Invariant lengths using existing Special Relativity

A field of random space-time events exhibiting complete spatial-temporal randomness appears statistically identical to all observers. Boost invariant lengths naturally emerge when we examine fluctuation scales of this field such as the nearest neighbor distance. If we interpret Planck's length as the characteristic fluctuation scale of quantum gravity, its boost invariance can then be understood without modifying Special Relativity.Comment: 5 pages, no figure

Statistical complexity of reasons for encounter in high users of out of hours primary care:analysis of a national service

Background: Managing demand for urgent and unscheduled care is a major problem for health services globally. A particular issue is that some patients appear to make heavy use of services, including primary care out of hours. We hypothesised that greater variation (statistical complexity) in reasons for attending primary care out of hours services may be a useful marker of patients at high risk of ongoing heavy service use. Methods: We analysed an anonymised dataset of contacts with the primary care out of hours care for Scotland in 2011. This contained 120,395 contacts from 13,981 high-using patients who made 5 or more contacts during a calendar year. We allocated the stated reason for each encounter into one of 14 categories. For each patient we calculated measures of statistical complexity of reasons for encounter including the count of different categories, Herfindahl index and statistical entropy of either the categories themselves, or the category transitions. We examined the association of these measures of statistical complexity with patient and healthcare use characteristics. Results: The high users comprised 2.4% of adults using the service and accounted for 15% of all contacts. Statistical complexity (as entropy of categories) increased with number of contacts but was not substantially influenced by either patient age or sex. This lack of association with age was unexpected as with increasing multi-morbidity one would expect greater variability in reason for encounter. Between 5 and 10 consultations, higher entropy was associated with a reduced likelihood of further consultations. In contrast, the occurrence of one or more contacts for a mental health problem was associated with increased likelihood of further consultations. Conclusion: Complexity of reason for encounter can be estimated in an out of hours primary care setting. Similar levels of statistical complexity are seen in younger and older adults (suggesting that it is more to do with consultation behaviour than morbidity) but it is not a predictor of ongoing high use of urgent care.</p

Do healthcare services behave as complex systems? Analysis of patterns of attendance and implications for service delivery

Background: The science of complex systems has been proposed as a way of understanding health services and the demand for them, but there is little quantitative evidence to support this. We analysed patterns of healthcare use in different urgent care settings to see if they showed two characteristic statistical features of complex systems: heavy-tailed distributions (including the inverse power law) and generative burst patterns. Methods: We conducted three linked studies. In study 1 we analysed the distribution of number of contacts per patient with an urgent care service in two settings: emergency department (ED) and primary care out-of-hours (PCOOH) services. We hypothesised that these distributions should be heavy-tailed (inverse power law or log-normal) in keeping with typical complex systems. In study 2 we analysed the distribution of bursts of contact with urgent care services by individuals: correlated bursts of activity occur in complex systems and represent a mechanism by which overall heavy-tailed distributions arise. In study 3 we replicated the approach of study 1 using data systematically identified from published sources. Results: Study 1 involved data from a PCOOH service in Scotland (725,000) adults, 1.1 million contacts) and an ED in New Zealand (60,000 adults, 98,000 contacts). The total number of contacts per individual in each dataset was statistically indistinguishable from an inverse power law (p &gt; 0.05) above 4 contacts for the PCOOH data and 3 contacts for the ED data. Study 2 found the distribution of contact bursts closely followed a heavy-tailed distribution (p &lt; 0.008), indicating the presence of correlated bursts. Study 3 identified data from 17 studies across 8 countries and found distributions similar to study 1 in all of them. Conclusions: Urgent healthcare use displays characteristic statistical features of large complex systems. These studies provide strong quantitative evidence that healthcare services behave as complex systems and have important implications for urgent care. Interventions to manage demand must address drivers for consultation across the whole system: focusing on only the highest users (in the tail of the distribution) will have limited impact on efficiency. Bursts of attendance - and ways to shorten them - represent promising targets for managing demand.</p

Self-Reported Health Among Sexual Minorities in the United States

Previous literature on LGBTQ+ people (lesbian, gay, bisexual, transgender, queer/questioning, and other sexual minorities) reports that this community experiences greater health problems than heterosexuals. LGBTQ+ people experience higher rates of chronic conditions, STIs, addiction, poor mental health, and cancer, which highlights the importance of capturing data regarding health. A growing concern is that social surveys fail to find meaningful ways to gather gender and sexuality data to understand possible health disparities for LGBTQ+ people. This study uses data from the General Social Survey to examine the physical and mental health outcomes of LGB people compared to straight people in a nationally representative sample of Americans. An analysis of potential disparities in the self-reported health of straight and LGB respondents finds that respondents who identified as bisexual reported significantly lower levels of self-rated health and more problems with mental health compared to respondents who identified as gay, lesbian, or heterosexual

A primary care Symptoms Clinic for patients with medically unexplained symptoms : pilot randomised trial

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The Effects of Stocking Density and Feeding Frequency on Aggressive and Cannibalistic Behaviors in Larval Hatchery-Reared Spotted Seatrout, \u3ci\u3eCynosion nebulosus\u3c/i\u3e

The Spotted Seatrout (Cynoscion nebulosus) is a euryhaline fish that inhabits coastal regions from Massachusetts to Texas. Due to its predaceous nature and proximity to coastal shorelines it is the most important marine finfish in the Gulf of Mexico. Because of this importance, Spotted Seatrout has been identified as a possible candidate for stock enhancement. Stock enhancement is the practice of releasing hatchery-reared juveniles to increase local recruitment beyond existing levels. However, raising enough Spotted Seatrout in an intensive aquaculture system has proven difficult due to aggression and cannibalism during the larval stages. The manipulation of stocking density as well as feeding frequency might be used to reduce aggression and cannibalism. The goal of this study was to determine the effects of stocking density and feeding frequency on aggressive and cannibalistic behaviors in larval hatchery-reared Spotted Seatrout at both small-and production-scales. For the first two small-scale experiments, fish larvae were filmed and behaviors were quantified. Three different aggressive behaviors were quantified: nip (aggressor strikes prey causing prey to dart), chase (aggressor moves more than one body length toward prey), and capture (predator captures and holds prey but unable to consume). From these experiments, the author found that in all stocking densities (15, 30, and 60 fish L-1) there was a significant increase in aggression and cannibalism with time since feeding; and the author identified a density threshold of 30 fish L-1, beyond which the intensity of aggressive behaviors did not increase. These results implied that aggression in early stage hatchery-reared Spotted Seatrout might be alleviated by increasing feeding frequency, and furthermore, the Spotted Seatrout possibly could be cultured at densities higher than the current protocol allows. From the second experiment, the author concluded that the 2 h feeding frequency treatment elicited fewer aggressive and cannibalistic acts than the 1 h, 4 h, and 8 h treatments. Lower levels of aggression and cannibalism associated with the 2 h feeding frequency treatment could be attributed to a balance between the optimal amount of live feed and the gut evacuation rate of larval Spotted Seatrout. In the third large-scale production experiment, I found a significantly lower per capita mortality and correspondingly higher specific growth rate for the 30 fish L-1 treatment than for the lower density 15 fish L-1 treatment. This difference resulted in a 45% higher production yield within the high density treatment. Due to logistical constraints, only two replicates were available for the production experiment. Thus, the statistical power of this experiment was low; however, directional trends consistently suggested biological importance. Feeding every 2 h suggested an apparent decrease in per capita mortality, leading to a 15% increase in production. The observed higher specific growth in the high density treatment likely reflected a decrease in aggression. Also, size heterogeneity did not differ between density treatments, reinforcing the case that using a higher stocking density and a 2 h feeding frequency schedule should be ideal for the production of larval Spotted Seatrout. Overall, the results from the production-scale run were consistent with the results of the two earlier small-scale experiments, suggesting that a stocking density of 30 fish L-1 and a feeding frequency of 2 h should be effective for reducing aggression and cannibalism in the culture of Spotted Seatrout

A taxonomy of explanations in a general practitioner clinic for patients with persistent “medically unexplained” physical symptoms

MSS1 and MSS2 were supported by grants from the Chief Scientist Office of the Scottish Government (references CZG/2/412 and CZH/4/945). We are grateful to the general practitioners and patients who participated in these studies.Peer reviewedPostprin