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For over three decades confirmatory factor analysis (CFA) has been used to test the construct validity of models of posttraumatic stress disorder (PTSD). The four symptom dimensions of PTSD in the fifth edition of Diagnostic and Statistical Manual of Mental Disorders(DSM–5) are based on CFA. Since the publication of DSM–5, the number of proposed factors has grown from four to seven. We review these models, focusing on (a) the number of symptoms per factor, indicating how well factors are identified; (b) correlations between factors, indicating how distinct they are; and (c) their external validation. Of the 27 CFAs published since 2013, almost all included factors composed of only two symptoms, and most relied on more than one. High factor correlations were the norm. Two thirds of models provided external validation. Discussion concerns implications for PTSD’s measurement and construct validity and recommendations for improving CFA in the PTSD literature.

For over 4 decades, educational researchers have been studying best practices for introducing writing into the curriculum. One successful strategy, a low-stakes writing exercise called “writing to learn” (WTL), has been implemented across several disciplines within higher education. In light of a growing interest in the use of technology and social media as an influential tool in the educational environment, we ask this question: “Does the source material used to prepare for WTL activities impact student learning and knowledge retention?” To address this question, we studied student performance on WTL exercises (in microbiology and introductory biology) that were based on material presented via (a) media (news videos, Podcasts, or YouTube) or (b) written articles and transcripts. Although our analysis did not indicate a significant effect of media use on students’ ability to understand and retain new information, we discuss the implications of our findings and the limitations underscored by the very intent of WTL activities in doing such pedagogical work. This study offers insight into the implementation of WTL activities, particularly in the natural sciences, and demonstrates the value of such practices.

A striking rise in the number of people affected by humanitarian crises has led to an increase in mental health and psychosocial support interventions to reduce the psychological effects of such crises. In a parallel trend, researchers have brought increased methodological rigour to their evaluation of these interventions. However, several methodological issues still constrain the quality and real-world relevance of the existing evidence base. We examine five core challenges in randomised controlled trials of mental health and psychosocial support interventions with conflict-affected and disaster-affected populations. These challenges are: translating intervention effects into metrics of real-world significance; giving adequate consideration to the selection and monitoring of control conditions; following rigorous processes to ensure outcome measures are culturally appropriate and psychometrically sound; ensuring and monitoring implementation variables, including fidelity, exposure, participant engagement, and the competence of implementation staff; and assessing mechanisms of change.

Displacement of native octylphosphonate (OPA) ligands for methylthiophenolate (CH3-TP) on the surfaces of CdSe quantum dots (QDs) causes a moderate (up to 50 meV) decrease in the band gap (Eg) of the QD. Plots of the corresponding increase in apparent excitonic radius, ΔR, of the QDs versus the surface coverage of CH3-TP, measured by 1H NMR, for several sizes of QDs reveal that this ligand adsorbs in two distinct binding modes, (1) a tightly bound mode (Ka= 1.0 ± 0.3 × 104M–1) capable of exciton delocalization, and (2) a more weakly bound mode (Ka= 8.3 ± 9.9 × 102M–1) that has no discernible effect on exciton confinement. For tightly bound CH3-TP, the degree of delocalization induced in the QD is approximately linearly related to the fractional surface area occupied by the ligand for all sizes of QDs. Comparison of the dependence of ΔRon surface coverage of CH3-TP over a range of physical radii of the QDs, R= 1.1–2.4 nm, to analogous plots simulated using a 3D spherical potential well model yield a value for the confinement barrier presented to the excitonic hole by tightly bound CH3-TP of ∼1 eV.

In this paper, the authors elaborate on a model proposed in 2010 that identifies major sources of stress affecting mental health among war affected populations. That model emphasised the importance of what was termed ‘daily stressors’, as well as direct exposure to war related violence as predictors of mental health status The authors first summarise the original model and discuss the widespread response to the 2010 paper among researchers and practitioners working in conflict and post conflict settings. Then, the authors expand on the model, suggesting that, like the trauma focused model it was meant to improve upon, the proposed 2010 model still presents an overly static view of the experience of living through organised violence. A transactional version of the model is now proposed, which the authors believe more closely approximates the lived experience of war and the multiple sources of stress it entails. Implications of this transactional model, and possible directions for future research and practice, are suggested.

Torture has been defined most precisely in legal contexts. Practitioners who work with torture survivors and researchers who study torture have frequently cited legal definitions, particularly those in the United States’ Torture Victims Relief Act, the United Nations Convention against Torture, or the World Medical Association’s Declaration of Tokyo. Few practitioners have operationalized these definitions and applied them in their practice. We describe how a New York City torture treatment clinic used a coding checklist that operationalizes the definitions, and present results. We found that in practice these definitions were nested; that using guidelines for applying the definitions in practice altered the number of cases meeting criteria for these definitions; and that the severity of psychological symptoms did not differ between those who were tortured and those who were not under any definition. We propose theoretical and practical implications of these findings.

Research with survivors of torture has generated considerable variability in prevalence rates of posttraumatic stress disorder (PTSD). Multiple risk and resilience factors may affect this variability, increasing or decreasing the likelihood of experiencing psychological distress. This study sought to investigate the effect of several such resilience factors, coping style, social support, cognitive appraisals, and social comparisons on PTSD symptom severity. Furthermore, this study examined whether coping style moderated the relationship between resilience variables and PTSD symptoms. Seventy-five torture survivors completed an intake interview and several self-report measures upon entry into a treatment program for survivors of torture. Results indicated that emotion-focused coping styles significantly moderated the relationship between cognitive appraisal and social comparison variables and PTSD, and usually increased the likelihood of developing severe symptoms. These results indicate that the salience of resilience variables may differ depending on the individual’s coping style, which present implications for clinical practice with torture survivors.

Darfur refugees face hardships associated with chronic displacement, including lack of basic needs and safety concerns. Psychiatric research on refugees has focused on trauma, but daily stressors may contribute more to variance in distress. This article reports rates of past trauma and current stressors among Darfur refugees and gauges the contribution of each to psychological distress and functional impairment. A representative sample of 848 Darfuris in 2 refugee camps were interviewed about traumatic events, stressors faced in the camps, psychological distress, and functional impairment. Basic needs and safety concerns were more strongly correlated with measures of distress (rs?=?.19-.31) than were war-related traumatic events (rs?=?.09-.20). Hierarchical regression supported models in which effects of trauma on distress were mediated by current stressors. Although war-related traumatic events are the initial causes of refugees' hardship, findings suggest that the day-to-day challenges and concerns in camps mediate psychological distress associated with these events.

The effects of hydration on the lowest triplet states of the DNA/RNA pyrimidines have been studied by including one and two water molecules explicitly. Three configurations for the singly hydrated cytosine moiety were located, and six for the doubly hydrated system. For thymine and uracil, four singly and eight doubly hydrated structures were found. The singlet−triplet energy gaps of all three pyrimidines (cytosine, thymine, and uracil) fall in the low-energy range of ultraviolet radiation (UVA). Energetic excited states can be a step leading to lesions in DNA, such as a mismatched base pairs. Although the adiabatic and vertical electronic excitation energies for all three pyrimidines slightly increase upon inclusion of additional water molecules, this effect upon the excitation energies is much smaller than hydration effects upon the electron affinities and ionization energies of the three nucleobases. Because both the ground state and the triplet state are neutral, the hydration energy difference between the two states is not significant (compared to those between the neutral and charged species), making the excitation energy less sensitive to hydration.

Although a subjective component of trauma is commonly recognized in diagnosing posttraumatic stress disorder (PTSD), there are few studies that specifically address Criterion A2, and none addressing this issue among undocumented immigrants. We assessed 212 arriving undocumented immigrants with diverse trauma histories to investigate concordance between objective and subjective factors of trauma (Criteria A1and A2) and across different types of trauma and PTSD. Concordance between Criteria A1and A2varied, with highest rates found for political violence. Interpersonal violence in general was associated with higher rates of PTSD. We identified a dose-response effect for PTSD, but this was not dependent on other events (i.e., other doses) meeting Criterion A2. Discussion focuses on Criterion A within the phenomenology of PTSD and the need to gauge subjective interpretations of trauma events among this population.

ABSTRACTIt has been proposed that increased phase variation frequencies in Neisseria meningitidisaugment transmissibility and invasiveness. A Himar1 marinertransposon mutant library was constructed in serogroup A N. meningitidisand screened for clones with increased phase variation frequencies. Insertions increasing the frequency of slippage events within mononucleotide repeat tracts were identified in three known phase variation-modulating genes (mutS, mutL, and uvrD), as well as six additional loci (pilP, fbpA, fbpB, NMA1233, and two intergenic regions). The implications of these insertion mutations are discussed.

ABSTRACTBiofilm formation by the human pathogen Neisseria meningitidiswas analyzed. Biofilm-forming meningococcal strains were identified and quantitated by crystal violet staining. Laser scanning confocal microscopy of the meningococcal biofilm revealed variable layers up to 90 μm in thickness. A total of 39 meningococcal isolates were studied; 23 were nasopharyngeal-carriage isolates, and 16 were invasive-disease isolates. Thirty percent of carriage isolates and 12.5% of invasive-disease isolates formed biofilms proficiently on a polystyrene surface. Generally, the strains that formed biofilms showed high-level cell surface hydrophobicity, characteristic of strains lacking a capsule. The inhibitory role of capsule in biofilm formation was further confirmed by comparing the biofilm-forming capabilities of a serogroup B wild-type strain of a disease-associated isolate to those of its capsule-deficient mutant (ctrA). Some strains of meningococci form biofilms, and this process is likely important in menigococcal colonization.

Among Mundt and colleagues’ (2014) criticisms of NET is that testing a particular intervention implies that it is meant to be delivered irrespective of systems of care. But trauma-focused treatments should be judged based on the specific problems they target; larger sets of problems are the purview of health systems research.