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991.
The roles of age, gender, inhibitory control, and parental supervision in children's pedestrian safety 总被引:2,自引:0,他引:2
OBJECTIVE: Thousands of American children are injured or killed each year as pedestrians, but behavioral factors in pedestrian injury etiology remain poorly understood. We examined the roles of children's individual differences (age, gender, and inhibitory control) and parental supervision in children's pedestrian behaviors. METHODS: Using the pretend road method, a sample of 85 children and 26 adults crossed a pretend crosswalk set adjacent to a real road. Safety of crossing the pretend road was determined based on actual traffic on the real road. Adults also crossed the real road. RESULTS: Adults' behavior on the real road paralleled that on the pretend road, supporting validity of the method. On the pretend road, younger children, boys, and children with less behavioral control engaged in riskier pedestrian behaviors. Children with less behavioral control responded more noticeably to increases in parental supervision. CONCLUSION: Results are discussed in relation to children's development and injury prevention. 相似文献
992.
The discharge of single motor units (n = 34) in the first dorsal interosseus muscle and the fluctuations in force during steady contractions were measured across a range of index finger abduction forces in old adults (77.1 +/- 6.9 yr, n = 20). These results were compared with previously reported data on 38 motor units from young adults (25.7 +/- 5.7 yr). Both minimal and peak discharge rates increased with recruitment threshold, but the strength of these relations was notably weaker for the old adults. Minimal discharge rates were similar for young and old adults (P = 0.77), whereas peak discharge rates were lower for old adults (P < 0.01). Consequently, the range of rate coding for each motor unit was substantially less for the old adults (7.1 pps) compared with the young adults (12.1 pps, P < 0.01). However, the variability in motor-unit discharge was similar for young and old adults; the coefficient of variation of the interspike intervals was similar at recruitment (old: 25.4%, young: 27.1%, P = 0.39) and declined with an increase in discharge rate (old: 13.2%, young: 14.2%, P = 0.21). Furthermore, the fluctuations in force during steady isometric contractions (2-95% of maximal force) were similar for young and old adults, except that the relative variability at the lowest force was greater for the old adults. A computational model of motor-unit recruitment and rate coding incorporated the experimental observations and was able to match the measured and simulated values for force steadiness across the operating range of the muscle. 相似文献
993.
AIMS: To compare immunohistochemical staining for oestrogen receptor, progesterone receptor and HER-2 between core biopsy and matched subsequent excisional specimens. METHODS: One hundred consecutive core biopsy cases and subsequent excisional specimens were retrieved and immunohistochemical staining performed. Proportion and intensity of staining for hormone receptors and HercepTest score were recorded for each case in a blinded fashion by the authors. RESULTS: Overall hormone receptor status was concordant between cores and excisions in 96.9% of cases. ER status was concordant between the core and excision in 95.8% of cases. The intensity of staining for ER was similar in both core and excision specimens. PR status was concordant in cores and excisions in 90.3% of cases. There was weaker PR staining in the excisional specimens when compared with the cores. HER-2 status was concordant in cores and excisions in 86.6% of cases. CONCLUSIONS: Hormone receptor staining produced similar results on core and excisional specimens, although a small number of additional hormone receptor positive cases could be detected by performing staining on a previously received core in the case of a negative result on the excisional specimen. HER-2 staining is less reproducible between cores and excisions, but the clinical significance of this observation remains to be tested. 相似文献
994.
995.
The integration of visual and auditory information can significantly amplify the sensory responses of superior colliculus (SC) neurons and the behaviors that depend on them. This response amplification depends on the development of SC inputs that are derived from two regions of cortex: the anterior ectosylvian sulcus (AES) and the rostral lateral suprasylvian sulcus (rLS). Neonatal ablation of these cortico-collicular areas has been shown to disrupt the development of the multisensory enhancement capabilities of SC neurons and the present results demonstrate that it also precludes the development of the normal multisensory enhancements in orientation behavior. Animals with neonatal ablation of AES and rLS were tested at maturity and found unable to benefit from the combination of visual and auditory cues in their efforts to localize targets in contralesional space. In contrast, their ipsilesional multisensory orientation capabilities were indistinguishable from those of normal animals. However, when only one of these cortical areas was removed during early life, later behavioral consequences were negligible. Whether similar compensatory processes would occur in adult animals remains to be determined. These observations, coupled with those from previous studies, also suggest that a surprisingly high proportion of SC neurons capable of multisensory integration must be present for orientation behavior benefits to be realized. Compensatory mechanisms can achieve this if early lesions spare either AES or rLS, but even the impressive plasticity of the neonatal brain cannot compensate for the early loss of both of them. 相似文献
996.
997.
Tatler BW Hutton SB 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2007,179(3):387-396
The antisaccade task requires participants to inhibit the reflexive tendency to look at a sudden onset target and instead
direct their gaze to the opposite hemifield. As such it provides a convenient tool with which to investigate the cognitive
and neural systems that support goal-directed behaviour. Recent models of cognitive control suggest that antisaccade performance
on a single trial should vary as a function of the outcome (correct antisaccade or erroneous prosaccade) of the previous trial.
In addition, repetition priming effects suggest that the spatial location of the target on the previous trial may also influence
current trial performance. Thus an analysis of contingency effects in antisaccade performance may provide new insights into
the factors that influence the monitoring and modulation of the antisaccade task and other ongoing behaviours. Using a multilevel
modelling analysis we explored previous trial effects on current trial performance in a large antisaccade dataset. We found
(1) repetition priming effects following correct antisaccades; (2) contrary to models of cognitive control antisaccade error
rates were increased on trials following an error, suggesting that failures to adequately maintain the task goal can persist
across more than one trial; and (3) current trial latencies varied according to the previous trial outcome (correct antisaccade,
slowly corrected error or rapidly corrected error). These results are discussed in terms of current models of antisaccade
performance and cognitive control and further demonstrate the utility of multilevel modelling for analysing antisaccade data. 相似文献
998.
Lisa Daniels Rachael W. Taylor Sheila M. Williams Rosalind S. Gibson Samir Samman Benjamin J. Wheeler Barry J. Taylor Elizabeth A. Fleming Nicola K. Hartley Anne-Louise M. Heath 《Journal of the Academy of Nutrition and Dietetics》2018,118(6):1006-1016.e1
Background
Little is known about zinc intakes and status during complementary feeding. This is particularly true for baby-led approaches, which encourage infants to feed themselves from the start of complementary feeding, although self-feeding may restrict the intake of zinc-rich foods.Objective
To determine the zinc intakes, sources, and biochemical zinc status of infants following Baby-Led Introduction to SolidS (BLISS), a modified version of Baby-Led Weaning (BLW), compared with traditional spoon-feeding.Design
Secondary analysis of the BLISS randomized controlled trial.Participants/setting
Between 2012 and 2014, 206 community-based participants from Dunedin, New Zealand were randomized to a Control or BLISS group.Intervention
BLISS participants received eight study visits (antenatal to 9 months) providing education and support regarding BLISS (ie, infant self-feeding from 6 months with modifications to address concerns about iron, choking, and growth).Main outcome measures
Dietary zinc intakes at 7 and 12 months (weighed 3-day diet records) and zinc status at 12 months (plasma zinc concentration).Statistical analyses performed
Regression analyses were used to investigate differences in dietary intakes and zinc status by group, adjusted for maternal education and parity and infant age and sex.Results
There were no significant differences in zinc intakes between BLISS and Control infants at 7 (median: 3.5 vs 3.5 mg/day; P=0.42) or 12 (4.4 vs 4.4 mg/day; P=0.86) months. Complementary food groups contributing the most zinc at 7 months were “vegetables” for Control infants, and “breads and cereals” for BLISS infants, then “dairy” for both groups at 12 months. There was no significant difference in mean±standard deviation plasma zinc concentration between the Control (62.8±9.8 μg/dL [9.6±1.5 μmol/L]) and BLISS (62.8±10.5 μg/dL [9.6±1.6 μmol/L]) groups (P=0.75).Conclusions
BLISS infants achieved similar zinc intake and status to Control infants. However, the BLISS intervention was modified to increase iron intake, which may have improved zinc intake, so these results should not be generalized to infants following unmodified BLW. 相似文献999.
Bo Zhang Giancarlo Pascali Naomi Wyatt Lidia Matesic Mitchell A. Klenner Tiffany R. Sia Adam J. Guastella Massimiliano Massi Andrea J. Robinson Benjamin H. Fraser 《Journal of labelled compounds & radiopharmaceuticals》2018,61(11):847-856
Fluorine‐18 labelled prosthetic groups (PGs) are often necessary for radiolabelling sensitive biological molecules such as peptides and proteins. Several shortcomings, however, often diminish the final yield of radiotracer. In an attempt to provide higher yielding and operationally efficient tools for radiolabelling biological molecules, we describe herein the first radiochemical synthesis of [18F]ethenesulfonyl fluoride ([18F]ESF) and its Michael conjugation with amino acids and proteins. The synthesis of [18F]ESF was optimised using a microfluidic reactor under both carrier‐added (c.a.) and no‐carrier‐added (n.c.a.) conditions, affording, in a straightforward procedure, 30‐50% radiochemical yield (RCY) for c.a. [18F]ESF and 60‐70% RCY for n.c.a. [18F]ESF. The conjugation reactions were performed at room temperature using 10 mg/mL precursor in aqueous/organic solvent mixtures for 15 min. The radiochemical stability of the final conjugates was evaluated in injectable formulation and rat serum, and resulted strongly substrate dependent and generally poor in rat serum. Therefore, in this work we have optimised a straightforward synthesis of [18F]ESF and its Michael conjugation with model compounds, without requiring chromatographic purification. However, given the general low stability of the final products, further studies will be required for improving conjugate stability, before assessing the use of this PG for PET imaging. 相似文献
1000.
Benjamin Gronier Helene M. Savignac Mathieu Di Miceli Sherif M. Idriss George Tzortzis Daniel Anthony Philip W.J. Burnet 《European neuropsychopharmacology》2018,28(1):211-224
We have previously shown that prebiotics (dietary fibres that augment the growth of indigenous beneficial gut bacteria) such as Bimuno? galacto-oligosaccharides (B-GOS®), increased N-methyl-D-aspartate (NMDA) receptor levels in the rat brain. The current investigation examined the functional correlates of these changes in B-GOS®-fed rats by measuring cortical neuronal responses to NMDA using in vivo NMDA micro-iontophoresis electrophysiology, and performance in the attentional set-shifting task. Adult male rats were supplemented with B-GOS® in the drinking water 3 weeks prior to in vivo iontophoresis or behavioural testing. Cortical neuronal responses to NMDA iontophoresis, were greater (+30%) in B-GOS® administered rats compared to non-supplemented controls. The intake of B-GOS® also partially hindered the reduction of NMDA responses by the glycine site antagonist, HA-966. In the attentional set-shifting task, B-GOS® -fed rats shifted from an intra-dimensional to an extra-dimensional set in fewer trials than controls, thereby indicating greater cognitive flexibility. An initial exploration into the mechanisms revealed that rats ingesting B-GOS® had increased levels of plasma acetate, and cortical GluN2B subunits and Acetyl Co-A Carboxylase mRNA. These changes were also observed in rats fed daily for 3 weeks with glyceryl triacetate, though unlike B-GOS®, cortical histone deacetylase (HDAC1, HDAC2) mRNAs were also increased which suggested an additional epigenetic action of direct acetate supplementation. Our data demonstrate that a pro-cognitive effect of B-GOS® intake in rats is associated with an increase in cortical NMDA receptor function, but the role of circulating acetate derived from gut bacterial fermentation of this prebiotic requires further investigation. 相似文献