4,846 research outputs found
Elevated lead levels in relation to low serum neuropeptide Y and adverse behavioral effects in preschool children with e-waste exposure
As a neurotoxicant, lead (Pb) primarily affects central nervous system, and particularly impacts developing brain. This study explores the associations of blood Pb level and children's behavioral health. A total of 213 preschool children aged 3-7 years old were recruited from Guiyu (the e-waste-exposed area) and Haojiang (the reference area). The behavioral health of children was assessed using the 'behavioral symptoms' subscale of the Strengths and Difficulties Questionnaire (SDQ). Results showed that there was a significant difference in percent of children categorized as "at risk" between Guiyu (48.2%) and Haojiang (13.9%) (p = 5.00 mu g/dL (high) than those with blood Pb level < 5.00 mu g/dL (low). After adjusting for confounding factors, children with lower NPY levels were at higher risk of having behavioral difficulties. In conclusion, Pb exposure in e-waste-exposed areas may lead to decrease in serum NPY and increase in the risk of children's behavioral problems. In addition, NPY may mediate the association between Pb exposure and behavioral difficulties. (C) 2020 Elsevier Ltd. All rights reserved
Standard metabolic rate predicts growth trajectory of juvenile Chinese crucian carp (Carassius auratus) under changing food availability
Phenotypic traits vary greatly within populations and can have a significant influence on aspects of performance. The present study aimed to investigate the effects of individual variation in standard metabolic rate (SMR) on growth rate and tolerance to food-deprivation in juvenile crucian carp (Carassius auratus) under varying levels of food availability. To address this issue, 19 high and 16 low SMR (individuals were randomly assigned to a satiation diet for 3 weeks, whereas another 20 high and 16 low SMR individuals were assigned to a restricted diet (approximately 50% of satiation) for the same period. Then, all fish were completely food-deprived for another 3 weeks. High SMR individuals showed a higher growth rate when fed to satiation, but this advantage of SMR did not exist in food-restricted fish. This result was related to improved feeding efficiency with decreased food intake in low SMR individuals, due to their low food processing capacity and maintenance costs. High SMR individuals experienced more mass loss during food-deprivation as compared to low SMR individuals. Our results here illustrate context-dependent costs and benefits of intraspecific variation in SMR whereby high SMR individuals show increased growth performance under high food availability but had a cost under stressful environments (i.e., food shortage)
MixNet: Toward Accurate Detection of Challenging Scene Text in the Wild
Detecting small scene text instances in the wild is particularly challenging,
where the influence of irregular positions and nonideal lighting often leads to
detection errors. We present MixNet, a hybrid architecture that combines the
strengths of CNNs and Transformers, capable of accurately detecting small text
from challenging natural scenes, regardless of the orientations, styles, and
lighting conditions. MixNet incorporates two key modules: (1) the Feature
Shuffle Network (FSNet) to serve as the backbone and (2) the Central
Transformer Block (CTBlock) to exploit the 1D manifold constraint of the scene
text. We first introduce a novel feature shuffling strategy in FSNet to
facilitate the exchange of features across multiple scales, generating
high-resolution features superior to popular ResNet and HRNet. The FSNet
backbone has achieved significant improvements over many existing text
detection methods, including PAN, DB, and FAST. Then we design a complementary
CTBlock to leverage center line based features similar to the medial axis of
text regions and show that it can outperform contour-based approaches in
challenging cases when small scene texts appear closely. Extensive experimental
results show that MixNet, which mixes FSNet with CTBlock, achieves
state-of-the-art results on multiple scene text detection datasets
Phase formation of polycrystalline MgB2 at low temperature using nanometer Mg powder
The MgB2 superconductor synthesized in a flowing argon atmosphere using
nanometer magnesium powder as the raw materials, denoted as Nano-MgB2, has been
studied by the technique of in-situ high temperature resistance measurement
(HT-RT measurement). The MgB2 phase is identified to form within the
temperature range of 430 to 490 C, which is much lower than that with the MgB2
sample fabricated in the same gas environment using the micron-sized magnesium
powder, denoted as Micro-MgB2, reported previously. The sample density of the
Nano-MgB2 reaches 1.7 g/cm3 with a crystal porosity structure less than a
micrometer, as determined by the scanning electron microscope (SEM) images,
while the Micro-MgB2 has a much more porous structure with corresponding
density of 1.0 g/cm3. This indicates that the Mg raw particle size, besides the
sintering temperature, is a crucial factor for the formation of high density
MgB2 sample, even at the temperature much lower than that of the Mg melting,
650 C. The X-ray diffraction (XRD) pattern shows a good MgB2 phase with small
amount of MgO and Mg and the transition temperature, TC, of the Nano-MgB2 was
determined as 39 K by the temperature dependent magnetization measurement
(M-T), indicating the existence of a good superconducting property.Comment: 10 pages, 4 figure, Solid State Communicatio
Variable stars detection in the field of open cluster NGC 188
This work presents the charge-coupled device (CCD) photometric survey of the
old open cluster NGC 188. Time-series V-band photometric observations were
conducted for ten nights in January 2017 using the Nanshan One-meter Wide-field
Telescope (NOWT) to search for variable stars in the field of the cluster
field. A total of 25 variable stars, including one new variable star, were
detected in the target field. Among the detected variables, 16 are cluster
member stars, and the others are identified as field stars. The periods, radial
velocities, effective temperatures, and classifications of the detected
variables are discussed in this work. Most of the stars' effective temperatures
are between 4200 K and 6600 K, indicating their spectral types are G or K. The
newly discovered variable is probably a W UMa system. In this study, a known
cluster variable star (V21 = V0769 Cep) is classified as an EA-type variable
star based on the presence of an 0.5 magnitude eclipse in its light curve
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