EUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2006
G. Spalletta
Alzheimer's disease (AD) is a neurodegenerative disorder with mixed cognitive and behavioural clinical manifestations. The possession of apolipoprotein-E (ApoE) ,4 allelic variant is one of the most important risk factors for developing late-onset AD (LOAD). In this study we analysed the relationship between the entire range of behavioural symptoms, cognitive deficit, and sociodemographic characteristics and ApoE ,4 allele possession with multivariate logistic regression models in LOAD patients. Patients included (n = 171) were consecutively admitted in a memory clinic for the first diagnostic visit. Levels of behaviour and cognition within the last month were assessed by the Neuropsychiatric Inventory and Mini Mental State Examination. Presence of clinically significant psychosis, delusions and hallucinations at the early stage of the illness, from the onset to the first visit, was measured with diagnostic criteria. ApoE ,4 allele possession was associated with increased levels of delusions within the last month from the first visit (OR 1.23; 95% CI 1.01,1.50; P < 0.05) and with the presence of categorical delusions at the early stage until the first visit (OR 3.11; 95% CI 1.21,8.01; P < 0.02). In this study, which considers the entire range of behavioural expressions in LOAD patients at the early stage of the illness, the relationship between behaviour and ApoE ,4 allele is confirmed for delusions only. [source]

PURGING THE GENOME WITH SEXUAL SELECTION: REDUCING MUTATION LOAD THROUGH SELECTION ON MALES

EVOLUTION, Issue 3 2009
Michael C. Whitlock
Healthy males are likely to have higher mating success than unhealthy males because of differential expression of condition-dependent traits such as mate searching intensity, fighting ability, display vigor, and some types of exaggerated morphological characters. We therefore expect that most new mutations that are deleterious for overall fitness may also be deleterious for male mating success. From this perspective, sexual selection is not limited to influencing those genes directly involved in exaggerated morphological traits but rather affects most, if not all, genes in the genome. If true, sexual selection can be an important force acting to reduce the frequency of deleterious mutations and, as a result, mutation load. We review the literature and find various forms of indirect evidence that sexual selection helps to eliminate deleterious mutations. However, direct evidence is scant, and there are almost no data available to address a key issue: is selection in males stronger than selection in females? In addition, the total effect of sexual selection on mutation load is complicated by possible increases in mutation rate that may be attributable to sexual selection. Finally, sexual selection affects population fitness not only through mutation load but also through sexual conflict, making it difficult to empirically measure how sexual selection affects load. Several lines of enquiry are suggested to better fill large gaps in our understanding of sexual selection and its effect on genetic load. [source]

PERSPECTIVE: PURGING THE GENETIC LOAD: A REVIEW OF THE EXPERIMENTAL EVIDENCE

EVOLUTION, Issue 12 2002
Peter Crnokrak
Abstract., Inbreeding depression, the reduction in fitness that accompanies inbreeding, is one of the most important topics of research in evolutionary and conservation genetics. In the recent literature, much attention has been paid to the possibility of purging the genetic load. If inbreeding depression is due to deleterious alleles, whose effect on fitness are negative when in a homozygous state, then successive generations of inbreeding may result in a rebound in fitness due to the selective decrease in frequency of deleterious alleles. Here we examine the experimental evidence for purging of the genetic load by collating empirical tests of rebounds in fitness-related traits with inbreeding in animals and plants. We gathered data from 28 studies including five mammal, three insect, one mollusc, and 13 plant species. We tested for purging by examining three measures of fitness-component variation with serial generations of inbreeding: (1) changes in inbreeding depression, (2) changes in fitness components of inbred lines relative to the original outbred line, and (3) purged population (outcrossed inbred lines) trait means as a function of ancestral outbred trait means. Frequent and substantial purging was found using all three measures, but was particularly pronounced when tracking changes in inbreeding depression. Despite this, we found little correspondence between the three measures of purging within individual studies, indicating that the manner in which a researcher chooses to estimate purging will affect interpretation of the results obtained. The discrepancy suggests an alternative hypothesis: rebounds in fitness with inbreeding may have resulted from adaptation to laboratory conditions and not to purging when using outcrossed inbred lines. However, the pronounced reduction in inbreeding depression for a number of studies provides evidence for purging, as the measure is likely less affected by selection for laboratory conditions. Unlike other taxon-specific reviews on this topic, our results provide support for the purging hypothesis, but firm predictions about the situations in which purging is likely or the magnitude of fitness rebound possible when populations are inbred remain difficult. Further research is required to resolve the discrepancy between the results obtained using different experimental approaches. [source]

FIXATION OF NEW ALLELES AND THE EXTINCTION OF SMALL POPULATIONS: DRIFT LOAD, BENEFICIAL ALLELES, AND SEXUAL SELECTION

EVOLUTION, Issue 6 2000
Michael C. Whitlock
Abstract With a small effective population size, random genetic drift is more important than selection in determining the fate of new alleles. Small populations therefore accumulate deleterious mutations. Left unchecked, the effect of these fixed alleles is to reduce the reproductive capacity of a species, eventually to the point of extinction. New beneficial mutations, if fixed by selection, can restore some of this lost fitness. This paper derives the overall change in fitness due to fixation of new deleterious and beneficial alleles, as a function of the distribution of effects of new mutations and the effective population size. There is a critical effective size below which a population will on average decline in fitness, but above which beneficial mutations allow the population to persist. With reasonable estimates of the relevant parameters, this critical effective size is likely to be a few hundred. Furthermore, sexual selection can act to reduce the fixation probability of deleterious new mutations and increase the probability of fixing new beneficial mutations. Sexual selection can therefore reduce the risk of extinction of small populations. [source]

COMPENSATING FOR OUR LOAD OF MUTATIONS: FREEZING THE MELTDOWN OF SMALL POPULATIONS

EVOLUTION, Issue 5 2000
Art Poon
Abstract We have investigated the reduction of fitness caused by the fixation of new deleterious mutations in small populations within the framework of Fisher's geometrical model of adaptation. In Fisher's model, a population evolves in an n -dimensional character space with an adaptive optimum at the origin. The model allows us to investigate compensatory mutations, which restore fitness losses incurred by other mutations, in a context-dependent manner. We have conducted a moment analysis of the model, supplemented by the numerical results of computer simulations. The mean reduction of fitness (i.e., expected load) scaled to one is approximately n/(n + 2Ne), where Ne is the effective population size. The reciprocal relationship between the load and Ne implies that the fixation of deleterious mutations is unlikely to cause extinction when there is a broad scope for compensatory mutations, except in very small populations. Furthermore, the dependence of load on n implies that pleiotropy plays a large role in determining the extinction risk of small populations. Differences and similarities between our results and those of a previous study on the effects of Ne and n are explored. That the predictions of this model are qualitatively different from studies ignoring compensatory mutations implies that we must be cautious in predicting the evolutionary fate of small populations and that additional data on the nature of mutations is of critical importance. [source]

Heritability of plasma amyloid , in typical late-onset Alzheimer's disease pedigrees

GENETIC EPIDEMIOLOGY, Issue 1 2001
Nilufer Ertekin-Taner
Abstract Plasma amyloid ,42 peptide (A,42) levels are significantly elevated in all genetic forms of early-onset Alzheimer's disease caused by familial Alzheimer's disease mutations or Down's syndrome. Moreover, recent studies have determined that both plasma A,42 and A,40 levels are significantly elevated in late-onset Alzheimer's disease (LOAD) patients, their cognitively normal first-degree relatives, and members of typical LOAD families when compared to appropriate controls. To determine the magnitude of the genetic component affecting plasma A, levels, we estimated the heritability of plasma A,42 and A,40 in 15 extended, multigenerational LOAD pedigrees, using a variance components method. Heritability estimates as high as 73 and 54% were found for plasma A,42 and A,40 levels, respectively. Inclusion of the ApoE ,4 dosage as a covariate was not found to have a significant effect on the heritability of these traits. These results suggest that genetic determinants other than ApoE account for a very substantial percentage of the phenotypic variance in plasma A, levels. The high heritability and the significant elevation of these traits in LOAD pedigrees suggest that at least some of the genetic determinants of plasma A, levels may lead to elevated A, and LOAD in these families. Thus, we suggest that plasma A, levels are quantitative traits that may be excellent surrogate markers for use in linkage analysis to identify loci that are important in typical LOAD. Genet. Epidemiol. 21:19,30, 2001. © 2001 Wiley-Liss, Inc. [source]

Genomic convergence to identify candidate genes for Alzheimer Disease on chromosome 10

HUMAN MUTATION, Issue 3 2009
Xueying Liang
Abstract A broad region of chromosome 10 (chr10) has engendered continued interest in the etiology of late-onset Alzheimer Disease (LOAD) from both linkage and candidate gene studies. However, there is a very extensive heterogeneity on chr10. We converged linkage analysis and gene expression data using the concept of genomic convergence that suggests that genes showing positive results across multiple different data types are more likely to be involved in AD. We identified and examined 28 genes on chr10 for association with AD in a Caucasian case-control dataset of 506 cases and 558 controls with substantial clinical information. The cases were all LOAD (minimum age at onset ,60 years). Both single marker and haplotypic associations were tested in the overall dataset and 8 subsets defined by age, gender, ApoE and clinical status. PTPLA showed allelic, genotypic and haplotypic association in the overall dataset. SORCS1 was significant in the overall data sets (p=0.0025) and most significant in the female subset (allelic association p=0.00002, a 3-locus haplotype had p=0.0005). Odds Ratio of SORCS1 in the female subset was 1.7 (p<0.0001). SORCS1 is an interesting candidate gene involved in the A, pathway. Therefore, genetic variations in PTPLA and SORCS1 may be associated and have modest effect to the risk of AD by affecting A, pathway. The replication of the effect of these genes in different study populations and search for susceptible variants and functional studies of these genes are necessary to get a better understanding of the roles of the genes in Alzheimer disease. 30, 463,471, 2009. © 2008 Wiley-Liss, Inc. [source]

DECISION SUPPORT FOR ALLOCATION OF WATERSHED POLLUTION LOAD USING GREY FUZZY MULTIOBJECTIVE PROGRAMMING,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2006
Ho-Wen Chen
ABSTRACT: This paper uses the grey fuzzy multiobjective programming to aid in decision making for the allocation of waste load in a river system under versatile uncertainties and risks. It differs from previous studies by considering a multicriteria objective function with combined grey and fuzzy messages under a cost benefit analysis framework. Such analysis technically integrates the prior information of water quality models, water quality standards, wastewater treatment costs, and potential benefits gained via in-stream water quality improvement. While fuzzy sets are characterized based on semantic and cognitive vagueness in decision making, grey numbers can delineate measurement errors in data collection. By employing three distinct set theoretic fuzzy operators, the synergy of grey and fuzzy implications may smoothly characterize the prescribed management complexity. With the aid of genetic algorithm in the solution procedure, the modeling outputs contribute to the development of an effective waste load allocation and reduction scheme for tributaries in this subwatershed located in the lower Tseng-Wen River Basin, South Taiwan. Research findings indicate that the inclusion of three fuzzy set theoretic operators in decision analysis may delineate different tradeoffs in decision making due to varying changes, transformations, and movements of waste load in association with land use pattern within the watershed. [source]

C677T polymorphism of methylenetetrahydrofolate reductase gene affects plasma homocysteine level and is a genetic factor of late-onset Alzheimer's disease

PSYCHOGERIATRICS, Issue 1 2004
Tomoyuki KIDA
Abstract Background:, Elevated plasma homocysteine levels are known as a risk for atherosclerotic vascular disease and venous thrombosis and have been shown as a risk for late-onset Alzheimer's disease (LOAD). Method:, To examine the effect of genetic factors predisposing to elevated plasma homocysteine levels on the occurrence of LOAD, we determined the genotype of a C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene and a variable number tandem repeat (VNTR) spanning exon 13,intron 13 boundary of cystathionine ,-synthase (CBS) gene in patients with LOAD and community-based control subjects. Results:, Logistic regression indicated that the MTHFR-T allele was a risk for LOAD (P < 0.05), independently from apolipoprotein E-,4 (APOE-,4) allele. Kaplan,Meier tests showed that in APOE-,4 non-carriers, individuals with the MTHFR-TT genotype have occurences of LOAD earlier than those with the MTHFR-CC genotype (P < 0.05). Multiple regression analysis indicates that MTHFR-T allele increases plasma homocysteine levels (P = 0.0002), while the number of X chromosomes decreases (P = 0.01). Plasma homocysteine level was not correlated with age, plasma albumin reflecting nutritional condition, and the dose of APOE-,4 allele. The CBS-20 VNTR allele showed the same trend to increase plasma homocysteine level as the MTHFR-T allele, but a risk effect for LOAD was not evident. Conclusion:, A genetic propensity for elevated plasma homocysteine levels, explained by the MTHFR-T allele encoding defective enzymatic function, is involved in the development of LOAD, particularly in APOE-,4 non-carriers, and that homocysteine metabolism could be a preventive target to LOAD in the elderly. [source]

CALHM1 Polymorphism is not Associated with Late-onset Alzheimer Disease

ANNALS OF HUMAN GENETICS, Issue 3 2009
Gary W. Beecham
Summary Data suggests that the P86L polymorphism (rs2986017) in the calcium homeostasis modulator 1 (CALHM1) gene interferes with CALHM1 functionality, increases A, levels, and is associated with late-onset Alzheimer's disease (LOAD). Previous studies have demonstrated association with P86L and LOAD in three of five case-control cohorts, and a joint analysis of all datasets showed association with a p-value of 2 × 10,10 and an allele-specific odds ratio of 1.44 (2,043 cases, 1,361 controls total). In this short communication we attempt to replicate these results in our case-control cohort (510 cases, 524 controls). We show no association between P86L and LOAD despite having sufficient power to detect at the reported odds ratios, and briefly discuss potential reasons for the discrepancy. [source]

Linkage and Association Study of Late-Onset Alzheimer Disease Families Linked to 9p21.3

ANNALS OF HUMAN GENETICS, Issue 6 2008
S. Züchner
Summary A chromosomal locus for late-onset Alzheimer disease (LOAD) has previously been mapped to 9p21.3. The most significant results were reported in a sample of autopsy-confirmed families. Linkage to this locus has been independently confirmed in AD families from a consanguineous Israeli-Arab community. In the present study we analyzed an expanded clinical sample of 674 late-onset AD families, independently ascertained by three different consortia. Sample subsets were stratified by site and autopsy-confirmation. Linkage analysis of a dense array of SNPs across the chromosomal locus revealed the most significant results in the 166 autopsy-confirmed families of the NIMH sample. Peak HLOD scores of 4.95 at D9S741 and 2.81 at the nearby SNP rs2772677 were obtained in a dominant model. The linked region included the cyclin-dependent kinase inhibitor 2A gene (CDKN2A), which has been suggested as an AD candidate gene. By re-sequencing all exons in the vicinity of CDKN2A in 48 AD cases, we identified and genotyped four novel SNPs, including a non-synonymous, a synonymous, and two variations located in untranslated RNA sequences. Family-based allelic and genotypic association analysis yielded significant results in CDKN2A (rs11515: PDT p = 0.003, genotype-PDT p = 0.014). We conclude that CDKN2A is a promising new candidate gene potentially contributing to AD susceptibility on chromosome 9p. [source]

No Association between SNP rs498055 on Chromosome 10 and Late-Onset Alzheimer Disease in Multiple Datasets

ANNALS OF HUMAN GENETICS, Issue 1 2008
Xueying Liang
Summary SNP rs498055 in the predicted gene LOC439999 on chromosome 10 was recently identified as being strongly associated with late-onset Alzheimer disease (LOAD). This SNP falls within a chromosomal region that has engendered continued interest generated from both preliminary genetic linkage and candidate gene studies. To independently evaluate this interesting candidate SNP we examined four independent datasets, three family-based and one case-control. All the cases were late-onset AD Caucasian patients with minimum age at onset , 60 years. None of the three family samples or the combined family-based dataset showed association in either allelic or genotypic family-based association tests at p < 0.05. Both original and OSA two-point LOD scores were calculated. However, there was no evidence indicating linkage no matter what covariates were applied (the highest LOD score was 0.82). The case-control dataset did not demonstrate any association between this SNP and AD (all p-values > 0.52). Our results do not confirm the previous association, but are consistent with a more recent negative association result that used family-based association tests to examine the effect of this SNP in two family datasets. Thus we conclude that rs498055 is not associated with an increased risk of LOAD. [source]

A NEW TEST APPARATUS AND METHOD FOR FRICTION FORCE MEASUREMENT IN JOURNAL BEARINGS UNDER DYNAMIC LOADING: Part I

EXPERIMENTAL TECHNIQUES, Issue 5 2005
A. Biyiklio
No abstract is available for this article. [source]

STORM DISCHARGE, LOADS, AND AVERAGE CONCENTRATIONS IN NORTHWEST OHIO RIVERS, 1975,1995,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 2 2001
R. Peter Richards
ABSTRACT: A computerized technique was developed to identify storm runoff episodes and calculate storm discharges, storm loads, and storm average concentrations for each event in datasets with up to 10,000 records. This technique was applied to four watersheds within the Lake Erie drainage basin and identified between 160 and 250 runoff events in each. Storm event loads and storm event mean concentrations were calculated for each runoff event for suspended solids, total phosphorus, soluble reactive phosphorus, nitrate, and total Kjeldahl nitrogen. The basic characteristics of the resulting data are described, as are systematic differences as a function of watershed size, seasonal differences, and trends over time. Many of the results of this study reflect the importance of nonpoint processes and improvements in agricultural best management practices in these watersheds. [source]

Managing the Unique Size-related Issues of Pediatric Resuscitation: Reducing Cognitive Load with Resuscitation Aids

ACADEMIC EMERGENCY MEDICINE, Issue 8 2002
Robert Luten MD
Abstract A resuscitation is a complicated event that requires for its optimal outcome the effective completion of a distinct series of actions, some simple, some complex, most occurring simultaneously or in close proximity. In children, these actions are determined not only by the clinical situation, but also by a series of age and size factors particular to each child. Different tasks require different levels of cognitive load, or mental effort. Cognitive load describes the mental burden experienced by the decision maker and will be higher when the task is less familiar or more demanding. In the setting of resuscitation, it refers to the cumulative demands of patient assessment, the ongoing decisions for each of the various steps, and decisions around procedural intervention (e.g., intubation). In children, the level of task complexity and, hence, cognitive load is increased by the unique component of variability of pediatric age and size, introducing logistical factors, many of which involve computations. The purpose of this paper is to examine the effects of age/size-related variables on the pediatric resuscitative process and to explore how these effects can be mitigated using resuscitation aids. The concept of cognitive load and its relation to performance in resuscitation is introduced and is used to demonstrate the effect of the various aids in the pediatric resuscitative process. [source]

Cost optimization of composite floors using neural dynamics model

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 11 2001
Hojjat Adeli
Abstract The design of composite beams is complicated and highly iterative. Depending on the design parameters a beam can be fully composite or partially composite. In the case of design on the basis of the American Institute of Steel Construction (AISC) Load and Resistance Factor Design (LRFD) one has to consider the plastic deformations. As pointed out by Lorenz, the real advantage of the LRFD code can be realized in the minimum cost design. In this article, we present a general formulation for the cost optimization of composite beams based on the AISC LRFD specifications by including the costs of (a) concrete, (b) steel beam, and (c) shear studs. The problem is formulated as a mixed integer-discrete non-linear programming problem and solved by the recently patented neural dynamics model of Adeli and Park (U.S. patent 5,815,394 issued on September 29, 1998). It is shown that use of the cost optimization algorithm presented in this article results in substantial cost savings. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Design Strategy of Minipig Molars Using Electronic Speckle Pattern Interferometry: Comparison of Deformation under Load between the Tooth-Mandible Complex and the Isolated Tooth,

ADVANCED MATERIALS, Issue 4 2009
Netta Lev-Tov Chattah
Using electronic speckle pattern interferometry minipig molars were tested under load inside the bone socket and when embedded in a stiff polymer. It is demonstrated that the molar bends in the direction of the load in both configurations even at low loads. This shows that the intrinsic reaction of the tooth crown to load is complemented by the structures supporting the tooth. [source]

Assessment Center Procedures: Cognitive Load During the Observation Phase

INTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 4 2002
Nanja J. Kolk
This study explores the traditional procedure of observing assessment center exercises while taking notes vs. an alternative procedure where assessors merely observe and postpone note-taking until immediately after the exercise. The first procedure is considered to be cognitively demanding due to the requirement of simultaneous note-taking and observing. Also, dual task processing (concurrent observing and note-taking) is considered to be especially demanding for assessors without rating experience. The procedures are evaluated using a 2 × 2 design (with note-taking/without note-taking × experienced/inexperienced). Some 121 experienced and inexperienced assessors rated videotaped candidates, observing either with or without taking notes. Results showed that experienced assessors yield significantly higher differential accuracy than inexperienced assessors. We did not find an effect of observation procedure on accuracy, interrater reliability or halo. Implications for future research are described. [source]

Allostatic Load and Frailty in Older Adults

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2009
Tara L. Gruenewald PhD
OBJECTIVES: To examine the association between allostatic load (AL), an index of multisystem physiological dysregulation, and frailty development over a 3-year follow-up in a sample of older adults. DESIGN: Longitudinal cohort study. SETTING: Community. PARTICIPANTS: High-functioning men and women aged 70 to 79 at study entry. MEASUREMENTS: Multisystem physiological dysregulation, or AL, was assessed according to 13 biomarkers of cardiovascular, endocrine, immune, and metabolic function. An AL score was computed as the total number of biomarkers for which participant values fell into high-risk biomarker quartiles. Frailty status (not frail, intermediate frail, frail) was determined according to the total number of five indicators of frailty: weight loss, exhaustion, weak grip, slow gait, and low physical activity. The association between level of AL at baseline and frailty status 3 years later was examined using ordinal logistic regression in 803 participants not frail at baseline. RESULTS: In a multivariable model adjusting for sociodemographic, health, and behavioral characteristics, each 1-unit increase in AL at baseline was associated with a 10% greater likelihood of frailty at the 3-year follow-up (cumulative adjusted odds ratio=1.10, 95% confidence interval=1.03,1.19). CONCLUSION: These findings support the hypothesis that dysregulation across multiple physiological systems is associated with greater risk of frailty. Greater levels of multisystem physiological dysregulation may serve as a warning sign of frailty development in later life. [source]

Frailty, Allostatic Load, and the Future of Predictive Gerontology

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2009
George A. Kuchel MD
No abstract is available for this article. [source]

Stereotypes and Shifting Standards: Some Paradoxical Effects of Cognitive Load

JOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 10 2003
Monica Biernat
Four studies tested a prediction derived from the shifting-standards model (Biernat, Manis, & Nelson, 1991) regarding the role stereotypes play in judgments of individual group members. Previous research has documented that stereotyping effects are stronger on objective than on subjective response scales, and the present studies found that these effects were intensified when participants were under heavy cognitive load. Stereotyping effects increased on objective judgment scales, but decreased on subjective scales. The latter is a paradoxical effect: By relying on stereotypes, one may increasingly use them as within-category comparative standards, which leads to the apparent reduction of stereotyping effects. [source]

Effect of High Pressure Pasteurization on Bacterial Load and Bioactivity of Echinacea Purpurea

JOURNAL OF FOOD SCIENCE, Issue 7 2010
Xiu-Min Chen
Abstract:, High hydrostatic pressure (HHP) technology was applied to organic Echinacea purpurea (E. purpurea) roots and flowers to determine the feasibility of using this technology for cold herb pasteurization, to produce microbiologically safe and shelf-stable products for the natural health products (NHPs) industry. HHP significantly (P < 0.01) reduced microbial contamination in both roots and flowers without affecting the phytochemical retention of chicoric and chlorogenic acids, and total alkamide contents. The antioxidant activity of E. purpurea methanol-derived extracts, evaluated in both chemical (2,2,-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) [ABTS] and oxygen radical absorption capacity [ORAC] assay) and in cell culture models (RAW264, 7 macrophage, H2O2 -induced intracellular oxidation, and lipopolysaccharide [LPS]-induced nitric oxide production), was not adversely affected by the application of HHP at both 2 and 5 min at 600 mPa. Furthermore, HHP did not affect the capacity of E. purpurea extracts to suppress nitric oxide production in LPS-activated macrophage cells. Therefore, our results show that HHP is an effective pasteurization process treatment to reduce microbial-contamination load while not adversely altering chemical and bioactive function of active constituents present in organic E. purpurea. Practical Application:, Our study reports for the first time, the effectiveness of using high hydrostatic pressure (HHP) technology pressure to pasteurize E. purpurea root and flower, and the comparative retention of bioactive phytochemicals. Therefore, this technique can be used in food and natural health product industries to produce high-quality, microbiologically safe, and shelf-stable products. [source]

Potential Application of Hot Rehydration Alone or in Combination with Hydrogen Peroxide to Control Pectin Methylesterase Activity and Microbial Load in Cold-stored Intermediate-moisture Sun-dried Figs

JOURNAL OF FOOD SCIENCE, Issue 3 2004
D. DEMIRBÜKER
ABSTRACT: Sun-dried figs contain a considerable amount of pectin methylesterase (PME) activity (22 JAM COOH/ min/g). The enzyme causes softening and loss of desired gummy texture in cold-stored intermediate-moisture (IM) sun-dried figs brought to a 28% to 29% moisture range. Partial reduction of PME activity (28%) delayed undesirable textural changes in IM figs rehydrated at 80 °C for 16 min. The heat treatment did not cause a considerable reduction in microbial load. However, the addition of 2.5% H2O2 to the rehydration medium at 80 °C reduced the initial total mesophilic aerobic count of figs by at least 90% and turned the figs from a brown color to a desirable and stable yellow-light brown. The in situ fig catalase remains after rehydration at 80 °C. Thus, by reducing the contact period of figs with H2O2 or by pureeing figs, it is possible to eliminate residual H2O2 and to obtain safe and SO2-free light-colored fig products. [source]

Allostatic Load and Failure to Progress

JOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 1 2008
Gene Cranston Anderson PhD
No abstract is available for this article. [source]

The Watershed Deposition Tool: A Tool for Incorporating Atmospheric Deposition in Water-Quality Analyses,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 4 2009
Donna B. Schwede
Abstract:, A tool for providing the linkage between air and water-quality modeling needed for determining the Total Maximum Daily Load (TMDL) and for analyzing related nonpoint-source impacts on watersheds has been developed. Using gridded output of atmospheric deposition from the Community Multiscale Air Quality (CMAQ) model, the Watershed Deposition Tool (WDT) calculates average per unit area and total deposition to selected watersheds and subwatersheds. CMAQ estimates the wet and dry deposition for all of its gaseous and particulate chemical species, including ozone, sulfur species, nitrogen species, secondary organic aerosols, and hazardous air pollutants at grid scale sizes ranging from 4 to 36 km. An overview of the CMAQ model is provided. The somewhat specialized format of the CMAQ files is not easily imported into standard spatial analysis tools. The WDT provides a graphical user interface that allows users to visualize CMAQ gridded data and perform further analyses on selected watersheds or simply convert CMAQ gridded data to a shapefile for use in other programs. Shapefiles for the 8-digit (cataloging unit) hydrologic unit code polygons for the United States are provided with the WDT; however, other user-supplied closed polygons may be used. An example application of the WDT for assessing the contributions of different source categories to deposition estimates, the contributions of wet and dry deposition to total deposition, and the potential reductions in total nitrogen deposition to the Albemarle-Pamlico basin stemming from future air emissions reductions is used to illustrate the WDT capabilities. [source]

EPA'S BASINS MODEL: GOOD SCIENCE OR SERENDIPITOUS MODELING?,

JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2000
Ray C. Whittemore
ABSTRACT: Better Assessment Science Integrating Point and Non-point Sources (BASINS) is a geographic-based watershed assessment tool developed by EPA's Office of Water to help states more efficiently target and evaluate water-bodies that are not meeting water quality standards. BASINS (EPA, 1996a, 1998) brings together data on water quality and quantity, land uses, point source loadings, and other related spatial data with supporting nonpoint and water quality models at a quicker and more effective pace. EPA developed BASINS, to better integrate point and nonpoint source water quality assessments for the Nation's 2100+ watersheds. In its zeal to achieve this endpoint, EPA has initiated a simplistic approach that was expected to grow through scientific enhancements as TMDL developers become more familiar with modeling requirements. BASINS builds upon federal databases of water quality conditions and point source loadings for numerous parameters where quality assurance is suspect in some cases. Its design allows comprehensive assessments and modeling in typical Total Maximum Daily Load (TMDL) computations. While the TMDL utility is the primary reason BASINS was developed, other longer-range water quality assessments will become possible as the Agency expands the suite of assessment models and databases in future releases. The simplistic approach to modeling and user-friendly tools gives rise, however, to technical and philosophical concerns related to default data usage. Seamless generation of model input files and the failure of some utilities to work properly suggest to NCASI that serious problems may still exist and prompts the need for a more rigorous peer-review. Furthermore, sustainable training becomes paramount, as some older modelers will be unfamiliar with Geographic Information System (GIS) technology and associated computer skills. Overall, however, BASINS was judged to be an excellent beginning tool to meet the complex environmental modeling needs in the 21st Century. [source]

Electrical Characteristics of an Electronic Control Device Under a Physiologic Load: A Brief Report

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2010
DONALD M. DAWES M.D.
Background:,Law enforcement officers use electronic control devices (ECDs), such as the TASER X26 (TASER International, Inc., Scottsdale, AZ, USA), to control resisting subjects. Some of the debate on the safety of the devices has centered on the electrical characteristics of the devices. The electrical characteristics published by TASER International have historically based on discharges into a 400 , resistor. There are no studies that the authors are aware of that report the electrical characteristics under a physiologic load. In this study, we make an initial attempt to determine the electrical characteristics of the TASER X26 during a 5-second exposure in human volunteers. Methods:,Subjects received an exposure to the dry, bare chest (top probe), and abdomen (bottom probe) with a standard TASER X26 in the probe deployment mode for 5 seconds. There were 10,11 pulse captures during the 5 seconds. Resistance was calculated using the sum of the absolute values of the instantaneous voltage measurements divided by the sum of the absolute values of the instantaneous current measurements (Ohm's Law). Results:,For the eight subjects, the mean spread between top and bottom probes was 12.1 inches (30.7 cm). The mean resistance was 602.3 ,, with a range of 470.5,691.4 ,. The resistance decreased slightly over the 5-second discharge with a mean decrease of 8.0%. The mean rectified charge per pulse was 123.0 ,C. The mean main phase charge per pulse was 110.5 ,C. The mean pulse width was 126.9 ,s. The mean voltage per pulse was 580.1 V. The mean current per pulse was 0.97 A. The average peak main phase voltage was 1899.2 V and the average peak main phase current was 3.10 A. Conclusions:,The mean tissue resistance was 602.3 , in this study. There was a decrease in resistance of 8% over the 5-second exposure. This physiologic load is different than the 400 , laboratory load used historically by the manufacturer. We recommend future characterization of these devices use a physiologic load for reporting electrical characteristics. We also recommend that all the electrical characteristics be reported. (PACE 2010; 33:330,336) [source]

A Holistic Simulation Approach from a Measured Load to Element Stress Using Combined Multi-body Simulation and Finite Element Modelling

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2009
Matthias Harter
The design of vehicle bodies requires the knowledge of the vehicle's structural response to external loads and disturbances. In rigid multi-body simulation the dynamic behaviour of complex systems is calculated with rigid bodies and neglect of body elasticity. On the other hand, in finite element models large degree of freedom numbers are used to represent the elastic properties of a single body. Both simulation methods can be combined, if the finite element model size is reduced to a degree of freedom number feasible to multi-body simulation. The application to practical purposes requires the use and interconnection of several different software tools. In this contribution a holistic method is presented, which starts with the measurement or synthesis of loads and excitations, continues with the integration of a reduced finite element model into a multi-body system, the dynamic response calculation of this combined model, and concludes with the result expansion to the full finite element model for calculating strain and stress values at any point of the finite element mesh. The applied software tools are Simpack, Nastran, and Matlab. An example is given with a railway vehicle simulated on measured track geometry. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Stochastic Response of a Continuous System with Stochastic Surface Irregularities to an Accelerated Load

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2003
C.A. Schenk
The problem of calculating the second moment characteristics of the response of a general class of nonconservative linear distributed parameter systems with stochastically varying surface roughness, excited by a moving concentrated load, is investigated. In particular the case of an accelerated load is discussed. The surface roughness is modeled as a Gaussian stationary second order process. For the stochastic representation of the surface roughness a orthogonal series expansion of the covariance kernel, the so called Karhunen-Loéve expansion, is applied. The resulting initial/boundary value problem is transformed by eigenfunction expansion into the modal state space. Second moment characteristics of the response are determined numerically by direct integration using a Runge-Kutta method. [source]

ORIGINAL ARTICLE: Analysis of Immunological Markers Associated with Pregnancy and HIV-1 Infection: Relevance in Perinatal Transmission in HIV-1-Infected Pregnant Women with Low Plasma Viral Load

AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2008
Naresh Sachdeva
Problem, In HIV-1-infected pregnant women with low plasma viral load, risk factors associated with perinatal HIV-1 transmission are not clearly understood. Method of study, We analyzed distribution of peripheral CD8 T-cell subsets, plasma cytokines and measured secretory leukocyte peptidase inhibitor (SLPI) and myeloid-related protein (MRP)-8 levels in whole-blood and cervico-vaginal fluid (CVF) specimens obtained from 35 HIV-1-infected pregnant women (group 1), 12 HIV-1-infected non-pregnant women (group 2) and 15 HIV-1 uninfected pregnant women (group 3). Results, The group 1 women had higher expression of CD38, human leukocyte antigen-DR and CD95 on CD8 T-cells and higher levels of plasma tumor necrosis factor-, and epidermal growth factor. CVF-SLPI levels were the highest in group-3, while MRP-8 levels were the highest in group 1 women in plasma and CVF (P < 0.01). Although there were no cases of perinatal HIV-1 transmission, group 1 women undergoing HIV-1-indicated cesarean section had lower levels of CVF-SLPI as compared with those undergoing normal vaginal delivery. Conclusion, Pregnancy contributes to the activation of peripheral CD8 T cells and increase in pro-inflammatory cytokines. Production of protective mucosal secretory factors such as SLPI is affected by HIV-1 infection in pregnant women and down-regulated SLPI levels may indirectly indicate a higher possibility of perinatal HIV-1 transmission. [source]