Examining the factor structure of anxiety and depression symptom items among adolescents in Santiago, Chile

The co-occurrence of emotional disorders among adolescents has received considerable empirical attention. This study aims to contribute to the understanding of co-occurring anxiety and depression by examining the factor structure of the Youth Self-Report used with a sample of low-income adolescents from Santiago, Chile. Data from two independent, randomly selected subsamples were analyzed using exploratory and confirmatory factor analyses. Results indicate the best fit for the data is a two-factor model of anxiety and depression symptoms, which factors anxiety and depression into separate latent constructs. Because the findings show that anxiety and depression are not measured by the same factor in this international sample, the results imply that a valid and useful distinction exists between these constructs. That these constructs are found to be separate factors suggests that anxiety and depression may have separate etiologies and consequences, which might be best addressed by separate intervention components. These findings are consistent with the viewpoint that anxiety and depression constructs have similar emotional features and, despite sharing a common underlying internalizing disorder, distinct items capture aspects of each construct.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3140221/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3140221/Accepted manuscrip

Defect-induced spin-glass magnetism in incommensurate spin-gap magnets

We study magnetic order induced by non-magnetic impurities in quantum paramagnets with incommensurate host spin correlations. In contrast to the well-studied commensurate case where the defect-induced magnetism is spatially disordered but non-frustrated, the present problem combines strong disorder with frustration and, consequently, leads to spin-glass order. We discuss the crossover from strong randomness in the dilute limit to more conventional glass behavior at larger doping, and numerically characterize the robust short-range order inherent to the spin-glass phase. We relate our findings to magnetic order in both BiCu2PO6 and YBa2Cu3O6.6 induced by Zn substitution.Comment: 6 pages, 5 figs, (v2) real-space RG results added; discussion extended, (v3) final version as publishe

Characterization of eukaryotic microbial diversity in hypersaline Lake Tyrrell, Australia.

This study describes the community structure of the microbial eukaryotic community from hypersaline Lake Tyrrell, Australia, using near full length 18S rRNA sequences. Water samples were taken in both summer and winter over a 4-year period. The extent of eukaryotic diversity detected was low, with only 35 unique phylotypes using a 97% sequence similarity threshold. The water samples were dominated (91%) by a novel cluster of the Alveolate, Apicomplexa Colpodella spp., most closely related to C. edax. The Chlorophyte, Dunaliella spp. accounted for less than 35% of water column samples. However, the eukaryotic community entrained in a salt crust sample was vastly different and was dominated (83%) by the Dunaliella spp. The patterns described here represent the first observation of microbial eukaryotic dynamics in this system and provide a multiyear comparison of community composition by season. The lack of expected seasonal distribution in eukaryotic communities paired with abundant nanoflagellates suggests that grazing may significantly structure microbial eukaryotic communities in this system

Personality and parenting processes associated with problem behaviors: a study of adolescents in Santiago, Chile

Considerable research in the U.S. has established that adolescent antisocial, aggressive, and attention problems have a negative influence on adolescents' ability to become productive members of society. However, although these behaviors appear in other cultures, little is known about the development of these problems among adolescents in countries other than the U.S.. This study contributes to our understanding of personality and parenting factors associated with adolescent problem behaviors using an international sample. Data are from a NIDA-funded study of 884 community-dwelling adolescents in Santiago, Chile (Mean age=14, SD=1.4, 48% females) of mid-to-low socioeconomic status. Results revealed that rule-breaking and aggressive behaviors were both associated with greater levels of adolescent drive but lower levels of parental monitoring and positive parenting by both parents. Adolescents who reported more attention problems were more likely to exhibit driven behavior, more behavioral inhibition, to report lower levels of parental monitoring, and positive parenting by mother and father. Results of interactions revealed that the influences of positive parenting and parental monitoring on adolescent aggressive behaviors varied as a function of the gender of the adolescent. Helping parents build on their parenting skills may result in important reductions in adolescent problem behaviors among U.S. and international adolescents.R01 HD033487 - NICHD NIH HHS; R01 DA021181 - NIDA NIH HHS; R01 DA021181-04 - NIDA NIH HH

Gravitomagnetic Moments of the Fundamental Fields

The quadratic form of the Dirac equation in a Riemann spacetime yields a gravitational gyromagnetic ratio \kappa_S = 2 for the interaction of a Dirac spinor with curvature. A gravitational gyromagnetic ratio \kappa_S = 1 is also found for the interaction of a vector field with curvature. It is shown that the Dirac equation in a curved background can be obtained as the square--root of the corresponding vector field equation only if the gravitational gyromagnetic ratios are properly taken into account.Comment: 8 pages, RevTeX Style, no figures, changed presentation -- now restricted to fields of spin 0, 1/2 and 1 -- some references adde

Critical properties of an aperiodic model for interacting polymers

We investigate the effects of aperiodic interactions on the critical behavior of an interacting two-polymer model on hierarchical lattices (equivalent to the Migadal-Kadanoff approximation for the model on Bravais lattices), via renormalization-group and tranfer-matrix calculations. The exact renormalization-group recursion relations always present a symmetric fixed point, associated with the critical behavior of the underlying uniform model. If the aperiodic interactions, defined by s ubstitution rules, lead to relevant geometric fluctuations, this fixed point becomes fully unstable, giving rise to novel attractors of different nature. We present an explicit example in which this new attractor is a two-cycle, with critical indices different from the uniform model. In case of the four-letter Rudin-Shapiro substitution rule, we find a surprising closed curve whose points are attractors of period two, associated with a marginal operator. Nevertheless, a scaling analysis indicates that this attractor may lead to a new critical universality class. In order to provide an independent confirmation of the scaling results, we turn to a direct thermodynamic calculation of the specific-heat exponent. The thermodynamic free energy is obtained from a transfer matrix formalism, which had been previously introduced for spin systems, and is now extended to the two-polymer model with aperiodic interactions.Comment: 19 pages, 6 eps figures, to appear in J. Phys A: Math. Ge