To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Most studies examining predictors of the onset of depression focus on variable centered regression methods that focus on the effects of multiple predictors. In contrast, person-centered approaches develop profiles of factors and these profiles can be examined as predictors of onset. Here, we developed profiles of adolescent psychosocial and clinical functioning among adolescents without a history of major depression.
Data come from a subsample of participants from the Oregon Adolescent Depression Project who completed self-report measures of functioning in adolescence and completed diagnostic and self-report measures at follow-up assessments up to approximately 15 years after baseline.
We identified four profiles of psychosocial and clinical functioning: Thriving; Average Functioning; Externalizing Vulnerability and Family Stress and Internalizing Vulnerability at the baseline assessment of participants without a history of depression at the initial assessment in mid-adolescence. Classes differed in the likelihood of onset and course of depressive disorders, experience of later anxiety and substance use disorders, and psychosocial functioning in adulthood. Moreover, the predictive utility of these classes was maintained when controlling for multiple other established risk factors for depressive disorders.
This work highlights the utility of examining multiple factors simultaneously to understand risk for depression.
Chondrules and matrix from carbonaceous chondrites exhibit complementary nucleosynthetic W isotope anomalies that result from the depletion of a metallic s-process carrier in the chondrules, and the enrichment of this carrier in the matrix. The complementarity is difficult to reconcile with an origin of chondrules in protoplanetary impacts and also with models in which chondrules and matrix formed independently of each other in distinct regions of the disk. Instead, the complementarity indicates that chondrules formed by localized melting of dust aggregates in the solar nebula. The Hf–W ages for metal-silicate fractionation in CV and CR chondrites are 2.2 ± 0.8 Ma and 3.6 ± 0.6 Ma after formation of Ca-Al-rich inclusions, and are indistinguishable from Al–Mg ages for CV and CR chondrules. The good agreement between these ages strongly suggests that 26Al was homogeneously distributed in the solar protoplanetary disk and that therefore Al–Mg ages are chronologically meaningful. The concordant Al–Mg and Hf–W ages reveal that chondrule formation (as dated by Al–Mg) was associated with metal-silicate fractionation (as dated by Hf–W), both within a given chondrite but also among the different subgroups of ordinary chondrites. These age data indicate that chondrules from a given chondrite group formed in a narrow time interval of <1 Ma, and that chondrule formation and chondrite accretion were closely linked in time and space. The rapid accretion of chondrules into a chondrite parent body is consistent with the isotopic complementarity, which requires that neither chondrules nor matrix were lost prior to chondrite accretion. Combined, these observations suggest that chondrule formation was an important step in the accretion of planetesimals.
Little is known about potential harmful effects as a consequence of self-guided internet-based cognitive behaviour therapy (iCBT), such as symptom deterioration rates. Thus, safety concerns remain and hamper the implementation of self-guided iCBT into clinical practice. We aimed to conduct an individual participant data (IPD) meta-analysis to determine the prevalence of clinically significant deterioration (symptom worsening) in adults with depressive symptoms who received self-guided iCBT compared with control conditions. Several socio-demographic, clinical and study-level variables were tested as potential moderators of deterioration.
Randomised controlled trials that reported results of self-guided iCBT compared with control conditions in adults with symptoms of depression were selected. Mixed effects models with participants nested within studies were used to examine possible clinically significant deterioration rates.
Thirteen out of 16 eligible trials were included in the present IPD meta-analysis. Of the 3805 participants analysed, 7.2% showed clinically significant deterioration (5.8% and 9.1% of participants in the intervention and control groups, respectively). Participants in self-guided iCBT were less likely to deteriorate (OR 0.62, p < 0.001) compared with control conditions. None of the examined participant- and study-level moderators were significantly associated with deterioration rates.
Self-guided iCBT has a lower rate of negative outcomes on symptoms than control conditions and could be a first step treatment approach for adult depression as well as an alternative to watchful waiting in general practice.
We present the first mid-infrared (MIR) detection of a field brown dwarf (BD) and the first ground-based MIR measurements of a disk around a young BD candidate. We prove the absence of warm dust surrounding the field BD LP 944–20. In the case of the young BD candidate Cha Hα2, we find clear evidence for thermal dust emission from a disk. Surprisingly, the object does not exhibit any silicate feature as previously predicted. We show that the flat spectrum can be explained by an optically thick flat dust disk but not by a flared one.
We have selected cold and massive (M > 100M⊙) cores as candidates for early phases of star formation from millimeter continuum surveys without associations at short wavelengths. We compared the millimeter continuum peak positions with IR and radio catalogs and excluded cores that had sources associated with the cores’ peaks. We compiled a list of 173 cores in over 117 regions that are candidates for very early phases of Massive Star Formation (MSF). Now with the Spitzer and Herschel archives, these cores can be characterized further. We are compiling this data set to construct the complete spectral energy distribution (SED) in the mid- and far-infrared with good spatial resolution and broad spectral coverage. This allow us to disentangle the complex regions and model the SED of the deeply embedded protostars/clusters. We present a status report of our efforts: a preview of the IR properties of all cores and their embedded source inferred from a grey body fit to the compiled SEDs.
The distribution of alloying elements in the constituent phases of a C-containing γ-TiAl based alloy has been characterized locally by atom probe tomography. The major elements of the alloy under consideration – Ti, Al, Nb, and Mo – are distributed uniformly within each of the constituent phases. Furthermore, Mo is preferentially dissolved in the βo-phase, whereas Nb content is similar in all phases. The selected C concentration of the alloy is below the overall solubility limit as no precipitates have been observed. Therefore, C is enriched in the α2-phase, whereas the βo-phase is depleted of C. In addition, βo/γ-interfaces have been prepared by site specific sample preparation and characterized by atom probe tomography. Segregation of Mo and C into the interfaces and their close vicinity was observed.
Understanding the fundamental properties of macromolecules has enhanced the development of emerging technologies used to improve biomedical research. Currently, there is a critical need for innovative platforms that can illuminate the function of biomedical reagents in a native environment. To address this need, we have developed an in situ approach to visualize the dynamic behavior of biomedically relevant macromolecules at the nanoscale. Newly designed silicon nitride devices containing integrated “microwells” were used to enclose active macromolecular specimens in liquid for transmission electron microscopy imaging purposes.We were able to successfully examine novel magnetic resonance imaging contrast reagents, micelle suspensions, liposome carrier vehicles, and transcribing viral assemblies. With each specimen tested, the integrated microwells adequately maintained macromolecules in discrete local environments while enabling thin liquid layers to be produced.
Preliminary work indicates that cognitive vulnerability to depression may be associated with variants of the serotonin transporter promoter polymorphism (5-HTTLPR) and the valine to methionine at position 66 (val66met) polymorphism of the brain-derived neurotrophic factor (BDNF) gene; however, existing reports come from small samples. The present study sought to replicate and extend this research in a sample of 375 community-dwelling children and their parents. Following a negative mood induction, children completed a self-referent encoding task tapping memory for positive and negative self-descriptive traits. Consistent with previous work, we found that children with at least one short variant of the 5-HTTLPR had enhanced memory for negative self-descriptive traits. The BDNF val66met polymorphism had no main effect but was moderated by maternal depression, such that children with a BDNF methionine allele had a heightened memory for negative self-descriptive traits when mothers had experienced depression during children's lifetimes; in contrast, children with a methionine allele had low recall of negative traits when mothers had no depression history. The findings provide further support for the notion that the 5-HTTLPR is associated with cognitive markers of depression vulnerability and that the BDNF methionine allele moderates children's sensitivity to contextual factors.
Accumulation of homocysteine and S-adenosylhomocysteine in bone has been shown to be associated with reduced bone quality in rats. The aim of the present study was to investigate whether high bone concentrations of homocysteine and S-adenosylhomocysteine as well as a low methylation capacity are related to an impaired bone morphology in humans. Concentrations of homocysteine and its precursors S-adenosylhomocysteine and S-adenosylmethionine were measured in femoral bone samples of eighty-two males and females (age 71 (sd 8) years) who underwent elective hip arthroplasty. Cancellous bone structure was analysed by histomorphometry. In addition, blood was sampled to measure serum concentrations of homocysteine. Results of bone and serum analyses were grouped for individuals with high or low bone concentrations of homocysteine, S-adenosylhomocysteine and S-adenosylmethionine, as well as for individuals with a high or a low methylation capacity, which is indicated by a low or a high S-adenosylhomocysteine:S-adenosylmethionine ratio (n 41, each). Histomorphometry showed a higher trabecular separation and a lower trabecular thickness, trabecular number and trabecular area in individuals with high bone concentrations of homocysteine and S-adenosylhomocysteine compared with individuals with low bone concentrations of homocysteine and S-adenosylhomocysteine. There was no association between the S-adenosylhomocysteine:S-adenosylmethionine ratio and bone morphology. It was found that 48 % of bone homocysteine was bound to the collagen of the extracellular bone matrix. Blood analyses demonstrated a significant correlation between serum and bone homocysteine. The results of the present study indicate an association between altered bone morphology and elevated bone concentrations of homocysteine and S-adenosylhomocysteine, but not between altered bone morphology and methylation capacity.
Researchers have long been interested in whether particular temperamental traits in childhood connote risk for depressive disorders. For example, children characterized as having high negative emotionality (NE; sadness, fear, anger) and low positive emotionality (PE; anhedonia, listlessness, and lack of enthusiasm) are hypothesized to be at risk for depression. Few studies, however, have examined whether (and how) these two temperamental dimensions interact to confer risk. In a sample of 329 preschoolers, the present study addressed this question by examining the relation between PE and NE and asymmetry in resting EEG activity in frontal and posterior regions, which are putative biomarkers for depression. Using a laboratory battery to define temperament, we found an interaction of PE and NE on posterior asymmetry. Specifically, when PE was high, NE was associated with greater relative right activity. When PE was low, NE was not related to posterior asymmetry. These results were driven by differences in EEG activity in right posterior regions, an area associated with emotional processing and arousal, and were specific to girls. We found no relation between temperament and frontal asymmetry. These findings suggest that, at least for girls, PE and NE may have an interactive effect on risk for depression.