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Several questions still exist in the literature on the relationship between cumulative exposure to work-related incidents and posttraumatic stress disorder (PTSD) in First Responders (FR).
To address three unanswered questions in the field.
(1) Are different cumulative exposure scoring algorithms similarly related to PTSD?
(2) Is PTSD associated only with incidents rated as severe and traumatic?
(3) Can we identify cut-off scores of cumulative exposure that maximize sensitivity and specificity to predict PTSD?
To better characterize the relationship between cumulative exposure and PTSD in FR.
The association between exposure and PTSD was examined with logistic and linear regression and with receiver operating characteristic analysis in 349 FR.
(1) The strength of the association between PTSD and total cumulative exposure indexes varied across different scoring algorithms.
(2) Compared to total cumulative exposure indexes and to sub-scores of exposure to non-traumatic and/or less severe incidents, sub-scores indexing exposure to severe traumatic events only were more strongly and significantly associated with PTSD.
(3) The use of two cut-off scores maximizes sensitivity and specificity to predict PTSD.
(1) The relationship between current PTSD and cumulative exposure is partially dependent on the approach used to quantify exposure.
(2) Focusing on the assessment of cumulative exposure to severe traumatic events is sufficient to predict PTSD, and might be more useful and effective in research and clinical decision-making.
(3) Sensitivity and specificity of exposure scores might help improve secondary prevention (early detection and effective intervention) of individuals at risk.
Item Response Theory (IRT) allows for dimensional scaling of the severity of a disorder, and comparison of symptoms’ properties across different measures of the same trait and across groups. IRT has never been applied to Posttraumatic Stress Disorder (PTSD).
To determine discrimination and severity parameters of PTSD symptoms measured with two instruments, and to examine gender- and age-related Differential Item Functioning (DIF) of PTSD indicators.
To inform the dimensional scaling of PTSD in youth.
IRT was applied to PTSD items measured with the DPS and the PTSD-RI in 6,733 9/11-exposed youths. DIF analysis was performed in the sample stratified by gender and age (8-13; 14-21).
DPS and PTSD-RI items are most informative at intermediate and severe levels of PTSD, respectively. Across instruments, discrimination was greatest for insomnia and nightmares, and lowest for 9/11-related thoughts. Severity parameters were highest for avoidance and numbing symptoms, and lowest for 9/11-related thoughts. The majority of PTSD symptoms showed significant DIF across subgroups.
DPS and PTSD-RI criteria are informative at different levels of PTSD severity. PTSD symptoms differentially discriminate among individuals along the PTSD continuum, and are most informative at different levels of PTSD severity. These results could inform dimensional scaling of PTSD, and allow for flexibility in assigning cut-off points for facilitating clinical decision-making. PTSD criteria do not provide the same information across subgroups defined by gender and age, suggesting that symptoms differ in the way they represent severe post-traumatic stress reactions across groups.
Improving quality of life (QOL) for people with dementia is a priority. In care homes, we often rely on proxy ratings from staff and family but we do not know if, or how, they differ in care homes.
We compared 1056 pairs of staff and family DEMQOL-Proxy ratings from 86 care homes across England. We explored factors associated with ratings quantitatively using multilevel modelling and, qualitatively, through thematic analysis of 12 staff and 12 relative interviews.
Staff and family ratings were weakly correlated (ρs = 0.35). Median staff scores were higher than family's (104 v. 101; p < 0.001). Family were more likely than staff to rate resident QOL as ‘Poor’ (χ2 = 55.91, p < 0.001). Staff and family rated QOL higher when residents had fewer neuropsychiatric symptoms and severe dementia. Staff rated QOL higher in homes with lower staff:resident ratios and when staff were native English speakers. Family rated QOL higher when the resident had spent longer living in the care home and was a native English. Spouses rated residents’ QOL higher than other relatives. Qualitative results suggest differences arise because staff felt good care provided high QOL but families compared the present to the past. Family judgements centre on loss and are complicated by decisions about care home placement and their understandings of dementia.
Proxy reports differ systematically between staff and family. Reports are influenced by the rater:staff and family may conceptualise QOL differently.
The extended timescales involved in the decay of radioactive wastes to safe levels mean that geological disposal facilities must continue to function effectively long into the future. It is therefore essential to consider long-term climate evolution in post-closure performance assessments in order to evaluate a geological disposal system's response and robustness to a variety of potential environmental changes, driven by both natural and anthropogenic forcings. In this paper, we illustrate the multiple decay components that characterize the primary driver of climate change – atmospheric CO2 – in response to fossil fuel carbon emissions. We perform a multi-exponential analysis on a series of atmospheric CO2 decay curves predicted by an Earth system model and create an empirical response function that encapsulates the long-term (>1 kyr) removal of excess CO2 from the atmosphere. We present this response function as a simple tool for rapidly projecting the future atmospheric CO2 concentration resulting from any plausible cumulative release of CO2. We discuss the implications of the long 'tail' to this atmospheric CO2 decay curve, both in terms of future climate evolution as well as potential impacts on radioactive waste repositories.
ZnO nanowire (NW) arrays were examined with Transmission Electron Microscopy (TEM) in cross-section after preparation by Focused Ion Beam (FIB) milling. This technique revealed that ZnO nanowires grown using a Au catalyzed vapor technique typically have Au particles at the NW tips, and also randomly dispersed across the base crystal growth that joins adjacent NWs. It is shown the adjacent NWs and the combined base growth is one crystal structure which can be used as a back electrical contact making fabrication of vertical array devices possible. However, the base growth displays detrimental features such as embedded Au particles and lattice defects which can affect the electrical output through depletion regions and scattering centers. In an effort to overcome these problems we investigate a growth method that is nucleated through a minor alteration of the a-plane sapphire surface roughness via a weak chemical etch. Observations of various stages of the growth show the growth nucleates as separate nanoislands that grow in c-plane alignment with Sapphire (1-210), and as growth continues these islands meet and form a polycrystalline film. Further growth initiates nanowire growth and the formation of a single crystal base layer and NW structure that can cover several square millimeter’s. This allows high quality arrays that are relatively free from defects to be formed without any metals contamination and ready for further device processing.
The purpose of this study was to extend the literature on the ontogeny of autism spectrum disorder (ASD) by examining early attainment and loss of specific sociocommunicative skills in children with autism (AUT; n = 125), pervasive developmental disorder not otherwise specified (PDD-NOS; n = 42), nonspectrum developmental delays (n = 46), and typical development (n = 31). The ages of skill attainment and loss were obtained from a caregiver interview. The findings indicated that children with AUT, PDD-NOS, and developmental delays diverged from typically developing children in attainment of sociocommunicative skills early in the first year of life. Loss of at least one skill was reported in a majority of children with AUT and PDD-NOS. Significant delays in attainment of skills were also reported in children who lost skills. The wide variation in skill attainment and loss reported across children indicates that symptom onset and regression may be best represented continuously, with at least some early delay and loss present for a great majority of children with ASD.
Risky decision making, a hallmark phenotype of substance use disorders (SUD), is thought to be associated with deficient feedback processing. Whether these aberrations are present prior to SUD onset or reflect merely a consequence of chronic substance use on the brain remains unclear. The present study investigated whether blunted feedback processing during risky decision making reflects a biological predisposition to SUD. We assessed event-related potentials elicited by positive and negative feedback during performance of a modified version of the Balloon Analogue Risk Task (BART) among high-risk adolescents with a parental history of SUD (HR; n = 61) and normal-risk controls (NR; n = 91). HR males made significantly more risky and faster decisions during the BART than did NR controls. Moreover, HR adolescents showed significantly reduced P300 amplitudes in response to both positive and negative feedback as compared to NR controls. These differences were not secondary to prolonged substance use exposure. Results are discussed in terms of feedback-specific processes. Reduced P300 amplitudes in the BART may reflect poor processing of feedback at the level of overall salience, which may keep people from effectively predicting the probability of future gains and losses. Though conclusions are tentative, blunted feedback processing during risky decision making may represent a promising endophenotypic vulnerability marker for SUD.
In recent years the number of pregnant women susceptible to rubella has increased markedly. In the West Midlands the proportion has risen from 1·4% in 2004 to 6·9% in 2011. Locally, the proportion of non-immune women ranges from 1·6% in those born prior to 1976 to 17·8% in those born since 1986. The latter group comprises those given MMR in their second year with no further booster doses. The number of non-immune women will continue to rise as a consequence of low MMR uptake in the late 1990s. Repeat testing of samples with values <10 IU/ml and the need to vaccinate women postnatally have increased the workload of laboratory and maternity units. Screening for rubella in pregnancy has no advantages for the current pregnancy and it may be time to review the universal MMR vaccination programme which in turn would remove the need for continuing this practice.
Although bats are one of the most successful and diverse of mammalian orders, studies that focus upon bat endoparasites are limited. To further knowledge of bat parasitology, pipistrelle bats (Pipistrellus pipistrellus and P. pygmaeus) were acquired from across the Greater Manchester and Lancashire region of England and examined for gastrointestinal helminths using morphological and molecular analyses†. Sixty-eight of 90 adult/juvenile bats (76% prevalence) were infected with at least 1 species of helminth and mean helminth abundance was 48·2 (+/−7·0). All helminths were digenean trematodes and the following species were identified in 51 P. pipistrellus specimens (prevalence in parentheses): Lecithodendrium linstowi (80·4%), L. spathulatum (19·6%), Prosthodendrium sp. (35·3%), Plagiorchis koreanus (29·4%) and Pycnoporus heteroporus (9·8%). Statistical analyses, incorporating multifactorial models, showed that male bats exhibited a significantly more aggregated helminth distribution and lower abundance than females. Positive associations were observed between L. linstowi and L. spathulatum, Prosthodendrium sp. and P. heteroporus and between L. spathulatum and P. koreanus. A revised phylogeny of bat-associated Lecithodendriidae, incorporating novel L. spathulatum and Prosthodendrium sp. 28S rRNA sequences, separated the controversial clade formed by L. linstowi and P. hurkovaae. Further studies are likely to assist the understanding of bat-parasite/pathogen relationships, helminth infracommunity structures and phylogenetics.
The allostatic load (AL) model represents an interdisciplinary approach to comprehensively conceptualize and quantify chronic stress in relation to pathologies throughout the life cycle. This article first reviews the AL model, followed by interactions among early adversity, genetics, environmental toxins, as well as distinctions among sex, gender, and sex hormones as integral antecedents of AL. We next explore perspectives on severe mental illness, dementia, and caregiving as unique human models of AL that merit future investigations in the field of developmental psychopathology. A complimenting transdisciplinary perspective is applied throughout, whereby we argue that the AL model goes beyond traditional stress–disease theories toward the advancement of person-centered research and practice that promote not only physical health but also mental health.
Mass casualty triage is the process of prioritizing multiple victims when resources are not sufficient to treat everyone immediately. No national guideline for mass casualty triage exists in the United States. The lack of a national guideline has resulted in variability in triage processes, tags, and nomenclature. This variability has the potential to inject confusion and miscommunication into the disaster incident, particularly when multiple jurisdictions are involved. The Model Uniform Core Criteria for Mass Casualty Triage were developed to be a national guideline for mass casualty triage to ensure interoperability and standardization when responding to a mass casualty incident. The Core Criteria consist of 4 categories: general considerations, global sorting, lifesaving interventions, and individual assessment of triage category. The criteria within each of these categories were developed by a workgroup of experts representing national stakeholder organizations who used the best available science and, when necessary, consensus opinion. This article describes how the Model Uniform Core Criteria for Mass Casualty Triage were developed.
(Disaster Med Public Health Preparedness. 2011;5:129-137)
Within the Herschel key project “The Warm And Dense ISM” (WADI) we systematically observe
a number of prominent photon-dominated regions (PDRs) to measure the impact of varying UV
fields on the energy balance, the chemical and dynamical structure of heated molecular
United Solar Ovonic has leveraged its history of making amorphous silicon solar cells on stainless steel substrates to develop amorphous silicon alloy (a-Si:H)-based solar cells and modules on ∼25 μm thick polymer substrate using high-throughput roll-to-roll deposition technology for space and near-space applications. The solar cells have a triple-junction a-Si:H/a-SiGe:H/a-SiGe:H structure deposited by conventional plasma enhanced CVD (PECVD) using roll-to-roll processing. The cells have distinct advantages in terms of high specific power (W/kg), high flexibility, ruggedness, rollability for stowage, and irradiation resistance. The large area (23.9 cm x 32.1 cm) individual cells manufactured in large quantity can be readily connected into modules and have achieved initial, 25 °C, AM0 aperture-area efficiency of 9.8% and initial specific power of 1200 W/kg. We have conducted light-soak studies and measured the temperature coefficient of the current-voltage characteristics to determine the stable values at an expected operating temperature of 60 °C. The stable total-area efficiency and specific power at 60 °C are 7.2% and 950 W/kg, respectively. In this paper, we review the challenges and progress made in development of the cells, highlight some applications, and discuss current efforts aimed at improving performance.
We present the progress made in attaining high-efficiency large-area nc-Si:H based multi-junction solar cells using Modified Very High Frequency technology. We focused our effort on improving the spatial uniformity and homogeneity of nc-Si:H film growth and cell performance. We also conducted both indoor and outdoor light soaking studies and achieved 11.2% stabilized efficiency on large-area (≥400 cm2) encapsulated a-Si:H/nc-Si:H/nc-Si:H triple-junction cells.
Residents must become proficient in a variety of procedures. The practice of learning procedural skills on patients has come under ethical scrutiny, giving rise to the concept of simulation-based medical education. Resident training in a simulated environment allows skill acquisition without compromising patient safety. We assessed the impact of a simulation-based procedural skills training course on residents' competence in the performance of critical resuscitation procedures.
We solicited self-assessments of the knowledge and clinical skills required to perform resuscitation procedures from a cross-sectional multidisciplinary sample of 28 resident study participants. Participants were then exposed to an intensive 8-hour simulation-based training program, and asked to repeat the self-assessment questionnaires on completion of the course, and again 3 months later. We assessed the validity of the self-assessment questionnaire by evaluating participants' skills acquisition through an Objective Structured Clinical Examination station.
We found statistically significant improvements in participants' ratings of both knowledge and clinical skills during the 3 self-assessment periods (p < 0.001). The participants' year of postgraduate training influenced their self-assessment of knowledge (F2,25 = 4.91, p < 0.01) and clinical skills (F2,25 = 10.89, p < 0.001). At the 3-month follow-up, junior-level residents showed consistent improvement from their baseline scores, but had regressed from their posttraining measures. Senior-level residents continued to show further increases in their assessments of both clinical skills and knowledge beyond the simulation-based training course.
Significant improvement in self-assessed theoretical knowledge and procedural skill competence for residents can be achieved through participation in a simulation-based resuscitation course. Gains in perceived competence appear to be stable over time, with senior learners gaining further confidence at the 3-month follow-up. Our findings support the benefits of simulation-based training for residents.
Hybridomas secreting monoclonal antibodies to HBsAg and HBcAg were prepared from immunized mice. An antibody capture radioimmunoassay was used to detect and select appropriate hybrids for propagation and cloning. The advantages of this assay were discussed. The resulting monoclonal antibodies were compared with conventional polyclonal antisera for the detection of virus antigens in liver tissue and found to give excellent results.