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Search Results: 1 - 10 of 462317 matches for " Frances A Tylavsky "
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Parental ages and levels of DNA methylation in the newborn are correlated
Ronald M Adkins, Fridtjof Thomas, Frances A Tylavsky, Julia Krushkal
BMC Medical Genetics , 2011, DOI: 10.1186/1471-2350-12-47
Abstract: Using a genome-wide survey of 27,578 CpG dinucleotides in a cohort of 168 newborns, we examined the relationship between DNA methylation in newborns and a variety of parental and newborn traits. We found that methylation levels of 144 CpGs belonging to 142 genes were significantly correlated with maternal age. A weaker correlation was observed with paternal age. Among these genes, processes related to cancer were over-represented, as were functions related to neurological regulation, glucose/carbohydrate metabolism, nucleocytoplasmic transport, and transcriptional regulation. CpGs exhibiting gender differences in methylation were overwhelmingly located on the X chromosome, although a small subset of autosomal CpGs were found in genes previously shown to exhibit gender-specific differences in methylation levels.These results indicate that there are differences in CpG methylation levels at birth that are related to parental age and that could influence disease risk in childhood and throughout life.DNA methylation is a normal, heritable epigenetic modification that down-regulates the expression of approximately 1/3 of human genes [1-3] and is key to the allele-specific imprinting of genes [4]. DNA methylation also plays an important role in disease. For example, overall DNA hypomethylation accompanied by gene-specific hypermethylation is a hallmark of cancer [5]. Additionally, shifts in DNA methylation patterns appear to be involved in the normal aging process and increase in disease susceptibility [6]. Indeed, there is ample evidence for characteristic changes in the patterns of DNA methylation with age.The earliest data supporting progressive changes in DNA methylation patterns with age came from global studies of blood that demonstrated lower levels of methylation in older individuals [7] and greater differences in methylation in older monozygotic twins [8]. Christensen et al. [9] examined 217 tissues sampled from a range of non-diseased solid tissues and blood. In
Calcium Intake and Body Composition in African-American Children and Adolescents at Risk for Overweight and Obesity
Frances A. Tylavsky,Patricia A. Cowan,Sarah Terrell,Merschon Hutson,Pedro Velasquez-Mieyer
Nutrients , 2010, DOI: 10.3390/nu2090950
Abstract: This study examined the role of calcium intake on body composition in 186 African-American adolescents at risk for overweight and obesity. The average weight of 89.8 kg ± 23.6 (SD) had a mean BMI z score of 2.2. Females with a calcium intake of < 314 mg/day had higher percent fat mass compared to those with the highest calcium intakes that were ≥ 634 mg/day. Compared to those with a low calcium intake (< 365 mg/day), those with the highest calcium intake of > 701 mg/day had higher intake of thiamin, folate, cobalamin, vitamin D, phosphorus, iron, zinc.
BMI and an Anthropometry-Based Estimate of Fat Mass Percentage Are Both Valid Discriminators of Cardiometabolic Risk: A Comparison with DXA and Bioimpedance
Benno Krachler,Eszter V?lgyi,Kai Savonen,Frances A. Tylavsky,Markku Alén,Sulin Cheng
Journal of Obesity , 2013, DOI: 10.1155/2013/862514
Abstract: Objective. To determine whether categories of obesity based on BMI and an anthropometry-based estimate of fat mass percentage (FM% equation) have similar discriminative ability for markers of cardiometabolic risk as measurements of FM% by dual-energy X-ray absorptiometry (DXA) or bioimpedance analysis (BIA). Design and Methods. A study of 40–79-year-old male ( ) and female ( ) Finns. Weight, height, blood pressure, triacylglycerols, HDL cholesterol, and fasting blood glucose were measured. Body composition was assessed by DXA and BIA and a FM%-equation. Results. For grade 1 hypertension, dyslipidaemia, and impaired fasting glucose >6.1 mmol/L, the categories of obesity as defined by BMI and the FM% equation had 1.9% to 3.7% ( ) higher discriminative power compared to DXA. For grade 2 hypertension the FM% equation discriminated 1.2% ( ) lower than DXA and 2.8% ( ) lower than BIA. Receiver operation characteristics confirmed BIA as best predictor of grade 2 hypertension and the FM% equation as best predictor of grade 1 hypertension. All other differences in area under curve were small (≤0.04) and 95% confidence intervals included 0. Conclusions. Both BMI and FM% equations may predict cardiometabolic risk with similar discriminative ability as FM% measured by DXA or BIA. 1. Introduction Obesity is associated with cardiometabolic risk [1, 2]. The most commonly used definition of obesity is the body mass index (BMI). With the advance of more sophisticated measurements tools, assessment of body composition, rather than body mass, is increasingly used to study obesity-associated health risks [3, 4]. Although BMI correlates well with fat mass percentage (FM%) [5] it gives only a fair estimate of FM% [6], and individuals with large muscle mass may be misclassified as overweight or obese [7]. Dual-energy X-ray absorptiometry (DXA) devices estimate FM% with acceptable accuracy and have become the reference method for estimating body composition [8]. However, their drawbacks are radiation exposure, relatively high cost, and limited accessibility. Compared to DXA, bioimpedance analysis (BIA) has been shown to provide a good degree of accuracy in various populations of healthy subjects with stable hydration levels and within the normal range of body fat [9–11]. Bioimpedance is dependent not only on body composition (water content) but also on body size (cross-sectional areas in trunk and limbs). Since the proportions of body segments depend not only on weight, age, and gender but also on race, estimation equations for FM% need to be population specific. However,
Dietary Patterns in Pregnancy and Effects on Nutrient Intake in the Mid-South: The Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) Study
Eszter V?lgyi,Kecia N. Carroll,Marion E. Hare,Karen Ringwald-Smith,Chandrika Piyathilake,Wonsuk Yoo,Frances A. Tylavsky
Nutrients , 2013, DOI: 10.3390/nu5051511
Abstract: Dietary patterns are sensitive to differences across socio-economic strata or cultural habits and may impact programing of diseases in later life. The purpose of this study was to identify distinct dietary patterns during pregnancy in the Mid-South using factor analysis. Furthermore, we aimed to analyze the differences in the food groups and in macro- and micronutrients among the different food patterns. The study was a cross-sectional analysis of 1155 pregnant women (mean age 26.5 ± 5.4 years; 62% African American, 35% Caucasian, 3% Other; and pre-pregnancy BMI 27.6 ± 7.5 kg/m 2). Using food frequency questionnaire data collected from participants in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) study between 16 and 28 weeks of gestation, dietary patterns were identified using factor analysis. Three major dietary patterns, namely, Healthy, Processed, and US Southern were identified among pregnant women from the Mid-South. Further analysis of the three main patterns revealed four mixed dietary patterns, i.e., Healthy-Processed, Healthy-US Southern, Processed-US Southern, and overall Mixed. These dietary patterns were different ( p < 0.001) from each other in almost all the food items, macro- and micro nutrients and aligned across socioeconomic and racial groups. Our study describes unique dietary patterns in the Mid-South, consumed by a cohort of women enrolled in a prospective study examining the association of maternal nutritional factors during pregnancy that are known to affect brain and cognitive development by age 3.
Trait-specific tracking and determinants of body composition: a 7-year follow-up study of pubertal growth in girls
Sulin Cheng, Eszter V?lgyi, Frances A Tylavsky, Arja Lyytik?inen, Timo T?rm?kangas, Leiting Xu, Shu Mei Cheng, Heikki Kr?ger, Markku Alèn, Urho M Kujala
BMC Medicine , 2009, DOI: 10.1186/1741-7015-7-5
Abstract: The study was a 7-year longitudinal cohort study. BM, LM and FM measured using dual-energy X-ray absorptiometry, self-reported dietary information, leisure time physical activity (LTPA) and other factors were assessed one to eight times in 396 girls aged 10 to 13 years (baseline), and in 255 mothers once.The location of a girl's BM, LM and FM in the lower, middle or upper part of the sample distribution was established before puberty and tracked in its percentile of origin over 7 years (r = 0.72 for BM, r = 0.61 for LM, and r = 0.65 for FM all p < 0.001 first vs. last measurements' ranking). Seventy-three percent of those in the lowest quartile for BM and 69% for LM, and 79% of those in the highest quartile for FM at baseline remained in their quartile at 7-year follow-up. Heritability was estimated to contribute 69% of the total variance of the BM, 50% of the LM, and 57% of the FM. Besides body size, diet index (explaining 9% of variance), breast feeding duration (6%) and mother's BM (9%) predicted high BM. Diet index and high LTPA predicted high LM (24% and 14%, respectively), and low FM (25% and 12%, respectively), and low level of parental education predicted high FM (4%).Individual levels of BM, LM and FM are established before puberty and track in a trait-specific manner until early adulthood. Girls who are prone to develop low BM and LM and high FM in adulthood can be identified in prepuberty. The developments of three components of body composition are inter-related during growth. BM was the most heritable trait while LM the most environmentally modifiable. Diet and physical activity played an important role in increasing LM and preventing the accumulation of excessive FM.The biology of bone, muscle and fat tissues and their associated disorders such as obesity, osteoporosis and sarcopenia are closely inter-related and share several common origins, including genetic and environmental factors [1-5]. Skeletal muscle, acting in conjunction with energy expenditu
Capacity building and human resource development for tobacco control in Latin America
Stillman,Frances A;
Salud Pública de México , 2010, DOI: 10.1590/S0036-36342010000800032
Abstract: objective. to assess capacity and human resources in latin america countries and compare with other countries. material and methods. data were gathered through needs assessments that were conducted at the 2009 world conference on tobacco or health, and the 2nd society for research on nicotine and tobacco-international american heart foundation, latin america tobacco control conference held in mexico city in 2009. results. in comparing latin america respondents to respondents from other countries, we found that the average number of years in tobacco control was higher and the majority of respondents reported higher levels of educational attainment. respondents reported lack of funding and other resources as their number one challenge, as well as, tobacco industry interference and lack of political will to implement tobacco control policies. conclusions. in latin america there are some countries that have made significant progress in building their capacity and human resources to address their tobacco epidemics, but much still needs to be done.
El Consejo Internacional de Psicólogos
Frances A. Mullen
Revista Latinoamericana de Psicología , 1976,
Abstract:
Visual Processing Speeds in Children
Steve Croker,Frances A. Maratos
Child Development Research , 2011, DOI: 10.1155/2011/450178
Abstract: The aim of this study was to investigate visual processing speeds in children. A rapid serial visual presentation (RSVP) task with schematic faces as stimuli was given to ninety-nine 6–10-year-old children as well as a short form of the WISC-III. Participants were asked to determine whether a happy face stimulus was embedded in a stream of distracter stimuli. Presentation time was gradually reduced from 500?ms per stimulus to 100?ms per stimulus, in 50?ms steps. The data revealed that (i) RSVP speed increases with age, (ii) children aged 8 years and over can discriminate stimuli presented every 100?ms—the speed typically used with RSVP procedures in adult and adolescent populations, and (iii) RSVP speed is significantly correlated with digit span and object assembly. In consequence, the RSVP paradigm presented here is appropriate for use in further investigations of processes of temporal attention within this cohort. 1. Introduction Human visual attention is limited in respect to both space (how many items can be attended to simultaneously) and time (how rapidly consecutive items can be processed). With regard to the former, it is known that spatial attention can be location based, object based, scene based, and/or a combination of the above (see Tipper and Weaver [1] for a review). Experimental manipulations of attentional selectivity within a visual scene have further demonstrated that attention to a specific location can be narrowed or widened depending upon task constraints; for example, the number of items to be memorised [2]. However, whilst the capacity of visual spatial attention has been extensively researched in both adults and children alike (e.g., Huang-Pollock et al. [3]), research into the ability to process sequentially presented stimuli (i.e., processes of temporal attention) has been conducted primarily with adolescents and adults. Typically, studies that investigate the time course of visual attention involve the rapid serial visual presentation (RSVP) paradigm in which one or two target items, embedded in a stream of distracter stimuli, must be identified. These investigations have been successful in charting the time-course of visual attention in adults [4, 5] and more recently in exploring a range of psychopathologies and developmental disorders in both adults and adolescents, such as schizophrenia [6], anxiety [7], and depression [8]. In adolescents displaying high trait impulsivity, it is observed that processes of temporal attention are impaired. That is, when having to identify two targets presented in quick succession (i.e.,
Peripheral arterial disease in polymyalgia rheumatica
Frances A Borg, Bhaskar Dasgupta
Arthritis Research & Therapy , 2009, DOI: 10.1186/ar2685
Abstract: Warrington and colleagues report an increased risk of peripheral arterial disease (PAD) in patients with polymyalgia rheumatica (PMR) compared with matched controls [1]. They found that 38 out of 353 PMR patients developed PAD versus 28 out of 705 control subjects over a median follow-up of 11 years (hazard ratio adjusted for conventional cardiovascular risk factors = 2.5, 95% confidence interval = 1.53 to 4.08). The same centre previously reported an increased likelihood of coronary and cerebrovascular disease in PMR [2]. The authors speculate that possible explanations for this are premature atherosclerosis related to inflammation, or the presence of subclinical vasculitis.An increased risk of cardiovascular disease is well established in inflammatory rheumatic diseases such as systemic lupus erythematosus and rheumatoid arthritis [3], over and above the risk explained by conventional cardiovascular risk factors. This increase appears to be related to chronic inflammation, with elevated levels of C-reactive protein associated with increased risk of cardiovascular disease, including PAD [4]. Atherosclerosis itself can be explained as an inflammatory process, with proinflammatory cytokines key in the development of endothelial dysfunction and the progression of atheromatous lesions.Homocysteine has been implicated in the development of atherosclerotic disease in the general population, and in patients with systemic lupus erythematosus and rheumatoid arthritis. Levels of homocysteine have also been found to be elevated in PMR [5].Although Warrington and colleagues found no correlation between PAD and PMR-related disease characteristics or the erythrocyte sedimentation rate at diagnosis, patients with PMR were at 2.5-fold increased risk even when adjusted for conventional risk factors for atherosclerosis [1]. This lack of association may simply reflect the limited statistical power of the study, which is acknowledged by the authors. Symptomatic PAD was an infrequent o
Random Field Model Reveals Structure of the Protein Recombinational Landscape
Philip A. Romero,Frances H. Arnold
PLOS Computational Biology , 2012, DOI: 10.1371/journal.pcbi.1002713
Abstract: We are interested in how intragenic recombination contributes to the evolution of proteins and how this mechanism complements and enhances the diversity generated by random mutation. Experiments have revealed that proteins are highly tolerant to recombination with homologous sequences (mutation by recombination is conservative); more surprisingly, they have also shown that homologous sequence fragments make largely additive contributions to biophysical properties such as stability. Here, we develop a random field model to describe the statistical features of the subset of protein space accessible by recombination, which we refer to as the recombinational landscape. This model shows quantitative agreement with experimental results compiled from eight libraries of proteins that were generated by recombining gene fragments from homologous proteins. The model reveals a recombinational landscape that is highly enriched in functional sequences, with properties dominated by a large-scale additive structure. It also quantifies the relative contributions of parent sequence identity, crossover locations, and protein fold to the tolerance of proteins to recombination. Intragenic recombination explores a unique subset of sequence space that promotes rapid molecular diversification and functional adaptation.
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