjects in south India. Diabet. Med. 20, 455,461 (2003) [source] Ethnicity and glycaemic control are major determinants of diabetic dyslipidaemia in MalaysiaDIABETIC MEDICINE, Issue 6 2001I. S. Ismail Abstract Aims To define the prevalence of dyslipidaemia in young diabetic patients in Peninsular Malaysia and the contributory factors of dyslipidaemia in these subjects. Methods This is a cross-sectional study involving 848 young diabetic patients from seven different centres, with representation from the three main ethnic groups. Clinical history and physical examination was done and blood taken for HbA1c, fasting glucose, total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol and triglycerides. Results The overall lipids were suboptimal, worse in Type 2 diabetes mellitus (DM) patients compared with Type 1 DM patients. Of the Type 2 patients, 73.2% had total cholesterol >,5.20 mmol/l, 90.9% had LDL-cholesterol >,2.60 mmol/l, 52.6% had HDL-cholesterol <,1.15 mmol/l and 27.3% had serum triglycerides >,2.30 mmol/l. There were ethnic differences in the lipid levels with the Malays having the highest total cholesterol (mean 6.19 mmol/l), and the highest LDL-cholesterol (mean 4.16 mmol/l), while the Chinese had the highest HDL-cholesterol (geometric mean 1.24 mmol/l). Ethnicity was an important determinant of total, LDL- and HDL-cholesterol in Type 2 DM, and LDL- and HDL-cholesterol and triglycerides in Type 1 DM. Glycaemic control was an important determinant of total, LDL-cholesterol and triglycerides in both Type 1 and Type 2 DM. Waist,hip ratio (WHR) was an important determinant of HDL-cholesterol and triglycerides in both types of DM. Gender was an important determinant of HDL-cholesterol in Type 2 DM, but not in Type 1 DM. Socioeconomic factors and diabetes care facilities did not have any effect on the dyslipidaemia. Conclusions The prevalence of dyslipidaemia was high especially in Type 2 DM patients. Ethnicity, glycaemic control, WHR, and gender were important determinants of dyslipidaemia in young diabetic patients. Diabet. Med. 18, 501,508 (2001) [source] Patterns of organic contaminants in eggs of an insectivorous, an omnivorous, and a piscivorous bird nesting on the Hudson River, New York, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2010Christine M. Custer Abstract Belted kingfisher (Ceryle alcyon), spotted sandpiper (Actitus macularia), and tree swallow (Tachycineta bicolor) eggs were collected in 2004 from the upper Hudson River, New York, USA. This area is one of the most polychlorinated biphenyl (PCB)-contaminated locations in North America. Multivariate analyses indicated among species differences in the concentration and composition of PCB congeners, polychlorinated dibenzo- p -dioxin (PCDD), and dibenzofuran (PCDF, PCDD-F when combined with PCDDs) congeners, and chlorinated pesticides. Total PCB concentrations followed the typical food chain biomagnification paradigm of higher concentrations in piscivorous bird eggs and lower concentrations in eggs of species that feed at lower trophic levels. Concentrations in the insectivorous swallows (geometric mean,=,6.8,µg/g wet wt) were approximately half the concentrations present in the piscivorous kingfisher (11.7,µg/g) or omnivorous sandpiper (12.6,µg/g). In contrast, PCB toxic equivalents (TEQs) were higher in swallows (1,790,pg/g wet wt) than in either kingfishers (776,pg/g) or sandpipers (881,pg/g). This difference can be mainly attributed to higher PCB77 concentrations in swallows relative to the other two species. Also contrary to the accepted food-chain paradigm, the sum of PCDD-F concentrations and the sum of their TEQs were higher in swallows than in either sandpipers or kingfishers. Metabolic pathway differences in the respective food chains of the three species probably accounted for the differences observed in PCB TEQ, total PCDD-F, and PCDD-F TEQ concentrations among species. Environ. Toxicol. Chem. 2010;29:2286,2296. © 2010 SETAC [source] Fluoride concentrations in antler bone of roe deer (Capreolus capreolus) indicate decreasing fluoride pollution in an industrialized area of western GermanyENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2001Uwe Kierdorf Abstract In order to reconstruct temporal changes in ambient fluoride levels in the industrialized Ruhr area (western Germany), we analyzed the bone fluoride content of 167 antlers of roe deer (Capreolus capreolus) killed between 1951 and 1999 in the northern part of this region. Individual values ranged between 110 and 8,178 mg F,/kg ash, and there was an overall marked decrease over the sampling period. Average bone fluoride concentrations in antlers from the periods 1980 through 1989 (geometric mean [95% confidence interval]: 1,490 [1,193,1,861] mg/kg ash) and 1990 through 1999 (753 [644,882] mg/kg ash) differed significantly (p < 0.001) and were both significantly (p < 0.001) lower than those from the periods 1951 through 1969 (3,720 [3,227,4,288] mg/kg ash) and 1970 through 1979 (2,573 [2,203,3,006] mg/kg ash). The findings are seen as indicative of a progressively reduced atmospheric fluoride deposition into the study area, caused by effective emission-control measures in Germany and neighboring countries. Because antlers are replaced annually, grow during a fixed period of some months, and are regularly collected and kept as trophies, they are well suited as monitoring units for analyzing temporal trends in environmental pollution by fluoride and other bone-seeking pollutants. [source] Transferability indices for health economic evaluations: methods and applicationsHEALTH ECONOMICS, Issue 6 2009Fernando Antonanzas Abstract In this paper, we have elaborated an index in two phases to measure the degree of transferability of the results of the economic evaluation of health technologies. In the first phase, we have considered the objective factors (critical and non-critical) to derive a general transferability index, which can be used to measure this internal property of the studies of economic evaluation applied to health technologies. In the second phase, with a more specific index, we have measured the degree of applicability of the results of a given study to a different setting. Both indices have been combined (arithmetic and geometric mean) to obtain a global transferability index. We have applied the global index to a sample of 27 Spanish studies on infectious diseases. We have obtained an average value for the index of 0.54, quite far from the maximum theoretical value of 1. We also found that 11 studies lacked some critical factor and were directly deemed as not transferable. Copyright © 2008 John Wiley & Sons, Ltd. [source] Some Parameters of Correlated Current and Radiated Field Pulses from Lightning to the Gaisberg TowerIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 1 2010Hannes Pichler Non-member Abstract Simultaneous measurements of lightning current and associated radiated electromagnetic field are of fundamental interest for various applications in lightning research. These data can be used for the evaluation of return stroke (RS) models or to investigate the so-called tower effect when lightning hits an elevated object. In this paper, we show the results of simultaneous measurements of current pulses from lightning strikes on the instrumented Gaisberg tower (Austria) and the correlated vertical E-field components at a distance of 78.8 and 108.7 km, respectively. We have analyzed some main lightning current parameters (peak current Ip, 30,90% rise time TI_30-90, and full width at half maximum TI_FWHM and the time-correlated field waveform parameters (Ep, 30,90% rise time TE_30-90, TE_FWHM, and the peak-to-zero time TE_PTZ. With a geometric mean of TI_FWHM = 19 ,s and Ip = 9.6 kA (N = 73) of the RS current pulses used in this study, those strokes are very similar to the strokes in triggered lightning in Florida and Alabama1. With a TE_PTZ of about 10 µs, the zero-crossing time of the radiated E-fields from the tower strokes are significantly shorter than the typical values of 30 , 40 µs (e.g.2). Correlation between the current and field parameters TI_FWHM versus TE_FWHM and TE_PTZ, respectively, is low (R2 = 0.29 and 0.14). We assume that the relatively short lightning channel in the case of the RSs in object-triggered upward flashes is the main reason for the observed short zero-crossing time. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Pharmacokinetics of mesalazine pellets in children with inflammatory bowel diseaseINFLAMMATORY BOWEL DISEASES, Issue 5 2004Heleen Wiersma MD Abstract Mesalazine is a first-line drug in pediatric inflammatory bowel disease (IBD), and is customarily used to induce and maintain remission in mild to moderate disease. In children, pharmacokinetic data are scarce, and dosage recommendations are largely extrapolated from studies in adults. Aim of the study was to obtain the pharmacokinetic profile of a new mesalazine pellet formulation in children with ulcerative colitis and Crohn's colitis. A single oral dose of 20 mg/kg mesalazine was administered to 13 patients (age 6,16 years). Serial blood and urine sampling for determination of mesalazine and acetylmesalazine was performed before and during 24 hours following ingestion. Maximum plasma concentration of mesalazine (Cmax) was 1332 ng/mL (geometric mean, geometric coefficient of variation [CV]: 0.57), obtained 3.7 hours (tmax; CV: 0.31) after drug administration. Systemic exposure as determined by area under the plasma concentration-time curve (AUC0,, ) was 8712 ng/ml*h (CV: 0.44). Terminal half-life of elimination of mesalazine was 3.5 hours (t1/2; CV: 1.43). This study presents extensive pharmacokinetic data on mesalazine in children with mild-moderately active ulcerative colitis and Crohn's colitis. In comparison with previous experience in adults, pharmacokinetics of mesalazine administered as pellets appear to be similar in both populations. [source] Reference genes identified in the silkworm Bombyx mori during metamorphism based on oligonucleotide microarray and confirmed by qRT-PCRINSECT SCIENCE, Issue 5 2008Gen-Hong Wang Abstract Gene expression quantification at mRNA level is very important for post-genomic studies, as gene expression level is the reflection of the special biological function of the target gene. Methods used for gene expression quantification, such as microarray or quantitative real-time polymerase chain reaction (qRT-PCR), require stable expressed reference genes. Thus, finding suitable control genes is essential for gene quantification. In this study, a genome-wide survey of reference genes during metamorphism was performed on silkworm Bombyx mori. Twelve genes were chosen as putative reference genes based on a whole genome oligonucleotide microarray normalized by external controls. Then, qRT-PCR was employed for further validation and selection of potential reference gene candidates. The results were analyzed, and stable genes were selected using geNorm 3.4 and NormFinder software. Finally, considering factors from every aspect, translation initiation factor 4A, translation initiation factor 3 subunit 4, and translation initiation factor 3 subunit 5 (represented by sw22934, swl4876, and swl3956) were selected as reliable internal controls across the examined developmental stages, while cytoplasmic actin (sw22671), the commonly used reference gene in a previous study was shown to vary drastically throughout the examined developmental stages. For future research, we recommend the use of the geometric mean of those three stable reference genes as an accurate normalization factor for data normalization of different developmental stages during metamorphism. [source] Evaluation of Common Bean for Drought Tolerance in Juana Diaz, Puerto RicoJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 5 2009T. G. Porch Abstract Drought tolerance is an increasingly important trait in common bean (Phaseolus vulgaris L.) due to the reduction in water resources, a shift in production areas and increasing input costs. The objective of this study was to evaluate 29 genotypes for drought tolerance under drought stress (DS) and reduced stress treatments in Juana Diaz, Puerto Rico. The use of DS and reduced stress treatments facilitated the identification of drought tolerant germplasm that also had good yield potential under more optimal conditions. Based on the results of seed yield under DS and reduced stress conditions, and DS indices, including the geometric mean (GM), stress tolerance index (STI) and percent yield reduction (YR), genotypes were identified with greater yield potential under the tested environment. Based on average GM over the 2 years, the superior common bean genotypes identified were SEA 5, G 21212, A 686, SEN 21 and SER 21. These genotypes performed well in both years and under both treatment conditions and thus may serve as parents for DS improvement and genetic analysis. [source] A force-field description of short-range repulsions for high density alkane molecular dynamics simulationsJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 16 2004Joseph M. Hayes Abstract The use of Buckingham (exp-6) van der Waals potentials in molecular dynamics (MD) simulations can quite successfully reproduce experimental thermodynamic data at low densities. However, they are less successful in producing a description of the repulsive regions of the potential energy surface (PES) that is in accord with the results of high-level ab initio computations. We show that Morse potentials can be parameterized to give excellent fits to both the attractive and repulsive regions of the PES. The best set of alkane van der Waals Morse function parameters reported to date for the description of nonbond repulsive interactions is presented, as determined by comparison with both ab initio and experimental results. C,C, H,H and C,H atom-pair potentials employing parameter sets based on the use of the geometric mean in the fitting procedure are found to be portable from methane to n- butane. Fitting to a combination of methane dimer interaction energies and forces from ab initio calculations yields parameter sets whose performance is superior to those determined from the interaction energies alone. Used in MD simulations, our newly developed parameter sets predict thermodynamic functions that show better agreement with experiment than those based on parameter sets in common use. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1953,1966, 2004 [source] The common patterns of natureJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 8 2009S. A. FRANK Abstract We typically observe large-scale outcomes that arise from the interactions of many hidden, small-scale processes. Examples include age of disease onset, rates of amino acid substitutions and composition of ecological communities. The macroscopic patterns in each problem often vary around a characteristic shape that can be generated by neutral processes. A neutral generative model assumes that each microscopic process follows unbiased or random stochastic fluctuations: random connections of network nodes; amino acid substitutions with no effect on fitness; species that arise or disappear from communities randomly. These neutral generative models often match common patterns of nature. In this paper, I present the theoretical background by which we can understand why these neutral generative models are so successful. I show where the classic patterns come from, such as the Poisson pattern, the normal or Gaussian pattern and many others. Each classic pattern was often discovered by a simple neutral generative model. The neutral patterns share a special characteristic: they describe the patterns of nature that follow from simple constraints on information. For example, any aggregation of processes that preserves information only about the mean and variance attracts to the Gaussian pattern; any aggregation that preserves information only about the mean attracts to the exponential pattern; any aggregation that preserves information only about the geometric mean attracts to the power law pattern. I present a simple and consistent informational framework of the common patterns of nature based on the method of maximum entropy. This framework shows that each neutral generative model is a special case that helps to discover a particular set of informational constraints; those informational constraints define a much wider domain of non-neutral generative processes that attract to the same neutral pattern. [source] Sensory Characterization of Dry Gins with Different Volatile ProfilesJOURNAL OF FOOD SCIENCE, Issue 6 2008M. Riu-Aumatell ABSTRACT:, The aim of this study was the sensory characterization of dry gins in relation to their chemical volatile composition. The development of a specific vocabulary was necessary as a basis for quality control and to ensure the brand flavor integrity. The lexicon was obtained according to ISO 11035 (1994), on the basis of discussions between the panelists and the panel leader, reference materials, and an aroma wheel. Ten notes of the preliminary vocabulary were reduced by calculating the geometric mean (M) and applying ANOVA and principal component analysis. Finally, juniper, citric, aniseed, spice, and licorice were applied to describe 4 London Dry Gins (G1 to G4) and 2 gins with geographic indications (G5 and G6) by generic descriptive analysis (GDA). The latter were characterized by citric and juniper notes, respectively, while G1 was characterized by spice and aniseed attributes. Licorice was uniform in all of the samples. Chemical volatile composition of samples obtained by headspace-solid phase microextraction (HS-SPME) coupled with gas chromatography/mass spectrometry (GC/MS) was in agreement with the sensory results. [source] Large differences in serum leptin levels between nonwesternized and westernized populations: the Kitava studyJOURNAL OF INTERNAL MEDICINE, Issue 6 2001S. Lindeberg Abstract.,Lindeberg S, Söderberg S, Ahrén B, Olsson T (Lund University; and Umeå University, Malmö, Sweden). Large differences in serum leptin levels between nonwesternized and westernized populations: the Kitava study. J Intern Med 2001; 249: 553,558. Objectives.,To compare serum leptin between nonwesternized and westernized populations. Setting., (i) The tropical island of Kitava, Trobriand Islands, Papua New Guinea and (ii) the Northern Sweden MONICA study population. Design.,Cross-sectional survey. Methods.,Fasting levels of serum leptin were analysed in 163 randomly selected Kitavans aged 20,86 years and in 224 Swedes aged 25,74. Main outcome measures.,Mean and determinants of serum leptin. Results.,Geometric mean of serum leptin in Kitavan males and females were 1.5 and 4.0 vs. 4.9 and 13.8 ng mL,1 in Swedish male and females (P < 0.0001 for both sexes). In Kitavans, observed geometric mean were close to predicted levels (1.8 ng mL,1 for males and 4.5 ng mL,1 for females) based on multiple linear regression equations including body mass index (BMI), triceps skinfolds (TSF) and age from the Swedish population-based sample. In Kitavans serum leptin was positively related to TSF amongst both sexes and, amongst females, to BMI. In Kitavans leptin was not related to fasting serum insulin. TSF explained 55% of the variation of leptin amongst females. There was a slight age-related increase of leptin amongst males. In Kitava leptin was not related to fasting serum insulin which was substantially lower than in Sweden. Conclusion.,The low concentrations of serum leptin amongst Kitavans probably relates to the absence of overweight and hyperinsulinaemia. At a population level serum leptin can apparently be predicted from simple measures of adiposity. [source] Gastroschisis: Early enteral feeds may improve outcomeJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 5 2000M Sharp Objective: Population-based retrospective review of gastroschisis from 1986 to 1996. Methods: This was a retrospective review of gastroschisis. Seventy cases were identified from the Birth Defects Registry of Western Australia (WA). Hospital medical records of live-born cases were reviewed. Results: The live-born incidence of gastroschisis in WA was 2.1 per 10 000 live births for the period 1986,96. The incidence in mothers aged less than 20 years was 8.3-fold that of women aged over 30 years (P < 0.0001). The incidence rate for the period 1995,96 was over twice the rate for 1986,88. Age at first enteral feed was significantly related with length of hospital stay and duration of total parental nutrition (TPN). Each day delay in commencing enteral feed was associated with an increase in hospital stay of 1.05 days and an increase in TPN duration of 1.06 days. The method of delivery of the infant, age at repair, length of anaesthetic time, duration of postoperative paralysis and gestational age was not associated with length of stay or TPN duration. The data were divided into two cohorts: (i) 1986,90; and (ii) 1991,96. There was a statistically significant reduction in hospital stay from a geometric mean of 45.7 (1986,90) to 22.9 days (1991,96). Conclusions: Gastroschisis has a favourable outlook, with 89.7% survival of live births. Over the 10 year period studied, there has been a reduction in length of hospital stay and duration of TPN. The age at which the infant is first fed enteral feeds appears to be important in affecting the length of hospital stay and the duration of TPN, with delays associated with a longer hospital stay and longer TPN duration. [source] Spatial variation of soil test phosphorus in a long-term grazed experimental grassland fieldWeijun Fu1, 2JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 3 2010Hubert Tunney Abstract The spatial variation of soil test P (STP) in grassland soils is becoming important because of the use of STP as a basis for policies such as the recently EU-introduced Nitrate Directive. This research investigates the spatial variation of soil P in grazed grassland plots with a long-term (38 y) experiment. A total of 326 soil samples (including 14 samples from an adjacent grass-wood buffer zone) were collected based on a 10 × 10 m2 grid system. The samples were measured for STP and other nutrients. The results were analyzed using conventional statistics, geostatistics, and a geographic information system (GIS). Soil test P concentrations followed a lognormal distribution, with a median of 5.30 mg L,1 and a geometric mean of 5.35 mg L,1. Statistically significant (p < 0.01) positive correlation between STP and pH was found. Spatial clusters and spatial outliers were detected using the local Moran's I index (a local indicator of spatial association) and were mapped using GIS. An obvious low-value spatial-cluster area was observed on the plots that received zero-P fertilizer application from 1968 to 1998 and a large high-value spatial-cluster area was found on the relatively high-P fertilizer application plots (15,kg ha,1 y,1). The local Moran's I index was also effective in detecting spatial outliers, especially at locations close to spatial-cluster areas. To obtain a reliable and stable spatial structure, semivariogram of soil-P data was produced after elimination of spatial outliers. A spherical model with a nugget effect was chosen to fit the experimental semivariogram. The spatial-distribution map of soil P was produced using the kriging interpolation method. The interpolated distribution map was dominated by medium STP values, ranging from 3 mg to 8 mg L,1. An evidently low-P-value area was present in the upper side of the study area, as zero or short-term P fertilizer was applied on the plots. Meanwhile, high-P-value area was located mainly on the plots receiving 15,kg P ha,1 y,1 (for 38 y) as these plots accumulated excess P after a long-term P-fertilizer spreading. The high- or low-value patterns were in line with the spatial clusters. Geostatistics, combined with GIS and the local spatial autocorrelation index, provides a useful tool for analyzing the spatial variation in soil nutrients. [source] Automated determination of venlafaxine in human plasma by on-line SPE-LC-MS/MS.JOURNAL OF SEPARATION SCIENCE, JSS, Issue 4 2009Application to a bioequivalence study Abstract A new automated SPE-LC-ESI-MS/MS method was developed and validated to quantify venlafaxine in human plasma using fluoxetine as an internal standard. The analytes were automatically extracted from plasma by C18 SPE cartridges, separated on a C8 RP column and analyzed by MS in the multiple reaction-monitoring (MRM) mode. The method has a chromatographic run time of 4.0 min and a linear calibration curve over the range of 0.25,200 ng/mL (r >0.997). The between-run precisions, based on the percent RSD for replicate quality controls (0.75; 80, and 200 ng/mL), were < 8.5% for all concentrations. The between-run accuracies, based on the percent relative error, were < 4.0%. This method was successfully employed in a bioequivalence study of two venlafaxine capsule formulations (test formulation from Eurofarma (Brazil) and Efexor XR, reference formulation, from Wyeth-Whitehall, Brazil) in 48 healthy volunteers of both sexes who received a single 150 mg dose of each formulation. More than 3000 samples were analyzed eliminating the analyst's exposure to hazardous organic solvents normally employed in off-line liquid,liquid extractions. The 90% confidence interval (CI) of the individual ratio geometric mean for Test/Reference was 91.6,103.4% for AUC0,48 h and 102.2,112.6% for Cmax. Since both 90% CI for AUC0,48 h and Cmax were included in the 80,125% interval proposed by the US Food and Drug Administration (FDA) and the Brazilian National Health Surveillance Agency (ANVISA), the test formulation was considered bioequivalent to Efexor XR according to both the rate and extent of absorption. [source] A SIMPLE METHOD FOR ESTIMATING BASEFLOW AT UNGAGED LOCATIONS,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2001Kenneth W. Potter ABSTRACT: Baseflow, or water that enters a stream from slowly varying sources such as ground water, can be critical to humans and ecosystems. We evaluate a simple method for estimating base-flow parameters at ungaged sites. The method uses one or more baseflow discharge measurements at the ungaged site and longterm streamflow data from a nearby gaged site. A given baseflow parameter, such as the median, is estimated as the product of the corresponding gage site parameter and the geometric mean of the ratios of the measured baseflow discharges and the concurrent discharges at the gage site. If baseflows at gaged and ungaged sites have a bivariate lognormal distribution with high correlation and nearly equal log variances, the estimated baseflow parameters are very accurate. We tested the proposed method using long-term streamflow data from two watershed pairs in the Driftless Area of southwestern Wisconsin. For one watershed pair, the theoretical assumptions are well met; for the other the log-variances are substantially different. In the first case, the method performs well for estimating both annual and long-term baseflow parameters. In the second, the method performs remarkably well for estimating annual mean and annual median baseflow discharge, but less well for estimating the annual lower decile and the long-term mean, median, and lower decile. In general, the use of four measurements in a year is not substantially better than the use of two. [source] Hepatitis B virus DNA levels, precore mutations, genotypes and histological activity in chronic hepatitis BJOURNAL OF VIRAL HEPATITIS, Issue 4 2000Lindh The present study aimed to clarify how viraemia levels reflect the clinical stages of chronic hepatitis B virus (HBV) infection, in particular studying whether ,healthy carriers' can be identified by analysing HBV DNA levels with a highly sensitive quantitative assay. Histology activity index (HAI), alanine aminotransferase (ALT) level, genotype and precore mutations were compared with the HBV DNA level, as measured using the Amplicor HBV Monitor assay in a prospective study. In 124 hepatitis B e antigen-negative (HBeAg,) patients, the majority with mild liver disease, log HBV DNA levels showed a Gaussian distribution around a geometric mean of 33 000 genome copies ml,1, and increasing HBV DNA level was associated with significantly higher inflammation (HAIinfl) and fibrosis (HAIfibr) scores and higher ALTi (ALT ÷ the upper reference value). Severe inflammation (HAIinfl , 7) was seen in 83% (five of six), 36% (eight of 22) and 3% (one of 37) of HBeAg, patients with HBV DNA > 107, > 2 × 105 and < 104 copies ml,1, respectively. In severe HBeAg, hepatitis, patients with precore wild-type infection had lower HBV DNA levels than those with precore mutants. In 36 HBeAg-positive (HBeAg+) patients, no correlation between HBV DNA level and liver damage was seen. Ninety-six per cent of HBeAg, patients with ALTi < 0.5 had HAIinfl , 3. In HBeAg, carriers with ALTi 0.5,1.0, the relative risk for severe inflammation, comparing HBV DNA > 2 × 105 copies ml,1vs < 2 × 105 copies ml,1, was 14.7. In conclusion, in HBeAg, carriers, HBV DNA < 104 copies ml,1 or ALTi < 0.5 indicates mild inflammation, while > 2 × 105 copies ml,1 of HBV DNA may justify further investigations. Precore status may be relevant for the interpretation of viraemia. [source] Enumeration of Escherichia coli O157 in cattle faeces using most probable number technique and automated immunomagnetic separationLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2004N. Fegan Abstract Aims:, To determine the numbers of Escherichia coli O157 present in the faeces of naturally infected cattle. Methods and Results:, A combination of the most probable number (MPN) technique and automated immunomagnetic separation (AIMS) was used to enumerate E. coli O157 in cattle faeces from both pasture-fed and grain-fed animals. A total of 22 E. coli O157 positive faecal samples were enumerated for E. coli O157 (10 from pasture-fed and 12 from grain-fed animals). The numbers of E. coli O157 in cattle faeces varied from undetectable (<3 MPN g,1 of faeces) to 2·4 × 104 MPN g,1. There was no significant difference (P = 0·06) between the numbers of E. coli O157 in pasture-fed or grain-fed cattle faeces, although the geometric mean (antilog of the mean of log10 transformed MPN values) was higher in grain-fed (130 MPN g,1) than in pasture-fed (13 MPN g,1). Conclusions:, Although the number of samples tested is small, the results indicate that E. coli O157 make up a small proportion of the total E. coli population present in cattle faeces. Significance and Impact of the Study:, Information on the numbers of E. coli O157 present in cattle will assist in developing more robust quantitative risk assessments and formulating intervention strategies. [source] Effect of Intramolecular Transfer to Polymer on Stationary Free Radical Polymerization of Alkyl Acrylates, 2,MACROMOLECULAR THEORY AND SIMULATIONS, Issue 2 2006Improved Consideration of Termination Abstract Summary: Procedures are developed to estimate kinetic rate coefficients from available rate data for the free radical solution polymerization of butyl acrylate at 50,°C. The analysis is based upon a complete mechanistic set that includes the formation of mid-chain radicals through backbiting and their subsequent reaction, and contains no assumptions on how the rate coefficient for cross-termination of mid-chain and end-chain radicals is related to the two homo-termination rate coefficients. After a thorough statistical analysis, the results of the fitting are combined with other recent literature data to provide a complete set of individual rate coefficients for the butyl acrylate system. Monomer addition to a mid-chain radical is estimated to be slower than addition to a chain-end radical by a factor of more than 400. The termination of two mid-chain radicals is estimated to be two orders of magnitude slower than termination of two end-chain radicals, with the cross-termination rate coefficient close to the geometric mean. Formation of a mid-chain radical by intramolecular chain transfer to polymer by a chain-end radical. [source] Dietary intake in sensitized children with recurrent wheeze and healthy controls: a nested case,control studyALLERGY, Issue 4 2006C. S. Murray Background:, The rising prevalence of asthma and allergic disease remains unexplained. Several risk factors have been implicated including diet, in particular poly-unsaturated fats and antioxidant intake. Methods:, A nested case,control study comparing the dietary intake of sensitized children with recurrent wheeze (age 3,5 years) and nonsensitized children who had never wheezed was carried out within an unselected population-based cohort. Cases and controls were matched for age, sex, parental atopy, indoor allergen exposure and pet ownership. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire and nutrient analysis program. Results:, Thirty-seven case,control pairs (23 male, mean age 4.4 years) participated. Daily total polyunsaturated fat intake was significantly higher in sensitized wheezers (g/day, geometric mean, 95% confidence intervals: 7.1, 6.4,7.9) compared with nonsensitized nonwheezy children (5.6, 5.0,6.3, P = 0.003). Daily omega-3 and omega-6 fat intakes were not significantly different between the two groups. No significant differences were found in intake of any antioxidant or antioxidant cofactors between the groups. Conclusions:, Young sensitized wheezy children had a significantly higher total polyunsaturated fat intake compared with nonsensitized nonwheezy children. However, we were unable to distinguish a significant difference in specific poly-unsaturated fat intakes. Otherwise the children in both groups had a very similar nutritional intake. [source] | |||||||||||||||||||||||||||||||||||||||||||