506 research outputs found
The effect of e-learning on the quality of orthodontic appliances
Purpose: The effect of e-learning on practical skills in medicine has not yet been thoroughly investigated. Todayâs multimedia learning environment and access to e-books provide students with more knowledge than ever before. The aim of this study is to evaluate the effect of online demonstrations concerning the quality of orthodontic appliances manufactured by undergraduate dental students. Materials and methods: The study design was a parallel-group randomized clinical trial. Fifty-four participants were randomly assigned to one of the three groups: 1) conventional lectures, 2) conventional lectures plus written online material, and 3) access to resources of groups one and two plus access to online video material. Three orthodontic appliances (Schwarz Plate, U-Bow Activator, and FrĂ€nkel Regulator) were manufactured during the course and scored by two independent raters blinded to the participants. A 15-point scale index was used to evaluate the outcome quality of the appliances. Results: In general, no significant differences were found between the groups. Concerning the appliances, the Schwarz Plate obtained the highest scores, whereas the FrĂ€nkel Regulator had the lowest scores; however, these results were independent of the groups. Females showed better outcome scores than males in groups two and three, but the difference was insignificant. Age of the participants also had no significant effect. Conclusion: The offer that students could use additional time and course-independent e-learning resources did not increase the outcome quality of the orthodontic appliances. The advantages of e-learning observed in the theoretical fields of medicine were not achieved in the educational procedures for manual skills. Factors other than e-learning may have a higher impact on manual skills, and this should be investigated in further studies
Changes of the Atlantic meridional overturning circulation of the past 30ka recorded in a depth transect at the Blake Outer Ridge
Oceans and climate are a tightly coupled system interacting with each other in various ways such as storage of
carbon dioxide in the deep ocean. Within the global conveyor belt the Atlantic Meridional Overturning Circulation (AMOC) holds a key function, transporting warm salty surface waters from the tropical to the northern Atlantic where deep water formation takes place. Following the continental rise of North America this newly formed deep water propagates southward as Western Boundary Undercurrent (WBUC) ventilating the deep Atlantic. In the past (e.g. the last glacial cycle) strength and geometry of the AMOC have changed significantly. This study aims to provide a better understanding of the temporal and spatial (also depth depended) evolution of the AMOC in the western Atlantic sector since the last glacial (âŒ30 ka). We have investigated four sediment cores of the Blake Outer Ridge (30°N, 74°W; ODP 1059 to 1062) in a depth transect from 3000 to 4700 m water depth in the main flow path of the WBUC. We measured four down-core profiles of neodymium (ΔNd) and 231Pa/230Th isotopes for the reconstruction of water mass provenance and circulation strength of the last âŒ30 ka. In contrast to published Nd isotope and 231Pa/230Th records from the Blake Ridge area our records are of unprecedented resolution, resolving climate key features of the North Atlantic region: Heinrich Stadials (HS) 1 and 2, the Last Glacial Maximum (LGM), the BĂžlling-AllerĂžd and Younger Dryas (YD). Radiogenic Nd isotope signatures during the LGM reveal AABW to be the prevalent water mass in the deep western North Atlantic. The trend to more unradiogenic signatures during the deglaciation point to an increased formation of NADW which was again replaced by AABW during YD. The Holocene shows the most unradiogenic signatures and therefore established NADW. The circulation strength-proxy 231Pa/230Th indicates reduced LGM deep circulation, a pronounced slowdown during HS1 and a strong and deep circulation during the Holocene. Compared to isotopic records from the Bermuda Rise (ODP 1063) we found depth depended geometry changes of the WBUC which have occurred through the last glacial. Here, we focus on how deep northern sourced water has reached during phases of reduced circulation (indicated by increased 231Pa/230Th ratios) and the timing of this southward progradation of lower NADW
Parental Perceived Control and Social Support: Linkages to Change in Parenting Behaviors During Early Adolescence
Prior studies have found that parents' perceptions of control over their lives and their social support may both be important for parenting behaviors. Yet, few studies have examined their unique and interacting influence on parenting behaviors during early adolescence. This longitudinal study of rural parents in two-parent families (N = 636) investigated (a) whether perceived control and social support when their youth were in sixth grade were independently or interactively associated with changes in parenting behaviors (discipline, standard setting) and parent-child warmth and hostility 6 months later and (b) if these linkages differed by parent gender. We also investigated the interactive links between perceived control, social support, and parenting. Specifically, we tested if parents' perceived control moderated the linkages between social support and parenting and if these linkages differed by parent gender. Greater perceived control predicted more increases in parents' consistent discipline and standard setting, whereas greater social support predicted increases in parent-child warmth and decreases in parent-child hostility. Parental perceived control moderated the effect of social support on parental warmth: For mothers only, social support was significantly linked to parent-child warmth only when mothers had low (but not high) perceived self-control. The discussion focuses on reasons why perceived control and social support may have associations with different aspects of parenting and why these might differ for mothers and fathers
Early treatment of posterior crossbite - a randomised clinical trial
Background: The aim of this randomised clinical trial was to assess the effect of early orthodontic treatment in contrast to normal growth effects for functional unilateral posterior crossbite in the late deciduous and early mixed dentition by means of three-dimensional digital model analysis.
Methods: This randomised clinical trial was assessed to analyse the orthodontic treatment effects for patients with functional unilateral posterior crossbite in the late deciduous and early mixed dentition using a two-step procedure: initial maxillary expansion followed by a U-bow activator therapy. In the treatment group 31 patients and in the control group 35 patients with a mean age of 7.3 years (SD 2.1) were monitored. The time between the initial assessment (T1) and the follow-up (T2) was one year. The orthodontic analysis was done by a three-dimensional digital model analysis. Using the âDigimodelâ software, the orthodontic measurements in the maxilla and mandible and for the midline deviation, the overjet and overbite were recorded.
Results: Significant differences between the control and the therapy group at T2 were detected for the anterior, median and posterior transversal dimensions of the maxilla, the palatal depth, the palatal base arch length, the maxillary arch length and inclination, the midline deviation, the overjet and the overbite.
Conclusions: Orthodontic treatment of a functional unilateral posterior crossbite with a bonded maxillary expansion device followed by U-bow activator therapy in the late deciduous and early mixed dentition is an effective therapeutic method, as evidenced by the results of this RCT. It leads to three-dimensional therapeutically induced maxillary growth effects. Dental occlusion is significantly improved, and the prognosis for normal craniofacial growth is enhanced
Investigating the Potential Causal Relationship Between Parental Knowledge and Youth Risky Behavior: a Propensity Score Analysis
This longitudinal study aims to explore the potential causal relationship between parental knowledge and youth risky behavior among a sample of rural, early adolescents (84% White, 47% male). Using Inverse Propensity Weighting, the sample was adjusted by controlling for 33 potential confounding variables. Confounding variables include other aspects of the parent-child relationship, parental monitoring, demographic variables and earlier levels of problem behavior. The effect of parental knowledge was significant for youth substance and polysubstance use initiation, alcohol and cigarette use, attitudes towards substance use, and delinquency. Our results suggest that parental knowledge may be causally related to substance use during middle school, as the relationship between knowledge and youth outcomes remained after controlling for 33 different confounding variables. The discussion focuses on understanding issues of causality in parenting and intervention implications
Mindful Parenting and Parent Technology Use: Examining the Intersections and Outlining Future Research Directions
Popular media attention and scientific research in both mindful parenting and technology use in the context of parenting has expanded in the 21st century; however, these two streams of research have largely evolved separately from one another. Thus, in this conceptual paper, we integrate the research on mindful parenting with that on parentsâ technology use and parenting to examine how parent technology use may impact or be linked with aspects of mindful parenting. Mindful parenting theory outlines five key components: listening with full attention, self-regulation in the parentâchild relationship, emotional awareness of self and child, nonjudgmental acceptance of self and child, and compassion for self and child. Parent technology use, in particular the use of mobile devices, has the potential to impact all five elements of mindful parenting. However, the relationship between mindful parenting and technology is complex, and there can be both positive and negative implications of parent technology use on mindful parenting. On the positive side, technology use might help parents regulate their emotions; access support; and develop more empathy, acceptance, and compassion for themselves and their children. Yet, parent technology use also has the potential to create distractions and disrupt parentâchild interactions, which may make it more difficult for parents to listen with full attention, maintain awareness of their own and their childâs emotions, and calmly respond to child behaviors with intentionality. Technology use may also create more opportunities for social comparisons and judgement, making it more difficult for parents to accept their children nonjudgmentally and have compassion for their children as they are. Future research is needed to understand the conditions under which technology use can hinder or promote mindful parenting and how interventions can promote mindful parenting skills and a positive uses of technology
Youthsâ Substance Use and Changes in Parental Knowledge-Related Behaviors During Middle School: A Person-Oriented Approach
Parental knowledge is a key protective factor for youthsâ risky behavior. Little is known about how longitudinal combinations of knowledge-related behaviors are associated with youthsâ substance use. This longitudinal study uses Latent Transition Analysis to identify latent patterns of parental knowledge-related behaviors occurring in mother-youth dyads during middle school and to investigate how changes in knowledge-related patterns are associated with youthsâ substance use in Grade 6 and the initiation of substance use from Grade 6 to 8. Using a sample of 536 rural dyads (53% female, 84% White), we assessed mother and youthsâ reports of parental knowledge, active parental monitoring efforts, youth disclosure, and parent-youth communication to identify six latent patterns of knowledge-related behaviors: High Monitors, Low Monitors, Communication-Focused, Supervision-Focused, Maternal Over-Estimators, and Youth Over-Estimators. Fifty percent or more of dyads in the High Monitors, Communication-Focused and Youth Over-Estimators were in the same status in both 6th and 8th grade: 98% of Low Monitors in Grade 6 were also in this status in Grade 8. The initiation of alcohol, smoking, and marijuana was associated significantly with transitions between patterns of knowledge-related behaviors. The initiation of alcohol and smoking were associated with increased odds of transitions into the Low Monitors from the Communication-Focused, Supervision-Focused, and Maternal Over-Estimators. However, the initiation of substance use was associated with decreased odds of transitions from the High Monitors to the Low Monitors and with increased odds of transitions from High Monitors to Supervision-Focused. The discussion focuses on the value of using a person-oriented dyadic approach with multiple reporters to study changes in knowledge-related behaviors over the middle school period
Understanding How Mindful Parenting May Be Linked to MotherâAdolescent Communication
Researchers have sought to understand the processes that may promote effective parent-adolescent communication because of the strong links to adolescent adjustment. Mindfulness, a relatively new construct in Western psychology that derives from ancient Eastern traditions, has been shown to facilitate communication and to be beneficial when applied in the parenting context. In this article, we tested if and how mindful parenting was linked to routine adolescent disclosure and parental solicitation within a longitudinal sample of rural and suburban, early adolescents and their mothers (n = 432; mean adolescent age = 12.14, 46% male, 72% Caucasian). We found that three factors -- negative parental reactions to disclosure, adolescent feelings of parental over-control, and the affective quality of the parent-adolescent relationship -- mediated the association between mindful parenting and adolescent disclosure and parental solicitation. Results suggest that mindful parenting may improve mother-adolescent communication by reducing parental negative reactions to information, adolescent perceptions of over-control, and by improving the affective quality of the parent-adolescent relationship. The discussion highlights intervention implications and future directions for research
230 Th normalization: new insights on an essential tool for quantifying sedimentary fluxes in the modern and quaternary ocean
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Costa, K. M., Hayes, C. T., Anderson, R. F., Pavia, F. J., Bausch, A., Deng, F., Dutay, J., Geibert, W., Heinze, C., Henderson, G., Hillaire-Marcel, C., Hoffmann, S., Jaccard, S. L., Jacobel, A. W., Kienast, S. S., Kipp, L., Lerner, P., Lippold, J., Lund, D., Marcantonio, F., McGee, D., McManus, J. F., Mekik, F., Middleton, J. L., Missiaen, L., Not, C., Pichat, S., Robinson, L. F., Rowland, G. H., Roy-Barman, M., Alessandro, Torfstein, A., Winckler, G., & Zhou, Y. 230 Th normalization: new insights on an essential tool for quantifying sedimentary fluxes in the modern and quaternary ocean. Paleoceanography and Paleoclimatology, 35(2), (2020): e2019PA003820, doi:10.1029/2019PA003820.230Th normalization is a valuable paleoceanographic tool for reconstructing highâresolution sediment fluxes during the late Pleistocene (last ~500,000 years). As its application has expanded to ever more diverse marine environments, the nuances of 230Th systematics, with regard to particle type, particle size, lateral advective/diffusive redistribution, and other processes, have emerged. We synthesized over 1000 sedimentary records of 230Th from across the global ocean at two time slices, the late Holocene (0â5,000 years ago, or 0â5 ka) and the Last Glacial Maximum (18.5â23.5 ka), and investigated the spatial structure of 230Thânormalized mass fluxes. On a global scale, sedimentary mass fluxes were significantly higher during the Last Glacial Maximum (1.79â2.17 g/cm2kyr, 95% confidence) relative to the Holocene (1.48â1.68 g/cm2kyr, 95% confidence). We then examined the potential confounding influences of boundary scavenging, nepheloid layers, hydrothermal scavenging, sizeâdependent sediment fractionation, and carbonate dissolution on the efficacy of 230Th as a constant flux proxy. Anomalous 230Th behavior is sometimes observed proximal to hydrothermal ridges and in continental margins where high particle fluxes and steep continental slopes can lead to the combined effects of boundary scavenging and nepheloid interference. Notwithstanding these limitations, we found that 230Th normalization is a robust tool for determining sediment mass accumulation rates in the majority of pelagic marine settings (>1,000 m water depth).We thank Zanna Chase and one anonymous reviewer for valuable feedback. K. M. C. was supported by a Postdoctoral Scholarship at WHOI. L. M. acknowledges funding from the Australian Research Council grant DP180100048. The contribution of C. T. H., J. F. M., and R. F. A. were supported in part by the U.S. National Science Foundation (USâNSF). G. H. R. was supported by the Natural Environment Research Council (grant NE/L002434/1). S. L. J. acknowledges support from the Swiss National Science Foundation (grants PP002P2_144811 and PP00P2_172915). This study was supported by the Past Global Changes (PAGES) project, which in turn received support from the Swiss Academy of Sciences and the USâNSF. This work grew out of a 2018 workshop in AixâMarseille, France, funded by PAGES, GEOTRACES, SCOR, USâNSF, AixâMarseille UniversitĂ©, and John Cantle Scientific. All data are publicly available as supporting information to this document and on the National Center for Environmental Information (NCEI) at https://www.ncdc.noaa.gov/paleo/study/28791
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