300 research outputs found

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

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    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.

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    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.

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    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

    The interaction between transpolar arcs and cusp spots

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    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

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

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    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 0ā€“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
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