Laboratory measurements of the physics of auroral electron acceleration by Alfvén waves.

While the aurora has attracted attention for millennia, important questions remain unanswered. Foremost is how auroral electrons are accelerated before colliding with the ionosphere and producing auroral light. Powerful Alfvén waves are often found traveling Earthward above auroras with sufficient energy to generate auroras, but there has been no direct measurement of the processes by which Alfvén waves transfer their energy to auroral electrons. Here, we show laboratory measurements of the resonant transfer of energy from Alfvén waves to electrons under conditions relevant to the auroral zone. Experiments are performed by launching Alfvén waves and simultaneously recording the electron velocity distribution. Numerical simulations and analytical theory support that the measured energy transfer process produces accelerated electrons capable of reaching auroral energies. The experiments, theory, and simulations demonstrate a clear causal relationship between Alfvén waves and accelerated electrons that directly cause auroras.

The use of mechanical restraint in Pacific Rim countries: an international epidemiological study.

AIMS: The use of mechanical restraint is a challenging area for psychiatry. Although mechanical restraint remains accepted as standard practice in some regions, there are ethical, legal and medical reasons to minimise or abolish its use. These concerns have intensified following the Convention on the Rights of Persons with Disabilities. Despite national policies to reduce use, the reporting of mechanical restraint has been poor, hampering a reasonable understanding of the epidemiology of restraint. This paper aims to develop a consistent measure of mechanical restraint and compare the measure within and across countries in the Pacific Rim. METHODS: We used the publicly available data from four Pacific Rim countries (Australia, New Zealand, Japan and the United States) to compare and contrast the reported rates of mechanical restraint. Summary measures were computed so as to enable international comparisons. Variation within each jurisdiction was also analysed. RESULTS: International rates of mechanical restraint in 2017 varied from 0.03 (New Zealand) to 98.9 (Japan) restraint events per million population per day, a variation greater than 3000-fold. Restraint in Australia (0.17 events per million) and the United States (0.37 events per million) fell between these two extremes. Variation as measured by restraint events per 1000 bed-days was less extreme but still substantial. Within all four countries there was also significant variation in restraint across districts. Variation across time did not show a steady reduction in restraint in any country during the period for which data were available (starting from 2003 at the earliest). CONCLUSIONS: Policies to reduce or abolish mechanical restraint do not appear to be effecting change. It is improbable that the variation in restraint within the four examined Pacific Rim countries is accountable for by psychopathology. Greater efforts at reporting, monitoring and carrying out interventions to achieve the stated aim of reducing restraint are urgently needed.

Plasma Turbulence at Comet 67P/Churyumov-Gerasimenko: Rosetta Observations.

We perform a power spectral analysis of magnetic field fluctuations measured by the Rosetta spacecraft's magnetometer at comet 67P/Churyumov-Gerasimenko. We interpret the power spectral signatures in terms of plasma turbulent processes and discover that different turbulent processes are prominent during different active phases of the comet. During the weakly active phase of the comet, dominant injection is prominent at low frequencies near 10-2 Hz, while partial energy cascade or dispersion is prominent at high frequencies near 10-1 Hz. During the intermediately active phase, uniform injection is prominent at low frequencies, while partial energy cascade or dispersion is prominent at high frequencies. During the strongly active phase of the comet, we find that partial energy cascade or dissipation is dominant at low frequencies, while partial energy cascade, dissipation, or dispersion is dominant at high frequencies. We infer that the temporal variations of the turbulent processes occur due to the evolution of the plasma environment of the comet as it orbits the Sun.

Highly structured slow solar wind emerging from an equatorial coronal hole.

During the solar minimum, when the Sun is at its least active, the solar wind1,2 is observed at high latitudes as a predominantly fast (more than 500 kilometres per second), highly Alfvénic rarefied stream of plasma originating from deep within coronal holes. Closer to the ecliptic plane, the solar wind is interspersed with a more variable slow wind3 of less than 500 kilometres per second. The precise origins of the slow wind streams are less certain4; theories and observations suggest that they may originate at the tips of helmet streamers5,6, from interchange reconnection near coronal hole boundaries7,8, or within coronal holes with highly diverging magnetic fields9,10. The heating mechanism required to drive the solar wind is also unresolved, although candidate mechanisms include Alfvén-wave turbulence11,12, heating by reconnection in nanoflares13, ion cyclotron wave heating14 and acceleration by thermal gradients1. At a distance of one astronomical unit, the wind is mixed and evolved, and therefore much of the diagnostic structure of these sources and processes has been lost. Here we present observations from the Parker Solar Probe15 at 36 to 54 solar radii that show evidence of slow Alfvénic solar wind emerging from a small equatorial coronal hole. The measured magnetic field exhibits patches of large, intermittent reversals that are associated with jets of plasma and enhanced Poynting flux and that are interspersed in a smoother and less turbulent flow with a near-radial magnetic field. Furthermore, plasma-wave measurements suggest the existence of electron and ion velocity-space micro-instabilities10,16 that are associated with plasma heating and thermalization processes. Our measurements suggest that there is an impulsive mechanism associated with solar-wind energization and that micro-instabilities play a part in heating, and we provide evidence that low-latitude coronal holes are a key source of the slow solar wind.

Evidence for electron Landau damping in space plasma turbulence.

How turbulent energy is dissipated in weakly collisional space and astrophysical plasmas is a major open question. Here, we present the application of a field-particle correlation technique to directly measure the transfer of energy between the turbulent electromagnetic field and electrons in the Earth's magnetosheath, the region of solar wind downstream of the Earth's bow shock. The measurement of the secular energy transfer from the parallel electric field as a function of electron velocity shows a signature consistent with Landau damping. This signature is coherent over time, close to the predicted resonant velocity, similar to that seen in kinetic Alfven turbulence simulations, and disappears under phase randomisation. This suggests that electron Landau damping could play a significant role in turbulent plasma heating, and that the technique is a valuable tool for determining the particle energisation processes operating in space and astrophysical plasmas.

Clinical Neuroscience in Practice: An Experiential Learning Course for Undergraduates Offered by Neurosurgeons and Neuroscientists.

Many pre-health students pursue extracurricular shadowing opportunities to gain clinical experience. The Virginia Tech School of Neuroscience introduced a formal course that provides a clinical experience superior to that received by many medical students. This course is composed of weekly 75-minute seminars that cover diseases affecting the nervous system, their diagnosis and treatment, complemented by weekly half-day intensive clinical experiences with unprecedented access to a team of neurosurgeons (in hospital operating rooms, Intensive Care Units, emergency room, angiographic suites, and wards). In the operating rooms, students routinely "scrub-in" for complex surgeries. On hospital rounds, students experience direct patient care and receive in-depth exposure to modern nervous system imaging. Students participate in two 24-hour "on-call" experiences with team providers. After call, students participate in cognitive and psychological studies to assess physiological and psychological effects of call-related sleep deprivation. Students prepare weekly essays on challenging socioeconomic and ethical questions, exploring subjects such as the cost of medicine and inequalities in access to health care. Towards the end of the course, students meet with the admission dean of the Virginia Tech Carilion medical school; they prepare a personal statement for medical school/graduate school applications, and attend a half-day block of mock medical school/graduate school interviews delivered by experienced clinicians. In lieu of a final exam, each student presents to the entire neurosurgery department, an in-depth clinical analysis of a case in which they participated. We provide details on implementation, challenges and outcomes based on experiences from three semesters with a total enrollment of approximately 60 students.

Relation between age of first drinking and mental health and alcohol and drug disorders in adulthood: evidence from a 35-year cohort study.

AIMS: To estimate associations between age of first drinking (AFD) and alcohol use disorder, nicotine dependence, cannabis dependence, illicit drug dependence, major depression and anxiety disorder in adulthood, net of a series of covariate factors. DESIGN: Data were obtained from a longitudinal birth cohort. SETTING: Christchurch, New Zealand. PARTICIPANTS: The Christchurch Health Development Study (CHDS), a longitudinal study of a cohort born in 1977 and studied to age 35 years. Analysis samples ranged in size from 1056 (ages 11-13 years) to 962 (age 35 years); 50.2% of the total sample was male. MEASUREMENTS: A measure of AFD (ages 5-13+ years) was generated using latent class analysis. Outcome measures included: major depression, anxiety disorders, alcohol use disorder, nicotine dependence, cannabis dependence and other illicit drug dependence during the period 15-35 years. Covariate factors measured during childhood included family socio-economic status, family functioning, parental alcohol-related attitudes/behaviours and individual factors. FINDINGS: Earlier AFD was associated significantly (P < 0.05) with increased risk of later alcohol use disorders, nicotine dependence and illicit drug dependence, and was associated marginally (P < 0.10) with cannabis dependence, but not depression or anxiety disorder. After controlling for covariate factors, the associations between AFD and outcomes were no longer statistically significant [alcohol use disorder: B = -0.07, 95% confidence interval (CI) = -0.22, 0.08; nicotine dependence: B = -0.15, 95% CI = -0.34, 0.04; illicit drug dependence: B = -0.29, 95% CI = -0.73, 0.15; cannabis dependence: B = -0.05, 95% CI = -0.31, 0.22]. CONCLUSIONS: The associations between age of first drinking and later alcohol/drug disorders appear to be accounted for at least to some degree by factors related to characteristics of the individual and family during childhood.

Multiscale Nature of the Dissipation Range in Gyrokinetic Simulations of Alfvénic Turbulence.

Nonlinear energy transfer and dissipation in Alfvén wave turbulence are analyzed in the first gyrokinetic simulation spanning all scales from the tail of the MHD range to the electron gyroradius scale. For typical solar wind parameters at 1 AU, about 30% of the nonlinear energy transfer close to the electron gyroradius scale is mediated by modes in the tail of the MHD cascade. Collisional dissipation occurs across the entire kinetic range k(⊥)ρ(I)≳1. Both mechanisms thus act on multiple coupled scales, which have to be retained for a comprehensive picture of the dissipation range in Alfvénic turbulence.

A dynamical model of plasma turbulence in the solar wind.

A dynamical approach, rather than the usual statistical approach, is taken to explore the physical mechanisms underlying the nonlinear transfer of energy, the damping of the turbulent fluctuations, and the development of coherent structures in kinetic plasma turbulence. It is argued that the linear and nonlinear dynamics of Alfvén waves are responsible, at a very fundamental level, for some of the key qualitative features of plasma turbulence that distinguish it from hydrodynamic turbulence, including the anisotropic cascade of energy and the development of current sheets at small scales. The first dynamical model of kinetic turbulence in the weakly collisional solar wind plasma that combines self-consistently the physics of Alfvén waves with the development of small-scale current sheets is presented and its physical implications are discussed. This model leads to a simplified perspective on the nature of turbulence in a weakly collisional plasma: the nonlinear interactions responsible for the turbulent cascade of energy and the formation of current sheets are essentially fluid in nature, while the collisionless damping of the turbulent fluctuations and the energy injection by kinetic instabilities are essentially kinetic in nature.

Toward astrophysical turbulence in the laboratory.

Turbulence is a ubiquitous phenomenon in space and astrophysical plasmas, driving a cascade of energy from large to small scales and strongly influencing the plasma heating resulting from the dissipation of the turbulence. Modern theories of plasma turbulence are based on the fundamental concept that the turbulent cascade of energy is caused by the nonlinear interaction between counterpropagating Alfvén waves, yet this interaction has never been observationally or experimentally verified. We present here the first experimental measurement in a laboratory plasma of the nonlinear interaction between counterpropagating Alfvén waves, the fundamental building block of astrophysical plasma turbulence. This measurement establishes a firm basis for the application of theoretical ideas developed in idealized models to turbulence in realistic space and astrophysical plasma systems.

Design and use of an Elsässer probe for analysis of Alfvén wave fields according to wave direction.

We have designed an electric and magnetic field probe which simultaneously measure both quantities in the directions perpendicular to the background magnetic field for application to Alfvén wave experiments in the Large Plasma Device at UCLA. This new probe allows for the projection of measured wave fields onto generalized Elsässer variables. Experiments were conducted in a singly ionized He plasma at 1850 G in which propagation of Alfvén waves was observed using this new probe. We demonstrate that a clear separation of transmitted and reflected signals and determination of Poynting flux and Elsässer variables can be achieved.

Gyrokinetic simulations of solar wind turbulence from ion to electron scales.

A three-dimensional, nonlinear gyrokinetic simulation of plasma turbulence resolving scales from the ion to electron gyroradius with a realistic mass ratio is presented, where all damping is provided by resolved physical mechanisms. The resulting energy spectra are quantitatively consistent with a magnetic power spectrum scaling of k(-2.8) as observed in in situ spacecraft measurements of the "dissipation range" of solar wind turbulence. Despite the strongly nonlinear nature of the turbulence, the linear kinetic Alfvén wave mode quantitatively describes the polarization of the turbulent fluctuations. The collisional ion heating is measured at subion-Larmor radius scales, which provides evidence of the ion entropy cascade in an electromagnetic turbulence simulation.

Nonlinear phase mixing and phase-space cascade of entropy in gyrokinetic plasma turbulence.

Electrostatic turbulence in weakly collisional, magnetized plasma can be interpreted as a cascade of entropy in phase space, which is proposed as a universal mechanism for dissipation of energy in magnetized plasma turbulence. When the nonlinear decorrelation time at the scale of the thermal Larmor radius is shorter than the collision time, a broad spectrum of fluctuations at sub-Larmor scales is numerically found in velocity and position space, with theoretically predicted scalings. The results are important because they identify what is probably a universal Kolmogorov-like regime for kinetic turbulence; and because any physical process that produces fluctuations of the gyrophase-independent part of the distribution function may, via the entropy cascade, result in turbulent heating at a rate that increases with the fluctuation amplitude, but is independent of the collision frequency.

Community mental health teams for people with severe mental illnesses and disordered personality.

BACKGROUND: Closure of asylums and institutions for the mentally ill, coupled with government policies focusing on reducing the number of hospital beds for people with severe mental illness in favor of providing care in a variety of nonhospital settings, underpins the rationale behind care in the community. A major thrust toward community care has been the development of community mental health teams.

Magnetic fluctuation power near proton temperature anisotropy instability thresholds in the solar wind.

The proton temperature anisotropy in the solar wind is known to be constrained by the theoretical thresholds for pressure-anisotropy-driven instabilities. Here, we use approximately 1x10;{6} independent measurements of gyroscale magnetic fluctuations in the solar wind to show for the first time that these fluctuations are enhanced along the temperature anisotropy thresholds of the mirror, proton oblique firehose, and ion cyclotron instabilities. In addition, the measured magnetic compressibility is enhanced at high plasma beta (beta_{ parallel} greater, similar1) along the mirror instability threshold but small elsewhere, consistent with expectations of the mirror mode. We also show that the short wavelength magnetic fluctuation power is a strong function of collisionality, which relaxes the temperature anisotropy away from the instability conditions and reduces correspondingly the fluctuation power.

Kinetic simulations of magnetized turbulence in astrophysical plasmas.

This Letter presents the first ab initio, fully electromagnetic, kinetic simulations of magnetized turbulence in a homogeneous, weakly collisional plasma at the scale of the ion Larmor radius (ion gyroscale). Magnetic- and electric-field energy spectra show a break at the ion gyroscale; the spectral slopes are consistent with scaling predictions for critically balanced turbulence of Alfvén waves above the ion gyroscale (spectral index -5/3) and of kinetic Alfvén waves below the ion gyroscale (spectral indices of -7/3 for magnetic and -1/3 for electric fluctuations). This behavior is also qualitatively consistent with in situ measurements of turbulence in the solar wind. Our findings support the hypothesis that the frequencies of turbulent fluctuations in the solar wind remain well below the ion cyclotron frequency both above and below the ion gyroscale.

The prevalence of personality disorder in schizophrenia and psychotic disorders: systematic review of rates and explanatory modelling.

BACKGROUND: Personality disorder (PD) in psychosis is poorly studied. As PD can affect outcome in mental disorders, it is important to understand its prevalence in order to plan services, understand prognosis more fully and maximize management options. MethodLiterature searching revealed 3972 potential papers. Twenty papers including 6345 patients were included in the final analysis. There was great variation in prevalence and multilevel modelling was used to identify possible reasons for this heterogeneity. RESULTS: The prevalence of PD varied from 4.5% to 100%. Multilevel analysis suggested country of study, study type, the instruments used to diagnose PD and patient care correlated with the prevalence data explaining the study level heterogeneity, with 34.2, 33.4, 17.0 and 4.5% by each variable respectively. Personality studies in Canada and Sweden reported lower PD prevalence, whereas in Spain it was higher than the multinational study. Compared with randomized controlled trials, case-control studies reported lower prevalence [odds ratio (OR)=0.35, 95% confidence interval (CI) 0.15-0.79] and observational studies higher prevalence (OR 70.5, 95% CI 8.5-583). Primary-care patients were less likely to be diagnosed (OR 0.02, 95% CI 0-0.19) than hospital patients, and out-patients had higher prevalence (OR 12.5, 95% CI 1.77-88.6). CONCLUSIONS: The reported prevalence of PD in schizophrenia varies significantly. Statistical modelling suggests care, country, study type and diagnostic tools for PD all bias prevalence rates. The number of papers reaching the inclusion criteria, the relative paucity of information and the difficulties in developing an accurate statistical model limited interpretation from the study.

Equipos comunitarios de salud mental (ECSM) para personas con enfermedades mentales graves y trastornos de personalidad

Antecedentes: El cierre de asilos e instituciones para pacientes con enfermedades mentales, acompañado de las políticas gubernamentales que se centran en la reducción del número de camas hospitalarias para los pacientes con enfermedades mentales graves y que están a favor de la prestación de asistencia en una variedad de ámbitos extrahospitalarios, respalda el fundamento para la atención comunitaria. Un paso importante hacia la atención comunitaria ha sido el desarrollo de equipos comunitarios de salud mental (ECSM). Objetivos: Evaluar la efectividad de los Equipos Comunitarios de Salud Mental (ECSM) en el tratamiento de cualquier tipo de enfermedad mental grave en comparación con el tratamiento estándar de estas enfermedades sin estos equipos. (AU)

Community mental health teams (CMHTs) for people with severe mental illnesses and disordered personality.

BACKGROUND: Closure of asylums and institutions for the mentally ill, coupled with government policies focusing on reducing the number of hospital beds for people with severe mental illness in favour of providing care in a variety of non-hospital settings, underpins the rationale behind care in the community. A major thrust towards community care has been the development of community mental health teams (CMHT). OBJECTIVES: To evaluate the effects of community mental health team (CMHT) treatment for anyone with serious mental illness compared with standard non-team management. SEARCH STRATEGY: We searched The Cochrane Schizophrenia Group Trials Register (March 2006). We manually searched the Journal of Personality Disorders, and contacted colleagues at ENMESH, ISSPD and in forensic psychiatry. SELECTION CRITERIA: We included all randomised controlled trials of CMHT management versus non-team standard care. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis, based on a fixed effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated weighted mean differences (WMD) again based on a fixed effects model. MAIN RESULTS: CMHT management did not reveal any statistically significant difference in death by suicide and in suspicious circumstances (n=587, 3 RCTs, RR 0.49 CI 0.1 to 2.2) although overall, fewer deaths occurred in the CMHT group. We found no significant differences in the number of people leaving the studies early (n=253, 2 RCTs, RR 1.10 CI 0.7 to 1.8). Significantly fewer people in the CMHT group were not satisfied with services compared with those receiving standard care (n=87, RR 0.37 CI 0.2 to 0.8, NNT 4 CI 3 to 11). Also, hospital admission rates were significantly lower in the CMHT group (n=587, 3 RCTs, RR 0.81 CI 0.7 to 1.0, NNT 17 CI 10 to 104) compared with standard care. Admittance to accident and emergency services, contact with primary care, and contact with social services did not reveal any statistical difference between comparison groups. AUTHORS' CONCLUSIONS: Community mental health team management is not inferior to non-team standard care in any important respects and is superior in promoting greater acceptance of treatment. It may also be superior in reducing hospital admission and avoiding death by suicide. The evidence for CMHT based care is insubstantial considering the massive impact the drive toward community care has on patients, carers, clinicians and the community at large.

Stereotactic 14G core biopsy of non-palpable breast cancer: what is the relationship between the number of core samples taken and the sensitivity for detection of malignancy?

AIM: Percutaneous 14-gauge core biopsy (CB) guided by digital stereotactic mammography is now an established technique in the investigation of women with non-palpable suspicious mammographic lesions. Diagnostic sensitivity of CB is affected both by the nature of the mammographic abnormality and by the number of core samples taken. METHODS AND RESULTS: A retrospective review of 500 women who have undergone CB in our institution showed that in 235 cases, invasive or non-invasive carcinoma was found on final surgical histology. Correlation between CB result and surgical histology revealed a significant increase in sensitivity for the diagnosis of malignancy if a larger number of cores were taken (84.3% for two cores and 90.2% for five cores vs. 97.9% for six or more cores). This trend was maintained when patients were subdivided according to mammographic abnormality, either soft tissue mass or microcalcifications. The effect on diagnostic sensitivity of increasing the number of tissue cores obtained was most pronounced in patients with microcalcifications graded as low or moderately suspicious for malignancy (70.1% for two cores and 79.1% for five cores vs 94.0% for six or more cores). The presence of an invasive component in a malignant lesion was correctly diagnosed using CB in 79.2% overall if at least six cores were taken. If the mammographic lesion was a soft tissue mass, this figure rose to 95.7%, but was only 35.7% if the visible lesion was composed of microcalcifications alone. CONCLUSION: Our series confirms the reliability of stereotactic CB in the diagnosis of breast carcinoma. Diagnostic sensitivity is improved by increasing the number of cores taken (to six or more), particularly in women with mammographic microcalcifications of an equivocal nature.