725 research outputs found
Active School Travel Intervention Methodologies in North America: A Systematic Review
Context: As children’s lifestyles have become increasingly sedentary, active school travel can be a relatively accessible way to increase their daily physical activity. In recent years, several different models of interventions have been utilized to promote children participating in active school travel. This review documents and analyzes the different active school travel intervention methodologies that have been used in North America (Canada or U.S.) by collecting, organizing, and evaluating data relating to all phases of active school travel interventions.
Evidence acquisition: This systematic review developed a key word search and applied it in six databases (BIOSIS Previews, GeoBase, PubMed, SCOPUS, SPORTDiscus, Web of Science) to gather scholarly literature. A total of 22 studies evaluating children’s active school travel interventions in a North American setting (four Canada, 18 U.S.) were identified for the period between January 2010 and March 2017.
Evidence synthesis: Applying the Safe Routes to School Education, Encouragement, Enforcement, Engineering, Equity, and Evaluation (“6 E’s”) framework, interventions were thematically assessed for their structure and organization, approaches and methods, and outcomes and discussions. Encouragement and education were the most commonly observed themes within the different methodologies of the studies reviewed. Details relating to intervention approaches and methods were common; whereas data relating to intervention structure and organization received much less attention.
Conclusions: Kingdon’s multiple streams approach was applied to frame the findings for program facilitators and evaluators. Within the multiple streams approach, several considerations are offered to address and potentially improve active school travel intervention conceptualization, partnerships, organization, and evaluation
Catalytic sites for 3'- and 5' incision of Escherichia coli nucleotide excision repair are both located in UvrC.
Medical Biochemistr
Transcriptome analysis of the central nervous system of the mollusc Lymnaea stagnalis
Background: The freshwater snail Lymnaea stagnalis (L. stagnalis) has served as a successful model for studies in the field of Neuroscience. However, a serious drawback in the molecular analysis of the nervous system of L. stagnalis has been the lack of large-scale genomic or neuronal transcriptome information, thereby limiting the use of this unique model. Results: In this study, we report 7,712 distinct EST sequences (median length: 847 nucleotides) of a normalized L. stagnalis central nervous system (CNS) cDNA library, resulting in the largest collection of L. stagnalis neuronal transcriptome data currently available. Approximately 42% of the cDNAs can be translated into more than 100 consecutive amino acids, indicating the high quality of the library. The annotated sequences contribute 12% of the predicted transcriptome size of 20,000. Surprisingly, approximately 37% of the L. stagnalis sequences only have a tBLASTx hit in the EST library of another snail species Aplysia californica (A. californica) even using a low stringency e-value cutoff at 0.01. Using the same cutoff, approximately 67% of the cDNAs have a BLAST hit in the NCBI non-redundant protein and nucleotide sequence databases (nr and nt), suggesting that one third of the sequences may be unique to L. stagnalis. Finally, using the same cutoff (0.01), more than half of the cDNA sequences (54%) do not have a hit in nematode, fruitfly or human genome data, suggesting that the L. stagnalis transcriptome is significantly different from these species as well. The cDNA sequences are enriched in the following gene ontology functional categories: protein binding, hydrolase, transferase, and catalytic enzymes. Conclusion: This study provides novel molecular insights into the transcriptome of an important molluscan model organism. Our findings will contribute to functional analyses in neurobiology, and comparative evolutionary biology. The L. stagnalis CNS EST database is available at http://www.Lymnaea.org/. © 2009 Feng et al; licensee BioMed Central Ltd
Caltubin, a Novel Molluscan Tubulin-Interacting Protein, Promotes Axonal Growth and Attenuates Axonal Degeneration of Rodent Neurons
Axotomized central neurons of most invertebrate species demonstrate a strong regenerative capacity, and as such may provide valuable molecular insights and new tools to promote axonal regeneration in injured mammalian neurons. In this study, we identified a novel molluscan protein, caltubin, ubiquitously expressed in central neurons of Lymnaea stagnalis and locally synthesized in regenerating neurites. Reduction of caltubin levels by gene silencing inhibits the outgrowth and regenerative ability of adult Lymnaea neurons and decreases local α- and β-tubulin levels in neurites. Caltubin binds to α- and/or β-tubulin in both Lymnaea and rodent neurons. Expression of caltubin in PC12 cells and mouse cortical neurons promotes NGF-induced axonal outgrowth and attenuates axonal retraction after injury. This is the first study illustrating that a xenoprotein can enhance outgrowth and prevent degeneration of injured mammalian neurons. These results may open up new avenues in molecular repair strategies through the insertion of molecular components of invertebrate regenerative pathways into mammalian neurons. ©2011 the authors
The effect of incorrect prior information on trust behavior in adolescents
During adolescence, social cognition and the brain undergo major developments. Social interactions become more important, and adolescents must learn that not everyone can be trusted equally. Prior knowledge about the trustworthiness of an interaction partner may affect adolescents' expectations about the partner. However, the expectations based on prior knowledge can turn out to be incorrect, causing the need to respond adaptively during the interaction. In the current fMRI study, we investigated the effect of incorrect prior knowledge on adolescent trust behavior and on the neural processes of trust. Thirty-three adolescents (Mage = 17.2 years, SDage = 0.5 years) played two trust games with partners whose behavior was preprogrammed using an algorithm that modeled trustworthy behavior. Prior to the start of both games, participants received information suggesting that the partner in one game was untrustworthy (raising incorrect expectations) and the partner in the other game trustworthy (raising correct expectations). Results indicated that participants adapted their trust behavior following incorrect prior expectations. No evidence for a change in trust behavior was shown when prior expectations were correct. fMRI analyses revealed that when receiving the partner's response, activity in the dorsolateral prefrontal cortex and in the superior parietal gyrus were increased when participants had incorrect expectations about the partner compared to when participants had correct expectations. When making trust decisions, no significant differences in neural activity were found when comparing the two games. This study provides insight into how adolescent trust behavior and neural mechanisms are affected by expectations and provides an increased understanding of the factors that influence adolescent social interaction
Highly anisotropic g-factor of two-dimensional hole systems
Coupling the spin degree of freedom to the anisotropic orbital motion of
two-dimensional (2D) hole systems gives rise to a highly anisotropic Zeeman
splitting with respect to different orientations of an in-plane magnetic field
B relative to the crystal axes. This mechanism has no analogue in the bulk band
structure. We obtain good, qualitative agreement between theory and
experimental data, taken in GaAs 2D hole systems grown on (113) substrates,
showing the anisotropic depopulation of the upper spin subband as a function of
in-plane B.Comment: 4 pages, 3 figure
Drift time measurement in the ATLAS liquid argon electromagnetic calorimeter using cosmic muons
- …