Comparative effectiveness of safety planning intervention with instrumental support calls (ISC) versus safety planning intervention with two-way text message caring contacts (CC) in adolescents and adults screening positive for suicide risk in emergency departments and primary care clinics: Protocol for a pragmatic randomized controlled trial.

BACKGROUND: Suicide is a leading cause of death in adolescents and adults in the US. Follow-up support delivered when patients return home after an emergency department (ED) or primary care encounter can significantly reduce suicidal ideation and attempts. Two follow-up models to augment usual care including the Safety Planning Intervention have high efficacy: Instrumental Support Calls (ISC) and Caring Contacts (CC) two-way text messages, but they have never been compared to assess which works best. This protocol for the Suicide Prevention Among Recipients of Care (SPARC) Trial aims to determine which model is most effective for adolescents and adults with suicide risk. METHODS: The SPARC Trial is a pragmatic randomized controlled trial comparing the effectiveness of ISC versus CC. The sample includes 720 adolescents (12-17 years) and 790 adults (18+ years) who screen positive for suicide risk during an ED or primary care encounter. All participants receive usual care and are randomized 1:1 to ISC or CC. The state suicide hotline delivers both follow-up interventions. The trial is single-masked, with participants unaware of the alternative treatment, and is stratified by adolescents/adults. The primary outcome is suicidal ideation and behavior, measured using the Columbia Suicide Severity Rating Scale (C-SSRS) screener at 6 months. Secondary outcomes include C-SSRS at 12 months, and loneliness, return to crisis care for suicidality, and utilization of outpatient mental health services at 6 and 12 months. DISCUSSION: Directly comparing ISC and CC will determine which follow-up intervention is most effective for suicide prevention in adolescents and adults.

Invited Article: Quantitative imaging of explosions with high-speed cameras.

The techniques presented in this paper allow for mapping of temperature, pressure, chemical species, and energy deposition during and following detonations of explosives, using high speed cameras as the main diagnostic tool. This work provides measurement in the explosive near to far-field (0-500 charge diameters) of surface temperatures, peak air-shock pressures, some chemical species signatures, shock energy deposition, and air shock formation.

High-speed two-camera imaging pyrometer for mapping fireball temperatures.

A high-speed imaging pyrometer was developed to investigate the behavior of flames and explosive events. The instrument consists of two monochrome high-speed Phantom v7.3 m cameras made by Vision Research Inc. arranged so that one lens assembly collects light for both cameras. The cameras are filtered at 700 or 900 nm with a 10 nm bandpass. The high irradiance produced by blackbody emission combined with variable shutter time and f-stop produces properly exposed images. The wavelengths were chosen with the expected temperatures in mind, and also to avoid any molecular or atomic gas phase emission. Temperatures measured using this pyrometer of exploded TNT charges are presented.

High-speed digital color imaging pyrometry.

Temperature measurements of high-explosive and combustion processes are difficult to obtain due to the speed and environment of the events. To overcome these challenges, we have characterized and calibrated a digital high-speed color camera that may be used to measure the temperature of such events. A two-color ratio method is used to calculate a temperature using the color filter array raw image data and a graybody assumption. If the raw image data are not available, temperatures may be calculated from the processed images or movies, depending on proper analysis of the digital color imaging pipeline. We analyze three transformations within the pipeline (demosaicing, white balance, and gamma correction) to determine their effect on the calculated temperature. Using this technique with a Phantom color camera, we have measured the temperature of exploded C-4 charges. The surface temperature of the resulting fireball was found to rapidly increase after detonation, and subsequently decayed to a constant value of approximately 1980 K.

Differential schlieren-interferometry with a simple adjustable Wollaston-like prism.

An adjustable Wollaston-like prism is characterized for use in shearing- and differential schlieren-interferometry with laser and white-light illumination. We demonstrate that a polycarbonate prism under mechanical loading behaves identically to Wollaston's classical birefringent beam splitter. A linear relationship is found between the pure bending moment applied to the polycarbonate prism and the resulting light-beam-divergence angle. The utility of this prism in shearing-interferometry is shown by using it in place of the knife-edge in small and large schlieren optical systems. It is inexpensive to fabricate, and it yields adjustable beam-divergence angles over a range of at least 0-24 arc min.