Simultaneous multi-frequency single-pulse properties of AXP XTE J1810-197

We have used the 76-m Lovell, 94-m equivalent WSRT and 100-m Effelsberg radio telescopes to investigate the simultaneous single-pulse properties of the radio emitting magnetar AXP XTE J1810-197 at frequencies of 1.4, 4.8 and 8.35 GHz during May and July 2006. We study the magnetar's pulse-energy distributions which are found to be very peculiar as they are changing on time-scales of days and cannot be fit by a single statistical model. The magnetar exhibits strong spiky single giant-pulse-like subpulses, but they do not fit the definition of the giant pulse or giant micropulse phenomena. Measurements of the longitude-resolved modulation index reveal a high degree of intensity fluctuations on day-to-day time-scales and dramatic changes across pulse phase. We find the frequency evolution of the modulation index values differs significantly from what is observed in normal radio pulsars. We find that no regular drifting subpulse phenomenon is present at any of the observed frequencies at any observing epoch. However, we find a quasi-periodicity of the subpulses present in the majority of the observing sessions. A correlation analysis indicates a relationship between components from different frequencies. We discuss the results of our analysis in light of the emission properties of normal radio pulsars and a recently proposed model which takes radio emission from magnetars into consideration.Comment: 15 pages, 11 figures, accepted for publication by MNRA

Perspectives on next steps in classification of oro-facial pain - Part 3: biomarkers of chronic oro-facial pain - from research to clinic

The purpose of this study was to review the current status of biomarkers used in oro-facial pain conditions. Specifically, we critically appraise their relative strengths and weaknesses for assessing mechanisms associated with the oro-facial pain conditions and interpret that information in the light of their current value for use in diagnosis. In the third section, we explore biomarkers through the perspective of ontological realism. We discuss ontological problems of biomarkers as currently widely conceptualised and implemented. This leads to recommendations for research practice aimed to a better understanding of the potential contribution that biomarkers might make to oro-facial pain diagnosis and thereby fulfil our goal for an expanded multidimensional framework for oro-facial pain conditions that would include a third axis

Numerical simulation of unconstrained cyclotron resonant maser emission

When a mainly rectilinear electron beam is subject to significant magnetic compression, conservation of magnetic moment results in the formation of a horseshoe shaped velocity distribution. It has been shown that such a distribution is unstable to cyclotron emission and may be responsible for the generation of Auroral Kilometric Radiation (AKR) an intense rf emission sourced at high altitudes in the terrestrial auroral magnetosphere. PiC code simulations have been undertaken to investigate the dynamics of the cyclotron emission process in the absence of cavity boundaries with particular consideration of the spatial growth rate, spectral output and rf conversion efficiency. Computations reveal that a well-defined cyclotron emission process occurs albeit with a low spatial growth rate compared to waveguide bounded simulations. The rf output is near perpendicular to the electron beam with a slight backward-wave character reflected in the spectral output with a well defined peak at 2.68GHz, just below the relativistic electron cyclotron frequency. The corresponding rf conversion efficiency of 1.1% is comparable to waveguide bounded simulations and consistent with the predictions of kinetic theory that suggest efficient, spectrally well defined radiation emission can be obtained from an electron horseshoe distribution in the absence of radiation boundaries.Publisher PD

Mortality after peritonitis in sub-saharan Africa: An issue of access to care

There is a lack of access to emergency surgical care in developing countries despite a burden of surgical disease. Health care systems are overwhelmed by the high volume of patients who need acute care and by insufficient capacity because of a lack of appropriate prehospital care, surgery-capable clinicians, and basic health care delivery infrastructures. Compared with high-income countries where mortality from peritonitis is less than 5%, mortality in this resource-poor setting is nearly 20%. These patients are particularly susceptible because of a lack of the prerequisite surgical infrastructure, which includes prompt triage and diagnosis, early transfer to a higher level of care, timely surgical intervention, and critical care services. This study identifies outcomes of patients with peritonitis and factors that contribute to mortality

Incidence of self-inflicted burn injury in patients with Major Psychiatric Illness

Introduction: Psychiatric disorders are mental illnesses that impair judgment, thought process and mood that can result in physical and emotional disability. According to DSM-IV, mental disorders increases risk of traumatic injury, particularly burn [1] (American Psychiatric Association, 2013). However, there are few studies that look at patients with pre-existing major psychiatric disorders and burn outcomes. We aim to assess the incidence and intentionality of burn injury in patients with pre-existing psychiatric disorders. Methods: This is a retrospective study of patients admitted to the UNC Jaycee Burn Center from 2002 to 2015 and entered in the burn registry. Variables analyzed include basic demographics, insurance status, total body surface area (TBSA) of burn, Charlson comorbidity index (CCI), burn etiology, presence of inhalation injury, burn circumstance, intensive care unit (ICU) and hospital length of stay (LOS) and mortality. Chi-square, Analysis of Variance (ANOVA), Kruskal–Wallis test and Multivariate logistic regression was used to analyze the data. Results: 11,650 adult and pediatric patients were entered in the burn registry from 2002 to 2015 and 494 (4.2%) adult and pediatric patients had preexisting major psychiatric illness (MPI). Within the large cohort of admitted burn patients, 90 (0.8%) patients presented with self-inflicted burn injuries. 41% of patients with SIB (n = 37/90) had MPI. The incidence of self-inflicted burn injury (SIB) within the MPI (n = 494) cohort was 7.5% (n = 37). Mean age of patients with and without self-inflicted burn injury was 35.3 (±11.6) vs. 41.8 (±17.3), respectively. Mean TBSA was significantly higher in patient with SIB at 18.6 (±16.5) vs. 8.5(±12.2) p < 0.001. Non-white race had significantly higher rate of SIB compared to white cohort. There was no significant difference in mortality rates between SIB and Non-SIB (5.4% vs. 3.7%, p = 0.609), respectively. Median Hospital LOS was significantly increased in patients with SIB compared to NSIB 31 (IQR = 55) vs. 9 (IQR = 20) days, p = 0.004. Multivariate logistic regression for predictors of self-inflicted burn injury showed that minorities were more likely to incur self-inflicted burn injury among patients with major psychiatric illnesses. Conclusion: The incidence of self-induced burn injury in patients with MPI is low and of all the self-inflicted burn patients, 60% did not have a major psychiatric illness identified. Our findings emphasize the importance of identifying patients with MPI with or without self-induced injury that may benefit from more extensive psychiatric screening after burn and counseling, particularly minority patients as they may benefit from additional mental health counseling following severe burn

The epidemiologic characteristics and outcomes following intentional burn injury at a regional burn center

Introduction: Intentional burn injury outcomes are usually more severe, have a high mortality and are seen more often in low and middle-income countries. This study will examine the epidemiological characteristics of intentional burn injury patients and mortality outcomes at a regional Burn Center. Methods: This is a retrospective study of 11,977 patients admitted to a regional Burn center from 2002 to 2015.Variables analyzed were basic demographics (sex, age, and race), total body surface area of burn (%TBSA), presence of inhalation injury, Charlson comorbidity index, intent of injury, mortality, and hospital and ICU length of stay (LOS). Chi-square tests, bivariate analysis and logistic regression models were utilized to determine the effect of burn intent on outcomes. Results: Eleven thousand eight hundred and twenty-three (n = 11,823) adult and pediatric patients from 2002 to 2015 were included in the study. Three hundred and forty-eight (n = 348, 2.9%) patients had intentional burn injuries (IBI). Patients with IBI were younger, 26.5 ± 20 years compared to the non-intentional burn injury (NIBI) group (32 ± 22 years, p < 0.001). Mean %TBSA was significantly higher in the IBI vs. NIBI group at 14.6 ± 20 vs. 6.4 ± 10%, p < 0.001, respectively. Overall, Non-whites (n = 230, 66%) were more likely to have IBI, p < 0.001. Inhalation injury and mortality were statistically significant in the IBI group compared to the NIBI group, (n = 54,16%) vs. (n = 30, 9%) and (n = 649,6%) vs. (n = 329,2.9%), p < 0.001, respectively. Multivariate logistic regression did not show any significant increase in odds of mortality based on burn intent. In subgroup analysis of self-inflicted (SIB) vs. assault burns, SIB patients were significantly older, 38 years (±14.7) vs. 22.4 years (±20.5), p < 0.001 and had a higher %TBSA, 26.5 (±29.6) vs. 10.3 (±13.6), p < 0.001. Seventy three percent (n = 187, 73%) of assault burn patients were Nonwhite and Whites were more likely to incur self-inflicted burns, (n = 53% p < 0.001). Conclusion: We show that patients with intentional burn injuries have an associated increased %TBSA and inhalation injury without increased adjusted odds for mortality. Intentional burns increase health care expenditures. Violence prevention initiatives and access to mental health providers may be beneficial in reducing intentional burn injury burden

The Effect of Pre-existing Seizure Disorders on Mortality and Hospital Length of Stay Following Burn Injury

Patients with a seizure disorder have a higher incidence of burn injury; however, there are limited studies that examine the association between pre-existing seizure disorders (PSD) and burn outcomes. This is a retrospective study of admitted burn patients. Variables analyzed include patient demographics, clinical characteristics, associated PSD, hospital length of stay (LOS), and mortality. Multivariate logistic regression was performed to analyze the impact of PSD on burn mortality and LOS. Seven thousand six hundred and forty patients met the inclusion criteria and 1.31% (n = 100) patients had a PSD. There was no difference in mortality rate between patients with or without PSD (odds ratio [OR] = 2.28, 95% confidence interval [CI] = 0.87 to 5.93). Multivariate logistic regression showed that patients with PSD had significantly increased odds of longer hospital LOS (OR = 2.85, 95% CI = 1.73 to 4.67). Seizure disorder management is mandatory in reducing burn injury and decreasing the costs associated with increased hospital LOS