602 research outputs found
Laboratory Characterization of Geogrid-Reinforced Unbound Granular Material for use in Flexible Pavement Structures
This thesis documents and summarizes research and background information carried on geogrid reinforced base course in pavement design. Research was experimental carried through Repeated Load Triaxial (RLT) tests at the Louisiana Transportation Research Center. The experimental tests were performed to observe the benefit of the geogrid as well as to differentiate between geogrid location, geometry and tensile modulus of the various geogrid. Experiments were also carried to further describe the Shakedown Theory and its use for characterization of base course materials. The experimental results showed that there was a benefit in placing the geogrid within the aggregate specimen. There were also noticeable differences in performance resulting from the geogrid placement location in the specimen as well as the different tensile strength of the geogrid. The results followed the intuitive expectation the stiffer the geogrid, the lesser the plastic deformation. Geometry had a noticeable effect as well when comparing the bi-axial (BX) geogrid and the tri-axial (TX) geogrid. The experimental results also showed that less deformation was obtained under cyclic loading for geogrid reinforced bases versus unreinforced bases. The results also supported that a change in moisture will yield different permanent strain values in repeated load tests. The same reinforcement trend obtained at optimum moisture content was also transferred for the moisture effect tests. The higher frequency tests with increased number of cycles also produced the same trend. The geogrid with the higher tensile modulus and the new geometry gave the best results
Reinstatement of preschoolers' event memory: the effects of encoding and reminding on recall
This study was designed to examine the impact of encoding and reminding experiences on preschoolers' event memory performance. Preschoolers between the ages of 42 and 60 months participated in a pretend camping event with an experimenter, and were interviewed about the event 1 day and 6 weeks later. The camping event was staged at their preschool and was comprised of three parts: packing supplies, fishing, and preparing a picnic. To test the effect of encoding on recall, the experimenter's statements during the camping event were scripted to be either elaborative or empty - styles modeled after the high- and low-elaborative styles of talk that mothers naturally exhibit. Half of the participants were engaged by the experimenter using the elaborative script, and the remaining half were engaged by the experimenter using the empty script. To test the effect of reminding on recall, four weeks after the camping event, half of the participants from the elaborative and empty event conditions were briefly reminded of the event by viewing the objects as they were setup originally. The remaining half of the children from the elaborative and empty event conditions were not reminded of the camping event. The results indicated that there were no significant effects of event (elaborative, empty), reminder (present, absent), or event x reminder on reporting during the immediate and final memory interviews. The absence of these effects are discussed in terms of several factors, including variability within the sample due to age, the lack of forgetting during the retention interval, and more broadly, in terms of previous experimenter-child and mother-child reminiscing studies, as well as reinstatement
Homelessness and severe mental illness in low- and middle-income countries: scoping review
Background
Despite being a global problem, little is known about the relationship between severe mental illness (SMI) and homelessness in low- and middle-income countries (LMICs). Homeless people with SMI are an especially vulnerable population and face myriad health and social problems. In LMICs, low rates of treatment for mental illness, as well as differing family support systems and cultural responses to mental illness, may affect the causes and consequences of homelessness in people with SMI.
Aims
To conduct a systematic, scoping review addressing the question: what is known about the co-occurrence of homelessness and SMI among adults living in LMICs?
Method
We conducted an electronic search, a manual search and we consulted with experts. Two reviewers screened titles and abstracts, assessed publications for eligibility and appraised study quality.
Results
Of the 49 included publications, quality was generally low: they were characterised by poor or unclear methodology and reporting of results. A total of 7 publications presented the prevalence of SMI among homeless people; 12 presented the prevalence of homelessness among those with SMI. Only five publications described interventions for this population; only one included an evaluation component.
Conclusions
Evidence shows an association between homelessness and SMI in LMICs, however there is little information on the complex relationship and direction of causality between the phenomena. Existing programmes should undergo rigorous evaluation to identify key aspects required for individuals to achieve sustainable recovery. Respect for human rights should be paramount when conducting research with this population.
Declaration of interest
None.
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Energy Analysis of the Danish Food Production System: Food-EROI and Fossil Fuel Dependency
Modern food production depends on limited natural resources for providing energy and fertilisers. We assess the fossil fuel dependency for the Danish food production system by means of Food Energy Returned on fossil Energy Invested (Food-EROI) and by the use of energy intensive nutrients from imported livestock feed and commercial fertilisers. The analysis shows that the system requires 221 PJ of fossil energy per year and that for each joule of fossil energy invested in farming, processing and transportation, 0.25 J of food energy is produced; 0.28 when crediting for produced bioenergy. Furthermore, nutrients in commercial fertiliser and imported feed account for 84%, 90% and 90% of total supply of N, P and K, respectively. We conclude that the system is unsustainable because it is embedded in a highly fossil fuel dependent system based on a non-circular flow of nutrients. As energy and thus nutrient constraints may develop in the coming decades, the current system may need to adapt by reducing use of fossil energy at the farm and for transportation of food and feed. An operational strategy may be to relocalise the supply of energy, nutrients, feed and food
Assessing the contributions of childhood maltreatment subtypes and depression case-control status on telomere length reveals a specific role of physical neglect
Background: Studies have provided evidence that both childhood maltreatment and depressive disorders are associated with shortened telomere lengths. However, as childhood maltreatment is a risk factor for depression, it remains unclear whether this may be driving shortened telomere lengths observed amongst depressed patients. Furthermore, it's unclear if the effects of maltreatment on telomere length shortening are more pervasive amongst depressed patients relative to controls, and consequently whether biological ageing may contribute to depression's pathophysiology. The current study assesses the effects of childhood maltreatment, depression case/control status, and the interactive effect of both childhood maltreatment and depression case/control status on relative telomere length (RTL). Method: DNA samples from 80 depressed subjects and 100 control subjects were utilized from a U.K. sample (ages 20-84), with childhood trauma questionnaire data available for all participants. RTL was quantified using quantitative polymerase chain reactions. Univariate linear regression analyses were used to assess the effects of depression status, childhood maltreatment and depression by childhood maltreatment interactions on RTL. The false discovery rate (q 50 years old). There were no significant depression case/control status by childhood maltreatment interactions. Limitations: A relatively small sample limited our power to detect interaction effects, and we were unable to consider depression chronicity or recurrence. Conclusion: Shortened RTL was specifically associated with childhood physical neglect, but not the other subtypes of maltreatment or depression case/control status. Our results suggest that the telomere-eroding effects of physical neglect may represent a biological mechanism important in increasing risk for ageing-related disorders. As physical neglect is more frequent amongst depressed cases generally, it may also represent a confounding factor driving previous associations between shorter RTL and depression case status.Peer reviewe
Identifying socio-demographic and socioeconomic determinants of health inequalities in a diverse London community: the South East London Community Health (SELCoH) study
<p>Abstract</p> <p>Background</p> <p>Responses to public health need require information on the distribution of mental and physical ill health by demographic and socioeconomic factors at the local community level.</p> <p>Methods</p> <p>The South East London Community Health (SELCoH) study is a community psychiatric and physical morbidity survey. Trained interviewers conducted face-to-face computer assisted interviews with 1698 adults aged 16 years and over, from 1076 randomly selected private households in two south London boroughs. We compared the prevalence of common mental disorders, hazardous alcohol use, long standing illness and general physical health by demographic and socioeconomic indicators. Unadjusted and models adjusted for demographic and socioeconomic indicators are presented for all logistic regression models.</p> <p>Results</p> <p>Of those in the sample, 24.2% reported common mental disorder and 44.9% reported having a long standing illness, with 15.7% reporting hazardous alcohol consumption and 19.2% rating their health as fair or poor. The pattern of indicators identifying health inequalities for common mental disorder, poor general health and having a long term illness is similar; individuals who are socioeconomically disadvantaged have poorer health and physical health worsens as age increases for all groups. The prevalence of poor health outcomes by ethnic group suggests that there are important differences between groups, particularly for common mental disorder and poor general health. Higher socioeconomic status was protective for common mental disorder, fair or poor health and long standing illness, but those with higher socioeconomic status reported higher levels of hazardous alcohol use. The proportion of participants who met the criteria for common mental disorder with co-occurring functional limitations was similar or greater to those with poor physical health.</p> <p>Conclusions</p> <p>Health service providers and policy makers should prioritise high risk, socially defined groups in combating inequalities in individual and co-occurring poor mental and physical problems. In population terms, poor mental health has a similar or greater burden on functional impairment than long term conditions and perceived health.</p
Metabolic effects of a mixed and a high-carbohydrate low-fat diet in man, measured over 24 h in a respiration chamber
Characterization of pearl millet root architecture and anatomy reveals three types of lateral roots
Pearl millet plays an important role for food security in arid regions of Africa and India. Nevertheless, it is considered an orphan crop as it lags far behind other cereals in terms of genetic improvement efforts. Breeding pearl millet varieties with improved root traits promises to deliver benefits in water and nutrient acquisition. Here, we characterize of early pearl millet root system development using several different root phenotyping approaches that include rhizotrons and microCT. We report that early stage pearl millet root system development is characterized by a fast growing primary root that quickly colonizes deeper soil horizons. We also describe root anatomical studies that revealed 3 distinct types of lateral roots that form on both primary roots and crown roots. Finally, we detected significant variation for two root architectural traits in pearl millet inbred lines. This study provides the basis for subsequent genetic experiments to identify loci associated with interesting early root development traits in this important cereal
Impact of different food label formats on healthiness evaluation and food choice of consumers: a randomized-controlled study
Abstract Background Front of pack food labels or signpost labels are currently widely discussed as means to help consumers to make informed food choices. It is hoped that more informed food choices will result in an overall healthier diet. There is only limited evidence, as to which format of a food label is best understood by consumers, helps them best to differentiate between more or less healthy food and whether these changes in perceived healthiness result in changes of food choice. Methods In a randomised experimental study in Hamburg/Germany 420 adult subjects were exposed to one of five experimental conditions: (1) a simple "healthy choice" tick, (2) a multiple traffic light label, (3) a monochrome Guideline Daily Amount (GDA) label, (4) a coloured GDA label and (5) a "no label" condition. In the first task they had to identify the healthier food items in 28 pair-wise comparisons of foods from different food groups. In the second task they were asked to select food portions from a range of foods to compose a one-day's consumption. Differences between means were analysed using ANOVAs. Results Task I: Experimental conditions differed significantly in the number of correct decisions (p Conclusion Different food label formats differ in the understanding of consumers. The current study shows, that German adults profit most from the multiple traffic light labels. Perceived healthiness of foods is influenced by this label format most often. Nevertheless, such changes in perceived healthiness are unlikely to influence food choice and consumption. Attempts to establish the informed consumer with the hope that informed choices will be healthier choices are unlikely to change consumer behaviour and will not result in the desired contribution to the prevention of obesity and diet related diseases.</p
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