Cluster spacecraft observations of a ULF wave enhanced by Space Plasma Exploration by Active Radar (SPEAR)

Space Plasma Exploration by Active Radar (SPEAR) is a high-latitude ionospheric heating facility capable of exciting ULF waves on local magnetic field lines. We examine an interval from 1 February 2006 when SPEAR was transmitting a 1 Hz modulation signal with a 10 min on-off cycle. Ground magnetometer data indicated that SPEAR modulated currents in the local ionosphere at 1 Hz, and enhanced a natural field line resonance with a 10 min period. During this interval the Cluster spacecraft passed over the heater site. Signatures of the SPEAR-enhanced field line resonance were present in the magnetic field data measured by the magnetometer on-board Cluster-2. These are the first joint ground- and space-based detections of field line tagging by SPEAR

Childhood cancer and paternal employment in agriculture: the role of pesticides.

Previous studies have suggested that the offspring of men potentially exposed to pesticides at work may be at increased risk of kidney cancer (Wilms' tumour), brain tumours, Ewing's bone sarcoma and acute leukaemia. This paper examines the association between potential occupational exposure of fathers to pesticides and offspring's death from cancer in a large national database. Records for 167703 childhood deaths occurring during 1959-63, 1970-78 and 1979-90 in England and Wales have been analysed. Among the offspring of men with potential occupational exposure to pesticides there were 5270 deaths, of which 449 were due to cancer. Associations were assessed using proportional mortality ratios (PMRs), with adjustment for age, year of death and paternal social class. Of the childhood cancers previously linked with potential paternal occupational exposure to pesticides, the only statistically significant excess was for kidney cancer (PMR=1.59, 95% CI=1.18-2.15, based on 42 deaths). Although these results offer some support for the suggestion that paternal occupational exposure to pesticides may be related to the subsequent development of kidney cancer in offspring, other explanations cannot be excluded. In the light of the findings presented here and elsewhere, further, more detailed, research into the nature of this relationship is warranted

Early Service leavers: a study of the factors associated with premature separation from the UK Armed Forces and the mental health of those that leave early.

BACKGROUND: Approximately 18,000 personnel leave the UK Armed Forces annually. Those leaving before completing the minimum term of their contracts are called early Service leavers (ESLs). This study aims to identify characteristics associated with being an ESL, and compare the post-discharge mental health of ESLs and other Service leavers (non-ESLs). METHOD: A cross-sectional study used data on ex-Serving UK Armed Forces personnel. ESLs were personnel leaving before completing their 3-4.5 years minimum Service contracts and were compared with non-ESLs. Multivariable logistic regression was used to estimate odds ratios and 95% confidence intervals for the associations between Service leaving status with socio-demographics, military characteristics and mental health outcomes. RESULTS: Of 845 Service leavers, 80 (9.5%) were ESLs. Being an ESL was associated with younger age, female sex, not being in a relationship, lower rank, serving in the Army and with a trend of reporting higher levels of childhood adversity, but not with deployment to Iraq. ESLs were at an increased risk of probable post-traumatic stress disorder (PTSD), common mental disorders, fatigue and multiple physical symptoms, but not alcohol misuse. CONCLUSIONS: The study suggests that operational Service is not a factor causing personnel to become an ESL. Current mental health problems were more commonly reported among ESLs than other Service leavers. There may be a need to target interventions to ESLs on leaving Service to smooth their transition to civilian life and prevent the negative mental health outcomes experienced by ESLs further down the line

Postdeployment Battlemind training for the U.K. armed forces: a cluster randomized controlled trial

OBJECTIVE: Combat exposure can increase the risk of subsequent psychological ill-health in armed forces (AF) personnel. A U.S. postdeployment psycho-educational intervention, Battlemind, showed a beneficial effect on mental health in U.S. military personnel exposed to high combat levels. We evaluated the effectiveness of an anglicized version of postdeployment Battlemind. METHOD: Battlemind was adapted for the United Kingdom. The main amendments were to sections about carrying weapons, driving, and alcohol misuse. The anglicized Battlemind was compared with the U.K. standard postdeployment brief in a cluster randomized controlled trial. At baseline, 2,443 U.K. AF personnel returning from Afghanistan via Cyprus completed questionnaires about their combat experiences and mental health. Of these, 1,616 (66%) completed 6-month follow-up questionnaires. We used the Posttraumatic Stress Disorder Checklist (PCL-C) to measure probable posttraumatic stress disorder and the General Health Questionnaire (GHQ-12) to measure common mental disorders. Secondary outcomes included alcohol misuse, assessed with the Alcohol Use Disorders Identification Test (AUDIT), and binge drinking. Mixed-effects models were used to account for possible cluster effects. RESULTS: We did not find a difference in mental health or overall AUDIT score. Those who received Battlemind versus the standard brief were less likely to report binge drinking, although the effect size was small (adjusted odds ratio = 0.73, 95% CI [0.58, 0.92]). CONCLUSIONS: The anglicized Battlemind did not improve mental health but had a modest impact on the reporting of binge drinking. Alcohol misuse is problematic in military populations; therefore, an intervention that reduces binge drinking may be helpful

Dementia in veterans and non-veterans in England: a cross-sectional survey

Background Concerns have been raised that military veterans are at greater risk of dementia due to increased rates of depression, post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI) found in this population. The prevalence of dementia in English veterans and whether this is different to non-veterans, however, are currently unknown. Aims To study the risk of dementia in the English veteran population, we aimed to calculate the prevalence of dementia in a group of veterans and compare this with a similar group, with no history of military service. Methods Male veterans and non-veterans aged over 64 years old were identified from the 2007 Adult Psychiatric Morbidity Survey, a national survey of community-dwelling adults in England. This survey was conducted via face-to-face interviews and incorporated questions on previous military service. Dementia was screened by using the modified Telephone Interview of Cognitive Status (TICS-M). Results A total of 496 male veterans and 294 non-veterans were identified. TICS-M scores indicated possible dementia in 24% of veterans and 26% non-veterans; after adjusting for age, the odds of possible dementia was significantly lower in veterans than non-veterans (adjusted OR 0.56; 95% CI 0.38–0.84, P < 0.01). Conclusions English male veterans were less likely to have dementia than similar male non-veterans. This study did not find any evidence to support the view that dementia is more common in veterans than non-veterans

The interaction between transpolar arcs and cusp spots

Transpolar arcs and cusp spots are both auroral phenomena which occur when the interplanetary magnetic field is northward. Transpolar arcs are associated with magnetic reconnection in the magnetotail, which closes magnetic flux and results in a "wedge" of closed flux which remains trapped, embedded in the magnetotail lobe. The cusp spot is an indicator of lobe reconnection at the high-latitude magnetopause; in its simplest case, lobe reconnection redistributes open flux without resulting in any net change in the open flux content of the magnetosphere. We present observations of the two phenomena interacting--i.e., a transpolar arc intersecting a cusp spot during part of its lifetime. The significance of this observation is that lobe reconnection can have the effect of opening closed magnetotail flux. We argue that such events should not be rare

First simultaneous measurements of waves generated at the bow shock in the solar wind, the magnetosphere and on the ground

On 5 September 2002 the Geotail satellite observed the cone angle of the Interplanetary Magnetic Field (IMF) change to values below 30° during a 56 min interval between 18:14 and 19:10 UT. This triggered the generation of upstream waves at the bow shock, 13 <I>R<sub>E</sub></I> downstream of the position of Geotail. Upstream generated waves were subsequently observed by Geotail between 18:30 and 18:48 UT, during times the IMF cone angle dropped below values of 10°. At 18:24 UT all four Cluster satellites simultaneously observed a sudden increase in wave power in all three magnetic field components, independent of their position in the dayside magnetosphere. We show that the 10 min delay between the change in IMF direction as observed by Geotail and the increase in wave power observed by Cluster is consistent with the propagation of the IMF change from the Geotail position to the bow shock and the propagation of the generated waves through the bow shock, magnetosheath and magnetosphere towards the position of the Cluster satellites. We go on to show that the wave power recorded by the Cluster satellites in the component containing the poloidal and compressional pulsations was broadband and unstructured; the power in the component containing toroidal oscillations was structured and shows the existence of multi-harmonic Alfvénic continuum waves on field lines. Model predictions of these frequencies fit well with the observations. An increase in wave power associated with the change in IMF direction was also registered by ground based magnetometers which were magnetically conjunct with the Cluster satellites during the event. To the best of our knowledge we present the first simultaneous observations of waves created by backstreaming ions at the bow shock in the solar wind, the dayside magnetosphere and on the ground

Parental social contact in the work place and the risk of childhood acute lymphoblastic leukaemia

To study the possible relation between parental social contact through occupation, a marker for a child's risk of infection, and childhood acute lymphoblastic leukaemia (ALL), the parents of 294 children with ALL aged 0–14.9 years and 376 matched controls were interviewed about their jobs after their child's birth up to the age of 3 years. Job titles were assigned to a level of social contact, and an index of occupational social contact months was created using the level and the job duration. Positive interactions between this index and rural residence associated with an increased risk of childhood ALL and common ALL (c-ALL) were observed (interaction P-value=0.02 for both, using tertiles of contact months; interaction P-value=0.05 and 0.02 for ALL and c-ALL, respectively, using continuous contact months); such findings were not observed when job durations were ignored. Our data suggest that duration of parental occupation may be important when examining the association between parental social contact in the workplace and childhood leukaemia