3,209 research outputs found
Gamma power in rural Pakistani children: links to executive function and verbal ability
Children in low- and middle-income countries are at high risk of cognitive deficits due to environmental deprivation that compromises brain development. Despite the high prevalence of unrealized cognitive potential, very little is known about neural correlates of cognition in this population. We assessed resting EEG power and cognitive ability in 105 highly disadvantaged 48-month-old children in rural Pakistan. An increase in EEG power in gamma frequency bands (21–30 Hz and 31–45 Hz) was associated with better executive function. For girls, EEG gamma power also related to higher verbal IQ. This study identifies EEG gamma power as a neural marker of cognitive function in disadvantaged children in low- and middle-income countries. Elevated gamma power may be a particularly important protective factor for girls, who may experience greater deprivation due to gender inequality.This research was supported by Grand Challenges Canada Saving Brains Initiative Grant 0061-03. The preparation of this article also was supported by a Scholar's Award from the William T. Grant Foundation to Jelena Obradovic. (0061-03 - Grand Challenges Canada Saving Brains Initiative; William T. Grant Foundation)Published versio
Structural Responses of Quasi-2D Colloid Fluids to Excitations Elicited by Nonequilibrium Perturbations
We investigate the response of a dense monodisperse quasi-two-dimensional
(q2D) colloid suspension when a particle is dragged by a constant velocity
optical trap. Consistent with microrheological studies of other geometries, the
perturbation induces a leading density wave and trailing wake, and we use
Stokesian Dynamics (SD) simulations to parse direct colloid-colloid and
hydrodynamic interactions. We go on to analyze the underlying individual
particle-particle collisions in the experimental images. The displacements of
particles form chains reminiscent of stress propagation in sheared granular
materials. From these data, we can reconstruct steady-state dipolar flow
patterns that were predicted for dilute suspensions and previously observed in
granular analogs to our system. The decay of this field differs, however, from
point Stokeslet calculations, indicating that the finite size of the colloids
is important. Moreover, there is a pronounced angular dependence that
corresponds to the surrounding colloid structure, which evolves in response to
the perturbation. Put together, our results show that the response of the
complex fluid is highly anisotropic owing to the fact that the effects of the
perturbation propagate through the structured medium via chains of
colloid-colloid collisions
Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers
We demonstrate a new approach for engineering group IV semiconductor-based
quantum photonic structures containing negatively charged silicon-vacancy
(SiV) color centers in diamond as quantum emitters. Hybrid SiC/diamond
structures are realized by combining the growth of nanoand micro-diamonds on
silicon carbide (3C or 4H polytype) substrates, with the subsequent use of
these diamond crystals as a hard mask for pattern transfer. SiV color
centers are incorporated in diamond during its synthesis from molecular diamond
seeds (diamondoids), with no need for ionimplantation or annealing. We show
that the same growth technique can be used to grow a diamond layer controllably
doped with SiV on top of a high purity bulk diamond, in which we
subsequently fabricate nanopillar arrays containing high quality SiV
centers. Scanning confocal photoluminescence measurements reveal optically
active SiV lines both at room temperature and low temperature (5 K) from
all fabricated structures, and, in particular, very narrow linewidths and small
inhomogeneous broadening of SiV lines from all-diamond nano-pillar arrays,
which is a critical requirement for quantum computation. At low temperatures (5
K) we observe in these structures the signature typical of SiV centers in
bulk diamond, consistent with a double lambda. These results indicate that high
quality color centers can be incorporated into nanophotonic structures
synthetically with properties equivalent to those in bulk diamond, thereby
opening opportunities for applications in classical and quantum information
processing
Competitive trait anxiety and general self-esteem of athletes according to the sport type and gender
Traditionally, anxiety has been interpreted as a negative emotional state characterized by nervousness, worry, fret, uncertainty and vague fear which could have an adverse effect on sports achievement. On the other hand, sport type and its specific nature and demands, may also be connected with the level of state and trait anxiety. This study aimed to investigate potential differences in the competitive trait anxiety level and general self-esteem according to gender in sports of different contact level. The sample consisted of 1024 (590 males and 434 females) young athletes. Independent variables were sport contact level (non-contact, contact and collision sports) and gender. Dependent variables were measured by the adjusted versions of Sport Competition Anxiety Test and Rosenberg Self-Esteem Scale. Basic descriptive statistics was calculated for all the groups, and the differences between them were established using χ² test and MANOVA. The results suggest significant differences in trait competitive anxiety per sport type, gender and their interaction, and no differences in the general self-esteem level. The current study reveals that not only the intensity but also the intergroup relationship of a sport contact level (non-contact, contact and collision sports) is gender determined. These findings are important in psycho-diagnostic procedure and choosing appropriate coping strategies for athletes
Gamma power in Pakistani children: Links to executive function and verbal ability
Children in low- and middle-income countries are at high risk of cognitive deficits due to environmental deprivation that compromises brain development. Despite the high prevalence of unrealized cognitive potential, very little is known about neural correlates of cognition in this population. We assessed resting EEG power and cognitive ability in 105 highly disadvantaged 48-month-old children in rural Pakistan. An increase in EEG power in gamma frequency bands (21-30Hz and 31-45Hz) was associated with better executive function. For girls, EEG gamma power also related to higher verbal IQ. This study identifies EEG gamma power as a neural marker of cognitive function in disadvantaged children in low- and middle-income countries. Elevated gamma power may be a particularly important protective factor for girls, who may experience greater deprivation due to gender inequality
High annual radon concentration in dwellings and natural radioactivity content in nearby soil in some rural areas of Kosovo and Metohija
Some previous studies on radon concentration in dwellings of some areas of Kosovo and Metohija have revealed a high average radon concentration, even though the detectors were exposed for three months only. In order to better design a larger study in this region, the annual measurements in 25 houses were carried out as a pilot study. For each house, CR-39-based passive devices were exposed in two rooms for the two consecutive six-month periods to account for seasonal variations of radon concentration. Furthermore, in order to correlate the indoor radon with radium in nearby soil and to improve the knowledge of the natural radioactivity in the region, soil samples near each house were collected and 226Ra, 232Th, 40K activity concentration were measured. The indoor radon concentration resulted quite high from the average (163 Bq/m3) and generally it did not differ considerably between the two rooms and the two six-month periods. The natural radionuclides in soil resulted to be distributed quite uniformly. Moreover, the correlation between the226Ra content in soil and radon concentration in dwellings resulted to be low (R2=0.26). The annual effective dose from radon and its short-lived progeny (5.5 mSv, in average) was calculated by using the last ICRP dose conversion factors. In comparison, the contribution to the annual effective dose of outdoor gamma exposure from natural radionuclides in soil is nearly negligible (66 mSv). In conclusion, the observed high radon levels are only partially correlated with radium in soil; moreover, a good estimate of the annual average of radon concentration can be obtained from a six-month measurement with a proper choice of exposure period, which could be useful when designing large surveys
A prebiotic galactooligosaccharide mixture reduces severity of hyperpnoea-induced bronchoconstriction and markers of airway inflammation
Gut microbes have a substantial influence on systemic immune function and allergic sensitisation. Manipulation of the gut microbiome through prebiotics may provide a potential strategy to influence the immunopathology of asthma. This study investigated the effects of prebiotic Bimuno-galactooligosaccharide (B-GOS) supplementation on hyperpnoea-induced bronchoconstriction (HIB), a surrogate for exercise-induced bronchoconstriction, and airway inflammation. A total of ten adults with asthma and HIB and eight controls without asthma were randomised to receive 5·5 g/d of either B-GOS or placebo for 3 weeks separated by a 2-week washout period. The peak fall in forced expiratory volume in 1 s (FEV1) following eucapnic voluntary hyperpnoea (EVH) defined HIB severity. Markers of airway inflammation were measured at baseline and after EVH. Pulmonary function remained unchanged in the control group. In the HIB group, the peak post-EVH fall in FEV1 at day 0 (−880 (SD 480) ml) was unchanged after placebo, but was attenuated by 40 % (−940 (SD 460) v. −570 (SD 310) ml, P= 0·004) after B-GOS. In the HIB group, B-GOS reduced baseline chemokine CC ligand 17 (399 (SD 140) v. 323 (SD 144) pg/ml, P =0·005) and TNF-α (2·68 (SD 0·98) v. 2·18 (SD 0·59) pg/ml, P= 0·040) and abolished the EVH-induced 29 % increase in TNF-α. Baseline C-reactive protein was reduced following B-GOS in HIB (2·46 (SD 1·14) v. 1·44 (SD 0·41) mg/l, P=0·015) and control (2·16 (SD 1·02) v. 1·47 (SD 0·33) mg/l, P=0·050) groups. Chemokine CC ligand 11 and fraction of exhaled nitric oxide remained unchanged. B-GOS supplementation attenuated airway hyper-responsiveness with concomitant reductions in markers of airway inflammation associated with HIB
Dietary Exposure and Risk Assessment of Aflatoxin M1 for Children Aged 1 to 9 Years Old in Serbia
The present study was conducted to estimate the exposure and characterize the risk for the child population of Serbia to Aflatoxin M1 (AFM1) from milk and milk-based food. A total of 3404 samples comprising milk and different milk-based food samples were collected from various regions of Serbia from 2017 to 2019. Evaluation of AFM1 exposure was carried out using the deterministic method, whereas risk characterization was evaluated using the margin of exposure (MOE) and the risk of hepatocellular carcinoma (HCC). Detection rates for AFM1 in milk and milk-based food samples ranged between 2% and 79%, with the highest incidence (79%) and mean level (22.34 ± 0.018 ng kg−1) of AFM1 being detected in pasteurized and UHT milk. According to the three consumption estimates, the values of estimated daily intake (EDI) were higher for toddlers as compared with children aged 3–9 years. Children aged 1–3 years had the highest risk of exposure to AFM1 in milk, with an estimated daily intake of 0.164 and 0.193 ng kg−1 bw day−1 using lower bound (LB) and upper bound (UB) exposure scenarios, respectively. Such difference could result from the higher consumption to weight in younger children. Based on the estimated daily intake (EDI) found in this study, the risk of AFM1 exposure due to consumption of milk and milk-based food was low since the MOE values obtained were >10,000. In addition, the risk of HCC cases/year/105 individuals of different age groups showed that the value of HCC, using potency estimates of 0.0017 (mean), was maximum (0.00034) in the age group 1–3 years, which indicates no health risk for the evaluated groups. The present study revealed the importance of controlling and preventing AFM1 contamination in milk through continuous monitoring and regular inspection to reduce the risk of AFM1 exposure, especially in children
The Intake of Phosphorus and Nitrites through Meat Products: A Health Risk Assessment of Children Aged 1 to 9 Years Old in Serbia
This study provides the data on dietary exposure of Serbian children to nitrites and phosphorus from meat products by combining individual consumption data with available analytical data of meat products. A total of 2603 and 1900 commercially available meat products were categorized into seven groups and analysed for nitrite and phosphorous content. The highest mean levels of nitrite content, expressed as NaNO2, were found in finely minced cooked sausages (40.25 ± 20.37 mg/kg), followed by canned meat (34.95 ± 22.12 mg/kg) and coarsely minced cooked sausages (32.85 ± 23.25 mg/kg). The EDI (estimated daily intake) of nitrites from meat products, calculated from a National Food Consumption Survey in 576 children aged 1–9 years, indicated that the Serbian children population exceeded the nitrite ADI (acceptable daily intake) proposed by EFSA (European Food Safety Authority) in 6.4% of children, with a higher proportion in 1–3-year-old participants. The mean phosphorus concentration varied from 2.71 ± 1.05 g/kg to 6.12 ± 1.33 g/kg in liver sausage and pate and smoked meat products, respectively. The EDI of phosphorus from meat products was far below the ADI proposed by EFSA, indicating that the use of phosphorus additives in Serbian meat products is generally in line with legislation
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