Impact of a neuro-intensive care service for newborns.

BACKGROUND: Advances in treating the injured neonatal brain have given rise to neuro-intensive care services for newborns. This study assessed the impact of one such service in a cohort of newborns treated with therapeutic hypothermia. METHODS: Our newborn neuro-intensive care service was started in November 2012. From January 2008 to October 2016, a cohort of 158 newborns was treated with therapeutic hypothermia, 29 before and 129 after the inception of the service. This study compared the outcomes of newborns treated by the service with those of newborns treated before. Multivariate regression analysis associating length-of-stay and treatment pre- or post-service was adjusted for five-minute Apgar score, time-to-target temperature, seizures, and mortality. RESULTS: The neuro-intensive care service was also associated with a decrease in mortality (17% before service to 5.4% with the service, p = 0.03), though this association is likely multifactorial and reflects the application of therapeutic hypothermia to a wider variety of patients. However, the service was independently associated with decreased length-of-stay (mean 22 pre-service to 13 days with the service, p < 0.0005.)CONCLUSIONS:The service educated referring hospitals in recognizing therapeutic hypothermia candidates, which increased the number of treated newborns, and created a number of procedures to streamline the delivery of treatment. While the increasing number and variety of patients treated could spuriously reduce length-of-stay, length-of-stay was still significantly reduced after adjustment, providing evidence that neuro-intensive care services for newborns can improve hospital outcomes.

Astronomy. ASASSN-15lh: A highly super-luminous supernova.

We report the discovery of ASASSN-15lh (SN 2015L), which we interpret as the most luminous supernova yet found. At redshift z = 0.2326, ASASSN-15lh reached an absolute magnitude of Mu ,AB = -23.5 ± 0.1 and bolometric luminosity Lbol = (2.2 ± 0.2) × 10(45) ergs s(-1), which is more than twice as luminous as any previously known supernova. It has several major features characteristic of the hydrogen-poor super-luminous supernovae (SLSNe-I), whose energy sources and progenitors are currently poorly understood. In contrast to most previously known SLSNe-I that reside in star-forming dwarf galaxies, ASASSN-15lh appears to be hosted by a luminous galaxy (MK ≈ -25.5) with little star formation. In the 4 months since first detection, ASASSN-15lh radiated (1.1 ± 0.2) × 10(52) ergs, challenging the magnetar model for its engine.

A strong ultraviolet pulse from a newborn type Ia supernova.

Type Ia supernovae are destructive explosions of carbon-oxygen white dwarfs. Although they are used empirically to measure cosmological distances, the nature of their progenitors remains mysterious. One of the leading progenitor models, called the single degenerate channel, hypothesizes that a white dwarf accretes matter from a companion star and the resulting increase in its central pressure and temperature ignites thermonuclear explosion. Here we report observations with the Swift Space Telescope of strong but declining ultraviolet emission from a type Ia supernova within four days of its explosion. This emission is consistent with theoretical expectations of collision between material ejected by the supernova and a companion star, and therefore provides evidence that some type Ia supernovae arise from the single degenerate channel.

The bright optical flash and afterglow from the gamma-ray burst GRB 130427A.

The optical light generated simultaneously with x-rays and gamma rays during a gamma-ray burst (GRB) provides clues about the nature of the explosions that occur as massive stars collapse. We report on the bright optical flash and fading afterglow from powerful burst GRB 130427A. The optical and >100-megaelectron volt (MeV) gamma-ray flux show a close correlation during the first 7000 seconds, which is best explained by reverse shock emission cogenerated in the relativistic burst ejecta as it collides with surrounding material. At later times, optical observations show the emergence of emission generated by a forward shock traversing the circumburst environment. The link between optical afterglow and >100-MeV emission suggests that nearby early peaked afterglows will be the best candidates for studying gamma-ray emission at energies ranging from gigaelectron volts to teraelectron volts.

Energy input and response from prompt and early optical afterglow emission in gamma-ray bursts.

The taxonomy of optical emission detected during the critical first few minutes after the onset of a gamma-ray burst (GRB) defines two broad classes: prompt optical emission correlated with prompt gamma-ray emission, and early optical afterglow emission uncorrelated with the gamma-ray emission. The standard theoretical interpretation attributes prompt emission to internal shocks in the ultra-relativistic outflow generated by the internal engine; early afterglow emission is attributed to shocks generated by interaction with the surrounding medium. Here we report on observations of a bright GRB that, for the first time, clearly show the temporal relationship and relative strength of the two optical components. The observations indicate that early afterglow emission can be understood as reverberation of the energy input measured by prompt emission. Measurements of the early afterglow reverberations therefore probe the structure of the environment around the burst, whereas the subsequent response to late-time impulsive energy releases reveals how earlier flaring episodes have altered the jet and environment parameters. Many GRBs are generated by the death of massive stars that were born and died before the Universe was ten per cent of its current age, so GRB afterglow reverberations provide clues about the environments around some of the first stars.

A link between prompt optical and prompt gamma-ray emission in gamma-ray bursts.

The prompt optical emission that arrives with the gamma-rays from a cosmic gamma-ray burst (GRB) is a signature of the engine powering the burst, the properties of the ultra-relativistic ejecta of the explosion, and the ejecta's interactions with the surroundings. Until now, only GRB 990123 had been detected at optical wavelengths during the burst phase. Its prompt optical emission was variable and uncorrelated with the prompt gamma-ray emission, suggesting that the optical emission was generated by a reverse shock arising from the ejecta's collision with surrounding material. Here we report prompt optical emission from GRB 041219a. It is variable and correlated with the prompt gamma-rays, indicating a common origin for the optical light and the gamma-rays. Within the context of the standard fireball model of GRBs, we attribute this new optical component to internal shocks driven into the burst ejecta by variations of the inner engine. The correlated optical emission is a direct probe of the jet isolated from the medium. The timing of the uncorrelated optical emission is strongly dependent on the nature of the medium.