83 research outputs found

    Evaluation of a Dutch school-based depression prevention program for youths in highrisk neighborhoods: study protocol of a two-armed randomized controlled trial

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    Contains fulltext : 102517.pdf (publisher's version ) (Open Access)Background Research has indicated that depression prevention programs attenuate the development of symptoms of depression in adolescents. To implement these programs on a large scale, implementation in a school setting with teachers providing the programs is needed. In the present study, the effectiveness of the Dutch depression prevention program Op Volle Kracht (OVK) provided by school teachers during school hours with adolescents from high risk neighborhoods will be tested. The mediating effects of cognitive distortions and alexithymia will be evaluated as well. We hypothesize that the OVK program will prevent or decrease reported depressive symptoms, and that this association will be mediated by cognitive distortions and alexithymia. Methods/Design Schools with at least 30% of their pupils living in low income areas in the Netherlands are invited to participate in the study. Classes from vocational training up to pre-university level are eligible and 1324 adolescents (11-14 years) will be participating in the study. Randomisation will be done at class level, randomly assigning participants to an intervention group (OVK) and a control group (care as usual), stratifying by school level (high versus low). Trained school teachers will be delivering the program, which covers cognitive-behavioral and social problem-solving skills. Longitudinal data will be collected with self-report measurements administered in the school setting at baseline, post intervention and at two follow ups (at 6 and 12 months). Primary outcome is the level of depressive symptoms, and secondary outcomes include: cognitive errors, response style, attributional style, alexithymia, stressful life events, substance use, happiness, and school grades. Discussion If the OVK program proves to be effective when it is provided by school teachers, a structural implementation of the program in the school curriculum will enhance the quality of the lives of adolescents and their families and will reduce costs in health care. In addition, the results of the study advances current knowledge on the underlying mechanisms of the development of depression and may aid the improvement of depression prevention programs in general.7 p

    Screening and early psychological intervention for depression in schools: systematic review and meta-analysis.

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    Abstract Depression in children and adolescents is considerably undertreated, and the school may be a good setting for identifying and treating depression. We conducted a meta-analysis of studies in which students were screened for depression, and those with depressive symptoms were treated with a psychological intervention. Only randomised controlled trials were included. Eight studies met the inclusion criteria. Five studies focused on younger children (7–14 years) and three studies were aimed at adolescents (12–19 years). In total 5803 students were screened, of whom 7.2% were included in the intervention studies (95% CI: 7.1–7.3). The ‘numbers-needed-to-screen’ was 31 (95% CI: 27–32), which means that 31 students had to be screened in order to generate one successfully treated case of depression. The effects of the psychological treatments at posttest were compared to control conditions in the 8 studies comprising 12 contrast groups, with a total of 413 students. The mean effect size was 0.55 (95% CI: 0.35– 0.76). There were not enough studies to examine whether specific psychotherapies were superior to other psychotherapies. Although the number of studies is small and their quality is limited, screening and early intervention at schools may be an effective strategy to reduce the burden of disease from depression in children and adolescents. More research on the (negative) effects of these interventions is needed

    Evidence for Paternal Leakage in Hybrid Periodical Cicadas (Hemiptera: Magicicada spp.)

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    Mitochondrial inheritance is generally assumed to be maternal. However, there is increasing evidence of exceptions to this rule, especially in hybrid crosses. In these cases, mitochondria are also inherited paternally, so “paternal leakage” of mitochondria occurs. It is important to understand these exceptions better, since they potentially complicate or invalidate studies that make use of mitochondrial markers. We surveyed F1 offspring of experimental hybrid crosses of the 17-year periodical cicadas Magicicada septendecim, M. septendecula, and M. cassini for the presence of paternal mitochondrial markers at various times during development (1-day eggs; 3-, 6-, 9-week eggs; 16-month old 1st and 2nd instar nymphs). We found evidence of paternal leakage in both reciprocal hybrid crosses in all of these samples. The relative difficulty of detecting paternal mtDNA in the youngest eggs and ease of detecting leakage in older eggs and in nymphs suggests that paternal mitochondria proliferate as the eggs develop. Our data support recent theoretical predictions that paternal leakage may be more common than previously estimated

    Abiotic ammonium formation in the presence of Ni-Fe metals and alloys and its implications for the Hadean nitrogen cycle

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    Experiments with dinitrogen-, nitrite-, nitrate-containing solutions were conducted without headspace in Ti reactors (200°C), borosilicate septum bottles (70°C) and HDPE tubes (22°C) in the presence of Fe and Ni metal, awaruite (Ni80Fe20) and tetrataenite (Ni50Fe50). In general, metals used in this investigation were more reactive than alloys toward all investigated nitrogen species. Nitrite and nitrate were converted to ammonium more rapidly than dinitrogen, and the reduction process had a strong temperature dependence. We concluded from our experimental observations that Hadean submarine hydrothermal systems could have supplied significant quantities of ammonium for reactions that are generally associated with prebiotic synthesis, especially in localized environments. Several natural meteorites (octahedrites) were found to contain up to 22 ppm Ntot. While the oxidation state of N in the octahedrites was not determined, XPS analysis of metals and alloys used in the study shows that N is likely present as nitride (N3-). This observation may have implications toward the Hadean environment, since, terrestrial (e.g., oceanic) ammonium production may have been supplemented by reduced nitrogen delivered by metal-rich meteorites. This notion is based on the fact that nitrogen dissolves into metallic melts

    Structural evolution and flip-flop recombination of chloroplast DNA in the fern genus Osmunda

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    The evolution and recombination of chloroplast genome structure in the fern genus Osmunda were studied by comparative restriction site mapping and filter hybridization of chloroplast DNAs (cpDNAs) from three species — 0. cinnamomea, 0. claytoniana and 0. regalis . The three 144 kb circular genomes were found to be colinear in organization, indicating that no major inversions or transpositions had occurred during the approximately 70 million years since their radiation from a common ancestor. Although overall size and sequence arrangement are highly conserved in the three genomes, they differ by an extensive series of small deletions and insertions, ranging in size from 50 bp to 350 by and scattered more or less at random throughout the circular chromosomes. All three chloroplast genomes contain a large inverted repeat of approximately 10 kb in size. However, hybridizations using cloned fragments from the 0. cinnamomea and 0. regalis genomes revealed the absence of any dispersed repeats in at least 50% of the genome. Analysis with restriction enzymes that fail to cleave the 10 kb inverted repeat indicated that each of the three fern chloroplast genomes exists as an equimolar population of two isomeric circles differing only in the relative orientation of their two single copy regions. These two inversion isomers are inferred to result from high frequency intramolecular recombination between paired inverted repeat segments. In all aspects of their general organization, recombinational heterogeneity, and extent of structural rearrangement and length mutation, these fern chloroplast genomes resemble very closely the chloroplast genomes of most angiosperms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46956/1/294_2004_Article_BF00418530.pd
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