162 research outputs found
Two Populations of Young Massive Star Clusters in Arp 220
We present new optical observations of young massive star clusters in Arp
220, the nearest ultraluminous infrared galaxy, taken in UBVI with the Hubble
Space Telescope ACS/HRC camera. We find a total of 206 probable clusters whose
spatial distribution is centrally concentrated toward the nucleus of Arp 220.
We use model star cluster tracks to determine ages, luminosities, and masses
for 14 clusters with complete UBVI indices or previously published
near-infrared data. We estimate rough masses for 24 additional clusters with I
< 24 mag from BVI indices alone. The clusters with useful ages fall into two
distinct groups: a ``young'' population (< 10 Myr) and an intermediate-age
population (~300 Myr). There are many clusters with masses clearly above 10^6
Msun and possibly even above 10^7 Msun in the most extreme instances. These
masses are high enough that the clusters being formed in the Arp 220 starburst
can be considered as genuine young globular clusters. In addition, this study
allows us to extend the observed correlation between global star formation rate
and maximum cluster luminosity by more than an order of magnitude in star
formation rate.Comment: 30 pages, 8 figures; figs 1-3 in color; accepted to Ap
Multiplicity in the experience of voice-hearing: A phenomenological inquiry
Although it is recognized that voice-hearers often report a large number and variety of voices there have been few investigations of this multiplicity. Understanding the phenomenology of voice-hearing can provide a firm foundation for theorizing about its causes. In this international online survey of voice-hearers, details were elicited of the content of up to five utterances associated with up to five voices from each respondent. The contents were independently rated and associated with characteristics of each voice such as its perceived age, whether it had changed over time, and whether it was of a familiar person. We investigated predictors (e.g., diagnoses, voice gender, age first heard) of utterance negativity, length, and whether voices referred to themselves. The average number of voices reported was approximately four. The majority were perceived as male and had negative content. Child-aged voices were significantly less negative than all other voices except those perceived as being elderly. Multi-level analyses indicated that there was significant variability at the level of different utterances within voices but variability was more prominent at the level of different voices within an individual. The data were inconsistent with general cognitive models for hearing voices such as the misattribution of inner speech and were more congruent with a dissociation model of voice-hearing. Our findings support approaches based on subtype or dimensional methods of classifying voices, and additionally indicate that research and clinical assessment may benefit from more systematic assessment of multiplicity
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Making sense of voices: a case series
The current evidence-base for the psychological treatment of distressing voices indicates the need for further clinical development. The Maastricht approach (also known as Making Sense of Voices) is popular within sections of the Hearing Voices Movement, but its clinical effectiveness has not been systematically evaluated. The aim of the approach is to develop a better understanding of the role of the voice, in part through opening a dialogue between the voice hearer and the voice. The current study was a (N=15) case series adopting a concurrent multiple baseline design. The Maastricht approach was offered for up to 9-months. The main outcome, weekly voice-related distress ratings, was not statistically significant during intervention or follow-up, although the effect size was in the moderate range. The PSYRATS Hallucination scale was associated with a large effect size both at the end of treatment, and after a 3-month follow-up period, although again the effect did not reach statistical significance. The results suggest further evaluation of the approach is warranted. However, given the large variance in individual participant outcome, it may be that a better understanding of response profiles is required before conducting a definitive randomised controlled trial
A density-temperature description of the outer electron radiation belt during geomagnetic storms
Bi-Maxwellian fits are made to energetic-electron flux measurements from seven satellites in geosynchronous orbit, yielding a number density (n) and temperature (T) description of the outer electron radiation belt. For 54.5 spacecraft years of measurements the median value of n is 3.7 × 10−4 cm−3, and the median value of T is 148 keV. General statistical properties of n, T, and the 1.1–1.5 MeV flux F are investigated, including local-time and solar-cycle dependencies. Using superposed-epoch analysis where the zero epoch is convection onset, the evolution of the outer electron radiation belt through high-speed-stream-driven storms is investigated. The number-density decay during the calm before the storm, relativistic-electron dropouts and recoveries, and the heating of the outer electron radiation belt during storms are analyzed. Using four different “triggers” (sudden storm commencement (SSC), southward interplanetary magnetic field (IMF) portions of coronal mass ejection (CME) sheaths, southward-IMF portions of magnetic clouds, and minimum Dst) a selection of CME-driven storms are analyzed with superposed-epoch techniques. For CME-driven storms, only a very modest density decay prior to storm onset is found. In addition, the compression of the outer electron radiation belt at the time of SSC is analyzed, the number-density increase and temperature decrease during storm main phase are characterized, and the increase in density and temperature during storm recovery phase is determined. During the different phases of storms, changes in the flux are sometimes in response to changes in the temperature, sometimes to changes in the number density, and sometimes to changes in both. Differences are found between the density-temperature and flux descriptions, and it is concluded that more information is available using the density-temperature description
Cognitive behavioural therapy for thought disorder in psychosis
Clinicians are often sceptical about offering cognitive behavioural therapy (CBT) to individuals experiencing thought disorder. This view may result from perceived difficulties in clients being able to learn and better understand their experiences through verbal dialogue. However, it may also partly be due to the lack of clear guidance on how to address and work with these difficulties within therapy. This paper provides recommendations for delivering CBT in individuals experiencing thought disorder. It considers how clinicians might conduct their cognitive behavioural assessment, formulation, and intervention, targeting unhelpful appraisals and behaviour, and generating insight. The aim is to better disseminate the techniques sometimes applied in clinical practice
Reflections on responses to the power threat meaning framework one year on
The project group reflects on the responses to the Power Threat Meaning Framework (PTMF) one year after publication. The group welcomes the interest shown in the document, and takes this opportunity to clarify some points, reflect on and learn from others, and suggest areas for future development
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Enabling meaningful use of AI-infused educational technologies for children with blindness: Learnings from the development and piloting of the PeopleLens curriculum
Novel AI-infused educational technologies can give children with blindness the opportunity to explore concepts learned incidentally through vision by using alternative perceptual modalities. However, more effort is needed to support the meaningful use of such technological innovations for evaluations at scale and later wide-spread adoption. This paper presents the development and pilot evaluation of a curriculum to enable educators to support blind learners' self-exploration of social attention using the PeopleLens technology. We reflect on these learnings to present four design guidelines for creating curricula aimed to enable meaningful use. We then consider how formulations of "success"by our participants can help us think about ways of assessing efficacy in low-incidence disability groups. We conclude by arguing for our community to widen the scope of discourse around assistive technologies from design and engineering to include supporting their meaningful use
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Social sensemaking with AI: Designing an open-ended AI experience with a blind child
AI technologies are often used to aid people in performing discrete tasks with well-defned goals (e.g., recognising faces in images). Emerging technologies that provide continuous, real-time information enable more open-ended AI experiences. In partnership with a blind child, we explore the challenges and opportunities of designing human-AI interaction for a system intended to support social sensemaking. Adopting a research-through-design perspective, we refect upon working with the uncertain capabilities of AI systems in the design of this experience. We contribute: (i) a concrete example of an open-ended AI system that enabled a blind child to extend his own capabilities; (ii) an illustration of the delta between imagined and actual use, highlighting how capabilities derive from the human-AI interaction and not the AI system alone; and (iii) a discussion of design choices to craft an ongoing human-AI interaction that addresses the challenge of uncertain outputs of AI systems
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