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1.
Artigo em Inglês | MEDLINE | ID: mdl-31662878

RESUMO

BACKGROUND: Given the range and reach of psychosocial support (PSS) interventions in humanitarian settings, within the continuum of mental health and psychosocial support services, evaluation of their impact is critical. Understanding stakeholders' perspectives on which PSS interventions of unknown effectiveness warrant rigorous evaluation is essential to identify research priorities. This project aimed to facilitate a process with stakeholders to reach consensus on PSS interventions that are of high priority for further research based on existing evidence and stakeholders' opinions. METHODS: Interviews with 109 stakeholders working on PSS programming in humanitarian settings served as the foundation for two in-person regional meetings and four webinars. Nominal Group Technique (NGT) was used to develop a priority PSS program list. The top five priorities from each meeting were combined for a final online survey distributed globally. RESULTS: Seventy participants across six meetings contributed to the prioritization process. Eighty-seven individuals completed the final online survey. 'Community based PSS' was the top-ranked research priority, followed by PSS integrated into basic services, providing PSS to caregivers to improve child wellbeing, PSS-focused gender-based violence programming, and classroom-based PSS interventions. CONCLUSIONS: NGT and online surveys were effective methods to engage stakeholders in a priority setting exercise to development a research agenda. Information from this stage of the project will be combined with findings from a concurrent systematic review to form the base of a second phase of work, which will include the development and implementation of a research strategy to strengthen the evidence base for those prioritized interventions.

2.
BMC Health Serv Res ; 19(1): 262, 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31036002

RESUMO

BACKGROUND: There is mounting evidence supporting the effectiveness of task-shifted mental health interventions in low- and middle-income countries (LMIC). However, there has been limited systematic scale-up or sustainability of these programs, indicating a need to study implementation. One barrier to progress is a lack of locally relevant and valid implementation measures. We adapted an existing brief dissemination and implementation (D&I) measure which includes scales for acceptability, appropriateness, feasibility and accessibility for local use and studied its validity and reliability among a sample of consumers in Ukraine. METHODS: Local qualitative data informed adaptation of the measure and development of vignettes to test the reliability and validity. Participants were veterans and internally displaced persons (IDPs) recruited as part of a separate validity study of adapted mental health instruments. We examined internal consistency reliability, test-retest reliability, and construct and criterion validity for each scale on the measure. We randomly assigned half the participants to respond to a vignette depicting existing local psychiatric services which we knew were not well regarded, while the other half was randomized to a vignette describing a potentially more well-implemented mental health service. Criterion validity was assessed by comparing scores on each scale by vignette and by overall summary ratings of the programs described in the vignettes. RESULTS: N = 169 participated in the qualitative study and N = 153 participated in the validity study. Qualitative findings suggested the addition of several items to the measure and indicated the importance of addressing professionalism/competency of providers in both the scales and the vignettes. Internal consistency reliabilities ranged from α = 0.85 for feasibility to α = 0.91 for appropriateness. Test-rest reliabilities were acceptable to good for all scales (rho: 0.61-0.79). All scales demonstrated substantial and significant differences in average scores by vignette assignment (ORs: 2.21-5.6) and overall ratings (ORs: 5.1-14.47), supporting criterion validity. CONCLUSIONS: This study represents an innovative mixed-methods approach to testing an implementation science measure in contexts outside the United States. Results support the reliability and validity of most scales for consumers in Ukraine. Challenges included large amounts of missing data due to participants' difficulties responding to questions about a hypothetical program.


Assuntos
Saúde Global , Ciência da Implementação , Serviços de Saúde Mental/organização & administração , Serviços de Saúde Mental/normas , Humanos , Psicometria , Pesquisa Qualitativa , Reprodutibilidade dos Testes , Projetos de Pesquisa , Ucrânia
3.
BMC Womens Health ; 19(1): 34, 2019 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-30764813

RESUMO

BACKGROUND: Epidemiological research suggests an interrelationship between mental health problems and the (re)occurrence of intimate partner violence (IPV). However, little is known about the impact of mental health treatments on IPV victimization or perpetration, especially in low- and middle-income countries (LMIC). METHODS: We conducted a systematic review to identify prospective, controlled studies of mental health treatments in LMIC. We defined 'mental health treatment' as an intervention for individuals experiencing mental ill health (including substance misuse) including a substantial psychosocial or pharmacological component. Studies had to measure a mental health and IPV outcome. We searched across multi-disciplinary databases using a structured search strategy. Screening of title/abstracts and full-text eligibility assessments were conducted by two researchers independently, data were extracted using a piloted spreadsheet, and a narrative synthesis was generated. RESULTS: We identified seven studies reported in 11 papers conducted in five middle-income countries. With the exception of blinding, studies overall showed acceptable levels of risk of bias. Four of the seven studies focused on dedicated mental health treatments in various populations, including: common mental disorders in earthquake survivors; depression in primary care; alcohol misuse in men; and alcohol misuse in female adult sex workers. The dedicated mental health treatments targeting depression or alcohol misuse consistently reduced levels of these outcomes. The two studies targeting depression also reduced short-term IPV, but no IPV benefits were identified in the two alcohol-focused studies. The other three studies evaluated integrated interventions, in which a focus on substance misuse was part of efforts to reduce HIV/AIDS and violence against particularly vulnerable women. In contrast to the dedicated mental health interventions, the integrated interventions did not consistently reduce mental ill health or alcohol misuse compared to control conditions. CONCLUSIONS: Too few studies have been conducted to judge whether mental health treatments may provide a beneficial strategy to prevent or reduce IPV in LMIC. Key future research questions include: whether promising initial evidence on the effects of depression interventions on reducing IPV hold more broadly, the required intensity of mental health components in integrated interventions, and the identification of mechanisms of IPV that are amenable to mental health intervention.


Assuntos
Vítimas de Crime/psicologia , Vítimas de Crime/estatística & dados numéricos , Violência por Parceiro Íntimo/prevenção & controle , Violência por Parceiro Íntimo/psicologia , Transtornos Mentais/terapia , Pobreza/psicologia , Pobreza/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
5.
QJM ; 112(3): 171-182, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30247655

RESUMO

BACKGROUND: The severity of Tuberous Sclerosis Complex (TSC) can vary among affected individuals. Complications of TSC can be life threatening, with significant impact on patients' quality of life. Management may vary dependent on treating physician, local and national policies, and funding. There are no current UK guidelines. We conducted a Delphi consensus process to reach agreed guidance for the management of patients with TSC in the UK. METHODS: We performed a literature search and reviewed the 2012/13 international guideline for TSC management. Based on these, a Delphi questionnaire was formed. We invited 86 clinicians and medical researchers to complete an online survey in two rounds. All the people surveyed were based in the UK. Clinicians were identified through the regional TSC clinics, and researchers were identified through publications. In round one, 55 questions were asked. In round two, 18 questions were asked in order to obtain consensus on the outstanding points that had been contentious in round one. The data was analysed by a core committee and subcommittees, which consisted of UK experts in different aspects of TSC. The Tuberous Sclerosis Association was consulted. RESULTS: About 51 TSC experts took part in this survey. Two rounds were required to achieve consensus. The responders were neurologists, nephrologists, psychiatrist, psychologists, oncologists, general paediatricians, dermatologist, urologists, radiologists, clinical geneticists, neurosurgeons, respiratory and neurodisability clinicians. CONCLUSIONS: These new UK guidelines for the management and surveillance of TSC patients provide consensus guidance for delivery of best clinical care to individuals with TSC in the UK.


Assuntos
Esclerose Tuberosa/epidemiologia , Esclerose Tuberosa/terapia , Humanos , Vigilância da População , Qualidade de Vida , Inquéritos e Questionários , Reino Unido/epidemiologia
6.
Artigo em Inglês | MEDLINE | ID: mdl-29868236

RESUMO

BACKGROUND: This paper reports on: (1) an evaluation of a common elements treatment approach (CETA) developed for comorbid presentations of depression, anxiety, traumatic stress, and/or externalizing symptoms among children in three Somali refugee camps on the Ethiopian/Somali border, and (2) an evaluation of implementation factors from the perspective of staff, lay providers, and families who engaged in the intervention. METHODS: This project was conducted in three refugee camps and utilized locally validated mental health instruments for internalizing, externalizing, and posttraumatic stress (PTS) symptoms. Participants were recruited from either a validity study or from referrals from social workers within International Rescue Committee Programs. Lay providers delivered CETA to youth (CETA-Youth) and families, and symptoms were re-assessed post-treatment. Providers and families responded to a semi-structured interview to assess implementation factors. RESULTS: Children who participated in the CETA-Youth open trial reported significant decreases in symptoms of internalizing (d  =  1.37), externalizing (d  =  0.85), and posttraumatic stress (d  =  1.71), and improvements in well-being (d  =  0.75). Caregivers also reported significant decreases in child symptoms. Qualitative results were positive toward the acceptability and appropriateness of treatment, and its feasibility. CONCLUSIONS: This project is the first to examine a common elements approach (CETA: defined as flexible delivery of elements, order, and dosing) with children and caregivers in a low-resource setting with delivery by lay providers. CETA-Youth may offer an effective treatment that is easier to implement and scale-up versus multiple focal interventions. A fullscale randomized clinical trial is warranted.

7.
Artigo em Inglês | MEDLINE | ID: mdl-29868239

RESUMO

BACKGROUND: Common mental health problems experienced by survivors of systematic violence include trauma, depression, and anxiety. A trial of mental health interventions by community mental health workers for survivors of systematic violence in southern Iraq showed benefits from two psychotherapies on trauma, depression, anxiety, and function: Common Elements Treatment Approach (CETA) and cognitive processing therapy (CPT). This study assessed whether other non-predetermined changes reported by intervention participants were more common than in the control group. METHODS: The trial involved 342 participants (CETA: 99 intervention, 50 control; CPT: 129 intervention, 64 control). Sixteen intervention-related changes since enrollment were identified from free-listing interviews of 15 early therapy completers. The changes were then added as a new quantitative module to the follow-up questionnaire. The changes were organized into eight groupings by thematic analysis - family, social standing, anger management, interest in regular activities, optimism, feeling close to God, avoiding smoking and drugs, and physical health. All participants were interviewed with this module and responses were compared between intervention and control participants. RESULTS: Multi-level, multi-variate regression models showed CETA intervention subjects with significant, positive changes relative to CETA controls on most themes. CPT intervention subjects showed little to no change compared with CPT controls in most themes. CONCLUSIONS: Participants receiving CETA reported more positive changes from therapy compared with controls than did participants receiving CPT. This study suggests differential effects of psychotherapy beyond the predetermined clinical outcome measures and that identification of these effects should be part of intervention evaluations.

8.
Artigo em Inglês | MEDLINE | ID: mdl-29507744

RESUMO

BACKGROUND: Recent political changes in Myanmar provide opportunities to expand mental health (MH) services. Given Myanmar's unique situation, we felt a need to assemble and interpret available local information on MH in Myanmar to inform service design, rather than simply drawing lessons from other countries. We reviewed academic and gray literature on the experience of MH problems in Myanmar and the suitability, availability, and effectiveness of MH and psychosocial programming. METHODS: We searched: (1) Google Scholar; (2) PubMed; (3) PsychInfo; (4) English-language Myanmar journals and databases; (5) the Mental Health and Psychosocial Support (MHPSS) Network resources website; (6) websites and (7) local contacts of organizations identified during 2010 and 2013 mapping exercise of MHPSS providers; (8) the Myanmar Information Management Unit (MIMU) website; (9) University libraries in Yangon and Mandalay; and (10) identified local MH professionals. RESULTS: Qualitative data suggest that MH conditions resulting from stress are similar to those experienced elsewhere. Fourteen intervention evaluations were identified: three on community-level interventions, three on adult religion-based practice (meditation), four adult psychotherapeutic interventions, and four child-focused interventions. Support for the acceptability and effectiveness of interventions is mostly anecdotal. With the exception of two rigorous, randomized control trials, most evaluations had serious methodologic limitations. CONCLUSIONS: Few evaluations of psychotherapeutic or psychosocial programs for people from Myanmar have been published in the black or gray literature. Incorporating rigorous evaluations into existing and future programs is imperative for expanding the evidence base for psychotherapeutic and psychosocial programs in this context.

9.
Rev Sci Instrum ; 89(1): 013301, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29390656

RESUMO

Laser-based ion acceleration is driven by electrical fields emerging when target electrons absorb laser energy and consecutively leave the target material. A direct correlation between these electrons and the accelerated ions is thus to be expected and predicted by theoretical models. We report on a modified wide-angle spectrometer, allowing the simultaneous characterization of angularly resolved energy distributions of both ions and electrons. Equipped with online pixel detectors, the RadEye1 detectors, the investigation of this correlation gets attainable on a single shot basis. In addition to first insights, we present a novel approach for reliably extracting the primary electron energy distribution from the interfering secondary radiation background. This proves vitally important for quantitative extraction of average electron energies (temperatures) and emitted total charge.

10.
Confl Health ; 12: 1, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29449879

RESUMO

BACKGROUND: Sexual violence is associated with a multitude of poor physical, emotional, and social outcomes. Despite reports of stigma by sexual violence survivors, limited evidence exists on effective strategies to reduce stigma, particularly in conflict-affected settings. We sought to assess the effect of group Cognitive Processing Therapy (CPT) on stigma and the extent to which stigma might moderate the effectiveness of CPT in treating mental health problems among survivors of sexual violence in the Democratic Republic of Congo. METHODS: Data were drawn from 405 adult female survivors of sexual violence reporting mental distress and poor functioning in North and South Kivu. Women were recruited through organizations providing psychosocial support and then cluster randomized to group CPT or individual support. Women were assessed at baseline, the end of treatment, and again six months later. Assessors were masked to women's treatment assignment. Linear mixed-effect regression models were used to estimate (1) the effect of CPT on feelings of perceived and internalized (felt) stigma, and (2) whether felt stigma and discrimination (enacted stigma) moderated the effects of CPT on combined depression and anxiety symptoms, posttraumatic stress, and functional impairment. RESULTS: Participants receiving CPT experienced moderate reductions in felt stigma relative to those in individual support (Cohen's D = 0.44, p = value = 0.02) following the end of treatment, though this difference was no longer significant six-months later (Cohen's D = 0.45, p = value = 0.12). Neither felt nor enacted stigma significantly moderated the effect of CPT on mental health symptoms or functional impairment. CONCLUSIONS: Group cognitive-behavioral based therapies may be an effective stigma reduction tool for survivors of sexual violence. Experiences and perceptions of stigma did not hinder therapeutic effects of group psychotherapy on survivors' mental health. TRIAL REGISTRATION: ClinicalTrials.gov NCT01385163.

11.
Artigo em Inglês | MEDLINE | ID: mdl-29230313

RESUMO

BACKGROUND: Self-report measurement instruments are commonly used to screen for mental health disorders in Low and Middle-Income Countries (LMIC). The Western origins of most depression instruments may constitute a bias when used globally. Western measures based on the DSM, do not fully capture the expression of depression globally. We developed a self-report scale design to address this limitation, the International Depression Symptom Scale-General version (IDSS-G), based on empirical evidence of the signs and symptoms of depression reported across cultures. This paper describes the rationale and process of its development and the results of an initial test among a non-Western population. METHODS: We evaluated internal consistency reliability, test-retest reliability and inter-rater reliability of the IDSS-G in a sample N = 147 male and female attendees of primary health clinics in Yangon, Myanmar. For criterion validity, IDSS-G scores were compared with diagnosis by local psychiatrists using the Structured Clinical Interview for DSM (SCID). Construct validity was evaluated by investigating associations between the IDSS-G and the Patient Health Questionnaire (PHQ), impaired function, and suicidal ideation. RESULTS: The IDSS-G showed high internal consistency reliability (α = 0.92), test-retest reliability (r = 0.87), and inter-rater reliability (ICC = 0.90). Strong correlations between the IDSS-G and PHQ-9, functioning, and suicidal ideation supported construct validity. Criterion validity was supported for use of the IDSS-G to identify people with a SCID diagnosed depressive disorder (major depression/dysthymia). The IDSS-G also demonstrated incremental validity by predicting functional impairment beyond that predicted by the PHQ-9. Results suggest that the IDSS-G accurately assesses depression in this population. Future testing in other populations will follow.

12.
Artigo em Inglês | MEDLINE | ID: mdl-29230314

RESUMO

BACKGROUND: Violence against women and girls (VAWG) is an urgent global health problem. Root causes for VAWG include the individual- and family-level factors of alcohol abuse, mental health problems, violence exposure, and related adverse experiences. Few studies in low- and middle-income countries (LMIC) have assessed the effectiveness of psychological interventions for reducing VAWG. This randomized controlled trial, part of the What Works to Prevent Violence Against Women and Girls consortium, examines the effectiveness of a common elements treatment approach (CETA) for reducing VAWG and comorbid alcohol abuse among families in Zambia. METHODS/DESIGN: Study participants are families consisting of three persons: an adult woman, her male husband or partner, and one of her children aged 8-17 (if available). Eligibility criteria include experience of moderate-to-severe intimate partner violence by the woman and hazardous alcohol use by her male partner. Family units are randomized to receive CETA or treatment as usual. The primary outcome is VAWG as measured by the Severity of Violence Against Women Scale, assessed along with secondary outcomes at 24 months post-baseline. Interim assessments are also conducted at 4-5 months (following CETA completion) and 12 months post-baseline. CONCLUSIONS: This ongoing trial is one of the first in sub-Saharan Africa to evaluate the use of an evidence-based common elements approach for reducing VAWG by targeting a range of individual- and family-level factors, including alcohol abuse. Results of this trial will inform policy on what interventions work to prevent VAWG in LMIC with local perspectives on scale up and wider implementation.

13.
Sci Rep ; 7(1): 17968, 2017 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-29269841

RESUMO

Burst Intensification by Singularity Emitting Radiation (BISER) is proposed. Singularities in multi-stream flows of emitting media cause constructive interference of emitted travelling waves, forming extremely localized sources of bright coherent emission. Here we for the first time demonstrate this extreme localization of BISER by direct observation of nano-scale coherent x-ray sources in a laser plasma. The energy emitted into the spectral range from 60 to 100 eV is up to ~100 nJ, corresponding to ~1010 photons. Simulations reveal that these sources emit trains of attosecond x-ray pulses. Our findings establish a new class of bright laboratory sources of electromagnetic radiation. Furthermore, being applicable to travelling waves of any nature (e.g. electromagnetic, gravitational or acoustic), BISER provides a novel framework for creating new emitters and for interpreting observations in many fields of science.

14.
Dev Cogn Neurosci ; 26: 84-90, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28654838

RESUMO

Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are associated with varied executive function (EF) difficulties. Callous-unemotional (CU) traits, a proposed antecedent of adult psychopathy, are often associated with intact or enhanced EF. Here we test whether CU traits may therefore modulate EF in ASD and ADHD, in which EF is typically impaired. We collected CU traits and measured event-related potentials (ERPs) that index EF during a cued-continuous performance test (CPT-OX) in boys with ASD, ADHD, comorbid ASD+ADHD and typical controls. We examined attentional orienting at cues (Cue-P3), inhibitory processing at non-targets (NoGo-P3) and conflict monitoring between target and non-target trials (Go-N2 vs. NoGo-N2). In children with ASD, higher CU traits were associated with an enhanced increase in N2 amplitude in NoGo trials compared to Go trials, which suggests relatively superior conflict monitoring and a potential cognitive strength associated with CU traits. The results emphasise the importance of considering the effects of co-occurring traits in the assessment of heterogeneity of EF profiles in neurodevelopmental disorders.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Transtorno do Espectro Autista/fisiopatologia , Função Executiva/fisiologia , Adolescente , Criança , Potenciais Evocados , Feminino , Humanos , Masculino , Projetos Piloto
15.
Sci Rep ; 7: 43548, 2017 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-28272471

RESUMO

Proton acceleration from nanometer thin foils with intense laser pulses is investigated experimentally. We analyzed the laser absorptivity by parallel monitoring of laser transmissivity and reflectivity with different laser intensities when moving the targets along the laser axis. A direct correlation between laser absorptivity and maximum proton energy is observed. Experimental results are interpreted in analytical estimation, exhibiting a coexistence of plasma expansion and light-sail form of radiation pressure acceleration (RPA-LS) mechanisms during the entire proton acceleration process based on the measured laser absorptivity and reflectivity.

16.
Soc Sci Med ; 183: 151-162, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28069271

RESUMO

To date global research on depression has used assessment tools based on research and clinical experience drawn from Western populations (i.e., in North American, European and Australian). There may be features of depression in non-Western populations which are not captured in current diagnostic criteria or measurement tools, as well as criteria for depression that are not relevant in other regions. We investigated this possibility through a systematic review of qualitative studies of depression worldwide. Nine online databases were searched for records that used qualitative methods to study depression. Initial searches were conducted between August 2012 and December 2012; an updated search was repeated in June of 2015 to include relevant literature published between December 30, 2012 and May 30, 2015. No date limits were set for inclusion of articles. A total of 16,130 records were identified and 138 met full inclusion criteria. Included studies were published between 1976 and 2015. These 138 studies represented data on 170 different study populations (some reported on multiple samples) and 77 different nationalities/ethnicities. Variation in results by geographical region, gender, and study context were examined to determine the consistency of descriptions across populations. Fisher's exact tests were used to compare frequencies of features across region, gender and context. Seven of the 15 features with the highest relative frequency form part of the DSM-5 diagnosis of Major Depressive Disorder (MDD). However, many of the other features with relatively high frequencies across the studies are associated features in the DSM, but are not prioritized as diagnostic criteria and therefore not included in standard instruments. The DSM-5 diagnostic criteria of problems with concentration and psychomotor agitation or slowing were infrequently mentioned. This research suggests that the DSM model and standard instruments currently based on the DSM may not adequately reflect the experience of depression at the worldwide or regional levels.


Assuntos
Depressão/complicações , Depressão/epidemiologia , Depressão/psicologia , Internacionalidade , Humanos
17.
J Evol Biol ; 30(1): 174-190, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27758066

RESUMO

In socially monogamous species, individuals can use extra-pair paternity and offspring sex allocation as adaptive strategies to ameliorate costs of genetic incompatibility with their partner. Previous studies on domesticated Gouldian finches (Erythrura gouldiae) demonstrated a genetic incompatibility between head colour morphs, the effects of which are more severe in female offspring. Domesticated females use differential sex allocation, and extra-pair paternity with males of compatible head colour, to reduce fitness costs associated with incompatibility in mixed-morph pairings. However, laboratory studies are an oversimplification of the complex ecological factors experienced in the wild and may only reflect the biology of a domesticated species. This study aimed to examine the patterns of parentage and sex ratio bias with respect to colour pairing combinations in a wild population of the Gouldian finch. We utilized a novel PCR assay that allowed us to genotype the morph of offspring before the morph phenotype develops and to explore bias in morph paternity and selection at the nest. Contrary to previous findings in the laboratory, we found no effect of pairing combinations on patterns of extra-pair paternity, offspring sex ratio or selection on morphs in nestlings. In the wild, the effect of morph incompatibility is likely much smaller, or absent, than was observed in the domesticated birds. Furthermore, the previously studied domesticated population is genetically differentiated from the wild population, consistent with the effects of domestication. It is possible that the domestication process fostered the emergence (or enhancement) of incompatibility between colour morphs previously demonstrated in the laboratory.


Assuntos
Tentilhões , Paternidade , Fenótipo , Animais , Cor , Feminino , Genótipo , Masculino , Reação em Cadeia da Polimerase , Razão de Masculinidade
18.
Phys Rev E ; 94(3-1): 033208, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27739766

RESUMO

We report on experiments irradiating isolated plastic spheres with a peak laser intensity of 2-3×10^{20}Wcm^{-2}. With a laser focal spot size of 10 µm full width half maximum (FWHM) the sphere diameter was varied between 520 nm and 19.3 µm. Maximum proton energies of ∼25 MeV are achieved for targets matching the focal spot size of 10 µm in diameter or being slightly smaller. For smaller spheres the kinetic energy distributions of protons become nonmonotonic, indicating a change in the accelerating mechanism from ambipolar expansion towards a regime dominated by effects caused by Coulomb repulsion of ions. The energy conversion efficiency from laser energy to proton kinetic energy is optimized when the target diameter matches the laser focal spot size with efficiencies reaching the percent level. The change of proton acceleration efficiency with target size can be attributed to the reduced cross-sectional overlap of subfocus targets with the laser. Reported experimental observations are in line with 3D3V particle in cell simulations. They make use of well-defined targets and point out pathways for future applications and experiments.

19.
Rev Sci Instrum ; 87(7): 071101, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27475539

RESUMO

An overview of progress and typical yields from intense laser-plasma acceleration of ions is presented. The evolution of laser-driven ion acceleration at relativistic intensities ushers prospects for improved functionality and diverse applications which can represent a varied assortment of ion beam requirements. This mandates the development of the integrated laser-driven ion accelerator system, the multiple components of which are described. Relevant high field laser-plasma science and design of controlled optimum pulsed laser irradiation on target are dominant single shot (pulse) considerations with aspects that are appropriate to the emerging petawatt era. The pulse energy scaling of maximum ion energies and typical differential spectra obtained over the past two decades provide guidance for continued advancement of laser-driven energetic ion sources and their meaningful applications.

20.
Psychol Med ; 46(12): 2595-604, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27353452

RESUMO

BACKGROUND: Many adults with autism spectrum disorder (ASD) remain undiagnosed. Specialist assessment clinics enable the detection of these cases, but such services are often overstretched. It has been proposed that unnecessary referrals to these services could be reduced by prioritizing individuals who score highly on the Autism-Spectrum Quotient (AQ), a self-report questionnaire measure of autistic traits. However, the ability of the AQ to predict who will go on to receive a diagnosis of ASD in adults is unclear. METHOD: We studied 476 adults, seen consecutively at a national ASD diagnostic referral service for suspected ASD. We tested AQ scores as predictors of ASD diagnosis made by expert clinicians according to International Classification of Diseases (ICD)-10 criteria, informed by the Autism Diagnostic Observation Schedule-Generic (ADOS-G) and Autism Diagnostic Interview-Revised (ADI-R) assessments. RESULTS: Of the participants, 73% received a clinical diagnosis of ASD. Self-report AQ scores did not significantly predict receipt of a diagnosis. While AQ scores provided high sensitivity of 0.77 [95% confidence interval (CI) 0.72-0.82] and positive predictive value of 0.76 (95% CI 0.70-0.80), the specificity of 0.29 (95% CI 0.20-0.38) and negative predictive value of 0.36 (95% CI 0.22-0.40) were low. Thus, 64% of those who scored below the AQ cut-off were 'false negatives' who did in fact have ASD. Co-morbidity data revealed that generalized anxiety disorder may 'mimic' ASD and inflate AQ scores, leading to false positives. CONCLUSIONS: The AQ's utility for screening referrals was limited in this sample. Recommendations supporting the AQ's role in the assessment of adult ASD, e.g. UK NICE guidelines, may need to be reconsidered.


Assuntos
Transtorno do Espectro Autista/diagnóstico , Escalas de Graduação Psiquiátrica/normas , Autorrelato/normas , Inquéritos e Questionários/normas , Adulto , Transtorno do Espectro Autista/epidemiologia , Comorbidade , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Adulto Jovem
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