1,650 research outputs found

    A randomized controlled trial of a cognitive-behavioral program for the prevention of depression in adolescents compared to nonspecific and no-intervention control conditions.

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    Adolescent depression is a common and recurrent disorder associated with significant impairment and other forms of psychopathology. Finding an effective intervention that prevents depression in adolescents is an important public health priority. Participants were 518 high school students (mean age = 15.09; SD = 0.76) from the mid-south of the United States. Participants were randomly assigned to one of three conditions: a cognitive-behavioral program (CB; n = 166), nonspecific control (NSp; n = 175), or a no-intervention control condition (NIC; n = 177). Both the CB and NSp conditions consisted of 90-minute sessions administered once a week over a 10-week period during regular school hours. Depressive symptoms were assessed with the Children’s Depression Inventory (CDI) at baseline, post-intervention, and at 4-, 8-, and 12-month follow-ups. The time by condition interaction was significant [F(8, 478.57) = 3.32, p = .001] indicating that at the 4-month follow-up, youth in the CB condition had significantly lower CDI scores compared to those in the NSp (p = 0.047, g = 0.29; CI: 0.06-0.52) and the NIC conditions (p = 0.003, g = 0.30; CI: 0.07-0.53). Future studies need to examine the importance of theory-driven change mechanisms, interpersonal relationships, and structural circumstances in schools as factors impacting the long-term effects of CB prevention programs

    Comparative proteomics of the two T. brucei PABPs suggests that PABP2 controls bulk mRNA

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    <div><p>Poly(A)-binding proteins (PABPs) regulate mRNA fate by controlling stability and translation through interactions with both the poly(A) tail and eIF4F complex. Many organisms have several paralogs of PABPs and eIF4F complex components and it is likely that different eIF4F/PABP complex combinations regulate distinct sets of mRNAs. Trypanosomes have five eIF4G paralogs, six of eIF4E and two PABPs, PABP1 and PABP2. Under starvation, polysomes dissociate and the majority of mRNAs, most translation initiation factors and PABP2 reversibly localise to starvation stress granules. To understand this more broadly we identified a protein interaction cohort for both <i>T</i>. <i>brucei</i> PABPs by cryo-mill/affinity purification-mass spectrometry. PABP1 very specifically interacts with the previously identified interactors eIF4E4 and eIF4G3 and few others. In contrast PABP2 is promiscuous, with a larger set of interactors including most translation initiation factors and most prominently eIF4G1, with its two partners TbG1-IP and TbG1-IP2. Only RBP23 was specific to PABP1, whilst 14 RNA-binding proteins were exclusively immunoprecipitated with PABP2. Significantly, PABP1 and associated proteins are largely excluded from starvation stress granules, but PABP2 and most interactors translocate to granules on starvation. We suggest that PABP1 regulates a small subpopulation of mainly small-sized mRNAs, as it interacts with a small and distinct set of proteins unable to enter the dominant pathway into starvation stress granules and localises preferentially to a subfraction of small polysomes. By contrast PABP2 likely regulates bulk mRNA translation, as it interacts with a wide range of proteins, enters stress granules and distributes over the full range of polysomes.</p></div

    Bidirectional relations of religious orientation and depressive symptoms in adolescents : a short-term longitudinal study.

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    Religious orientation can be divided into intrinsic and extrinsic: intrinsically oriented individuals “live their religion,” whereas extrinsically oriented individuals practice religion mainly to gain external benefits. In adults, depression has been found to correlate negatively with intrinsic religious orientation and positively with extrinsic orientation. Studies of the relation between religiosity and depression typically have not been longitudinal, conducted with adolescents, controlled for the influence of other factors associated with depression (i.e., negative cognitions), or examined the reverse relation of depression predicting religious orientation. Our four-month longitudinal study of 273 ninth-grade students addressed these issues. Results showed that higher intrinsic religious orientation measured at baseline significantly predicted lower self-reported depressive symptoms four months later, controlling for initial level of depressive symptoms and cognitive style; in contrast, extrinsic orientation and the interaction between religious orientation and life events did not significantly predict later depressive symptoms. Self-reported depressive symptoms, however, did not predict either intrinsic or extrinsic religious orientation four months later. Factors contributing to different findings for adolescents versus adults in the relation between extrinsic religious orientation and depression are suggested

    On Computing Probabilistic Abductive Explanations

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    The most widely studied explainable AI (XAI) approaches are unsound. This is the case with well-known model-agnostic explanation approaches, and it is also the case with approaches based on saliency maps. One solution is to consider intrinsic interpretability, which does not exhibit the drawback of unsoundness. Unfortunately, intrinsic interpretability can display unwieldy explanation redundancy. Formal explainability represents the alternative to these non-rigorous approaches, with one example being PI-explanations. Unfortunately, PI-explanations also exhibit important drawbacks, the most visible of which is arguably their size. Recently, it has been observed that the (absolute) rigor of PI-explanations can be traded off for a smaller explanation size, by computing the so-called relevant sets. Given some positive {\delta}, a set S of features is {\delta}-relevant if, when the features in S are fixed, the probability of getting the target class exceeds {\delta}. However, even for very simple classifiers, the complexity of computing relevant sets of features is prohibitive, with the decision problem being NPPP-complete for circuit-based classifiers. In contrast with earlier negative results, this paper investigates practical approaches for computing relevant sets for a number of widely used classifiers that include Decision Trees (DTs), Naive Bayes Classifiers (NBCs), and several families of classifiers obtained from propositional languages. Moreover, the paper shows that, in practice, and for these families of classifiers, relevant sets are easy to compute. Furthermore, the experiments confirm that succinct sets of relevant features can be obtained for the families of classifiers considered.Comment: arXiv admin note: text overlap with arXiv:2207.04748, arXiv:2205.0956

    Mechanism of Iron-Catalyzed Oxidative α-Amination of Ketones with Sulfonamides

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    We report the mechanism of the iron-catalyzed oxidative α-amination of ketones with sulfonamides. Using linear free energy relationships, competition experiments, and identification of reaction intermediates, we have found that the mechanism of this reaction proceeds through rate-limiting electron transfer to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) from an iron enolate in the process of forming an α-DDQ adduct. The adduct then serves as the electrophile for substitution with sulfonamide nucleophiles, accelerated by iron and additional DDQ. This mechanistic study rules out formation of an α-carbocation intermediate and purely radical mechanistic hypotheses

    Shock-induced plasticity in nanocrystalline iron: Large-scale molecular dynamics simulations

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    Large-scale nonequilibrium molecular dynamics (MD) simulations of shock waves in nanocrystalline iron show evidence of plasticity before the polymorphic transformation takes place. The atomistic structure in the shock direction shows an elastic precursor, plastic deformation, and shock-induced phase transformation from bcc to hcp iron. In this Rapid Communication, large-scale MD models show that the shock response of iron is highly related to the ramp time of the applied shocks. For long ramp times we observe significant plastic relaxation and formation of microstructure defects. Pressure-induced phase transformations in iron are accompanied by stress relaxation achieving almost fully relaxed three-dimensional hydrostatic final states. The evolution of the stress relaxation is in agreement with theory and experiments. Analysis of the x-ray diffraction patterns calculated from the atomistic structure using the Debye equation revealed pronounced anisotropy of the line broadening that is caused by stacking faults in hcp Fe and by dislocations in bcc Fe.Fil: Luu, Hoang Thien. Clausthal University of Applied Technology; AlemaniaFil: Ravelo, RamĂłn. University of Texas at El Paso; Estados UnidosFil: Rudolph, Martin. TU Bergakademie Freiberg; AlemaniaFil: Bringa, Eduardo Marcial. Universidad de Mendoza; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Germann, Timothy C.. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Rafaja, David. TU Bergakademie Freiberg; AlemaniaFil: Gunkelmann, Nina. Clausthal University of Applied Technology; Alemani

    Probing quasar lifetimes with proximate 2121-centimetre absorption in the diffuse intergalactic medium at redshifts z≄6z\geq 6

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    Enhanced ionizing radiation in close proximity to redshift z≳6z\gtrsim 6 quasars creates short windows of intergalactic Lyα\alpha transmission blueward of the quasar Lyα\alpha emission lines. The majority of these Lyα\alpha near-zones are consistent with quasars that have optically/UV bright lifetimes of tQ∌105−107 yrt_{\rm Q}\sim 10^{5}-10^{7}\rm\,yr. However, lifetimes as short as tQâ‰Č104 yrt_{\rm Q}\lesssim 10^{4}\rm\,yr appear to be required by the smallest Lyα\alpha near-zones. These short lifetimes present an apparent challenge for the growth of ∌109 M⊙\sim 10^{9}\rm\,M_{\odot} black holes at z≳6z\gtrsim 6. Accretion over longer timescales is only possible if black holes grow primarily in an obscured phase, or if the quasars are variable on timescales comparable to the equilibriation time for ionized hydrogen. Distinguishing between very young quasars and older quasars that have experienced episodic accretion with Lyα\alpha absorption alone is challenging, however. We therefore predict the signature of proximate 21-cm absorption around z≳6z\gtrsim 6 radio-loud quasars. For modest pre-heating of intergalactic hydrogen by the X-ray background, where the spin temperature TSâ‰Č102 KT_{\rm S} \lesssim 10^{2}\rm\,K prior to any quasar heating, we find proximate 21-cm absorption should be observable in the spectra of radio-loud quasars. The extent of the proximate 21-cm absorption is sensitive to the integrated lifetime of the quasar. Evidence for proximate 21-cm absorption from the diffuse intergalactic medium within 2−3 pMpc2-3\rm\,pMpc of a (radio-loud) quasar would be consistent with a short quasar lifetime, tQâ‰Č105 yrt_{\rm Q}\lesssim 10^{5}\rm\,yr, and would provide a complementary constraint on models for high redshift black hole growth.Comment: 19 pages, 12 figures, 2 tables. Accepted for publication in MNRA

    The experience of family carers attending a joint reminiscence group with people with dementia: A thematic analysis

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    Reminiscence therapy has the potential to improve quality of life for people with dementia. In recent years reminiscence groups have extended to include family members, but carers' experience of attending joint sessions is undocumented. This qualitative study explored the experience of 18 family carers attending 'Remembering Yesterday Caring Today' groups. Semi-structured interviews were transcribed and subjected to thematic analysis. Five themes were identified: experiencing carer support; shared experience; expectations (met and unmet), carer perspectives of the person with dementia's experience; and learning and comparing. Family carers' experiences varied, with some experiencing the intervention as entirely positive whereas others had more mixed feelings. Negative aspects included the lack of respite from their relative, the lack of emphasis on their own needs, and experiencing additional stress and guilt through not being able to implement newly acquired skills. These findings may explain the failure of a recent trial of joint reminiscence groups to replicate previous findings of positive benefit. More targeted research within subgroups of carers is required to justify the continued use of joint reminiscence groups in dementia care
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