Gender and socioeconomic disparities in BMI trajectories in the Seychelles using birth cohorts generated from serial population-based surveys.

ABSTRACT: BACKGROUND: The relationship between body mass index (BMI) and socioeconomic status (SES) tends to change over time and across populations. In this study, we examined, separately in men and women, whether the association between BMI and SES changed over successive birth cohorts in the Seychelles (Indian Ocean, African region). METHODS: We used data from all participants in three surveys conducted in 1989, 1994 and 2004 in independent random samples of the population aged 25-64 years in the Seychelles (N= 3'403). We used linear regression to model mean BMI according to age, cohort, SES and smoking status, allowing for a quadratic term for age to account for a curvilinear relation between BMI and age and interactions between SES and age and between SES and cohorts to test whether the relation between SES and BMI changed across subsequent cohorts. All analyses were performed separately in men and women. RESULTS: BMI increased with age in all birth cohorts. BMI was lower in men of low SES than high SES but was higher in women of low SES than high SES. In all SES categories, BMI increased over successive cohorts (1.24 kg/m2 in men and 1.51 kg/m2 for a 10-year increase in birth cohorts, p <0.001). The difference in BMI between men or women of high vs. low SES did not change significantly across successive cohorts (the interaction between SES and year of birth of cohort was statistically not significant). Smoking was associated with lower BMI in men and women (respectively -1.55 kg/m2 and 2.46 kg/m2, p <0.001). CONCLUSIONS: Although large differences exist between men and women, social patterning of BMI did not change significantly over successive cohorts in this population of a middle-income country in the African region.

Grade and Cross Slope Estimation from LIDAR-based Surface Models, 2003

Many transportation agencies maintain grade as an attribute in roadway inventory databases; however, the information is often in an aggregated format. Cross slope is rarely included in large roadway inventories. Accurate methods available to collect grade and cross slope include global positioning systems, traditional surveying, and mobile mapping systems. However, most agencies do not have the resources to utilize these methods to collect grade and cross slope on a large scale. This report discusses the use of LIDAR to extract roadway grade and cross slope for large-scale inventories. Current data collection methods and their advantages and disadvantages are discussed. A pilot study to extract grade and cross slope from a LIDAR data set, including methodology, results, and conclusions, is presented. This report describes the regression methodology used to extract and evaluate the accuracy of grade and cross slope from three dimensional surfaces created from LIDAR data. The use of LIDAR data to extract grade and cross slope on tangent highway segments was evaluated and compared against grade and cross slope collected using an automatic level for 10 test segments along Iowa Highway 1. Grade and cross slope were measured from a surface model created from LIDAR data points collected for the study area. While grade could be estimated to within 1%, study results indicate that cross slope cannot practically be estimated using a LIDAR derived surface model.

Towards an ecological index for tropical soil quality based on soil macrofauna

The objective of this work was to construct a simple index based on the presence/absence of different groups of soil macrofauna to determine the ecological quality of soils. The index was tested with data from 20 sites in South and Central Tabasco, Mexico, and a positive relation between the model and the field observations was detected. The index showed that diverse agroforestry systems had the highest soil quality index (1.00), and monocrops without trees, such as pineapple, showed the lowest soil quality index (0.08). Further research is required to improve this model for natural systems that have very low earthworm biomass (<10 g m-2) and a high number of earthworm species (5-7), as it is in the tropical rain forest, whose soil quality index was medium (0.5). The application of this index will require an illustrated guide for its users. Further studies are required in order to test the use of this index by farmers.

Early detection of lung cancer: a statement from an expert panel of the Swiss university hospitals on lung cancer screening.

The discussion about setting up a program for lung cancer screening was launched with the publication of the results of the National Lung Screening Trial, which suggested reduced mortality in high-risk subjects undergoing CT screening. However, important questions about the benefit-harm balance and the details of a screening program and its cost-effectiveness remain unanswered. A panel of specialists in chest radiology, respiratory medicine, epidemiology, and thoracic surgery representing all Swiss university hospitals prepared this joint statement following several meetings. The panel argues that premature and uncontrolled introduction of a lung cancer screening program may cause substantial harm that may remain undetected without rigorous quality control. This position paper focuses on the requirements of running such a program with the objective of harmonizing efforts across the involved specialties and institutions and defining quality standards. The underlying statement includes information on current evidence for a reduction in mortality with lung cancer screening and the potential epidemiologic implications of such a program in Switzerland. Furthermore, requirements for lung cancer screening centers are defined, and recommendations for both the CT technique and the algorithm for lung nodule assessment are provided. In addition, related issues such as patient management, registry, and funding are addressed. Based on the current state of the knowledge, the panel concludes that lung cancer screening in Switzerland should be undertaken exclusively within a national observational study in order to provide answers to several critical questions before considering broad population-based screening for lung cancer.

Diagnosis of tuberculosis infection using interferon-γ-based assays

Interferon-γ-based assays, collectively known as IFN-γ release assays (IGRAs), have emerged as a reliable alternative to the old tuberculin skin test (TST) for the immunodiagnosis of tuberculosis (TB) infection. The 2 commercially available tests, the enzyme-linked immunosorbent assay (ELISA), QuantiFERON-TB Gold Intube (QFT-IT), and the enzyme-linked immunospot assay (ELISPOT), T-SPOT.TB, are more accurate than TST for the diagnosis of TB, since they are highly specific and correlate better with the existence of risk factors for the infection. According to the available data, T-SPOT.TB obtains a higher number of positive results than QFT-IT, while its specificity seems to be lower. Although the sensitivity of the IFN-γ -based assays may be impaired to some extent by cellular immunosuppression and extreme ages of life, they perform better than TST in these situations. Data from longitudinal studies suggest that IFN-γ-based tests are better predictors of subsequent development of active TB than TST; however this prognostic value has not been consistently demonstrated. This review focuses on the clinical use of the IFN-γ -based tests in different risk TB groups, and notes the main limitations and areas for future development.

Public health impact of statin prescribing strategies based on JUPITER Modeling study from a population-based study.

OBJECTIVE: To evaluate the public health impact of statin prescribing strategies based on the Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin Study (JUPITER). METHODS: We studied 2268 adults aged 35-75 without cardiovascular disease in a population-based study in Switzerland in 2003-2006. We assessed the eligibility for statins according to the Adult Treatment Panel III (ATPIII) guidelines, and by adding "strict" (hs-CRP≥2.0mg/L and LDL-cholesterol <3.4mmol/L), and "extended" (hs-CRP≥2.0mg/L alone) JUPITER-like criteria. We estimated the proportion of CHD deaths potentially prevented over 10years in the Swiss population. RESULTS: Fifteen % were already taking statins, 42% were eligible by ATPIII guidelines, 53% by adding "strict", and 62% by adding "extended" criteria, with a total of 19% newly eligible. The number needed to treat with statins to avoid one CHD death over 10years was 38 for ATPIII, 84 for "strict" and 92 for "extended" JUPITER-like criteria. ATPIII would prevent 17% of CHD deaths, compared with 20% for ATPIII+"strict" and 23% for ATPIII + "extended" criteria (+6%). CONCLUSION: Implementing JUPITER-like strategies would make statin prescribing for primary prevention more common and less efficient than it is with current guidelines.

Interrogating eleven fast-evolving genes for signatures of recent positive selection in worldwide human populations

Different signatures of natural selection persist over varying time scales in our genome, revealing possible episodes of adaptative evolution during human history. Here, we identify genes showing signatures of ancestral positive selection in the human lineage and investigate whether some of those genes have been evolving adaptatively in extant human populations. Specifically, we compared more than 11,000 human genes with their orthologs inchimpanzee, mouse, rat and dog and applied a branch-site likelihood method to test for positive selection on the human lineage. Among the significant cases, a robust set of 11 genes were then further explored for signatures of recent positive selection using SNP data. We genotyped 223 SNPs in 39 worldwide populations from the HGDP Diversity panel and supplemented this information with available genotypes for up to 4,814 SNPs distributed along 2 Mb centered on each gene. After exploring the allele frequency spectrum, population differentiation and the maintainance of long unbroken haplotypes, we found signals of recent adaptative phenomena in only one of the 11 candidate gene regions. However, the signal ofrecent selection in this region may come from a different, neighbouring gene (CD5) ratherthan from the candidate gene itself (VPS37C). For this set of positively-selected genes in thehuman lineage, we find no indication that these genes maintained their rapid evolutionarypace among human populations. Based on these data, it therefore appears that adaptation forhuman-specific and for population-specific traits may have involved different genes.

Development of Craniofacial Bone Defect Reconstruction Implant Based on Fibre-Reinforced Composite with Photopolymerisable Resin Systems. Experimental studies in vitro and in vivo.

Reconstruction of defects in the craniomaxillofacial (CMF) area has mainly been based on bone grafts or metallic fixing plates and screws. Particularly in the case of large calvarial and/or craniofacial defects caused by trauma, tumours or congenital malformations, there is a need for reliable reconstruction biomaterials, because bone grafts or metallic fixing systems do not completely fulfill the criteria for the best possible reconstruction methods in these complicated cases. In this series of studies, the usability of fibre-reinforced composite (FRC) was studied as a biostable, nonmetallic alternative material for reconstructing artificially created bone defects in frontal and calvarial areas of rabbits. The experimental part of this work describes the different stages of the product development process from the first in vitro tests with resin-impregnated fibrereinforced composites to the in vivo animal studies, in which this FRC was tested as an implant material for reconstructing different size bone defects in rabbit frontal and calvarial areas. In the first in vitro study, the FRC was polymerised in contact with bone or blood in the laboratory. The polymerised FRC samples were then incubated in water, which was analysed for residual monomer content by using high performance liquid chromatography (HPLC). It was found that this in vitro polymerisation in contact with bone and blood did not markedly increase the residual monomer leaching from the FRC. In the second in vitro study, different adhesive systems were tested in fixing the implant to bone surface. This was done to find an alternative implant fixing system to screws and pins. On the basis of this study, it was found that the surface of the calvarial bone needed both mechanical and chemical treatments before the resinimpregnated FRC could be properly fixed onto it. In three animal studies performed with rabbit frontal bone defects and critical size calvarial bone defect models, biological responses to the FRC implants were evaluated. On the basis of theseevaluations, it can be concluded that the FRC, based on E-glass (electrical glass) fibres forming a porous fibre veil enables the ingrowth of connective tissues to the inner structures of the material, as well as the bone formation and mineralization inside the fibre veil. Bone formation could be enhanced by using bioactive glass granules fixed to the FRC implants. FRC-implanted bone defects healed partly; no total healing of defects was achieved. Biological responses during the follow-up time, at a maximum of 12 weeks, to resin-impregnated composite implant seemed to depend on the polymerization time of the resin matrix of the FRC. Both of the studied resin systems used in the FRC were photopolymerised and the heat-induced postpolymerisation was used additionally.

Immunopathogenesis of Asthma and Atopic Diseases – The specific Role of a selected Panel of Genes in human T helper Cell Differentiation

T helper cell (Th) functions are crucial for proper immune defence against various intra- and extracellular pathogens. According to the specific immune responses, Th cells can be classified into subtypes, Th1 and Th2 cells being the most frequently characterized classes. Th1 and Th2 cells interact with other immune cells by regulating their functions with specific cytokine production. IFN, IL-2 and TNF- are the cytokines predominantly produced by Th1 cells whereas Th2 cells produce Th2-type cytokines, such as IL-4, IL-5 and IL-13. Upon TCR activation and in the presence of polarizing cytokines, Th cells differentiate into effector subtypes from a common precursor cell. IFN and IL-12 are the predominant Th1 polarizing cytokines whereas IL-4 directs Th2 polarization. The cytokines mediate their effects through specific receptor signalling. The differentiation process is complex, involving various signalling molecules and routes, as well as functions of the specific transcription factors. The functions of the Th1/Th2 cells are tightly regulated; however, knowledge on human Th cell differentiation is, as yet, fairly poor. The susceptibility for many immune-mediated disorders often originates from disturbed Th cell responses. Thus, research is needed for defining the molecular mechanisms involved in the differentiation and balanced functions of the Th cells. Importantly, the new information obtained will be crucial for a better understanding of the pathogenesis of immune-mediated disorders, such as asthma or autoimmune diseases. In the first subproject of this thesis, the role of genetic polymorphisms in the human STAT6, GATA3 and STAT4 genes were investigated for asthma or atopy susceptibility in Finnish asthma families by association analysis. These genes code for key transcription factors regulating Th cell differentiation. The study resulted in the identification of a GATA3 haplotype that associated with asthma and related traits (high serum IgE level). In the second subproject, an optimized method for human primary T cell transfection and enrichment was established. The method can be utilized for functional studies for the selected genes of interest. The method was also utilized in the third subproject, which aimed at the identification of novel genes involved in early human Th cell polarization (0-48h) using genome-wide oligonucleotide arrays. As a result, numerous genes and ESTs with known or unknown functions were identified in the study. Using an shRNA knockdown approach, a panel of novel IL-4/STAT6 regulated genes were identified in the functional studies of the genes. Moreover, one of the genes, NDFIP2, with a previously uncharacterized role in the human Th differentiation, was observed to promote IFN production of the differentiated Th1 cells. Taken together, the results obtained have revealed potential new relevant candidate genes serving as a basis for further studies characterizing the detailed networks involved in the human Th cell differentiation as well as in the genetic susceptibility of Th-mediated immune disorders.

The PsyCoLaus study: methodology and characteristics of the sample of a population-based survey on psychiatric disorders and their association with genetic and cardiovascular risk factors.

ABSTRACT: BACKGROUND: The Psychiatric arm of the population-based CoLaus study (PsyCoLaus) is designed to: 1) establish the prevalence of threshold and subthreshold psychiatric syndromes in the 35 to 66 year-old population of the city of Lausanne (Switzerland); 2) test the validity of postulated definitions for subthreshold mood and anxiety syndromes; 3) determine the associations between psychiatric disorders, personality traits and cardiovascular diseases (CVD), 4) identify genetic variants that can modify the risk for psychiatric disorders and determine whether genetic risk factors are shared between psychiatric disorders and CVD. This paper presents the method as well as somatic and sociodemographic characteristics of the sample. METHODS: All 35 to 66 year-old persons previously selected for the population-based CoLaus survey on risk factors for CVD were asked to participate in a substudy assessing psychiatric conditions. This investigation included the Diagnostic Interview for Genetic Studies to elicit diagnostic criteria for threshold disorders according to DSM-IV and algorithmically defined subthreshold syndromes. Complementary information was gathered on potential risk and protective factors for psychiatric disorders, migraine and on the morbidity of first-degree family members, whereas the collection of DNA and plasma samples was part of the original somatic study (CoLaus). RESULTS: A total of 3,691 individuals completed the psychiatric evaluation (67% participation). The gender distribution of the sample did not differ significantly from that of the general population in the same age range. Although the youngest 5-year band of the cohort was underrepresented and the oldest 5-year band overrepresented, participants of PsyCoLaus and individuals who refused to participate revealed comparable scores on the General Health Questionnaire, a self-rating instrument completed at the somatic exam. CONCLUSIONS: Despite limitations resulting from the relatively low participation in the context of a comprehensive and time-consuming investigation, the PsyCoLaus study should significantly contribute to the current understanding of psychiatric disorders and comorbid somatic conditions by: 1) establishing the clinical relevance of specific psychiatric syndromes below the DSM-IV threshold; 2) determining comorbidity between risk factors for CVD and psychiatric disorders; 3) assessing genetic variants associated with common psychiatric disorders and 4) identifying DNA markers shared between CVD and psychiatric disorders.

A non-extensive maximum entropy based regulations method for bad conditioned inverse problems

A regularization method based on the non-extensive maximum entropy principle is devised. Special emphasis is given to the q=1/2 case. We show that, when the residual principle is considered as constraint, the q=1/2 generalized distribution of Tsallis yields a regularized solution for bad-conditioned problems. The so devised regularized distribution is endowed with a component which corresponds to the well known regularized solution of Tikhonov (1977).

Univariate versus multivariate modeling of panel data

Panel data can be arranged into a matrix in two ways, called 'long' and 'wide' formats (LFand WF). The two formats suggest two alternative model approaches for analyzing paneldata: (i) univariate regression with varying intercept; and (ii) multivariate regression withlatent variables (a particular case of structural equation model, SEM). The present papercompares the two approaches showing in which circumstances they yield equivalent?insome cases, even numerically equal?results. We show that the univariate approach givesresults equivalent to the multivariate approach when restrictions of time invariance (inthe paper, the TI assumption) are imposed on the parameters of the multivariate model.It is shown that the restrictions implicit in the univariate approach can be assessed bychi-square difference testing of two nested multivariate models. In addition, commontests encountered in the econometric analysis of panel data, such as the Hausman test, areshown to have an equivalent representation as chi-square difference tests. Commonalitiesand differences between the univariate and multivariate approaches are illustrated usingan empirical panel data set of firms' profitability as well as a simulated panel data.

Appropriateness of colonoscopy in Europe (EPAGE II). Screening for colorectal cancer.

BACKGROUND AND STUDY AIMS: To summarize the published literature on assessment of appropriateness of colonoscopy for screening for colorectal cancer (CRC) in asymptomatic individuals without personal history of CRC or polyps, and report appropriateness criteria developed by an expert panel, the 2008 European Panel on the Appropriateness of Gastrointestinal Endoscopy, EPAGE II. METHODS: A systematic search of guidelines, systematic reviews, and primary studies regarding colonoscopy for screening for colorectal cancer was performed. The RAND/UCLA Appropriateness Method was applied to develop appropriateness criteria for colonoscopy in these circumstances. RESULTS: Available evidence for CRC screening comes from small case-controlled studies, with heterogeneous results, and from indirect evidence from randomized controlled trials (RCTs) on fecal occult blood test (FOBT) screening and studies on flexible sigmoidoscopy screening. Most guidelines recommend screening colonoscopy every 10 years starting at age 50 in average-risk individuals. In individuals with a higher risk of CRC due to family history, there is a consensus that it is appropriate to offer screening colonoscopy at < 50 years. EPAGE II considered screening colonoscopy appropriate above 50 years in average-risk individuals. Panelists deemed screening colonoscopy appropriate for younger patients, with shorter surveillance intervals, where family or personal risk of colorectal cancer is higher. A positive FOBT or the discovery of adenomas at sigmoidoscopy are considered appropriate indications. CONCLUSIONS: Despite the lack of evidence based on randomized controlled trials (RCTs), colonoscopy is recommended by most published guidelines and EPAGE II criteria available online (http://www.epage.ch), as a screening option for CRC in individuals at average risk of CRC, and undisputedly as the main screening tool for CRC in individuals at moderate and high risk of CRC.

Analysing the competitive advantage of Internet based marketing research company starting in Finland

The purpose of this master's thesis was to analyse a competitive advantage of an Internet based marketing research company based on a competitive strategy oriented way. First Internet panel was compared to mostly used marketing research method, telephone interview. Secondly fourteen potential clients were interviewed personally. Intention was to find out what the potential clients thinkabout Zapera Finland Ltd and what kind of competitive strategy could be chosen considering costs, product differentiation, competition, research method, segmentation of business line and substitution. Finally the interviews were analysed and some strategic suggestions were made based on the competitive advatage(s). Conclusion was that Zapera Finland Ltd can choose a competitive strategy based on both the cost advantage and the product differentiation in a narrow competition scope.