Quantifying the Size and Duration of a Microburst-Producing Chorus Region on 5 December 2017.

Microbursts are impulsive (<1 s) injections of electrons into the atmosphere, thought to be caused by nonlinear scattering by chorus waves. Although attempts have been made to quantify their contribution to outer belt electron loss, the uncertainty in the overall size and duration of the microburst region is typically large, so that their contribution to outer belt loss is uncertain. We combine datasets that measure chorus waves (Van Allen Probes [RBSP], Arase, ground-based VLF stations) and microburst (>30 keV) precipitation (FIREBIRD II and AC6 CubeSats, POES) to determine the size of the microburst-producing chorus source region beginning on 5 December 2017. We estimate that the long-lasting (∼30 hr) microburst-producing chorus region extends from 4 to 8 Δ MLT and 2-5 Δ L. We conclude that microbursts likely represent a major loss source of outer radiation belt electrons for this event.

Low back pain and other overuse injuries in a group of Japanese triathletes.

OBJECTIVE: To document the incidence of low back pain and other overuse injuries in a group of triathletes, and to investigate any associations with various physical and triathlon related factors. METHODS: By means of a questionnaire, the physical characteristics, training habits, and the incidences of overuse injuries of 92 Japanese triathletes (70 males, 22 females) were documented. Student's t and chi 2 tests were used to determine the significance of any associations with injury incidence, as well as differences between subjects experiencing or not experiencing low back pain in the previous year. RESULTS: Low back pain was experienced by 32% of subjects in the previous year. The majority (54%) of low back pain episodes lasted under seven days, suggesting mainly soft tissue involvement, and 19% lasted over three months, suggesting involvement of the intervertebral discs. Weekly trunk flexor muscle training frequency was significantly greater (P = 0.035) for the low back pain subjects. Close to significant differences for average weekly cycling time, trunk flexor muscle training time, and low intensity aerobic training, as well near significant associations for weight training and average weekly triathlon training load, were also found. No other factors were significantly associated with low back pain. Low back injuries accounted for 28% of all injuries. Only the knee was a more common single site of injury (33%). CONCLUSIONS: The three most common injuries suffered by the triathletes were of the knee, back and shoulder. The low back pain suffered by many triathletes could be of a potentially serious nature. It is suggested that cycling is a major risk factor for low back pain in triathletes.

A three-year follow-up study of patients in a day treatment program.

A 3-year follow-up study was conducted with 73 psychiatric patients in a Finnish day treatment program. The treatment outcome for these patients, who carried a wide range of diagnoses, was measured using psychiatric rehospitalization as a criterion. There were a large number of patients who were disabled and had been receiving social security benefits during the 3 years following discharge from the day treatment program. The rehospitalized cases involved mainly patients with a diagnosis of schizophrenia or personality disorder; use of neuroleptic medication was significantly associated with poor results. The numbers of psychiatric hospitalizations before treatment in the day treatment program in 1985 was found to be independent of hospitalizations during follow-up years. The results of the study support the claim that day treatment does not increase the likelihood of rehospitalization. Day treatment may reduce the length of stay during rehospitalization, but it is also clear that it cannot stop the rehospitalization of patients with severe diagnoses.