The structure of cognition in 9 and 10 year-old children and associations with problem behaviors: Findings from the ABCD study's baseline neurocognitive battery

The Adolescent Brain Cognitive Development (ABCD) study is poised to be the largest single-cohort long-term longitudinal study of neurodevelopment and child health in the United States. Baseline data on N= 4521 children aged 9-10 were released for public access on November 2, 2018. In this paper we performed principal component analyses of the neurocognitive assessments administered to the baseline sample. The neurocognitive battery included seven measures from the NIH Toolbox as well as five other tasks. We implemented a Bayesian Probabilistic Principal Components Analysis (BPPCA) model that incorporated nesting of subjects within families and within data collection sites. We extracted varimax-rotated component scores from a three-component model and associated these scores with parent-rated Child Behavior Checklist (CBCL) internalizing, externalizing, and stress reactivity. We found evidence for three broad components that encompass general cognitive ability, executive function, and learning/memory. These were significantly associated with CBCL scores in a differential manner but with small effect sizes. These findings set the stage for longitudinal analysis of neurocognitive and psychopathological data from the ABCD cohort as they age into the period of maximal adolescent risk-taking.

Phenolic compounds profile and antioxidant properties of six sweet cherry (Prunus avium) cultivars

Sweet cherry (Prunus avium) fruits are a nutritionally important food rich in dietary phenolic compounds. The aim of this study was to investigate the phenolic profile and chemometric discrimination of fruits from six cherry cultivars using a quantitative metabolomics approach, which combine non-targeted mass spectrometry and chemometric analysis. The assessment of the phenolic fingerprint of cherries allowed the tentative identification of 86 compounds. A total of 40 chlorogenic acids were identified in cherry fruit, which pointed out hydroxycinnamic acid derivatives as the main class of phenolics by number of compounds. Among the compounds detected, 40 have been reported for the first time in sweet cherry fruit. Hydroxycinnamic acids are also the quantitatively most represented class of phenolic compounds in the cherry cultivars with the exception of Lapins and Durone della Marca where the most representative class of phenolic compounds were anthocyanins and flavan-3-ols, respectively. This non-targeted approach allowed the tentative identification of the cultivar-compound relationships of these six cherry cultivars. Both anthocyanins and colorless phenolic compounds profile appeared to be cultivar-dependent. In detail, anthocyanins and flavonols patterns have the potential to be used for the determination of a varietal assignment of cherries.

Dietary patterns of university students in the UK: a cross-sectional study

Background

University represents a key transition into adulthood for many adolescents but there are associated concerns about health and behaviours. One important aspect relates to diet and there is emerging evidence that university students may consume poor quality diets, with potential implications for body weight and long-term health. This research aimed to characterise dietary patterns of university students in the UK and their sociodemographic and lifestyle antecedents.

Methods

An online, cross-sectional survey was undertaken with a convenience sample of 1448 university students from five UK universities (King’s College London, Universities of St Andrews, Southampton and Sheffield, and Ulster University). The survey comprised a validated food frequency questionnaire alongside lifestyle and sociodemographic questions. Dietary patterns were generated from food frequency intake data using principal components analysis. Nutrient intakes were estimated to characterise the nutrient profile of each dietary pattern. Associations with sociodemographic variables were assessed through general linear modelling.

Results

Dietary analyses revealed four major dietary patterns: ‘vegetarian’; ‘snacking’; ‘health-conscious’; and ‘convenience, red meat & alcohol’. The ‘health-conscious’ pattern had the most favourable micronutrient profile. Students’ gender, age, year of study, geographical location and cooking ability were associated with differences in pattern behaviour. Female students favoured the ‘vegetarian’ pattern, whilst male students preferred the ‘convenience, red meat & alcohol’ pattern. Less healthful dietary patterns were positively associated with lifestyle risk factors such as smoking, low physical activity and take-away consumption. The health-conscious pattern had greatest nutrient density. The ‘convenience, red meat & alcohol’ pattern was associated with higher weekly food spending; this pattern was also identified most consistently across universities. Students reporting greater cooking ability tended towards the ‘vegetarian’ and ‘health-conscious’ patterns.

Conclusions

Food intake varied amongst university students. A substantial proportion of students followed health-promoting diets, which had good nutrient profiles obviating a need for dietary intervention. However, some students consumed poor diets, incurred greater food costs and practised unfavourable lifestyle behaviours, which may have long-term health effects. University policy to improve students’ diets should incorporate efforts to promote student engagement in cooking and food preparation, and increased availability of low cost healthier food items.

Electronic supplementary material

The online version of this article (10.1186/s12937-018-0398-y) contains supplementary material, which is available to authorized users.

Nutrition literacy predicts adherence to healthy/unhealthy diet patterns in adults with a nutrition-related chronic condition

OBJECTIVE

To describe the relationship between adherence to distinct dietary patterns and nutrition literacy.

DESIGN

We identified distinct dietary patterns using principal covariates regression (PCovR) and principal components analysis (PCA) from the Diet History Questionnaire II. Nutrition literacy was assessed using the Nutrition Literacy Assessment Instrument (NLit). Cross-sectional relationships between dietary pattern adherence and global and domain-specific NLit scores were tested by multiple linear regression. Mean differences in diet pattern adherence among three predefined nutrition literacy performance categories were tested by ANOVA.

SETTING

Metropolitan Kansas City, USA.

PARTICIPANTS

Adults (n 386) with at least one of four diet-related diseases.

RESULTS

Three diet patterns of interest were derived: a PCovR prudent pattern and PCA-derived Western and Mediterranean patterns. After controlling for age, sex, BMI, race, household income, education level and diabetes status, PCovR prudent pattern adherence positively related to global NLit score (P < 0·001, β = 0·36), indicating more intake of prudent diet foods with improved nutrition literacy. Validating the PCovR findings, PCA Western pattern adherence inversely related to global NLit (P = 0·003, β = -0·13) while PCA Mediterranean pattern positively related to global NLit (P = 0·02, β = 0·12). Using predefined cut points, those with poor nutrition literacy consumed more foods associated with the Western diet (fried foods, sugar-sweetened beverages, red meat, processed foods) while those with good nutrition literacy consumed more foods associated with prudent and Mediterranean diets (vegetables, olive oil, nuts).

CONCLUSIONS

Nutrition literacy predicted adherence to healthy/unhealthy diet patterns. These findings warrant future research to determine if improving nutrition literacy effectively improves eating patterns.

Impact of anthropogenic and natural processes on the evolution of groundwater chemistry in a rapidly urbanized coastal area, South China

The moving of manufacturing industry from developed countries to Dongguan, China, promoted the semi-urbanization and rural industrialization in this area. It is urgent to acquire the impact of the enhanced anthropogenic pressure on the evolution of groundwater chemistry in this area. The objectives, in this study, were to understand the evolution of groundwater chemistry in Dongguan area based on the comparison of hydrochemical data variations and land use changes during the urbanization, to distinguish the impact of natural processes and anthropogenic activities on the groundwater chemistry by using principal components analysis (PCA) and hierarchical cluster analysis (HCA), and to discuss the origins of trace elements in groundwater. Eighteen physico-chemical parameters were investigated at 73 groundwater sites during July 2006. By analyzing the hydrochemical data, it shows that lateral flow from rivers and agricultural irrigation are the mechanisms controlling the groundwater chemistry in the river network area where the cation exchange of Na(+) in sediments taken up by the exchanger Ca(2+) occurs. Seawater intrusion is the mechanism controlling the groundwater chemistry in the coast area where the cation exchange of Ca(2+) in sediments taken up by the exchanger Na(+) occurs. The ion exchange reaction for fissured aquifer is weak in the study area. In addition, the comparison of hydrochemical data between in 2006 and in 1980 shows that anthropogenic activities such as excessive application of agricultural fertilizers, inappropriate emissions of domestic sewage and excessive emissions of SO2 are responsible for the occurrences of groundwater with NO3(-), SO4(2-) and Mg(2+) types. Four principal components (PCs) were extracted from PCA, which explain 80.86% of the total parameters in water chemistry: PC1, the seawater intrusion and As contamination; PC2, the water-rock interaction, surface water recharge and acidic precipitation; PC3, heavy metal pollution from industry; and PC4, agricultural pollution and sewage intrusion. Four clusters were generated from HCA: cluster 1 is mainly influenced by the industrialization; cluster 2 is mainly affected by the water-rock interaction and the irrigation and lateral flow of river water; cluster 3 is mainly influenced by the seawater intrusion; and cluster 4 is mainly influenced by the sewage intrusion and agricultural pollution. The results show that both natural processes such as seawater intrusion, water-rock interaction and lateral flow of river water and anthropogenic activities such as industrialization, sewage intrusion and agricultural pollution are the two major factors for the evolution of groundwater chemistry in Dongguan area.

Complex systems dynamics in aging: new evidence, continuing questions

There have long been suggestions that aging is tightly linked to the complex dynamics of the physiological systems that maintain homeostasis, and in particular to dysregulation of regulatory networks of molecules. This review synthesizes recent work that is starting to provide evidence for the importance of such complex systems dynamics in aging. There is now clear evidence that physiological dysregulation—the gradual breakdown in the capacity of complex regulatory networks to maintain homeostasis—is an emergent property of these regulatory networks, and that it plays an important role in aging. It can be measured simply using small numbers of biomarkers. Additionally, there are indications of the importance during aging of emergent physiological processes, functional processes that cannot be easily understood through clear metabolic pathways, but can nonetheless be precisely quantified and studied. The overall role of such complex systems dynamics in aging remains an important open question, and to understand it future studies will need to distinguish and integrate related aspects of aging research, including multi-factorial theories of aging, systems biology, bioinformatics, network approaches, robustness, and loss of complexity.

The Adult Repetitive Behaviours Questionnaire-2 (RBQ-2A): A Self-Report Measure of Restricted and Repetitive Behaviours

In two studies we developed and tested a new self-report measure of restricted and repetitive behaviours (RRB) suitable for adults. In Study 1, The Repetitive Behaviours Questionnaire-2 for adults (RBQ-2A) was completed by a sample of 163 neurotypical adults. Principal components analysis revealed two components: Repetitive Motor Behaviours and Insistence on Sameness. In Study 2, the mean RBQ-2A scores of a group of adults with autism spectrum disorder (ASD; N = 29) were compared to an adult neurotypical group (N = 37). The ASD sample had significantly higher total and subscale scores. These results indicate that the RBQ-2A has utility as a self-report questionnaire measure of RRBs suitable for adults, with potential clinical application.

Intersecting household-level health and socio-economic vulnerabilities and the COVID-19 crisis: An analysis from the UK

The effects of COVID-19 are likely to be socially stratified. Disease control measures introduced during the COVID-19 pandemic mean that people spend much more time in their immediate households, due to lockdowns, the need to self-isolate, and school and workplace closures. This has elevated the importance of certain household–level characteristics for individuals’ current and future wellbeing. The multi-dimensional poverty and health inequalities literature suggests that poor health and socio-economic conditions cluster in the general population, which may exacerbate societal inequalities over time. This study investigates how COVID-19-related health- and socio-economic vulnerabilities co-occur at the household level, and how they are distributed across household types and geographical areas in the United Kingdom. Using a nationally representative cross-sectional study of UK households and individuals and applying principal components analysis, we derived summary measures representing different dimensions of household vulnerabilities critical during the COVID-19 epidemic: health, employment, housing, financial and digital. Our analysis highlights four key findings. First, although COVID-19-related health risks are concentrated in retirement-age households, a substantial proportion of working-age households also face these risks. Second, different types of households exhibit different vulnerabilities, with working-age households more likely to face financial and housing precarities, and retirement-age households health and digital vulnerabilities. Third, there are area-level differences in the distribution of household-level vulnerabilities across England and the constituent countries of the United Kingdom. Fourth, in many households, different dimensions of vulnerabilities intersect; this is especially prevalent among working-age households. The findings imply that the short- and long-term consequences of the COVID-19 crisis are likely to significantly vary by household type. Policy measures that aim to mitigate the health and socio-economic consequences of the COVID-19 pandemic should consider how vulnerabilities cluster and interact with one another both within individuals and different household types, and how these may exacerbate already existing inequalities.

Raman spectral analysis for rapid screening of dengue infection

Infection with the dengue virus is currently clinically detected according to different biomarkers in human blood plasma, commonly measured by enzyme linked immunosorbent assays, including non-structural proteins (Ns1), immunoglobulin M (IgM) and immunoglobulin G (IgG). However, there is little or no mutual correlation between the biomarkers, as demonstrated in this study by a comparison of their levels in samples from 17 patients. As an alternative, the label free, rapid screening technique, Raman spectroscopy has been used for the characterisation/diagnosis of healthy and dengue infected human blood plasma samples. In dengue positive samples, changes in specific Raman spectral bands associated with lipidic and amino acid/protein content are observed and assigned based on literature and these features can be considered as markers associated with dengue development. Based on the spectroscopic analysis of the current, albeit limited, cohort of samples, Principal Components Analysis (PCA) coupled Factorial Discriminant Analysis, yielded values of 97.95% sensitivity and 95.40% specificity for identification of dengue infection. Furthermore, in a comparison of the normal samples to the patient samples which scored low for only one of the biomarker tests, but high or medium for either or both of the other two, PCA-FDA demonstrated a sensitivity of 97.38% and specificity of 86.18%, thus providing an unambiguous screening technology.

Socioeconomic differences in nicotine exposure and dependence in adult daily smokers

BACKGROUND

Socioeconomic status (SES) is a major determinant of tobacco use but little is known whether SES affects nicotine exposure and the degree of nicotine dependence.

METHODS

The Pennsylvania Adult Smoking Study is a cross-sectional study of smoke exposure and nicotine dependence among adults conducted in central Pennsylvania between June 2012 and April 2014. The study included several measures of SES, including assessments of education and household income, as well as occupation, home ownership, health insurance, household density and savings accounts. Measurements included saliva for the nicotine metabolites cotinine (COT), 3-'hydroxycotinine (3HC) and total metabolites (COT +3HC). Puffing behavior was determined using portable smoking topography devices.

RESULTS

The income levels of lighter smokers (< 20 cigarettes per day) was $10,000 more than heavier smokers. Higher Fagerström Test for Nicotine Dependence scores were associated with lower income and job status, scores ranged from 5.4 in unemployed, 4.4 in blue-collar, and 3.8 in white-collar workers. In principal components analysis used to derive SES indicators, household income, number in household, and type of dwelling were the major SES correlates of the primary component. Job category was the major correlate of the second component. Lower SES predicted significantly higher adjusted total nicotine metabolite levels in the unemployed group. Job category was significantly associated with total daily puffs, with the highest level in the unemployed, followed by blue-collar workers, after adjustment for income.

CONCLUSIONS

Among smokers, there was a relationship between lower SES and increased nicotine dependence, cigarettes per day and nicotine exposure, which varied by job type.

Spatiotemporal ecological vulnerability analysis with statistical correlation based on satellite remote sensing in Samara, Russia

In the present global situation, when everywhere ecology is degraded due to the extreme exhaustion of natural resources. Therefore spatiotemporal ecological vulnerability analysis is necessary for the current situation for sustainable development with protection of fragile eco-environment. Remote sensing is a unique tool to provide complete and continuous land surface information at different scales, which can use for eco-environment analysis. A methodology constructed on the principal component analysis (PCA) to identify satellite remote sensing ecological index (RSEI) for ecological vulnerability analysis and distribution based on four land surface parameters (dryness, greenness, temperature and moisture) by using Landsat TM/ETM+/OLI/TIRS data in the Samara region Russia. The results were verified by the following four methods: location-based, categorization-based, correlation-based and city center to outwards distance-based comparisons. Results indicate that ecological condition was improved from 2010 to 2015 as RSEI increased from 0.79 to 0.98 and from 2015 to 2020 the ecological condition was degraded as RSEI decreased from 0.98 to 0.82 but overall it was improved in this decade. RSEI distribution curve shows moderate to good and excellent ecological conditions and degraded ecological condition was basically characterized by high human interference and socioeconomic activities in the study area. Such a technique is a baseline for highly accurate ecological conditions mapping, monitoring and can use for decision making, management and sustainable development.

BLIND ordering of large-scale transcriptomic developmental timecourses

RNA-Seq enables the efficient transcriptome sequencing of many samples from small amounts of material, but the analysis of these data remains challenging. In particular, in developmental studies, RNA-Seq is challenged by the morphological staging of samples, such as embryos, since these often lack clear markers at any particular stage. In such cases, the automatic identification of the stage of a sample would enable previously infeasible experimental designs. Here we present the 'basic linear index determination of transcriptomes' (BLIND) method for ordering samples comprising different developmental stages. The method is an implementation of a traveling salesman algorithm to order the transcriptomes according to their inter-relationships as defined by principal components analysis. To establish the direction of the ordered samples, we show that an appropriate indicator is the entropy of transcriptomic gene expression levels, which increases over developmental time. Using BLIND, we correctly recover the annotated order of previously published embryonic transcriptomic timecourses for frog, mosquito, fly and zebrafish. We further demonstrate the efficacy of BLIND by collecting 59 embryos of the sponge Amphimedon queenslandica and ordering their transcriptomes according to developmental stage. BLIND is thus useful in establishing the temporal order of samples within large datasets and is of particular relevance to the study of organisms with asynchronous development and when morphological staging is difficult.

Cardiorespiratory fitness is positively associated with a healthy dietary pattern in New Zealand adolescents

OBJECTIVE

To examine the association between cardiorespiratory fitness and dietary patterns in adolescents.

DESIGN

Food choice was assessed using the validated New Zealand Adolescent FFQ. Principal components analysis was used to determine dietary patterns. Trained research assistants measured participants' height and body mass. Cardiorespiratory fitness was assessed in a subset of participants using the multistage 20 m shuttle run. The level and stage were recorded, and the corresponding VO2max was calculated. Differences in mean VO2max according to sex and BMI were assessed using t tests, while associations between cardiorespiratory fitness and dietary patterns were examined using linear regression analyses adjusted for age, sex, school attended, socio-economic deprivation and BMI.

SETTING

Secondary schools in Otago, New Zealand.

SUBJECTS

Students (n 279) aged 14-18 years who completed an online lifestyle survey during a class period.

RESULTS

Principal components analysis produced three dietary patterns: 'Treat Foods', 'Fruits and Vegetables' and 'Basic Foods'. The 279 participants who provided questionnaire data and completed cardiorespiratory fitness testing had a mean age of 15·7 (sd 0·9) years. Mean VO2max was 45·8 (sd 6·9) ml/kg per min. The 'Fruits and Vegetables' pattern was positively associated with VO2max in the total sample (β=0·04; 95%CI 0·02, 0·07), girls (β=0·06; 95% CI 0·03, 0·10) and boys (β=0·03; 95% CI 0·01, 0·05).

CONCLUSIONS

These results indicate that increase in cardiorespiratory fitness was associated with a healthier dietary pattern, suggesting both should be targeted as part of a global lifestyle approach. Longitudinal studies are needed to confirm this association in relation to health outcomes in New Zealand adolescents.

Multivariate statistical analysis of water chemistry conditions in three wastewater stabilization ponds with algae blooms and pH fluctuations

The wastewater stabilization ponds (WSPs) at a wastewater treatment facility in eastern Ontario, Canada, have experienced excessive algae growth and high pH levels in the summer months. A full range of parameters were sampled from the system and the chemical dynamics in the three WSPs were assessed through multivariate statistical analysis. The study presents a novel approach for exploratory analysis of a comprehensive water chemistry dataset, incorporating principal components analysis (PCA) and principal components (PC) and partial least squares (PLS) regressions. The analyses showed strong correlations between chl-a and sunlight, temperature, organic matter, and nutrients, and weak and negative correlations between chl-a and pH and chl-a and DO. PCA reduced the data from 19 to 8 variables, with a good fit to the original data matrix (similarity measure of 0.73). Multivariate regressions to model system pH in terms of these key parameters were performed on the reduced variable set and the PCs generated, for which strong fits (R(2) > 0.79 with all data) were observed. The methodologies presented in this study are applicable to a wide range of natural and engineered systems where a large number of water chemistry parameters are monitored resulting in the generation of large data sets.

Actual sexual risk and perceived risk of HIV acquisition among HIV-negative men who have sex with men in Toronto, Canada

Background

Theory suggests that perceived human immunodeficiency virus (HIV) risk and actual HIV risk behaviour are cyclical whereby engaging in high risk behaviour can increase perceived risk, which initiates precautionary behaviour that reduces actual risk, and with time reduces perceived risk. While current perceived risk may impact future actual risk, it is less clear how previous actual risk shapes current perceived risk. If individuals do not base their current perceived risk on past behaviour, they lose the protective effect of perceived risk motivating precautionary behaviour. Our goal was to determine the impact of actual risk on perceived risk.

Methods

Sexually active men who have sex with men (MSM) were recruited at the Maple Leaf Medical Clinic in downtown Toronto from September 2010 to June 2012. Participants completed a socio-behavioural questionnaire using an Audio Computer Assisted Self-Interview (ACASI). Actual HIV risk (primary predictor) was constructed by applying principal component analysis (PCA) to eight sexual risk survey questions and comprised three components which reflected sex with casual partners, sex with HIV-positive regular partners and sex with HIV unknown status regular partners. Perceived HIV risk (outcome) was measured by asking participants what the chances were that they would ever get HIV. Multivariable logistic regression was used to measure the association between actual and perceived HIV risk.

Results

One hundred and fifty HIV-negative MSM were recruited (median age 44.5 years [IQR 37–50 years]). Twenty percent of MSM perceived their HIV risk to be high. The odds of having a high perceived risk was significantly higher in those with high actual HIV risk indicated by low condom use with an HIV-positive regular partner compared to those with low actual HIV risk indicated by high condom use with an HIV-positive regular partner (Odds Ratio (OR) 18.33, 95 % confidence interval (CI) 1.65–203.45). Older age was associated with lower perceived risk but only age 40–49 compared to less than 30 was statistically significant (OR 0.12, 95 % CI 0.016–0.86). The odds of having high perceived risk was significantly associated with men who used poppers in the previous 6 months compared to those who did not use poppers (OR 5.64, 95 % CI 1.20–26.48).

Conclusions

Perceived HIV risk increased significantly as condom use with an HIV-positive regular partner decreased. However, perceived HIV risk was not associated with condom use with casual partners or HIV unknown status regular partners, even though these behaviours could be considered risky. The relationship between perceived and actual risk in HIV studies is complex and has implications on how health care workers address the issue of risky sexual behaviour and perceived risk.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-2859-6) contains supplementary material, which is available to authorized users.

[A deprivation index to reform the financing model of primary care in Catalonia (Spain)]

OBJECTIVE

To build a deprivation index for the assignation of the budgets of the primary healthcare teams in Catalonia (Spain) valid for both urban and rural environments and updatable with greater frequency than indices built from census variables.

METHOD

Starting from a review of the most common deprivation indices, variables were selected from sources that allow frequent updating and are representative at the territorial level of primary care. The correlations were calculated between the chosen variables and variables of need for healthcare and morbidity. principal components analysis was applied. Finally, the correlations of the index built with the MEDEA index and with variables of use of healthcare resources and morbidity was calculated stratifying by geographical dispersion.

RESULTS

The variables of income, occupation and education are the ones with the highest correlation with the need for healthcare and morbidity. The composed socioeconomic index (CSI) ranges from -.01 to 5.68, with an average value of 2.60 and a standard deviation of .91. The correlation between the CSI and the MEDEA index is .89. The CSI correlates with use for healthcare in both urban and rural environments, although in rural environments the association is lower.

CONCLUSIONS

The CSI was built with data that allow frequent updating and was integrated in the model for allocating resources to primary healthcare starting in 2017.

Principal components analysis of Raman spectral data for screening of Hepatitis C infection

In the current study, Raman spectroscopy is employed for the identification of the biochemical changes taking place during the development of Hepatitis C. The Raman spectral data acquired from the human blood plasma samples of infected and healthy individuals is analysed by Principal Components Analysis and the Raman spectral markers of the Hepatitis C Virus (HCV) infection are identified. Spectral changes include those associated with nucleic acidsat720 cm^-1, 1077 cm^-1 1678 (CO stretching mode of dGTP of RNA), 1778 cm^-1 (RNA), with proteins at 1641 cm^-1(amide-I), 1721 cm^-1(CC stretching of proteins) and lipids at 1738 cm^-1(CO of ester group in lipids). These differences in Raman spectral features of blood plasma samples of the patients and healthy volunteers can be associated with the development of the biochemical changes during HCV infection.

Dietary patterns and depressive symptoms in a UK cohort of men and women: a longitudinal study

OBJECTIVE

There is evidence to suggest that individual components of dietary intake are associated with depressive symptoms. Studying the whole diet, through dietary patterns, has become popular as a way of overcoming intercorrelations between individual dietary components; however, there are conflicting results regarding associations between dietary patterns and depressive symptoms. We examined the associations between dietary patterns extracted using principal component analysis and depressive symptoms, taking account of potential temporal relationships.

DESIGN

Depressive symptoms in parents were assessed using the Edinburgh Postnatal Depression Scale (EPDS) when the study child was 3 and 5 years of age. Scores >12 were considered indicative of the presence of clinical depressive symptoms. Diet was assessed via FFQ when the study child was 4 years of age.

SETTING

Longitudinal population-based birth cohort.

SUBJECTS

Mothers and fathers taking part in the Avon Longitudinal Study of Parents and Children when their study child was 3-5 years old.

RESULTS

Unadjusted results suggested that increased scores on the 'processed' and 'vegetarian' patterns in women and the 'semi-vegetarian' pattern in men were associated with having EPDS scores ≥13. However, after adjustment for confounders all results were attenuated. This was the case for all those with available data and when considering a sub-sample who were 'disease free' at baseline.

CONCLUSIONS

We found no association between dietary patterns and depressive symptoms after taking account of potential confounding factors and the potential temporal relationship between them. This suggests that previous studies reporting positive associations may have suffered from reverse causality and/or residual confounding.

Proteomic perspective of Quercus suber somatic embryogenesis

Quercus suber L. is a forest tree with remarkable ecological, social and economic value in the southern Europe ecosystems. To circumvent the difficulties of breeding such long-lived species like Q. suber in a conventional fashion, clonal propagation of Q. suber elite trees can be carried out, although this process is sometimes unsuccessful. To help decipher the complex program underlying the development of Q. suber somatic embryos from the first early stage until maturity, a proteomic approach based on DIGE and MALDI-MS has been envisaged. Results highlighted several key processes involved in the three developmental stages (proliferative, cotyledonary and mature) of Q. suber somatic embryogenesis studied. Results show that the proliferation stage is characterized by fermentation as an alternative energy source at the first steps of somatic embryo development, as well as by up-regulation of proteins involved in cell division. In this stage reactive oxygen species play a role in proliferation, while other proteins like CAD and PR5 seem to be implied in embryonic competence. In the transition to the cotyledonary stage diverse ROS detoxification enzymes are activated and reserve products (mainly carbohydrates and proteins) are accumulated, whereas energy production is increased probably to participate in the synthesis of primary metabolites such as amino acids and fatty acids. Finally, in the mature stage ethylene accumulation regulates embryo development.

BIOLOGICAL SIGNIFICANCE

Quercus suber L. is a forest tree with remarkable ecological, social and economic value in the southern Europe ecosystems. To circumvent the difficulties of breeding such long-lived species like Q. suber in a conventional fashion, clonal propagation of Q. suber elite trees can be carried out, although this process is sometimes unsuccessful. To help decipher the complex program underlying the development of Q. suber somatic embryos from the first early stage until maturity, in deep studies become necessary. This article is part of a Special Issue entitled: Translational Plant Proteomics.

A real-time classification algorithm for EEG-based BCI driven by self-induced emotions

BACKGROUND AND OBJECTIVE

The aim of this paper is to provide an efficient, parametric, general, and completely automatic real time classification method of electroencephalography (EEG) signals obtained from self-induced emotions. The particular characteristics of the considered low-amplitude signals (a self-induced emotion produces a signal whose amplitude is about 15% of a really experienced emotion) require exploring and adapting strategies like the Wavelet Transform, the Principal Component Analysis (PCA) and the Support Vector Machine (SVM) for signal processing, analysis and classification. Moreover, the method is thought to be used in a multi-emotions based Brain Computer Interface (BCI) and, for this reason, an ad hoc shrewdness is assumed.

METHOD

The peculiarity of the brain activation requires ad-hoc signal processing by wavelet decomposition, and the definition of a set of features for signal characterization in order to discriminate different self-induced emotions. The proposed method is a two stages algorithm, completely parameterized, aiming at a multi-class classification and may be considered in the framework of machine learning. The first stage, the calibration, is off-line and is devoted at the signal processing, the determination of the features and at the training of a classifier. The second stage, the real-time one, is the test on new data. The PCA theory is applied to avoid redundancy in the set of features whereas the classification of the selected features, and therefore of the signals, is obtained by the SVM.

RESULTS

Some experimental tests have been conducted on EEG signals proposing a binary BCI, based on the self-induced disgust produced by remembering an unpleasant odor. Since in literature it has been shown that this emotion mainly involves the right hemisphere and in particular the T8 channel, the classification procedure is tested by using just T8, though the average accuracy is calculated and reported also for the whole set of the measured channels.

CONCLUSIONS

The obtained classification results are encouraging with percentage of success that is, in the average for the whole set of the examined subjects, above 90%. An ongoing work is the application of the proposed procedure to map a large set of emotions with EEG and to establish the EEG headset with the minimal number of channels to allow the recognition of a significant range of emotions both in the field of affective computing and in the development of auxiliary communication tools for subjects affected by severe disabilities.

Assessing subtypes of restricted and repetitive behaviour using the Adult Repetitive Behaviour Questionnaire-2 in autistic adults

Background

The majority of previous research into restricted and repetitive behaviours (RRBs) has focussed on children, partly due to a lack of suitable measures for RRBs in adults. This study aimed to explore the psychometric properties of the Adult Repetitive Behaviour Questionnaire-2 (RBQ-2A) in a large sample of autistic adults using a self-report questionnaire method.

Methods

The RBQ-2A and Autism-Spectrum Quotient (AQ) were administered online. Data from 275 autistic adults aged 18-66 (M = 36.56, SD = 12.24; 100 men and 171 women) were analysed using polychoric principal components analysis (PCA). Reliability and validity were assessed using Cronbach's alpha and correlation analyses.

Results

PCA resulted in two components of the RBQ-2A, interpretable as repetitive sensory and motor behaviours (RSMB) and insistence on sameness (IS). Both components showed acceptable internal consistency (α = .70 and .81 respectively) and were significantly moderately correlated with scores on the AQ (r _s  = .25 and .42). Participants' scores on IS were higher than their scores on RSMB. RSMB, but not IS, was negatively associated with age, particularly in older adults (≥ 50 years). There were no gender differences.

Conclusions

The RBQ-2A is a reliable and valid self-report measure of RRBs in the present sample of autistic adults. As one of the few measures of RRBs aimed at adults, it is suitable for adults with the ability to read and complete a self-report questionnaire. Results build on previous work with children using the Repetitive Behaviour Questionnaire-2 (RBQ-2).

Correlations between peripheral parasite load and common clinical and laboratory alterations in dogs with visceral leishmaniasis

Intensity of peripheral parasite infection has an important role in the transmission of Leishmania spp. from one host to another. As parasite load quantification is still an expensive procedure to be used routinely in epidemiological surveillance, the use of surrogate predictors may be an important asset in the identification of dogs with high transmitting ability. The present study examined whether common clinical and laboratory alterations can serve as predictors of peripheral parasitism in dogs naturally infected with Leishmania spp. Thirty-seven dogs were examined in order to establish correlations between parasite load (PL) in multiple peripheral tissues and common clinical and laboratory findings in canine visceral leishmaniasis (CVL). Quantitative polymerase chain reaction was employed to determine PL in conjunctival swabs, ear skin, peripheral blood and buffy coat. Additionally, a series of hematological, biochemical and oxidative stress markers were quantified. Correlations between net peripheral infection and severity of clinical alterations and variation in laboratory parameters were assessed through a new analytical approach, namely Compressed Parasite Load Data (CPLD), which uses dimension reduction techniques from multivariate statistics to summarize PL across tissues into a single variable. The analysis revealed that elevation in PL is positively correlated with severity of clinical sings commonly observed in CVL, such as skin lesions, ophthalmic alterations, onycogriphosis, popliteal lymphadenomegaly and low body mass. Furthermore, increase in PL was found to be followed by intensification of non-regenerative anemia, neutrophilia, eosinopenia, hepatic injury and oxidative imbalance. These results suggest that routinely used clinical and laboratory exams can be predictive of intensity of peripheral parasite infection, which has an important implication in the identification of dogs with high transmitting ability.

The effect of anthropogenic activity on BTEX, NO2, SO2, and CO concentrations in urban air of the spa city of Sopot and medium-industrialized city of Tczew located in North Poland

The major goal of the present study is to compare the air quality of two urban locations situated in Northern Poland - the spa City of Sopot and the medium-industrialized city of Tczew using chemometric methods. As a criterion for the assessment of atmospheric air quality, measurements of benzene, toluene, ethylbenzene and total xylenes were used (collected from atmospheric air using diffusion-type passive samplers) as well as measurements of inorganic compounds - CO, NO2 and SO2, which were subject to routine control and determined by means of automatic analysers. Studies related to determination of defined chemical compounds in the urban air in the monitored area were performed from January 2013 to December 2014. By interpreting the results obtained and using basic multivariate statistical tools (cluster analysis and principal components analysis), major sources of emissions of determined pollutants in the air in urbanized areas were defined. The study also shows the potential influence of the sea breeze on concentrations of chemical compounds in the atmospheric air in the spa city of Sopot.

Using kinematic reduction for studying grasping postures. An application to power and precision grasp of cylinders

The kinematic analysis of human grasping is challenging because of the high number of degrees of freedom involved. The use of principal component and factorial analyses is proposed in the present study to reduce the hand kinematics dimensionality in the analysis of posture for ergonomic purposes, allowing for a comprehensive study without losing accuracy while also enabling velocity and acceleration analyses to be performed. A laboratory study was designed to analyse the effect of weight and diameter in the grasping posture for cylinders. This study measured the hand posture from six subjects when transporting cylinders of different weights and diameters with precision and power grasps. The hand posture was measured using a Vicon(®) motion-tracking system, and the principal component analysis was applied to reduce the kinematics dimensionality. Different ANOVAs were performed on the reduced kinematic variables to check the effect of weight and diameter of the cylinders, as well as that of the subject. The results show that the original twenty-three degrees of freedom of the hand were reduced to five, which were identified as digit arching, closeness, palmar arching, finger adduction and thumb opposition. Both cylinder diameter and weight significantly affected the precision grasping posture: diameter affects closeness, palmar arching and opposition, while weight affects digit arching, palmar arching and closeness. The power-grasping posture was mainly affected by the cylinder diameter, through digit arching, closeness and opposition. The grasping posture was largely affected by the subject factor and this effect couldn't be attributed only to hand size. In conclusion, this kinematic reduction allowed identifying the effect of the diameter and weight of the cylinders in a comprehensive way, being diameter more important than weight.