492 research outputs found

    Lability in the parent's hostility and warmth toward their adolescent: Linkages to youth delinquency and substance use

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    According to family systems and life course theories, periods of intense change, such as early adolescence, can disrupt stable family systems, leading to changes in family relationships. In this longitudinal study, we investigate 2 types of change in parental hostility and warmth toward their children during early adolescence (Grades 6 to 8)-developmental trends (linear declines) and lability (within-person fluctuations around developmental trends)-and their linkages to youth substance use and delinquency in Grade 9 (N = 618). We also test if the linkages between lability and youth risky behavior are moderated by youth gender. After controlling for between-person differences in level and developmental trends, we find greater lability (more fluctuations) in youth-reported parents' warmth and hostility are associated with greater youth delinquency, tobacco use, and polysubstance use initiation. The associations between youth-reported lability in mother and father hostility and polysubstance use demonstrated an inverted U shape pattern: Moderate levels of lability were associated with higher substance use but very low and high lability was associated with relatively lower rates of substance use. Many of the linkages between lability and youth delinquency were significant for girls but not boys. Fewer effects of lability on youth outcomes were found using parent reports. Developmental trends in parents' warmth and hostility were also associated with youth delinquency. Lability has unique implications for youth adjustment, yet appears to differ by youth outcome, gender, and reporter. The discussion focuses on mechanisms that might link changes in parent-youth warmth and hostility to youth risky behavior

    Spine deviations and orthodontic treatment of asymmetric malocclusions in children

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    Background: The aim of this randomized clinical trial was to assess the effect of early orthodontic treatment for unilateral posterior cross bite in the late deciduous and early mixed dentition using orthopedic parameters. Methods: Early orthodontic treatment was performed by initial maxillary expansion and subsequent activator therapy (Münster treatment concept). The patient sample was initially comprised of 80 patients with unilateral posterior cross bite (mean age 7.3 years, SD 2.1 years). After randomization, 77 children attended the initial examination appointment (therapy = 37, control = 40); 31 children in the therapy group and 35 children in the control group were monitored at the follow-up examination (T2). The mean interval between T1 and T2 was 1.1 years (SD 0.2 years). Rasterstereography was used for back shape analysis at T1 and T2. Using the profile, the kyphotic and lordotic angle, the surface rotation, the lateral deviation, pelvic tilt and pelvic torsion, statistical differences at T1 and T2 between the therapy and control groups were calculated (t-test). Our working hypothesis was, that early orthodontic treatment can induce negative therapeutic changes in body posture through thoracic and lumbar position changes in preadolescents with uniltaral cross bite. Results: No clinically relevant differences between the control and the therapy groups at T1 and T2 were found for the parameters of kyphotic and lordotic angle, the surface rotation, lateral deviation, pelvic tilt, and pelvic torsion. Conclusions: Our working hypothesis was tested to be not correct (within the limitations of this study). This randomized clinical trial demonstrates that in a juvenile population with unilateral posterior cross bite the selected early orthodontic treatment protocol does not affect negatively the postural parameters

    Parental Perceived Control and Social Support: Linkages to Change in Parenting Behaviors During Early Adolescence

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    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

    Youth Internalizing Problems and Changes in Parent–Child Relationships Across Early Adolescence: Lability and Developmental Trends

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    Few longitudinal studies examine how changes in parent–child relationships are associated with changes in youth internalizing problems. In this longitudinal study, we investigated how developmental trends (linear change) and year-to-year lability (within-person fluctuations) in parental warmth and hostility across Grades 6 to 8 predict youth internalizing problems in Grade 9 (N = 618) and whether these linkages differ for boys and girls. Developmental trends (greater decreases in warmth and increases in hostility) were associated with more youth internalizing problems. Greater year-to-year lability (more fluctuations) in father hostility and warmth were also associated with more internalizing problems. Greater lability in mother warmth was associated with more internalizing problems for girls only. The strongest effects of lability on internalizing problems were found for youth with the highest lability scores. This study underscores the importance of differentiating developmental trends from lability in parent–child relationships, both of which may be important for youth internalizing problems

    Early treatment of posterior crossbite - a randomised clinical trial

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    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 ‘Digimodel’ 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

    Structure and performance characteristics of mold flux films for continuous casting of special alloy steels

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    Flux films and liquid slags for low-expansion alloy Fe-36Ni, austenitic stainless steel 304 and martensiticstainless steel 420J2 were taken from casting mold. Chemical compositions were measured by chemicalanalysis; apparent morphologies of flux films were photographed; cross-section structure, thickness, crystallinefraction and crystalline phases of flux films were examined by SEM, EDS and XRD; viscosity and breaktemperature were calculated by models. The results showed flux films and liquid slags have similar chemicalcompositions, but there is a certain difference from the original powders. Flux films for the three steel gradeshave obvious layered structure and main crystalline phase cuspidine, viscosity and break temperature keepsteady during casting. Heat transfer across flux films characterized by morphology, thickness, viscosity, breaktemperature and crystalline fraction of flux films showed flux film for austenitic stainless steel 304, martensiticstainless steel 420J2 and low-expansion alloy steel Fe-36Ni have the best, moderate and the lowest ability tocontrol heat transfer. Heat transfer across flux films agrees with solidification characteristic of steel gradesgenerally. Low-expansion alloy Fe-36Ni has good surface quality and there is no occurrence of hot-rollingcracking. Stainless steels 304 and 420J2 have no surface cracking but local depressions

    Understanding How Mindful Parenting May Be Linked to Mother–Adolescent Communication

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    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

    Human paternal and maternal demographic histories: Insights from high-resolution Y chromosome and mtDNA sequences

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    BACKGROUND: Comparisons of maternally-inherited mitochondrial DNA (mtDNA) and paternally-inherited non-recombining Y chromosome (NRY) variation have provided important insights into the impact of sex-biased processes (such as migration, residence pattern, and so on) on human genetic variation. However, such comparisons have been limited by the different molecular methods typically used to assay mtDNA and NRY variation (for example, sequencing hypervariable segments of the control region for mtDNA vs. genotyping SNPs and/or STR loci for the NRY). Here, we report a simple capture array method to enrich Illumina sequencing libraries for approximately 500 kb of NRY sequence, which we use to generate NRY sequences from 623 males from 51 populations in the CEPH Human Genome Diversity Panel (HGDP). We also obtained complete mtDNA genome sequences from the same individuals, allowing us to compare maternal and paternal histories free of any ascertainment bias. RESULTS: We identified 2,228 SNPs in the NRY sequences and 2,163 SNPs in the mtDNA sequences. Our results confirm the controversial assertion that genetic differences between human populations on a global scale are bigger for the NRY than for mtDNA, although the differences are not as large as previously suggested. More importantly, we find substantial regional variation in patterns of mtDNA versus NRY variation. Model-based simulations indicate very small ancestral effective population sizes (<100) for the out-of-Africa migration as well as for many human populations. We also find that the ratio of female effective population size to male effective population size (N(f)/N(m)) has been greater than one throughout the history of modern humans, and has recently increased due to faster growth in N(f) than N(m). CONCLUSIONS: The NRY and mtDNA sequences provide new insights into the paternal and maternal histories of human populations, and the methods we introduce here should be widely applicable for further such studies

    A novel candidate region for genetic adaptation to high altitude in Andean populations

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    Humans living at high altitude (≥ 2,500 meters above sea level) have acquired unique abilities to survive the associated extreme environmental conditions, including hypoxia, cold temperature, limited food availability and high levels of free radicals and oxidants. Long-term inhabitants of the most elevated regions of the world have undergone extensive physiological and/or genetic changes, particularly in the regulation of respiration and circulation, when compared to lowland populations. Genome scans have identified candidate genes involved in altitude adaption in the Tibetan Plateau and the Ethiopian highlands, in contrast to populations from the Andes, which have not been as intensively investigated. In the present study, we focused on three indigenous populations from Bolivia: two groups of Andean natives, Aymara and Quechua, and the low-altitude control group of Guarani from the Gran Chaco lowlands. Using pooled samples, we identified a number of SNPs exhibiting large allele frequency differences over 900,000 genotyped SNPs. A region in chromosome 10 (within the cytogenetic bands q22.3 and q23.1) was significantly differentiated between highland and lowland groups. We resequenced ~1.5 Mb surrounding the candidate region and identified strong signals of positive selection in the highland populations. A composite of multiple signals like test localized the signal to FAM213A and a related enhancer; the product of this gene acts as an antioxidant to lower oxidative stress and may help to maintain bone mass. The results suggest that positive selection on the enhancer might increase the expression of this antioxidant, and thereby prevent oxidative damage. In addition, the most significant signal in a relative extended haplotype homozygosity analysis was localized to the SFTPD gene, which encodes a surfactant pulmonary-associated protein involved in normal respiration and innate host defense. Our study thus identifies two novel candidate genes and associated pathways that may be involved in high-altitude adaptation in Andean populations.Guido Valverde, Hang Zhou, Sebastian Lippold, Cesare de Filippo, Kun Tang, David López Herráez, Jing Li, Mark Stonekin
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