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1.
Phys Rev Lett ; 124(11): 113003, 2020 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-32242681

RESUMEN

Polarized atomic beam sources have been in operation for many years to produce either nuclear polarized atomic hydrogen or deuterium beams. In recent experiments, such a source was used to polarize both isotopes independently at the same time. By recombination of the atoms, hydrogen-deuterium molecules with all possible nuclear spin combinations can be created. Those spin isomers are useful for further applications, like precision spectroscopy, as polarized targets for laser-particle acceleration, polarized fuel for fusion reactors, or as an option for future measurements of electric dipole moments.

2.
Phys Rev Lett ; 120(2): 022002, 2018 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-29376676

RESUMEN

Taking advantage of the high acceptance and axial symmetry of the WASA-at-COSY detector, and the high polarization degree of the proton beam of COSY, the reaction p[over →]p→ppη has been measured close to threshold to explore the analyzing power A_{y}. The angular distribution of A_{y} is determined with the precision improved by more than 1 order of magnitude with respect to previous results, allowing a first accurate comparison with theoretical predictions. The determined analyzing power is consistent with zero for an excess energy of Q=15 MeV, signaling s-wave production with no evidence for higher partial waves. At Q=72 MeV the data reveal strong interference of Ps and Pp partial waves and cancellation of (Pp)^{2} and Ss^{*}Sd contributions. These results rule out the presently available theoretical predictions for the production mechanism of the η meson.

3.
Phys Rev Lett ; 121(5): 052001, 2018 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-30118290

RESUMEN

Exclusive measurements of the quasifree pp→ppπ^{+}π^{-} reaction have been carried out at WASA@COSY by means of pd collisions at T_{p}=1.2 GeV. Total and differential cross sections have been extracted covering the energy region T_{p}=1.08-1.36 GeV, which is the region of N^{*}(1440) and Δ(1232)Δ(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange are at variance with the measured differential cross sections and underpredict substantially the experimental total cross section. An isotensor ΔN dibaryon resonance with I(J^{P})=2(1^{+}) produced associatedly with a pion is able to overcome these deficiencies.

4.
J Intellect Disabil Res ; 61(3): 255-265, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27585827

RESUMEN

BACKGROUND: Problematic drinkers favour the processing of alcohol-related stimuli at the cost of other stimuli and also find it difficult to disengage their attention from these stimuli. This is indicative of an attentional bias towards alcohol. The goal of this study was to examine this bias in problematic drinkers with and without mild to borderline intellectual disability (MBID) using both eye tracking methodology and behavioural data (i.e. reaction time (RT) data). METHOD: Participants (N = 133) were divided into four groups based on (estimated) full scale intelligence quotient (IQ) and severity of alcohol use-related problems. The severity of substance use-related problems was assessed with the Alcohol Use Disorder Identification Test (AUDIT). The visual dot probe task was used to measure the attentional bias. We analysed both eye tracking data and behavioural data (i.e. RT data) of the visual dot probe task. RESULTS: Problematic drinkers were not more likely than light drinkers to direct their attention towards pictures of alcoholic beverages, did not look at these pictures longer than light drinkers and did also not respond faster than light drinkers to probes replacing pictures of alcoholic beverages. However, the strength of the attentional bias varied profusely. CONCLUSION: Taking the large variability in the strength of the attentional bias and the poor psychometric qualities of the measures into consideration, it is concluded that the use of these measures for clinical purposes is discouraged.


Asunto(s)
Trastornos Relacionados con Alcohol/fisiopatología , Sesgo Atencional/fisiología , Discapacidad Intelectual/fisiopatología , Adolescente , Adulto , Anciano , Medidas del Movimiento Ocular/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas/normas , Índice de Severidad de la Enfermedad , Adulto Joven
5.
Phys Rev Lett ; 117(5): 054801, 2016 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-27517774

RESUMEN

We observe a deuteron beam polarization lifetime near 1000 s in the horizontal plane of a magnetic storage ring (COSY). This long spin coherence time is maintained through a combination of beam bunching, electron cooling, sextupole field corrections, and the suppression of collective effects through beam current limits. This record lifetime is required for a storage ring search for an intrinsic electric dipole moment on the deuteron at a statistical sensitivity level approaching 10^{-29} e cm.

6.
Prev Med ; 88: 224-9, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27143498

RESUMEN

Objective To evaluate the effectiveness of a home-based alcohol prevention program to delay initiation of alcohol use in children. Methods In 2011, a total of 1349 sixth-grade children (M=12.15, SD=0.47) and their mothers who could read and write Dutch were recruited from primary schools in the northern part of the Netherlands. They participated in a cluster randomized controlled trial with two conditions; (1) intervention group (5 modules which families received by mail every 4weeks over 5months), (2) control group (a factsheet information brochure). An independent statistician allocated the schools to the conditions (allocation ratio (1:1)). Participants and data-analyst were blind to randomization. The primary outcome was alcohol initiation. Results Of the participants, 680 were randomized to the intervention and 669 to the control condition. In the intervention condition (N=540) 5.4% of the children drank alcohol compared to 7.1% in the control condition (N=601). The difference was not significant (OR=.99, 95% CI=.96-1.02, p=52). Conclusion The present study showed no effects of 'In control: No alcohol!' on alcohol initiation. A critical evaluation of program design and content, and future studies in different target groups, are suggested. The trial is registered at trialregister.nl, number NTR2474.


Asunto(s)
Consumo de Bebidas Alcohólicas/prevención & control , Educación en Salud/métodos , Madres/educación , Niño , Femenino , Humanos , Masculino , Países Bajos , Folletos , Evaluación de Programas y Proyectos de Salud
7.
J Intellect Disabil Res ; 60(3): 242-53, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26667160

RESUMEN

BACKGROUND: Substance use disorders (SUD) are associated with several neurobiological disruptions, including biases in attention and approach/avoidance behaviour. The aims of this study were to compare the strength of cognitive biases between light and problematic drinkers, to explore the role of IQ on the cognitive biases and to study the psychometric qualities of the measures. METHOD: Participants (N = 130) were divided into four groups based on IQ and severity of alcohol use-related problems: light (n = 28) and problematic drinkers (n = 25) with (sub)average IQ and light (n = 33) and problematic drinkers (n = 44) with mild to borderline intellectual disability (MBID). All participants performed the visual dot probe task and the approach avoidance task to measure the strength of cognitive biases. RESULTS: In contrast with the hypothesis, no cognitive biases were found in problematic drinkers. Full scale IQ nor level of craving influenced the strength of the cognitive biases in light and problematic drinkers, although IQ did influence task performance (i.e. large intra-individual, trial-to-trial variation in reaction time). The internal consistency of the visual dot probe task was good, whereas the internal consistency of the approach avoidance task was poor. CONCLUSION: Cognitive biases seem to vary within the group of problematic drinkers as a whole. The psychometric qualities of the measures are problematic, especially in relation to the intra-individual variability in reaction time found in participants with MBID. Until the implications of this variability on the validity of implicit measures and establishing bias scores are more clear, the use of these measures in individuals with MBID calls for scrutiny.


Asunto(s)
Consumo de Bebidas Alcohólicas/psicología , Trastornos Relacionados con Alcohol/psicología , Actitud , Discapacidad Intelectual/psicología , Adulto , Femenino , Humanos , Masculino , Índice de Severidad de la Enfermedad
8.
J Intellect Disabil Res ; 60(3): 191-200, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26631986

RESUMEN

BACKGROUND: Students without intellectual disability (ID) start experimenting with tobacco and alcohol between 12 and 15 years of age. However, data for 12- to 15-year old students with ID are unavailable. Prevention programs, like 'PREPARED ON TIME' (based on the attitude-social influence-efficacy model), are successful, but their efficacy has not been studied in students with ID. The objectives of this study were (1) to undertake a cluster randomised control trial to test the efficacy of the e-learning program among 12- to 15-year old students with mild and borderline ID in secondary special-needs schools and (2) to examine the tobacco and alcohol use for this population. METHODS: Five schools, randomly selected to be part of either the experimental group or the control group, participated in this study. Passive informed consent was used in which parents and their children can refuse to participate in the study, resulting in 111 students in the experimental group and 143 students in the control group. A total of 210 students completed both baseline and follow-up questionnaires. Primary outcome variables are the knowledge and attitude towards alcohol and tobacco use. This study is registered in the ISRCTN registry with number ISRCTN95279686. RESULTS: Baseline findings showed that a large proportion of all respondents had initiated smoking (49%) and drinking (75%), well above the expected numbers based on national figures. 'PREPARED ON TIME' did not affect the behavioural determinants (i.e. attitude, subjective norm and self-efficacy), except modelling on smoking. Additionally, alcohol-related knowledge of students in the experimental group increased after the completion of the program. CONCLUSIONS: To obtain effective results on behavioural outcomes from 'PREPARED ON TIME', a greater degree of flexibility (i.e. repetition, extension of the program, role playing, etc.) is required. Furthermore, prevention needs to be implemented at a younger age, as 6% of the students tried their first cigarette and 15% of the students drank alcohol at the age of 10 years or younger.


Asunto(s)
Consumo de Bebidas Alcohólicas/epidemiología , Educación en Salud/métodos , Discapacidad Intelectual/epidemiología , Fumar/epidemiología , Trastornos Relacionados con Sustancias/prevención & control , Adolescente , Niño , Educación de las Personas con Discapacidad Intelectual , Femenino , Humanos , Masculino , Instituciones Académicas/estadística & datos numéricos , Resultado del Tratamiento
9.
J Youth Adolesc ; 45(12): 2406-2416, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27071947

RESUMEN

Lonely adolescents report that they have poor social skills, but it is unknown whether this is due to an accurate perception of a social skills deficit, or a biased negative perception. This is an important distinction, as actual social skills deficits require different treatments than biased negative perceptions. In this study, we compared self-reported social skills evaluations with peer-reported social skills and meta-evaluations of social skills (i.e., adolescents' perceptions of how they believe their classmates evaluate them). Based on the social skills view, we expected negative relations between loneliness and these three forms of social skills evaluations. Based on the bias view, we expected lonely adolescents to have more negative self- and meta-evaluations compared to peer-evaluations of social skills. Participants were 1342 adolescents (48.64 % male, M age = 13.95, SD = .54). All classmates rated each other in a round-robin design to obtain peer-evaluations. Self- and meta-evaluations were obtained using self-reports. Data were analyzed using polynomial regression analyses and response surface modeling. The results indicated that, when self-, peer- and meta-evaluations were similar, a greater sense of loneliness was related to poorer social skills. Loneliness was also related to larger discrepancies between self- and peer-evaluations of loneliness, but not related to the direction of these discrepancies. Thus, for some lonely adolescents, loneliness may be related to an actual social skills deficit, whereas for others a biased negative perception of one's own social skills or a mismatch with the environment may be related to their loneliness. This implies that different mechanisms may underlie loneliness, which has implications for interventions.


Asunto(s)
Relaciones Interpersonales , Soledad/psicología , Grupo Paritario , Psicología del Adolescente , Autoimagen , Habilidades Sociales , Adolescente , Femenino , Humanos , Masculino , Modelos Psicológicos , Países Bajos , Variaciones Dependientes del Observador , Psicometría , Autoinforme , Encuestas y Cuestionarios
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