The PICASSO and COUPP collaborations use superheated liquid detectors to search for cold dark matter through the direct detection of weakly interacting massive particles (WIMPs). These experiments, ...located in the underground laboratory of SNOLAB, Canada, detect phase transitions triggered by nuclear recoils in the keV range induced by interactions with WIMPs. We present details of the construction and operation of these detectors as well as the results, obtained by several years of observations. We also introduce PICO, a joint effort of the two collaborations to build a second generation ton-scale bubble chamber with 250 liters of active liquid.
Men and women differ dramatically in their rates of alcohol use disorder (AUD), and researchers have long been interested in identifying mechanisms underlying male vulnerability to problem drinking. ...Surveys suggest that social processes underlie sex differences in drinking patterns, with men reporting greater social enhancement from alcohol than women, and all-male social drinking contexts being associated with particularly high rates of hazardous drinking. But experimental evidence for sex differences in social-emotional response to alcohol has heretofore been lacking. Research using larger sample sizes, a social context, and more sensitive measures of alcohol's rewarding effects may be necessary to better understand sex differences in the etiology of AUD. This study explored the acute effects of alcohol during social exchange on speech volume-an objective measure of social-emotional experience that was reliably captured at the group level. Social drinkers (360 male; 360 female) consumed alcohol (.82 g/kg males; .74 g/kg females), placebo, or a no-alcohol control beverage in groups of 3 over 36-min. Within each of the 3 beverage conditions, equal numbers of groups consisted of all males, all females, 2 females and 1 male, and 1 female and 2 males. Speech volume was monitored continuously throughout the drink period, and group volume emerged as a robust correlate of self-report and facial indexes of social reward. Notably, alcohol-related increases in group volume were observed selectively in all-male groups but not in groups containing any females. Results point to social enhancement as a promising direction for research exploring factors underlying sex differences in problem drinking.
Physicists have long wondered whether the gravitational interactions between matter and antimatter might be different from those between matter and itself. Although there are many indirect ...indications that no such differences exist and that the weak equivalence principle holds, there have been no direct, free-fall style, experimental tests of gravity on antimatter. Here we describe a novel direct test methodology; we search for a propensity for antihydrogen atoms to fall downward when released from the ALPHA antihydrogen trap. In the absence of systematic errors, we can reject ratios of the gravitational to inertial mass of antihydrogen >75 at a statistical significance level of 5%; worst-case systematic errors increase the minimum rejection ratio to 110. A similar search places somewhat tighter bounds on a negative gravitational mass, that is, on antigravity. This methodology, coupled with ongoing experimental improvements, should allow us to bound the ratio within the more interesting near equivalence regime.
Psychotherapists routinely use both specific and nonspecific strategies to deliver empirically supported treatments (ESTs). Psychotherapy adherence monitoring has traditionally focused on assessing ...therapist use of EST-specific strategies (to distinguish between ESTs), paying less attention to nonspecific techniques common to multiple psychotherapies. This study used the Collaborative Study Psychotherapy Rating Scale (CSPRS) to evaluate therapist use of both specific and nonspecific techniques in 2 affect-focused ESTs for depression. Blinded raters evaluated 180 recorded sessions of interpersonal psychotherapy (IPT) and brief supportive psychotherapy (BSP). Because IPT and BSP both emphasize attention to affective states and developing a warm therapy relationship, we expected overlap across scales measuring therapist warmth, empathy, and focus on feelings. In contrast, we expected differences in scales measuring therapist directiveness, as well as IPT- and BSP-specific interventions. Results showed raters displayed good interrater reliability on primary subscales and could discriminate between 2 treatments with considerable overlap. Both IPT and BSP therapists used similarly high levels of nonspecific, facilitative interventions. Expectedly, IPT therapists were more directive and used more IPT-specific strategies, while BSP therapists utilized more nondirective, supportive strategies. Unexpectedly, BSP therapists showed greater focus on feelings than IPT therapists. Exploratory analyses suggested that greater focus on feelings in early sessions was associated with greater depressive symptom reduction in the first 8 weeks of treatment for both ESTs. Additional treatment adherence research is needed to investigate both shared and distinctive features of ESTs, as well as the effect of the relative use of specific versus nonspecific interventions on psychotherapy outcomes.
Terapeuta uso de estrategias específicas e inespecíficas a través de dos psicoterapias enfocadas en el afecto para la depresión: papel del monitoreo de la adherencia Divergence and Convergence: An Examination of Cognitive-Behavioral and Dynamic Therapies, Theoretical and Clinical Perspectives
Psicoterapeutas rutinariamente usan ambos específicos e inespecíficos estrategias para dar tratamientos empíricamente soportados (TES; EST, en inglés). Seguimiento de la adherencia a la psicoterapia ha sido tradicionalmente enfocado sobre evaluando los terapeutas en el uso de estrategias que son especificas al EST (para distinguir entre TES), dando menos atención a las técnicas inespecíficos que son común a varias formas de psicoterapia. Este estudio uso la Escala de la Colaboración Estudio Psicoterapia (CSPRS, en inglés) para evaluar los terapeutas en el uso de ambos especifico e inespecífico técnicas en 2 TES enfocados en los sentimientos para depresión. Evaluadores cegados evaluaron 180 sesiones grabadas de psicoterapia interpersonal (PTI, IPT en inglés) y psicoterapia de breve apoyo (PBA, BSP en inglés). Porque ambos PTI y PBS enfatizan atención a los estados de sentimiento y al desarrollo de una relación cálida en terapia, nosotros esperamos el traslapo a través de escalas que miden terapeutas sobre cálida, empatía, y enfoque en sentimientos. En contraste, esperamos diferencias en las escalas midiendo la directividad de un terapeuta, además de diferencias en las intervenciones especificas en PTI y PBS. Los resultados muestrearon buena confiabilidad entre los evaluadores en las subescalas primarias y podrían distinguir entre 2 tratamientos con considerable traslapo. Tanto PTI y PBS terapeutas usaron muy similares niveles de intervenciones facilitadoras inespecíficos. Como esperamos, terapeutas de PTI eran más directos y usaron más estrategias específicas a PTI, mientras los terapeutas de PBS utilizaron estrategias indirectas de apoyo. Inesperado, los terapeutas de PBS mostraron mayor enfoque en los sentimientos que los terapeutas de PTI. Análisis exploratorios sugieren que mayor enfoque en los sentimientos en las primeras sesiones fueron asociados con mayor reducción en síntomas depresivas en las primeras 8 semanas de tratamiento por ambos TES. Adicional investigación en la adherencia al tratamiento es necesario para investigar características compartidas y distintivas en los TES, tanto como el efecto del uso relativo de intervenciones especificas e inespecíficas sobre los resultados de la psicoterapia.
治疗师使用特定的和非特定的策略在两个以情绪为主的对抑郁症的心理治疗：依从监测的作用
心理治疗师通常使用特定的和非特定的策略来提供实证支持的治疗（ESTs）。心理治疗依从性监测传统上侧重于评估治疗师使用EST特定性策略（以区分于ESTs），较少注意多种心理治疗中常见的非特定性技术。本研究使用了协同研究心理治疗评估量表（CSPRS）来评估特定性和非特定性技术在两个以情绪为重点的抑郁症EST中的治疗方法。评估者评估了180次记录的人际心理治疗（IPT）和简短支持性心理治疗（BSP）。因为IPT和BSP都强调对情感状态的关注和发展温暖的治疗关系，所以我们预计在测量量表中对治疗师的温暖，同情和感情的重叠。相比之下，我们预期衡量治疗师指导方面，以及IPT和BSP特定性干预措施之间的差异。结果显示，评估者在主要子量表上表现出良好的内部可靠性，并且可以区分2种具有相当重叠的治疗。 IPT和BSP治疗师都使用同样高水平的非特定性，促进性干预措施。同预期的是，IPT治疗师更具指导性，并采用更多的IPT特定策略，而BSP治疗师则采用更多的非指导性支持策略。意外的是，BSP治疗师比IPT治疗师更加重视感觉。探索性分析表明，早期以感觉为更多关注的治疗与两种EST治疗前8周的抑郁症状减轻有关。我们需要更多的治疗依从性研究来调查ESTs的共同特征和独特特征，以及相对的使用特定性与非特定性干预措施对心理治疗结果的影响。
The hydrogen atom is one of the most important and influential model systems in modern physics. Attempts to understand its spectrum are inextricably linked to the early history and development of ...quantum mechanics. The hydrogen atom's stature lies in its simplicity and in the accuracy with which its spectrum can be measured and compared to theory. Today its spectrum remains a valuable tool for determining the values of fundamental constants and for challenging the limits of modern physics, including the validity of quantum electrodynamics and--by comparison with measurements on its antimatter counterpart, antihydrogen--the validity of CPT (charge conjugation, parity and time reversal) symmetry. Here we report spectroscopy of a pure antimatter atom, demonstrating resonant quantum transitions in antihydrogen. We have manipulated the internal spin state of antihydrogen atoms so as to induce magnetic resonance transitions between hyperfine levels of the positronic ground state. We used resonant microwave radiation to flip the spin of the positron in antihydrogen atoms that were magnetically trapped in the ALPHA apparatus. The spin flip causes trapped anti-atoms to be ejected from the trap. We look for evidence of resonant interaction by comparing the survival rate of trapped atoms irradiated with microwaves on-resonance to that of atoms subjected to microwaves that are off-resonance. In one variant of the experiment, we detect 23 atoms that survive in 110 trapping attempts with microwaves off-resonance (0.21 per attempt), and only two atoms that survive in 103 attempts with microwaves on-resonance (0.02 per attempt). We also describe the direct detection of the annihilation of antihydrogen atoms ejected by the microwaves.
The ALPHA experiment, located at CERN, aims to compare the properties of antihydrogen atoms with those of hydrogen atoms. The neutral antihydrogen atoms are trapped using an octupole magnetic trap. ...The trap region is surrounded by a three layered silicon detector used to reconstruct the antiproton annihilation vertices. This paper describes a method we have devised that can be used for reconstructing annihilation vertices with a good resolution and is more efficient than the standard method currently used for the same purpose.
The ALPHA antihydrogen trapping apparatus Amole, C.; Andresen, G.B.; Ashkezari, M.D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2014, Letnik:
735
Journal Article
Recenzirano
Odprti dostop
The ALPHA collaboration, based at CERN, has recently succeeded in confining cold antihydrogen atoms in a magnetic minimum neutral atom trap and has performed the first study of a resonant transition ...of the anti-atoms. The ALPHA apparatus will be described herein, with emphasis on the structural aspects, diagnostic methods and techniques that have enabled antihydrogen trapping and experimentation to be achieved.
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