Measuring situation awareness in complex systems: Comparison of measures study

Situation Awareness (SA) is a distinct critical commodity for teams working in complex industrial systems and its measurement is a key provision in system, procedural and training design efforts. This article describes a study that was undertaken in order to compare three different SA measures (a freeze probe recall approach, a post trial subjective rating approach and a critical incident interview technique) when used to assess participant SA during a military planning task. The results indicate that only the freeze probe recall method produced a statistically significant correlation with performance on the planning task and also that there was no significant correlation between the three methods, which suggests that they were effectively measuring different things during the trials. In conclusion, the findings, whilst raising doubts over the validity of post trial subjective rating and interview-based approaches, offer validation evidence for the use of freeze probe recall approaches to measure SA. The findings are subsequently discussed with regard to their implications for the future measurement of SA in complex collaborative systems

Representing situation awareness in collaborative systems: A case study in the energy distribution domain

The concept of Distributed Situation Awareness (DSA) is currently receiving increasing attention from the human factors community. This article investigates DSA in a collaborative real-world industrial setting by discussing the results derived from a recent naturalistic study undertaken within the UK energy distribution domain. The results describe the DSA-related information used by the networks of agents involved in the scenarios analysed, the sharing of this information between the agents, and the salience of different information elements used. Thus the structure, quality and content of each network’s DSA is discussed, along with the implications for DSA theory. The findings reinforce the notion that when viewing SA in collaborative systems, it is useful to focus on the co-ordinated behaviour of the system itself, rather than on the individual as the unit of analysis and suggest that the findings from such assessments can potentially be used to inform system, procedure and training design

A cluster-randomized controlled trial to reduce sedentary behavior and promote physical activity and health of 8-9 year olds: The Transform-Us! Study

Background: Physical activity (PA) is associated with positive cardio-metabolic health and emerging evidence suggests sedentary behavior (SB) may be detrimental to children&rsquo;s health independent of PA. The primary aim of the Transform-Us! study is to determine whether an 18-month, behavioral and environmental intervention in the school and family settings results in higher levels of PA and lower rates of SB among 8-9 year old children compared with usual practice (post-intervention and 12-months follow-up). The secondary aims are to determine the independent and combined effects of PA and SB on children&rsquo;s cardio-metabolic health risk factors; identify the factors that mediate the success of the intervention; and determine whether the intervention is cost-effective.Methods/design: A four-arm cluster-randomized controlled trial (RCT) with a 2 &times; 2 factorial design, with schools as the unit of randomization. Twenty schools will be allocated to one of four intervention groups, sedentary behavior (SB-I), physical activity (PA-I), combined SB and PA (SB+PA-I) or current practice control (C), which will be evaluated among approximately 600 children aged 8-9 years in school year 3 living in Melbourne, Australia. All children in year 3 at intervention schools in 2010 (8-9 years) will receive the intervention over an 18-month period with a maintenance &lsquo;booster&rsquo; delivered in 2012 and children at all schools will be invited to participate in the evaluation assessments. To maximize the sample and to capture new students arriving at intervention and control schools, recruitment will be on-going up to the post-intervention time point. Primary outcomes are time spent sitting and in PA assessed via accelerometers and inclinometers and survey.Discussion: To our knowledge, Transform-Us! is the first RCT to examine the effectiveness of intervention strategies for reducing children&rsquo;s overall sedentary time, promoting PA and optimizing health outcomes. The integration of consistent strategies and messages to children from teachers and parents in both school and family settings is a critical component of this study, and if shown to be effective, may have a significant impact on educational policies as well as on pedagogical and parenting practices.<br /

Rings in the Solar System: a short review

Rings are ubiquitous around giant planets in our Solar System. They evolve jointly with the nearby satellite system. They could form either during the giant planet formation process or much later, as a result of large scale dynamical instabilities either in the local satellite system, or at the planetary scale. We review here the main characteristics of rings in our solar system, and discuss their main evolution processes and possible origin. We also discuss the recent discovery of rings around small bodies.Comment: Accepted for the Handbook of Exoplanet

RELICS: spectroscopy of gravitationally lensed z ≃ 2 reionization-era analogues and implications for C III] detections at z > 6

Recent observations have revealed the presence of strong C III] emission (EWCIII]>20 Å) in z > 6 galaxies, the origin of which remains unclear. In an effort to understand the nature of these line emitters, we have initiated a survey targeting C III] emission in gravitationally lensed reionization-era analogues identified in Hubble Space Telescope imaging of clusters from the Reionization Lensing Cluster Survey. Here, we report initial results on four galaxies selected to have low stellar masses (2–8 × 107 M⊙) and J125-band flux excesses indicative of intense [O III] + H β emission (EW[OIII]+Hβ = 500–2000 Å), similar to what has been observed at z > 6. We detect C III] emission in three of the four sources, with the C III] EW reaching values seen in the reionization era (EWCIII]≃17−22 Å) in the two sources with the strongest optical line emission (EW[OIII]+Hβ≃2000 Å). We have obtained a Magellan/FIRE (Folded-port InfraRed Echellette) near-infrared spectrum of the strongest C III] emitter in our sample, revealing gas that is both metal poor and highly ionized. Using photoionization models, we are able to simultaneously reproduce the intense C III] and optical line emission for extremely young (2–3 Myr) and metal-poor (0.06–0.08 Z⊙) stellar populations, as would be expected after a substantial upturn in the star formation rate of a low-mass galaxy. The sources in this survey are among the first for which C III] has been used as the primary means of redshift confirmation. We suggest that it should be possible to extend this approach to z > 6 with current facilities, using C III] to measure redshifts of objects with IRAC excesses indicating EW[OIII]+Hβ≃2000 Å, providing a method of spectroscopic confirmation independent of Ly α

Explanation and relations. How do general practitioners deal with patients with persistent medically unexplained symptoms: a focus group study

Contains fulltext : 80758.pdf (publisher's version ) (Open Access)BACKGROUND: Persistent presentation of medically unexplained symptoms (MUS) is troublesome for general practitioners (GPs) and causes pressure on the doctor-patient relationship. As a consequence, GPs face the problem of establishing an ongoing, preferably effective relationship with these patients. This study aims at exploring GPs' perceptions about explaining MUS to patients and about how relationships with these patients evolve over time in daily practice. METHODS: A qualitative approach, interviewing a purposive sample of twenty-two Dutch GPs within five focus groups. Data were analyzed according to the principles of constant comparative analysis. RESULTS: GPs recognise the importance of an adequate explanation of the diagnosis of MUS but often feel incapable of being able to explain it clearly to their patients. GPs therefore indicate that they try to reassure patients in non-specific ways, for example by telling patients that there is no disease, by using metaphors and by normalizing the symptoms. When patients keep returning with MUS, GPs report the importance of maintaining the doctor-patient relationship. GPs describe three different models to do this; mutual alliance characterized by ritual care (e.g. regular physical examination, regular doctor visits) with approval of the patient and the doctor, ambivalent alliance characterized by ritual care without approval of the doctor and non-alliance characterized by cutting off all reasons for encounter in which symptoms are not of somatic origin. CONCLUSION: GPs feel difficulties in explaining the symptoms. GPs report that, when patients keep presenting with MUS, they focus on maintaining the doctor-patient relationship by using ritual care. In this care they meticulously balance between maintaining a good doctor-patient relationship and the prevention of unintended consequences of unnecessary interventions

Patients with persistent medically unexplained symptoms in general practice: characteristics and quality of care

<p>Abstract</p> <p>Background</p> <p>Medically unexplained physical symptoms (MUPS) are common in general practice (GP), and are even more problematic as they become persistent. The present study examines the relationship between persistent MUPS in general practice on the one hand and quality of life, social conditions, and coping on the other hand. Additionally, it is examined how patients with persistent MUPS evaluate the quality of GP-care.</p> <p>Methods</p> <p>Data were used from a representative survey of morbidity in Dutch general practice, in which data from the electronic medical records were extracted. A random sample of patients participated in an extensive health interview and completed self-reported measures on social isolation, coping and the quality of GP-care. Patients with persistent MUPS (N = 192) were compared with general practice patients not meeting the criteria for persistent MUPS (N = 7.314), and with a group of patients that visited the GP in comparable rates for medical diagnoses (N = 2.265). Multiple logistic regression analyses were used to control for relevant socio-demographic variables and chronic diseases.</p> <p>Results</p> <p>After adjustment for demographics and chronic diseases, patients with persistent MUPS reported more psychological distress, more functional impairment, more social isolation, and they evaluated the quality of GP-care less positive than the other two patient groups. Although the majority of MUPS patients were positive about the quality of GP-care, they more often felt that they were not taken seriously or not involved in treatment decisions, and more often reported that the GP did not take sufficient time. The three groups did not differ with respect to the statement that the GP unnecessarily explains physical problems as psychological ones.</p> <p>Conclusion</p> <p>Strengthening MUPS patients' social network and encouraging social activities may be a meaningful intervention in which the GP may play a stimulating role. To further improve MUPS patients' satisfaction with GP-care, GPs may pay extra attention to taking sufficient time when treating MUPS patients, taking the problems seriously, and involving them in treatment decisions.</p

Gap Junction Mediated Intercellular Metabolite Transfer in the Cochlea Is Compromised in Connexin30 Null Mice

Connexin26 (Cx26) and connexin30 (Cx30) are two major protein subunits that co-assemble to form gap junctions (GJs) in the cochlea. Mutations in either one of them are the major cause of non-syndromic prelingual deafness in humans. Because the mechanisms of cochlear pathogenesis caused by Cx mutations are unclear, we investigated effects of Cx30 null mutation on GJ-mediated ionic and metabolic coupling in the cochlea of mice. A novel flattened cochlear preparation was used to directly assess intercellular coupling in the sensory epithelium of the cochlea. Double-electrode patch clamp recordings revealed that the absence of Cx30 did not significantly change GJ conductance among the cochlear supporting cells. The preserved electrical coupling is consistent with immunolabeling data showing extensive Cx26 GJs in the cochlea of the mutant mice. In contrast, dye diffusion assays showed that the rate and extent of intercellular transfer of multiple fluorescent dyes (including a non-metabolizable D-glucose analogue, 2-NBDG) among cochlear supporting cells were severely reduced in Cx30 null mice. Since the sensory epithelium in the cochlea is an avascular organ, GJ-facilitated intercellular transfer of nutrient and signaling molecules may play essential roles in cellular homeostasis. To test this possibility, NBDG was used as a tracer to study the contribution of GJs in transporting glucose into the cochlear sensory epithelium when delivered systemically. NBDG uptake in cochlear supporting cells was significantly reduced in Cx30 null mice. The decrease was also observed with GJ blockers or glucose competition, supporting the specificity of our tests. These data indicate that GJs facilitate efficient uptake of glucose in the supporting cells. This study provides the first direct experimental evidence showing that the transfer of metabolically-important molecules in cochlear supporting cells is dependent on the normal function of GJs, thereby suggesting a novel pathogenesis process in the cochlea for Cx-mutation-linked deafness

What questions do patients undergoing lower extremity joint replacement surgery have?

BACKGROUND: The value of the Internet to deliver preoperative education would increase if there was variability in questions patients want answered. This study's goal was to have patients consulting an orthopedic surgeon about undergoing either a total hip arthroplasty (THA) or a total knee arthroplasty (TKA) rate the importance of different questions concerning their care. METHODS: We assembled questions patients might have about joint replacement surgery by analyzing the literature and querying a pilot group of patients and surgeons. Twenty-nine patients considering undergoing THA and 19 patients considering TKR completed a written survey asking them to rate 30 different questions, with a 5 point Likert scale from 1 (least important) – 5 (most important). RESULTS: For patients considering THA or TKR, the 4 highest rated questions were: Will the surgery affect my abilities to care for myself?, Am I going to need physical therapy?, How mobile will I be after my surgery?, When will I be able to walk normally again? The mean percentage disagreement was 42% for questions answered by TKR patients and 47% for the THA group. Some patients gave a high rating to questions lowly rated by the rest of the group. CONCLUSIONS: Although there was enough agreement to define a core set of questions that should be addressed with most patients considering THA or TKA, some of the remaining questions were also highly important to some patients. The Web may offer a flexible medium for accommodating this large variety of information needs