EVIDENCE FOR THE MAGNETIC BREAKOUT MODEL IN AN EQUATORIAL CORONAL-HOLE JET.

Small, impulsive jets commonly occur throughout the solar corona, but are especially visible in coronal holes. Evidence is mounting that jets are part of a continuum of eruptions that extends to much larger coronal mass ejections and eruptive flares. Because coronal-hole jets originate in relatively simple magnetic structures, they offer an ideal testbed for theories of energy buildup and release in the full range of solar eruptions.

A universal model for solar eruptions.

Magnetically driven eruptions on the Sun, from stellar-scale coronal mass ejections to small-scale coronal X-ray and extreme-ultraviolet jets, have frequently been observed to involve the ejection of the highly stressed magnetic flux of a filament. Theoretically, these two phenomena have been thought to arise through very different mechanisms: coronal mass ejections from an ideal (non-dissipative) process, whereby the energy release does not require a change in the magnetic topology, as in the kink or torus instability; and coronal jets from a resistive process involving magnetic reconnection. However, it was recently concluded from new observations that all coronal jets are driven by filament ejection, just like large mass ejections.

Three-Dimensional Simulations of Tearing and Intermittency in Coronal Jets.

Observations of coronal jets increasingly suggest that local fragmentation and intermittency play an important role in the dynamics of these events. In this work we investigate this fragmentation in high-resolution simulations of jets in the closed-field corona. We study two realizations of the embedded-bipole model, whereby impulsive helical outflows are driven by reconnection between twisted and untwisted field across the domed fan plane of a magnetic null.

Invasive infections due to a fish pathogen, Streptococcus iniae. S. iniae Study Group.

Background: Streptococcus iniae is a pathogen in fish, capable of causing invasive disease and outbreaks in aquaculture farms. During the winter of 1995-1996 in the greater Toronto area there was a cluster of four cases of invasive S. iniae infection in people who had recently handled fresh, whole fish from such farms.

The utility of restriction endonuclease analysis and phage typing in the epidemiologic investigation of a Staphylococcus aureus outbreak in a neonatal nursery.

Outbreaks of Staphylococcus aureus infections in neonatal units require prompt investigation and implementation of control measures. From January to March 1990, a marked increase in the number of S. aureus infections was observed in a neonatal nursery.