bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using epidemiological models to estimate the health effects of diet behaviour change: the example of tailored fruit and vegetable promotion
Authors: Veerman J Lennert , Barendregt Jan J , Mackenbach Johan P , Brug Johannes 
Published: June 2006

AbstractObjectiveTo explore the use of epidemiological modelling for the estimation of health effects of behaviour change interventions, using the example of computer-tailored nutrition education aimed at fruit and vegetable consumption in The Netherlands.DesignThe effects of the intervention on changes in consumption were obtained from an earlier evaluation study. The effect on health outcomes was estimated using an epidemiological multi-state life table model. Input data for the model consisted of relative risk estimates for cardiovascular disease and cancers, data on disease occurrence and mortality, and survey data on the consumption of fruits and vegetables.ResultsIf the computer-tailored nutrition education reached the entire adult population and the effects were sustained, it could result in a mortality decrease of 0.4 to 0.7% and save 72 to 115 life-years per 100 000 persons aged 25 years or older. Healthy life expectancy is estimated to increase by 32.7 days for men and 25.3 days for women. The true effect is likely to lie between this theoretical maximum and zero effect, depending mostly on durability of behaviour change and reach of the intervention.ConclusionEpidemiological models can be used to estimate the health impact of health promotion interventions.
Risk factors for overweight among Brazilian adolescents of low-income families: a case–control study
Authors: Silveira Daniela , De Aguiar Carrazedo Taddei José Augusto , Escrivão Maria Arlete Meil Schimith , Oliveira Fernanda Luisa Ceragioli , Ancona-Lopez Fabio 
Published: June 2006

AbstractObjectiveTo study risk factors for overweight among Brazilian adolescents of low-income families.DesignCase–control study of obese and non-obese adolescents.SettingAnthropometric survey including 1420 students (aged 14–19 years) attending a public high school in São Paulo, Brazil.MethodsSelection of 83 overweight (body mass index (BMI) >85th percentile) and 89 non-overweight (BMI >5th percentile and <85th percentile) subjects, frequency-matched by age, gender, pubertal development and socio-economic status. Among the nutritional, familial and behavioural data available, five covariates (parents' obesity, adolescents' past obesity, to have a best friend, dietary restriction and habit of napping) were included in the fitted hierarchical conditional logistic regression models.MeasurementsParents or guardians and adolescents were weighed, measured and answered a pre-tested questionnaire applied by trained nutritionists and paediatricians.ResultsThe prevalence of overweight was 15.2%. As previous risks, obese parents and obesity during infancy presented odds ratios (OR) and 95% confidence intervals (CI) of 2.23 (1.15–4.35) and 3.60 (1.47–8.80), respectively. As concurrent factors, the habit of napping, to have a best friend and reported dietary restriction presented OR (95% CI) of 3.43 (1.32–8.92), 5.15 (1.76–15.07) and 7.26 (2.95–17.88), respectively. Dietary patterns, frequency of obesogenic foods and other physical activity indicators presented no statistical significance.ConclusionIn case–control studies, OR may overestimate the true risks. Parents' obesity and previous childhood obesity were identified as risk factors; therefore these factors should be the target for preventive programmes and policies in order to prevent the burden of obesity in the near future.
Validation of a food-frequency questionnaire for use in pregnancy
Authors: Mouratidou Theodora , Ford Fiona , Fraser Robert B 
Published: June 2006

AbstractObjectivesAs a part of an ongoing project to develop a nutritional screening tool, we evaluated the performance of a semi-quantitative food-frequency questionnaire (FFQ) in terms of validity in a Sheffield Caucasian pregnant population using two different statistical approaches – the correlation coefficient and the limits of agreement (LOA). The FFQ was designed specifically for pregnant women and previously used in a large-scale study.DesignA validation study.SettingA community-based field study of a general population of pregnant women booked for their first antenatal appointment at the Jessop Wing, Royal Hallamshire Hospital, Sheffield, UK.SubjectsOne hundred and twenty-three women of different socio-economic status, aged between 17 and 43 years, provided complete dietary data.ResultsThe validity of the FFQ was tested against a series of two 24-hour recalls. As expected, the intakes of all examined nutrients, except for iodine, carotene, vitamin E, biotin, vitamin C and alcohol, were higher when determined by the FFQ than when determined by 24-hour recall. Pearson's correlation coefficient between the two methods ranged from 0.19 (added sugar, zinc) to 0.47 (Englyst fibre). The LOA were broader for some of the nutrients, e.g. protein, Southgate fibre and alcohol, and an increasing lack of agreement between the two methods was identified with higher dietary intakes.ConclusionsThe FFQ gave useful estimates of the nutrient intakes of Caucasian pregnant women and appears to be a valid tool for categorising pregnant women according to dietary intake. The FFQ performed well for most nutrients and had acceptable agreement with the 24-hour recall.
An assessment of inter-rater agreement of the literature filtering process in the development of evidence-based dietary guidelines
Authors: Cooper Marcia , Ungar Wendy , Zlotkin Stanley 
Published: June 2006

AbstractObjectiveTo determine whether the literature filtering process, a vital initial component of a systematic literature review, could be successfully completed by nutrition professionals or non-professionals.DesignUsing a diet–disease relationship as the guideline topic, inter-rater agreement for the title and abstract filtering processes between and among professionals and non-professionals was assessed and compared with an expert reference standard. Predetermined eligibility criteria were applied by all raters to 185 titles and 90 abstracts. Filtering decisions were initially made independently and then revised after a within-pair consensus meeting.SubjectsThe raters were six dietitians (RD) and six nutrition graduate students (Grad). To assess inter-rater agreement (reliability), each group was divided into three pairs.ResultsWeighted and unweighted kappa statistics and percentage agreement were calculated to determine the inter-rater agreement within pairs. Sensitivity and specificity estimates were determined by comparing responses with those of an expert reference standard. Overall, Grad pairs demonstrated greater inter-rater agreement than RD pairs for title filtering (P < 0.05); no differences were observed for abstract filtering. Compared with the expert reference standard, every rater and pair had false-negative responses for both title and abstract filtering.ConclusionsAfter consensus meetings, both RDs and Grads were comparable in their agreement on title and abstract filtering, although important differences remained compared with the expert reference standard. This study provides preliminary findings on the value of utilising a non-expert pair in developing guidelines, and suggests that the literature filtering process is complex and quite subjective.
Effort during visual search and counting: Insights from pupillometry
Authors: Porter Gillian , Troscianko Tom , Gilchrist Iain D. 
Published: June 2006

We investigated the processing effort during visual search and counting tasks using a pupil dilation measure. Search difficulty was manipulated by varying the number of distractors as well as the heterogeneity of the distractors. More difficult visual search resulted in more pupil dilation than did less difficult search. These results confirm a link between effort and increased pupil dilation. The pupil dilated more during the counting task than during target-absent search, even though the displays were identical, and the two tasks were matched for reaction time. The moment-to-moment dilation pattern during search suggests little effort in the early stages, but increasingly more effort towards response, whereas the counting task involved an increased initial effort, which was sustained throughout the trial. These patterns can be interpreted in terms of the differential memory load for item locations in each task. In an additional experiment, increasing the spatial memory requirements of the search evoked a corresponding increase in pupil dilation. These results support the view that search tasks involve some, but limited, memory for item locations, and the effort associated with this memory load increases during the trials. In contrast, counting involves a heavy locational memory component from the start.
Mobilization of Cd upon acidification of agricultural soils: column study and field modelling
Authors: Degryse F. , Vlassak V. , Smolders E. , Merckx R. 
Published: June 2006

SummaryThe potential effect of acidification of contaminated sandy soils on Cd transport in the unsaturated zone was assessed. Forty‐eight soil profiles were sampled at five depths in a polluted field that was set aside in 1992. The Cd concentration in the top 30 cm of this field was, on average, 10 mg kg−1. A column experiment was carried out with one of the topsoil samples. Homogeneously packed columns were leached with 0.001 m CaCl2, adjusted to pH 3 or pH 5.7, at a pore water velocity of 6 cm day−1. The Cd and proton transport was predicted with coupled transport equations. The Cd transport was modelled by assuming local equilibrium and by using sorption parameters derived from batch experiments, while acidification was modelled with a kinetic approach, on the assumption that proton buffering was due to cation exchange and mineral weathering. Organic matter was the main contributor to the cation exchange capacity of these soils. Observed and predicted pH and Cd profiles in the columns agreed well. With the same model, the proton and Cd transport at field scale was calculated for each of the 48 profiles sampled (‘grid model’). It was predicted that the field‐averaged Cd concentration in the seepage water will increase from 6 μg litre−1 at present to 200 μg litre−1 over 260 years, which greatly exceeds the maximum permissible concentration (MPC) in groundwater of 5 μg litre−1. Predictions of Cd transport using field‐averaged soil properties yielded a later breakthrough time and a larger peak Cd concentration than predicted with the grid model, which illustrates the impact of spatial variability on solute transport. Continuation of liming practices is a possible solution to prevent breakthrough of Cd at concentrations far in excess of the MPC.
Determining soil saturated hydraulic conductivity and sorptivity from single ring infiltration tests
Authors: Touma J. , Voltz M. , Albergel J. 
Published: June 2006

SummaryThe difference between the cumulative infiltration occurring during three‐dimensional axisymmetric and one‐dimensional vertical flow is a linear function of time. The slope of this line is a function of the source radius, initial and final volumetric soil water contents and the soil sorptivity. This allows the determination of the sorptivity and saturated conductivity of the soil from data of axisymmetric flow in a single ring of small diameter under negligible head of water. The method is based on the optimization of the sorptivity and saturated conductivity on the one‐dimensional vertical cumulative infiltration inferred from axisymmetric flow data. To examine the reliability of the method to determine these parameters, numerical three‐ and one‐dimensional data are generated on soils with known hydrologic properties from the literature. The linearity versus time of the difference of the two types of flow is verified. Several physically based expressions for the vertical cumulative infiltration as a function of time are considered. The optimized values of the sorptivity and saturated conductivity are compared to the their real known values. Despite the large errors on the optimized parameters, namely the saturated conductivity, the error on the vertical predicted cumulative infiltration is limited to 10%. This makes possible the application of this method on a large scale for hydrological modelling purposes.
Retention mechanisms of white perch (Morone americana) and striped bass (Morone saxatilis) early‐life stages in an estuarine turbidity maximum: an integrative fixed‐location and mapping approach
Authors: NORTH E. W. , HOUDE E. D. 
Published: June 2006

AbstractThe small‐scale distribution and retention mechanisms of white perch (Morone americana) and striped bass (M. saxatilis) early‐life stages were investigated in the upper Chesapeake Bay estuarine turbidity maximum (ETM). Physical measurements and biological collections were made at fixed‐location stations within the ETM during three research cruises in 1998 and two in 1999. Results were compared with mapping surveys of physical properties and organism distributions above, within, and below the ETM. Physical conditions at the fixed stations differed markedly among cruises and between years due to differences in freshwater flow and wind. In each year, striped bass and white perch larval concentrations were highest in waters of salinity 1–4. Larvae were more abundant in the ETM region in 1998, a high‐flow year, suggesting that the ETM provides favorable nursery habitat when low salinity waters and the ETM coincide in high freshwater‐flow conditions. In 1998, the earliest pelagic life stages of fish larvae (eggs, yolk‐sac larvae) and the copepod Eurytemora affinis, an important prey of feeding larvae, apparently were retained in deep, landward‐flowing water within the salt front and ETM region. Statistical analyses indicated that distributions of white perch and striped bass post‐yolk‐sac larvae were associated with E. affinis distributions and suggested that retention of larval fish could result from tracking prey. Comparing fixed‐station and mapping approaches demonstrates the importance of sampling at different spatial scales within the ETM region and suggests that larvae are faced with trade‐offs between selecting zones of high retention or high visual‐feeding success.
Net assimilation rate, specific leaf area and leaf mass ratio: which is most closely correlated with relative growth rate? A meta‐analysis
Authors: SHIPLEY B. 
Published: June 2006

Summary

Data were compiled consisting of 1240 observations (614 species) from 83 different experiments published in 37 different studies, in order to quantify the relative importance of net assimilation rate (NAR, g cm−2 day−1), specific leaf area (SLA, cm2 g−1) and leaf mass ratio (LMR, g g−1) in determining relative growth rate (RGR, g g−1 day−1), and how these change with respect to daily quantum input (DQI, moles m−2 day−1) and growth form (herbaceous or woody).
Each of ln(NAR), ln(SLA) and ln(LMR) were separately regressed on ln(RGR) using mixed model regressions in order to partition the between‐experiment and within‐experiment variation in slopes and intercepts. DQI and plant type were then added to these models to see if they could explain some of the between‐experiment variation in the relative importance of each growth component.
LMR was never strongly related to RGR. In general, NAR was the best general predictor of variation in RGR. However, for determining RGR the importance of NAR decreased, and the importance of SLA increased, with decreasing daily quantum input in experiments containing herbaceous species. This did not occur in experiments involving woody species.
Annual basal area increment and growth duration of Pinus taeda in response to eight years of free‐air carbon dioxide enrichment
Authors: MOORE DAVID J. P. , AREF SUSANNE , HO RINGO M. , PIPPEN JEFFREY S. , HAMILTON JASON G. , DE LUCIA EVAN H. 
Published: June 2006

AbstractRising CO2 is predicted to increase forest productivity, although the duration of the response and how it might be altered by variation in rainfall, temperature and other environmental variables are not well understood. We measured the basal area of rapidly growing Pinus taeda trees exposed to free‐air CO2 enrichment for 8 years and used these measurements to estimate monthly and annual growth. We used these measurements in a statistical model to estimate the start and end of growth in each year. Elevated CO2 increased the basal area increment (BAI) of trees by 13–27%. In most years, exposure to elevated CO2 increased the growth rate but not the duration of the active growth period. With the exception of 1 year following an extreme drought and a severe ice storm, BAI was positively correlated with the amount of rainfall during the active growth period. The interannual variation in the relative enhancement of BAI caused by elevated CO2 was strongly related to temperature and rainfall, and was greatest in years with high vapor pressure deficit. There was no evidence of a systematic reduction in the stimulation of growth during the first 8 years of this experiment, suggesting that the hypothesized limitation of the CO2 response caused by nitrogen availability has yet to occur.
The CD1d‐binding glycolipid α‐galactosylceramide enhances humoral immunity to T‐dependent and T‐independent antigen in a CD1d‐dependent manner
Authors: Lang Gillian A. , Exley Mark A. , Lang Mark L. 
Published: June 2006

SummarySpecific interaction of class II/peptide with the T‐cell receptor (TCR) expressed by class II‐restricted CD4+ T helper (Th) cells is essential for in vivo production of antibodies reactive with T‐dependent antigen. In response to stimulation with CD1d‐binding glycolipid, Vα14+ TCR‐expressing, CD1d‐restricted natural killer T (NKT) cells may provide additional help for antibody production. We tested the hypothesis that the CD1d‐binding glycolipid α‐galactosylceramide (α‐GC) enhances production of antibodies reactive with T‐dependent antigen in vivo. α‐GC enhanced antibody production in vivo in a CD1d‐dependent manner in the presence of class II‐restricted Th cells and induced a limited antibody response in Th‐deficient mice. α‐GC also led to alterations in isotype switch, selectively increasing production of immunoglobulin G2b. Further analysis revealed that α‐GC led to priming of class II‐restricted Th cells in vivo. Additionally, we observed that α‐GC enhanced production of antibodies reactive with T‐independent antigen, showing the effects of NKT cells on B cells independently of Th cells. Our data show that NKT cells have multiple effects on the induction of a humoral immune response. We propose that NKT cells could be exploited for the development of novel vaccines where protective antibody is required.
Bistability in bacteria
Authors: Dubnau David , Losick Richard 
Published: June 2006

SummaryGene expression in bacteria is traditionally studied from the average behaviour of cells in a population, which has led to the assumption that under a particular set of conditions all cells express genes in an approximately uniform manner. The advent of methods for visualizing gene expression in individual cells reveals, however, that populations of genetically identical bacteria are sometimes heterogeneous, with certain genes being expressed in a non‐uniform manner across the population. In some cases, heterogeneity is manifested by the bifurcation into distinct subpopulations, and we adopt the common usage, referring to this phenomenon as bistability. Here we consider four cases of bistability, three from Bacillus subtilis and one from Escherichia coli, with an emphasis on random switching mechanisms that generate alternative cell states and the biological significance of phenotypic heterogeneity. A review describing additional examples of bistability in bacteria has been published recently.
LmrCD is a major multidrug resistance transporter in Lactococcus lactis
Authors: Lubelski Jacek , De Jong Anne , Van Merkerk Ronald , Agustiandari Herfita , Kuipers Oscar P. , Kok Jan , Driessen Arnold J. M. 
Published: June 2006

SummaryWhen Lactococcus lactis is challenged with drugs it displays a multidrug resistance (MDR) phenotype. In silico analysis of the genome of L. lactis indicates the presence of at least 40 putative MDR transporters, of which only four, i.e. the ABC transporters LmrA, LmrC and LmrD, and the major facilitator LmrP, have been experimentally associated with the MDR. To understand the molecular basis of the MDR phenotype in L. lactis, we have performed a global transcriptome analysis comparing four independently isolated drug‐resistant strains of L. lactis with the wild‐type strain. The results show a strong and consistent upregulation of the lmrC and lmrD genes in all four strains, while the mRNA levels of other putative MDR transporters were not significantly altered. Deletion of lmrCD renders L. lactis sensitive to several toxic compounds, and this phenotype is associated with a reduced ability to secrete these compounds. Another gene, which is strongly upregulated in all mutant strains, specifies LmrR (YdaF), a local transcriptional repressor of lmrCD that belongs to the PadR family of transcriptional regulators and that binds to the promoter region of lmrCD. These results demonstrate that the heterodimeric MDR ABC transporter LmrCD is a major determinant of both acquired and intrinsic drug resistance of L. lactis.
Fault‐bend folding as an end‐member solution of (double‐edge) fault‐propagation folding
Authors: Tavani Stefano , Storti Fabrizio 
Published: June 2006

AbstractFault‐bend folding is the most commonly used kinematic mechanism to interpret the architecture and evolution of thrust‐related anticlines in thrust wedges. However, its basic requirement of an instantaneous propagation of the entire fault before hangingwall deformation, limits its kinematic effectiveness. To overcome this limitation, we used the interdependence between fold shape and fault slip vs. propagation rate (S/P ratio) implemented in double‐edge fault‐propagation folding. We show that very small S/P values produce fault‐propagation anticlines that, when transported forelandward along an upper décollement layer, closely resemble fault‐bend anticlines. Accordingly, if small geometric discrepancies between the two solutions are accepted, transported double‐edge fault‐propagation provides an effective kinematic alternative to fault‐bend folding. Even at very low S/P values, it in fact predicts a fast but finite propagation rate of the fault. We thus propose that double‐edge fault‐propagation folding provides a broadly applicable model of fault‐related folding that includes fault‐bend folding as an end‐member kinematic solution.Terra Nova, 18, 270–275, 2006