Precursory scale increase and long-term seismogenesis in California and Northern Mexico

A sudden increase in the scale of seismicity has occurred as a long-term precursor to twelve major earthquakes in California and Northern Mexico. These include all earthquakes along the San Andreas system during 1960-2000 with magnitude M •6.4. The full list is as follows: Colorado Delta, 1966, M 6.3; Borrego Mt., 1968, M 6.5; San Fernando, 1971, M 6.6; Brawley, 1979, M 6.4; Mexicali, 1980, M 6.1; Coalinga, 1983, M 6.7; Superstition Hills, 1987, M 6.6; Loma Prieta, 1989, M 7.0; Joshua Tree, 1992, M 6.1; Landers, 1992, M 7.3; Northridge, 1994, M 6.6; Hector Mine, 1999, M 7.1. Such a Precursory Scale Increase () was inferred from the modelling of long-term seismogenesis as a three-stage faulting process against a background of self-organised criticality. The location, onset-time and level of • are predictive of the location, time and magnitude of the future earthquake. Precursory swarms, which occur widely in subduction regions, are a special form of • ; the more general form is here shownto occur frequently in a region of continental transform. Other seismicity precursors, including quiescence and foreshocks, contribute to or modulate the increased seismicity that characterises • . The area occupied by • is small compared with those occupied by the seismicity precursors known as AMR, M8 and LURR. Further work is needed to formulate as a testable hypothesis, and to carry out the appropriate forecasting tests

Bath's law Derived from the Gutenberg-Richter law and from Aftershock Properties

The empirical Bath's law states that the average difference in magnitude between a mainshock and its largest aftershock is 1.2, regardless of the mainshock magnitude. Following Vere-Jones [1969] and Console et al. [2003], we show that the origin of Bath's law is to be found in the selection procedure used to define mainshocks and aftershocks rather than in any difference in the mechanisms controlling the magnitude of the mainshock and of the aftershocks. We use the ETAS model of seismicity, which provides a more realistic model of aftershocks, based on (i) a universal Gutenberg-Richter (GR) law for all earthquakes, and on (ii) the increase of the number of aftershocks with the mainshock magnitude. Using numerical simulations of the ETAS model, we show that this model is in good agreement with Bath's law in a certain range of the model parameters.Comment: major revisions, in press in Geophys. Res. Let

No evidence for tactile communication of direction in foraging Lasius ants

The idea that ants communicate when meeting on a trail is beguiling, but evidence for this is scarce. Physical communication in ants has been demonstrated to play a role as a modulator of behaviours such as alarm and recruitment. Honeybees can communicate the location of a resource using an advanced motor display – the waggle dance. However, no equivalent of the waggle dance has been described for any ant species, and it is widely believed that ants cannot communicate the location of resources using motor displays. One group of researchers report several demonstrations of such communication in Formica ants; however, these results have been largely ignored. More recently some evidence arose that Lasius niger foragers returning from a food source can communicate to outgoing foragers the direction that should be taken at the next bifurcation by means of physical contact on the trail. Here, we make a concerted effort to replicate these results. Although initial results seemed to indicate physical communication, once stringent controls to eliminate pheromone cues were put in place, no evidence for physical communication of food location could be found. This null result was replicated independently by a different research group on a closely related species, L. neglectus. We conclude that neither L. niger nor L. neglectus foragers communicate resource location using physical contact. Our results increase the burden of proof required for other claims of physical communication of direction in ants, but do not completely rule out this possibility

Coding accuracy for Parkinson's disease hospital admissions:implications for healthcare planning in the UK

ObjectivesHospital Episode Statistics data are used for healthcare planning and hospital reimbursements. Reliability of these data is dependent on the accuracy of individual hospitals reporting Secondary Uses Service (SUS) which includes hospitalisation. The number and coding accuracy for Parkinson's disease hospital admissions at a tertiary centre in Birmingham was assessed.Study designRetrospective, routine-data–based study.MethodsA retrospective electronic database search for all Parkinson's disease patients admitted to the tertiary hospital over a 4-year period (2009–2013) was performed on the SUS database using International Classification of Disease codes, and on the local inpatient electronic prescription database, Prescription and Information Communications System, using medication prescriptions. Capture-recapture methods were used to estimate the number of patients and admissions missed by both databases.ResultsFrom the two databases, between July 2009 and June 2013, 1068 patients with Parkinson's disease accounted for 1999 admissions. During these admissions, the Parkinson's disease was coded as a primary or secondary diagnosis. Ninety-one percent of these admissions were recorded on the SUS database. Capture-recapture methods estimated that the number of Parkinson's disease patients admitted during this period was 1127 patients (95% confidence interval: 1107–1146). A supplementary search of both SUS and Prescription and Information Communications System was undertaken using the hospital numbers of these 1068 patients. This identified another 479 admissions. SUS database under-estimated Parkinson's disease admissions by 27% during the study period.ConclusionThe accuracy of disease coding is critical for healthcare policy planning and must be improved. If the under-reporting of Parkinson's disease admissions on the SUS database is repeated nationally, expenditure on Parkinson's disease admissions in England is under-estimated by approximately £61 million per year

Mental health in hospital emergency departments: cross-sectional analysis of attendances in England 2013/2014

Objective: To describe the population of patients who attend emergency departments (ED) in England for mental health reasons. / Methods: Cross-sectional observational study of 6 262 602 ED attendances at NHS (National Health Service) hospitals in England between 1 April 2013 and 31 March 2014. We assessed the proportion of attendances due to psychiatric conditions. We compared patient sociodemographic and attendance characteristics for mental health and non-mental health attendances using logistic regression. / Results: 4.2% of ED attendances were attributable to mental health conditions (median 3.2%, IQR 2.6% to 4.1%). Those attending for mental health reasons were typically younger (76.3% were aged less than 50 years), of White British ethnicity (73.2% White British), and resident in more deprived areas (59.9% from the two most deprived Index of Multiple Deprivation quintiles (4 and 5)). Mental health attendances were more likely to occur ‘out of hours’ (68.0%) and at the weekend (31.3%). Almost two-thirds were brought in by ambulance. A third required admission, but around a half were discharged home. / Conclusions: This is the first national study of mental health attendances at EDs in England. We provide information for those planning and providing care, to ensure that clinical resources meet the needs of this patient group, who comprise 4.2% of attendances. In particular, we highlight the need to strengthen the availability of hospital and community care ‘out of hours.

‘Sons of athelings given to the earth’: Infant Mortality within Anglo-Saxon Mortuary Geography

FOR 20 OR MORE YEARS early Anglo-Saxon archaeologists have believed children are underrepresented in the cemetery evidence. They conclude that excavation misses small bones, that previous attitudes to reporting overlook the very young, or that infants and children were buried elsewhere. This is all well and good, but we must be careful of oversimplifying compound social and cultural responses to childhood and infant mortality. Previous approaches have offered methodological quandaries in the face of this under-representation. However, proportionally more infants were placed in large cemeteries and sometimes in specific zones. This trend is statistically significant and is therefore unlikely to result entirely from preservation or excavation problems. Early medieval cemeteries were part of regional mortuary geographies and provided places to stage events that promoted social cohesion across kinship systems extending over tribal territories. This paper argues that patterns in early Anglo-Saxon infant burial were the result of female mobility. Many women probably travelled locally to marry in a union which reinforced existing social networks. For an expectant mother, however, the safest place to give birth was with experience women in her maternal home. Infant identities were affected by personal and legal association with their mother’s parental kindred, so when an infant died in childbirth or months and years later, it was their mother’s identity which dictated burial location. As a result, cemeteries central to tribal identities became places to bury the sons and daughters of a regional tribal aristocracy

Symmetry breaking in mass-recruiting ants: extent of foraging biases depends on resource quality

The communication involved in the foraging behaviour of social insects is integral to their success. Many ant species use trail pheromones to make decisions about where to forage. The strong positive feedback caused by the trail pheromone is thought to create a decision between two or more options. When the two options are of identical quality, this is known as symmetry breaking, and is important because it helps colonies to monopolise food sources in a competitive environment. Symmetry breaking is thought to increase with the quantity of pheromone deposited by ants, but empirical studies exploring the factors affecting symmetry breaking are limited. Here, we tested if (i) greater disparity between two food sources increased the degree to which a higher quality food source is favoured and (ii) if the quality of identical food sources would affect the degree of symmetry breaking that occurs. Using the mass-recruiting Pharaoh ant, Monomorium pharaonis, we carried out binary choice tests to investigate how food quality affects the choice and distribution of colony foraging decisions. We found that colonies could coordinate foraging to exploit food sources of greater quality, and a greater contrast in quality between the food sources created a stronger collective decision. Contrary to prediction, we found that symmetry breaking decreased as the quality of two identical food sources increased. We discuss how stochastic effects might lead to relatively strong differences in the amount of pheromone on alternative routes when food source quality is low. Significance statement: Pheromones used by social insects should guide a colony via positive feedback to distribute colony members at resources in the most adaptive way given the current environment. This study shows that when food resources are of equal quality, Pharaoh ant foragers distribute themselves more evenly if the two food sources are both of high quality compared to if both are of low quality. The results highlight the way in which individual ants can modulate their response to pheromone trails which may lead colonies to exploiting resources more evenly when in a resource rich environment

Proposed quality indicators and recommended standard reporting items in performance of EBUS bronchoscopy: An official world association for bronchology and interventional pulmonology expert panel consensus statement

Background: Since their introduction, both linear and radial endobronchial ultrasound (EBUS) have become an integral component of the practice of Pulmonology and Thoracic Oncology. The quality of health care can be measured by comparing the performance of an individual or a health service with an ideal threshold or benchmark. The taskforce sought to evaluate quality indicators in EBUS bronchoscopy based on clinical relevance/importance and on the basis that observed significant variation in outcomes indicates potential for improvement in health care outcomes. Methods: A comprehensive literature review informed the composition of a comprehensive list of candidate quality indicators in EBUS. A multiple-round modified Delphi consensus process was subsequently performed with the aim of reaching consensus over a final list of quality indicators and performance targets for these indicators. Standard reporting items were developed, with a strong preference for items where evidence demonstrates a relationship with quality indicator outcomes. Results: Twelve quality Indicators are proposed, with performance targets supported by evidence from the literature. Standardized reporting items for both radial and linear EBUS are recommended, with evidence supporting their utility in assessing procedural outcomes presented. Conclusion: This statement is intended to provide a framework for individual proceduralists to assess the quality of EBUS they provide their patients through the identification of clinically relevant, feasible quality measures. Emphasis is placed on outcome measures, with a preference for consistent terminology to allow communication and benchmarking between centres