163 research outputs found

    Identity Formation in Adolescence: Change or Stability?

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    The aim of this five-wave longitudinal study of 923 early to middle adolescents (50.7% boys; 49.3% girls) and 390 middle to late adolescents (43.3% boys and 56.7% girls) is to provide a comprehensive view on change and stability in identity formation from ages 12 to 20. Several types of change and stability (i.e., mean-level change, rank-order stability, and profile similarity) were assessed for three dimensions of identity formation (i.e., commitment, in-depth exploration, and reconsideration), using adolescent self-report questionnaires. Results revealed changes in identity dimensions towards maturity, indicated by a decreasing tendency for reconsideration, increasingly more in-depth exploration, and increasingly more stable identity dimension profiles. Mean levels of commitment remained stable, and rank-order stability of commitment, in-depth exploration, and reconsideration did not change with age. Overall, girls were more mature with regard to identity formation in early adolescence, but boys had caught up with them by late adolescence. Taken together, our findings indicate that adolescent identity formation is guided by progressive changes in the way adolescents deal with commitments, rather than by changes in the commitments themselves

    Executive control of bureaucracy and presidential cabinet appointments in East Asian democracies

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    This article examines the role of cabinet appointments in controlling the bureaucracy in presidential democracies. I demonstrate how administrative challenges stemming from the structure of the bureaucracy shape presidential choice of ministers. Analyzing a sample of four East Asian cases from 1986 through 2013, I find that presidents are more likely to select ministers from the civil service as bureaucracies are more professionalized, controlling for several political factors. Further evidence from qualitative interviews and case studies suggests that, in professionalized systems equipped with a sizable pool of talent but lacking responsiveness, presidents tend to promote ideologically aligned senior civil servants. However, in politicized systems, where presidents easily obtain responsiveness but face a low level of competence, policy experts tend to be selected from outside the bureaucracy. My findings have important implications for the regulatory governance and state capacity of East Asia, demonstrating the value of balancing between responsiveness and competence

    Prognostic factors for recovery following acute lateral ankle ligament sprain: a systematic review.

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    BACKGROUND: One-third of individuals who sustain an acute lateral ankle ligament sprain suffer significant disability due to pain, functional instability, mechanical instability or recurrent sprain after recovery plateaus at 1 to 5Β years post injury. The identification of early prognostic factors associated with poor recovery may provide an opportunity for early-targeted intervention and improve outcome. METHODS: We performed a comprehensive search of AMED, EMBASE, Psych Info, CINAHL, SportDiscus, PubMed, CENTRAL, PEDro, OpenGrey, abstracts and conference proceedings from inception to September 2016. Prospective studies investigating the association between baseline prognostic factors and recovery over time were included. Two independent assessors performed the study selection, data extraction and quality assessment of the studies. A narrative synthesis is presented due to inability to meta-analyse results due to clinical and statistical heterogeneity. RESULTS: The search strategy yielded 3396 titles/abstracts after duplicates were removed. Thirty-six full text articles were then assessed, nine of which met the study inclusion criteria. Six were prospective cohorts, and three were secondary analyses of randomised controlled trials. Results are presented for nine studies that presented baseline prognostic factors for recovery after an acute ankle sprain. Age, female gender, swelling, restricted range of motion, limited weight bearing ability, pain (at the medial joint line and on weight-bearing dorsi-flexion at 4Β weeks, and pain at rest at 3Β months), higher injury severity rating, palpation/stress score, non-inversion mechanism injury, lower self-reported recovery, re-sprain within 3Β months, MRI determined number of sprained ligaments, severity and bone bruise were found to be independent predictors of poor recovery. Age was one prognostic factor that demonstrated a consistent association with outcome in three studies, however cautious interpretation is advised. CONCLUSIONS: The associations between prognostic factors and poor recovery after an acute lateral ankle sprain are largely inconclusive. At present, there is insufficient evidence to recommend any factor as an independent predictor of outcome. There is a need for well-conducted prospective cohort studies with adequate sample size and long-term follow-up to provide robust evidence on prognostic factors of recovery following an acute lateral ankle sprain. TRIAL REGISTRATION: Prospero registration: CRD42014014471

    Characterization of Salmonella Type III Secretion Hyper-Activity Which Results in Biofilm-Like Cell Aggregation

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    We have previously reported the cloning of the Salmonella enterica serovar Typhimurium SPI-1 secretion system and the use of this clone to functionally complement a Ξ”SPI-1 strain for type III secretion activity. In the current study, we discovered that S. Typhimurium cultures containing cloned SPI-1 display an adherent biofilm and cell clumps in the media. This phenotype was associated with hyper-expression of SPI-1 type III secretion functions. The biofilm and cell clumps were associated with copious amounts of secreted SPI-1 protein substrates SipA, SipB, SipC, SopB, SopE, and SptP. We used a C-terminally FLAG-tagged SipA protein to further demonstrate SPI-1 substrate association with the cell aggregates using fluorescence microscopy and immunogold electron microscopy. Different S. Typhimurium backgrounds and both flagellated and nonflagellated strains displayed the biofilm phenotype. Mutations in genes essential for known bacterial biofilm pathways (bcsA, csgBA, bapA) did not affect the biofilms formed here indicating that this phenomenon is independent of established biofilm mechanisms. The SPI-1-mediated biofilm was able to massively recruit heterologous non-biofilm forming bacteria into the adherent cell community. The results indicate a bacterial aggregation phenotype mediated by elevated SPI-1 type III secretion activity with applications for engineered biofilm formation, protein purification strategies, and antigen display

    What Do We Know About Neuropsychological Aspects Of Schizophrenia?

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    Application of a neuropsychological perspective to the study of schizophrenia has established a number of important facts about this disorder. Some of the key findings from the existing literature are that, while neurocognitive impairment is present in most, if not all, persons with schizophrenia, there is both substantial interpatient heterogeneity and remarkable within-patient stability of cognitive function over the long-term course of the illness. Such findings have contributed to the firm establishment of neurobiologic models of schizophrenia, and thereby help to reduce the social stigma that was sometimes associated with purely psychogenic models popular during parts of the 20th century. Neuropsychological studies in recent decades have established the primacy of cognitive functions over psychopathologic symptoms as determinants of functional capacity and independence in everyday functioning. Although the cognitive benefits of both conventional and even second generation antipsychotic medications appear marginal at best, recognition of the primacy of cognitive deficits as determinants of functional disability in schizophrenia has catalyzed recent efforts to develop targeted treatments for the cognitive deficits of this disorder. Despite these accomplishments, however, some issues remain to be resolved. Efforts to firmly establish the specific neurocognitive/neuropathologic systems responsible for schizophrenia remain elusive, as do efforts to definitively demonstrate the specific cognitive deficits underlying specific forms of functional impairment. Further progress may be fostered by recent initiatives to integrate neuropsychological studies with experimental neuroscience, perhaps leading to measures of deficits in cognitive processes more clearly associated with specific, identifiable brain systems

    Variance in Centrality within Rock Hyrax Social Networks Predicts Adult Longevity

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    BACKGROUND: In communal mammals the levels of social interaction among group members vary considerably. In recent years, biologists have realized that within-group interactions may affect survival of the group members. Several recent studies have demonstrated that the social integration of adult females is positively associated with infant survival, and female longevity is affected by the strength and stability of the individual social bonds. Our aim was to determine the social factors that influence adult longevity in social mammals. METHODOLOGY/PRINCIPAL FINDINGS: As a model system, we studied the social rock hyrax (Procavia capensis), a plural breeder with low reproductive skew, whose groups are mainly composed of females. We applied network theory using 11 years of behavioral data to quantify the centrality of individuals within groups, and found adult longevity to be inversely correlated to the variance in centrality. In other words, animals in groups with more equal associations lived longer. Individual centrality was not correlated with longevity, implying that social tension may affect all group members and not only the weakest or less connected ones. CONCLUSIONS/SIGNIFICANCE: Our novel findings support previous studies emphasizing the adaptive value of social associations and the consequences of inequality among adults within social groups. However, contrary to previous studies, we suggest that it is not the number or strength of associations that an adult individual has (i.e. centrality) that is important, but the overall configuration of social relationships within the group (i.e. centrality SD) that is a key factor in influencing longevity

    Integration of the Ξ²-Catenin-Dependent Wnt Pathway with Integrin Signaling through the Adaptor Molecule Grb2

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    THE COMPLEXITY OF WNT SIGNALING LIKELY STEMS FROM TWO SOURCES: multiple pathways emanating from frizzled receptors in response to wnt binding, and modulation of those pathways and target gene responsiveness by context-dependent signals downstream of growth factor and matrix receptors. Both rac1 and c-jun have recently been implicated in wnt signaling, however their upstream activators have not been identified.Here we identify the adapter protein Grb2, which is itself an integrator of multiple signaling pathways, as a modifier of beta-catenin-dependent wnt signaling. Grb2 synergizes with wnt3A, constitutively active (CA) LRP6, Dvl2 or CA-beta-catenin to drive a LEF/TCF-responsive reporter, and dominant negative (DN) Grb2 or siRNA to Grb2 block wnt3A-mediated reporter activity. MMP9 is a target of beta-catenin-dependent wnt signaling, and an MMP9 promoter reporter is also responsive to signals downstream of Grb2. Both a jnk inhibitor and DN-c-jun block transcriptional activation downstream of Dvl2 and Grb2, as does DN-rac1. Integrin ligation by collagen also synergizes with wnt signaling as does overexpression of Focal Adhesion Kinase (FAK), and this is blocked by DN-Grb2.These data suggest that integrin ligation and FAK activation synergize with wnt signaling through a Grb2-rac-jnk-c-jun pathway, providing a context-dependent mechanism for modulation of wnt signaling

    Dietary Profile of Rhinopithecus bieti and Its Socioecological Implications

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    To enhance our understanding of dietary adaptations and socioecological correlates in colobines, we conducted a 20-mo study of a wild group of Rhinopithecus bieti (Yunnan snub-nosed monkeys) in the montane Samage Forest. This forest supports a patchwork of evergreen broadleaved, evergreen coniferous, and mixed deciduous broadleaved/coniferous forest assemblages with a total of 80 tree species in 23 families. The most common plant families by basal area are the predominantly evergreen Pinaceae and Fagaceae, comprising 69% of the total tree biomass. Previous work has shown that lichens formed a consistent component in the monkeys’ diet year-round (67%), seasonally complemented with fruits and young leaves. Our study showed that although the majority of the diet was provided by 6 plant genera (Acanthopanax, Sorbus, Acer, Fargesia, Pterocarya, and Cornus), the monkeys fed on 94 plant species and on 150 specific food items. The subjects expressed high selectivity for uncommon angiosperm tree species. The average number of plant species used per month was 16. Dietary diversity varied seasonally, being lowest during the winter and rising dramatically in the spring. The monkeys consumed bamboo shoots in the summer and bamboo leaves throughout the year. The monkeys also foraged on terrestrial herbs and mushrooms, dug up tubers, and consumed the flesh of a mammal (flying squirrel). We also provide a preliminary evaluation of feeding competition in Rhinopithecus bieti and find that the high selectivity for uncommon seasonal plant food items distributed in clumped patches might create the potential for food competition. The finding is corroborated by observations that the subjects occasionally depleted leafy food patches and stayed at a greater distance from neighboring conspecifics while feeding than while resting. Key findings of this work are that Yunnan snub-nosed monkeys have a much more species-rich plant diet than was previously believed and are probably subject to moderate feeding competition
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