Does early responsive parenting have a special importance for children's development or is consistency across early childhood necessary?

The role of early versus ongoing maternal responsiveness in predicting cognitive and social development was examined in home visits for mothers, full-term children (n?=?103), and medically low-risk (n?=?102) and high-risk (n?=?77) preterm children at 5 ages. There were 4 maternal clusters based on warm and contingent responsiveness behaviors observed early (at 6, 12, and 24 months) and late (at 3 and 4 years): high early, high late; high early, low late; low early, moderate late; and low early, low late. Children, especially preterm children, showed faster cognitive growth when mothers were consistently responsive. Social growth was similar in the consistently responsive (high-high) and the early-responsive inconsistent (high-low) clusters, but greater deceleration at 4 years among children with mothers in the inconsistent cluster refuted the notion of a unique role for early responsiveness. The importance of consistent responsiveness, defined by an affective-emotional construct, was evident even when a broader constellation of parenting behaviors was considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Teacher key opinion leaders and mental health consultation in low-income urban schools.

Diffusion theory posits that information is disseminated throughout a social network by the persuasion of key opinion leaders (KOLs). This study examined the relative and combined influence of peer-identified KOL teachers (n = 12) and mental health providers (n = 21) on classroom teachers' (n = 61) self-reported use of commonly recommended classroom practices for children with attention-deficit/hyperactivity disorder in 6 low-income urban African American communities, relative to teachers (n = 54) at 4 matched schools who received mental health provider consultation only. Mixed-effects regression models showed that KOLs in collaboration with mental health providers promoted higher rates of teachers' self-reported use of recommended strategies than mental health providers alone, and that these effects were mediated by KOL support but not by mental health provider support. The results suggest an expanded role for KOL teachers as indigenous and natural supports for the dissemination and implementation of school-based mental health programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptions of European American and African American instructors teaching race-focused courses.

In 2 studies (N = 907), we developed and validated the Perceptions of Diversity Instructors (PDI-32) measure, which assesses college students' ratings of instructors teaching a race-focused diversity course. We also explored how the professor's race/ethnicity, students' attitudes toward similarities and differences, and perceived professor bias influenced students' ratings. Supporting the source effects outlined in the persuasion literature and prior qualitative research, the results indicated that students expect African American instructors to be more biased (subjective/judgmental) but assume European American instructors to have less content expertise (inexpert/unaware). Also, students who are more open to discussing diversity issues rated the instructors more positively. Finally, students' expectation of professor bias mediated the relationship between the professor's race/ethnicity and students' evaluations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Organic PM Emissions from Vehicles: Composition,O/C Ratio,and Dependence on PM Concentration

A suite of real-time instruments was used to sample vehicle emissions at the California Air Resources Board Haagen-Smit facility. Eight on-road, spark-ignition gasoline and three alternative vehicles were tested on a chassis dynamometer and the emissions were diluted to atmospherically relevant concentrations (0.5–30 μg/m³). An Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-MS) characterized the real-time behavior of the nonrefractory organic and inorganic particulate matter (PM) in vehicle emissions. It was found that the emission of particulate organic matter (POM) was strongly affected by engine temperature and engine load and that the emission concentrations could vary significantly by vehicle. Despite the small sample size, consistent trends in chemical characteristics were observed. The composition of vehicle POM was found to be related to overall PM mass concentration where the oxygen-to-carbon (O/C) ratio tended to increase at lower concentration and had an average value of 0.057 ± 0.047, with a range from 0.022 to 0.15. The corresponding fraction of particle-phase CO₂⁺, or f₄₄, ranged from 1.1% to 8.6% (average = 2.1%) and exhibited a linear variation with O/C. The average mass spectrum from all vehicles tested was also compared to those of hydrocarbon-like organic aerosol (HOA) observed in ambient air and the agreement is very high. The results of these tests offer the vehicle emissions community a first glimpse at the real-time chemical composition and variation of vehicle PM emissions for a variety of conditions and vehicle types at atmospherically relevant conditions and without chemical interferences from other primary or secondary aerosol sources.

Copyright 2015 American Association for Aerosol Research     

Model Experiments of the Resuspension Caused by Road Traffic

In the literature field experiments were performed in which factors affecting the resuspension of particulate material by road traffic were investigated. The factors involved were in most cases the particle size and the speed of the car. In some cases even the size of the car was varied (medium-sized car or truck). The present experiments were made to obtain a better understanding of the influence of the aerodynamic effects (not the tire effects) affecting resuspension by road traffic. In the experiments a model was used to investigate the influence of its shape, its velocity, and its distance to the surface. The experiments also included the size of the particles and the kind of surface from which the particles were resuspended. These experiments were performed in order to make possible a better interpretation of the field tests     

Aerosol Metrology Supporting Air Quality Monitoring in the United Kingdom and Europe

Regulatory measurements of particle mass concentration in air, such as PM₁₀ and PM_2.5, have been required in Europe for many years, but have been problematic as issues affecting the comparability of measurements, even when made by the reference method, have become apparent. The importance of airborne particulate matter for human health, and the complexity of the atmospheric processes affecting it, have led to many other parameters, such as particle number concentration, size distribution and composition being monitored, in some cases also as a regulatory requirement. Generally the metrological aspects have been covered by the monitoring network operators, with little involvement from National Metrology Institutes (NMIs). The United Kingdom (UK) National Physical Laboratory is unusual in being an NMI that also operates air quality networks on behalf of the government, directly involved in the full range of activities from fundamental metrology, standardisation of methods, and field operation. More recently, some of the measurement issues have started to be addressed by a group of NMIs within the European Metrology Research Programme. This paper outlines some of the key metrological problems in this area, and the current position in dealing with them from a UK and European perspective.     

Enhancement of fiber orientation distribution reconstruction in diffusion-weighted imaging by single channel blind source separation

In diffusion-weighted imaging (DWI), reliable fiber tracking results rely on the accurate reconstruction of the fiber orientation distribution function (fODF) in each individual voxel. For high angular resolution diffusion imaging (HARDI), deconvolution-based approaches can reconstruct the complex fODF and have advantages in terms of computational efficiency and no need to estimate the number of distinct fiber populations. However, HARDI-based methods usually require relatively high b-values and a large number of gradient directions to produce good results. Such requirements are not always easy to meet in common clinical studies due to limitations in MRI facilities. Moreover, most of these approaches are sensitive to noise. In this study, we propose a new framework to enhance the performance of the spherical deconvolution (SD) approach in low angular resolution DWI by employing a single channel blind source separation (BSS) technique to decompose the fODF initially estimated by SD such that the desired fODF can be extracted from the noisy background. The results based on numerical simulations and two phantom datasets demonstrate that the proposed method achieves better performance than SD in terms of robustness to noise and variation in b-values. In addition, the results show that the proposed method has the potential to be applied to low angular resolution DWI which is commonly used in clinical studies.     

Isothermal crystallization of lightly sulfonated syndiotactic polystyrene/montmorillonite clay nanocomposites

Lightly sulfonated syndiotactic polystyrene (sPS) nanocomposites were prepared using a solution intercalation technique, and the effect of montmorillonite clay on the crystallization kinetics of sulfonated sPS ionomer nanocomposites was systematically studied. Wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM) were used to evaluate the dispersion of clay platelets within sPS and sulfonated sPS ionomer (SsPS) matrices. Experimental results obtained from WAXD and TEM revealed a predominately exfoliated morphology within the SsPS ionomer containing 5 wt.% of organically-modified clay. The corresponding non-sulfonated sPS control exhibited a mixed morphological structure consisting of intercalated platelets and many platelets that were present as micron-sized agglomerates. Using differential scanning calorimetry (DSC), the Avrami approach was used to elucidate information related to nucleation and growth within the sPS and SsPS systems during the isothermal crystallization process. Pristine and organically-modified clays significantly increased the overall crystallization rate of the SsPS ionomer, while the nanoclays slightly decreased the crystallization rate of the non-ionic sPS. The mechanistic origins of increased crystallization rates within the SsPS ionomer clay nanocomposites were attributed to multiple phenomena including disruption of the ionomer electrostatic network and a nucleating effect due to the presence of well-separated, homogeneously dispersed clay platelets.     

Fermented goats’ milk produced with selected multiple starters as a potentially functional food

A screening among five lactic acid bacteria, used alone or in combination, led to select a mixed starter (Streptococcus thermophilus CR12, Lactobacillus casei LC01, Lactobacillus helveticus PR4, Lactobacillus plantarum 1288) capable to produce a fermented goats’ milk containing γ-aminobutyric acid (GABA) and angiotensin-I converting enzyme (ACE)-inhibitory peptides. The fermented milk was characterized by cell counts of lactic acid bacteria not lower than 7.0 log cfu g⁻¹, even after 45 days of storage at 4 °C. Fermentation of goats’ milk resulted in the production of ca. 28 mg kg⁻¹ of GABA. Furthermore the fermented goats’ milk had an in vitro ACE-inhibitory activity of ca. 73%. Prolonged cold storage did not significantly affect both the concentration of GABA and the ACE-inhibitory activity. Moreover, the taurine content did not significantly vary during both fermentation and the entire storage period.