479 research outputs found
Three Dimensional Mapping of Texture in Dental Enamel
We have used synchrotron x-ray diffraction to study the crystal orientation in human dental enamel as a function of position within intact tooth sections. Keeping tooth sections intact has allowed us to construct 2D and 3D spatial distribution maps of the magnitude and orientation of texture in dental enamel. We have found that the enamel crystallites are most highly aligned at the expected occlusal points for a maxillary first premolar, and that the texture direction varies spatially in a three dimensional curling arrangement. Our results provide a model for texture in enamel which can aid researchers in developing dental composite materials for fillings and crowns with optimal characteristics for longevity, and will guide clinicians to the best method for drilling into enamel, in order to minimize weakening of remaining tooth structure, during dental restoration procedure
Dual Benefits of a Student-Assisted Interprofessional Men’s Healthy Lifestyle Pilot Program
Reprinted by permission of SAGE PublicationsMen are less willing to seek health professional advice than women and die more often than women from preventable causes. Therefore, it is important to increase male engagement with health initiatives. This study reports the outcomes of a student-assisted, interprofessional, 12-week health program for overweight adult males. The program included weekly health education and structured, supervised group exercise sessions. Thirteen males (participants) and 18 university students (session facilitators) completed the program. Participants were assessed for a range of health and physical activity measures and health and health profession knowledge. Participants demonstrated significant improvement in activity, knowledge, and perceptions of physical and mental function, and appreciated the guided, group sessions. Students completed an interprofessional readiness questionnaire and reported significant improvement in the understanding of the benefits of interprofessional education and of their role in health care. This program provides evidence of the dual benefit that occurs from the delivery of a student-assisted, interprofessional men’s health program to at-risk community members
Chromosomal loci important for cotyledon opening under UV-B in Arabidopsis thaliana
<p>Abstract</p> <p>Background</p> <p>Understanding of the genetic architecture of plant UV-B responses allows extensive targeted testing of candidate genes or regions, along with combinations of those genes, for placement in metabolic or signal transduction pathways.</p> <p>Results</p> <p>Composite interval mapping and single-marker analysis methods were used to identify significant loci for cotyledon opening under UV-B in four sets of recombinant inbred lines. In addition, loci important for canalization (stability) of cotyledon opening were detected in two mapping populations. One candidate locus contained the gene <it>HY5</it>. Mutant analysis demonstrated that HY5 was required for UV-B-specific cotyledon opening.</p> <p>Conclusions</p> <p>Structured mapping populations provide key information on the degree of complexity in the genetic control of UV-B-induced cotyledon opening in Arabidopsis. The loci identified using quantitative trait analysis methods are useful for follow-up testing of candidate genes.</p
The evaluation of exposure risks for natural transmission of scrapie within an infected flock
Background: Although the epidemiology of scrapie has been broadly understood for many years, attempts to introduce voluntary or compulsory controls to eradicate the disease have frequently failed. Lack of precision in defining the risk factors on farm has been one of the challenges to designing control strategies. This study attempted to define which parts of the annual flock management cycle represented the greatest risk of infection to naive lambs exposed to the farm environment at different times.Results: In VRQ/VRQ lambs exposed to infected sheep at pasture or during lambing, and exposed to the buildings in which lambing took place, the attack rate was high and survival times were short. Where exposure was to pasture alone the number of sheep affected in each experimental group was reduced, and survival times were longer and related to length of exposure.Conclusion: At the flock level, eradication and control strategies for scrapie must take into account the need to decontaminate buildings used for lambing, and to reduce (or prevent) the exposure of lambs to infected sheep, especially in the later stages of incubation, and at lambing. The potential for environmental contamination from pasture should also be considered. Genotype selection may still prove to be the only viable tool to prevent infection from contaminated pasture, reduce environmental contamination and limit direct transmission from sheep to sheep
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TEAMwork: Testing Emotional Attunement and Mutuality During Parent-Adolescent fMRI.
The parent-child relationship and family context influence the development of emotion regulation (ER) brain circuitry and related skills in children and adolescents. Although both parents' and children's ER neurocircuitry simultaneously affect how they interact with one another, neuroimaging studies of parent-child relationships typically include only one member of the dyad in brain imaging procedures. The current study examined brain activation related to parenting and ER in parent-adolescent dyads during concurrent fMRI scanning with a novel task - the Testing Emotional Attunement and Mutuality (TEAM) task. The TEAM task includes feedback trials indicating the other dyad member made an error, resulting in a monetary loss for both participants. Results indicate that positive parenting practices as reported by the adolescent were positively correlated with parents' hemodynamic activation of the ventromedial prefrontal cortex, a region related to empathy, during these error trials. Additionally, during feedback conditions both parents and adolescents exhibited fMRI activation in ER-related regions, including the dorsolateral prefrontal cortex, anterior insula, fusiform gyrus, thalamus, caudate, precuneus, and superior parietal lobule. Adolescents had higher left amygdala activation than parents during the feedback condition. These findings demonstrate the utility of dyadic fMRI scanning for investigating relational processes, particularly in the parent-child relationship
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