A nearby long gamma-ray burst from a merger of compact objects.

Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (greater than two seconds) duration are produced by the core-collapse of massive stars1, and those of short (less than two seconds) duration by the merger of compact objects, such as two neutron stars2. A third class of events with hybrid high-energy properties was identified3, but never conclusively linked to a stellar progenitor. The lack of bright supernovae rules out typical core-collapse explosions4-6, but their distance scales prevent sensitive searches for direct signatures of a progenitor system. Only tentative evidence for a kilonova has been presented7,8. Here we report observations of the exceptionally bright GRB 211211A, which classify it as a hybrid event and constrain its distance scale to only 346 megaparsecs. Our measurements indicate that its lower-energy (from ultraviolet to near-infrared) counterpart is powered by a luminous (approximately 1042 erg per second) kilonova possibly formed in the ejecta of a compact object merger.

Influence of spatial-intensity contrast in ultraintense laser-plasma interactions.

Increasing the intensity to which high power laser pulses are focused has opened up new research possibilities, including promising new approaches to particle acceleration and phenomena such as high field quantum electrodynamics. Whilst the intensity achievable with a laser pulse of a given power can be increased via tighter focusing, the focal spot profile also plays an important role in the interaction physics. Here we show that the spatial-intensity distribution, and specifically the ratio of the intensity in the peak of the laser focal spot to the halo surrounding it, is important in the interaction of ultraintense laser pulses with solid targets. By comparing proton acceleration measurements from foil targets irradiated with by a near-diffraction-limited wavelength scale focal spot and larger F-number focusing, we find that this spatial-intensity contrast parameter strongly influences laser energy coupling to fast electrons. We find that for multi-petawatt pulses, spatial-intensity contrast is potentially as important as temporal-intensity contrast.

The Scattered Light Time-history Diagnostic suite at the National Ignition Facility.

The Scattered Light Time-history Diagnostic (SLTD) is being implemented at the National Ignition Facility (NIF) to greatly expand the angular coverage of absolute scattered-light measurements for direct- and indirect-drive inertial confinement fusion (ICF) experiments. The SLTD array will ultimately consist of 15 units mounted at a variety of polar and azimuthal angles on the NIF target chamber, complementing the existing NIF backscatter suite. Each SLTD unit collects and diffuses scattered light onto a set of three optical fibers, which transport the light to filtered photodiodes to measure scattered light in different wavelength bands: stimulated Brillouin scattering (350 nm-352 nm), stimulated Raman scattering (430 nm-760 nm), and ω/2 (695 nm-745 nm). SLTD measures scattered light with a time resolution of ∼1 ns and a signal-to-noise ratio of up to 500. Currently, six units are operational and recording data. Measurements of the angular dependence of scattered light will strongly constrain models of laser energy coupling in ICF experiments and allow for a more robust inference of the total laser energy coupled to implosions.

Development of a method to determine the cost of breast cancer treatment with chemotherapy at Groote Schuur Hospital, Cape Town, South Africa.

BACKGROUND: There has been no comprehensive study determining the financial burden of breast cancer in the South African (SA) public sector. OBJECTIVES: To develop a method to determine the cost of breast cancer treatment with chemotherapy per episode of care and to quantify the associated costs relating to chemotherapy at Groote Schuur Hospital (GSH), a government hospital in SA. These costs included costs associated with the management of adverse events arising from chemotherapy. METHODS: Retrospective patient-level data were collected for 200 patients from electronic databases and patient folders between 2013 and 2015. Direct medical costs were determined from the health funder's perspective. The information collected was categorised into the following cost components: chemotherapy medicines, support medicines, administration of chemotherapy, laboratory tests, radiology scans and imaging, doctor consultations and adverse events. Time-and-motion studies were conducted on a set of new patients and the data obtained were used for the study sample of 200 patients. All the above costs were used to determine the cost of chemotherapy per episode of care. The episode of care was defined as the care provided from 2 months prior to the date of commencing chemotherapy (pre-chemotherapy phase), during chemotherapy (treatment phase) and until 6 months after the date when the last cycle of chemotherapy was administered (follow-up phase). RESULTS: A method was developed to determine the episode-of-care costs for breast cancer at GSH. The total direct medical cost for treatment of breast cancer at GSH for 200 patients was ZAR3 154 877, and the average episode-of-care cost per patient was ZAR15 774. The average cost of management of adverse events arising from the various treatment modalities was ZAR13 133 per patient. It was found that the cost of treating a patient with adverse events was 1.8 times higher than the cost of treating a patient without adverse events. Of the patients, 86.5% managed to complete their prescribed chemotherapy treatment cycles, and the average cost of treatment of these patients was 1.3 times more than the average cost for patients who could not complete their treatment, based on the number of treatment cycles received. CONCLUSION: A comprehensive method to determine the costs associated with breast cancer management per episode of care was developed, and costs were quantified at GSH according to the treatment protocol used at the hospital.

The design of a line velocity interferometer for any reflector for inertial confinement experiments on the Z-machine.

A line VISAR (Velocity Interferometer System for Any Reflector) has been designed and commissioned at the Sandia National Laboratory's Z-machine. The instrument consists of an F/2 collection system, beam transport, and an interferometer table that contains two Mach-Zehnder type interferometers and an eight channel Gated Optical Imaging (GOI) system. The VISAR probe laser operates at the 532 nm wavelength, and the GOI bandpass is 540-600 nm. The output of each interferometer is passed to an optical streak camera with four selectable sweep speeds. The system is designed with three interchangeable optics modules to select a full field of view of 1 mm, 2 mm, or 4 mm. The optical beam transport system connects the target image plane to the interferometers and the gated optical imagers. The target is integrated into a sacrificial final optics assembly that is integral to the transport beamline.

Time resolved detection of two-plasmon decay using three-halves harmonic emission on the National Ignition Facility.

Supra-thermal (>100 keV) electrons generated by laser plasma interactions can be detrimental to the performance of ignition experiments conducted on the National Ignition Facility (NIF). On a NIF shot, the amount of electrons is estimated by measuring the hard X-rays passing through the hohlraum wall. The primary sources of hot electrons in a hohlraum are Stimulated Raman Scattering (SRS) and two plasmon decay (TPD). While SRS is well diagnosed on the NIF, there has been no diagnosis of TPD. We have designed and implemented a new diagnostic to characterize the time history of TPD on the NIF. The instrument provides a time resolved measurement of the 3/2 ω harmonic emission which is indicative of the presence of TPD. We describe the diagnostic setup, calibration, and the preliminary results obtained on NIF hohlraum experiments. We find evidence of a correlation between measured hard X-rays generated from the hot electron bremsstrahlung and the TPD emission.

Near-100 MeV protons via a laser-driven transparency-enhanced hybrid acceleration scheme.

The range of potential applications of compact laser-plasma ion sources motivates the development of new acceleration schemes to increase achievable ion energies and conversion efficiencies. Whilst the evolving nature of laser-plasma interactions can limit the effectiveness of individual acceleration mechanisms, it can also enable the development of hybrid schemes, allowing additional degrees of control on the properties of the resulting ion beam. Here we report on an experimental demonstration of efficient proton acceleration to energies exceeding 94 MeV via a hybrid scheme of radiation pressure-sheath acceleration in an ultrathin foil irradiated by a linearly polarised laser pulse. This occurs via a double-peaked electrostatic field structure, which, at an optimum foil thickness, is significantly enhanced by relativistic transparency and an associated jet of super-thermal electrons. The range of parameters over which this hybrid scenario occurs is discussed and implications for ion acceleration driven by next-generation, multi-petawatt laser facilities are explored.

Plasmodium DNA-mediated TLR9 activation of T-bet+ B cells contributes to autoimmune anaemia during malaria.

Infectious pathogens contribute to the development of autoimmune disorders, but the mechanisms connecting these processes are incompletely understood. Here we show that Plasmodium DNA induces autoreactive responses against erythrocytes by activating a population of B cells expressing CD11c and the transcription factor T-bet, which become major producers of autoantibodies that promote malarial anaemia. Additionally, we identify parasite DNA-sensing through Toll-like receptor 9 (TLR9) along with inflammatory cytokine receptor IFN-γ receptor (IFN-γR) as essential signals that synergize to promote the development and appearance of these autoreactive T-bet+ B cells. The lack of any of these signals ameliorates malarial anaemia during infection in a mouse model. We also identify both expansion of T-bet+ B cells and production of anti-erythrocyte antibodies in ex vivo cultures of naive human peripheral blood mononuclear cells (PBMC) exposed to P. falciprum infected erythrocyte lysates. We propose that synergistic TLR9/IFN-γR activation of T-bet+ B cells is a mechanism underlying infection-induced autoimmune-like responses.

Significant and variable linear polarization during the prompt optical flash of GRB 160625B.

Newly formed black holes of stellar mass launch collimated outflows (jets) of ionized matter that approach the speed of light. These outflows power prompt, brief and intense flashes of γ-rays known as γ-ray bursts (GRBs), followed by longer-lived afterglow radiation that is detected across the electromagnetic spectrum. Measuring the polarization of the observed GRB radiation provides a direct probe of the magnetic fields in the collimated jets. Rapid-response polarimetric observations of newly discovered bursts have probed the initial afterglow phase, and show that, minutes after the prompt emission has ended, the degree of linear polarization can be as high as 30 per cent-consistent with the idea that a stable, globally ordered magnetic field permeates the jet at large distances from the central source. By contrast, optical and γ-ray observations during the prompt phase have led to discordant and often controversial results, and no definitive conclusions have been reached regarding the origin of the prompt radiation or the configuration of the magnetic field. Here we report the detection of substantial (8.3 ± 0.8 per cent from our most conservative simulation), variable linear polarization of a prompt optical flash that accompanied the extremely energetic and long-lived prompt γ-ray emission from GRB 160625B. Our measurements probe the structure of the magnetic field at an early stage of the jet, closer to its central black hole, and show that the prompt phase is produced via fast-cooling synchrotron radiation in a large-scale magnetic field that is advected from the black hole and distorted by dissipation processes within the jet.

Using X-ray spectroscopy of relativistic laser plasma interaction to reveal parametric decay instabilities: a modeling tool for astrophysics.

By analyzing profiles of experimental x-ray spectral lines of Si XIV and Al XIII, we found that both Langmuir and ion acoustic waves developed in plasmas produced via irradiation of thin Si foils by relativistic laser pulses (intensities ~1021 W/cm2). We prove that these waves are due to the parametric decay instability (PDI). This is the first time that the PDI-induced ion acoustic turbulence was discovered by the x-ray spectroscopy in laser-produced plasmas. These conclusions are also supported by PIC simulations. Our results can be used for laboratory modeling of physical processes in astrophysical objects and a better understanding of intense laser-plasma interactions.

Large Intra-abdominal desmoid tumour: complete resection with preservation of function.

Desmoid tumours are benign monoclonal myofibroblastic neoplasms arising from musculoaponeurotic stromal tissue. They infiltrate local tissue but have no known metastatic potential. The management of desmoid tumours is complicated by their unpredictable nature and rarity, which makes study into their behaviour, and therefore treatment, a challenge. We present a case of intra-abdominal desmoid tumour and discuss the recommended approach to management.

An extremely luminous panchromatic outburst from the nucleus of a distant galaxy.

Variable x-ray and γ-ray emission is characteristic of the most extreme physical processes in the universe. We present multiwavelength observations of a unique γ-ray-selected transient detected by the Swift satellite, accompanied by bright emission across the electromagnetic spectrum, and whose properties are unlike any previously observed source. We pinpoint the event to the center of a small, star-forming galaxy at redshift z = 0.3534. Its high-energy emission has lasted much longer than any γ-ray burst, whereas its peak luminosity was ∼100 times higher than bright active galactic nuclei. The association of the outburst with the center of its host galaxy suggests that this phenomenon has its origin in a rare mechanism involving the massive black hole in the nucleus of that galaxy.

Prediction of mortality in adult emergency department patients with sepsis.

OBJECTIVES: To determine the efficacy of the abbreviated Mortality in Emergency Department Sepsis (MEDS) score, the Modified Early Warning (MEW) score and near-patient-test (NPT) lactate levels in predicting 28-day mortality in adult emergency department (ED) patients with sepsis. METHODS: A retrospective cohort study of adult ED patients with sepsis admitted to hospital was conducted in a large urban teaching and a district general hospital. Data were collected during four time periods between 1 January 2006 and 31 January 2007. Inclusion criteria were age > or =16 years and an ED diagnosis of sepsis. Primary outcome for all patients was 28-day mortality. Patients were preassigned to risk groups according to their abbreviated MEDS score, MEW score and NPT lactate. RESULTS: 307 ED patients with sepsis were included in the study. Among these there were 72 deaths (23%). Mortality rates for the low-, moderate- and high-risk groups of the abbreviated MEDS score were 1/63 (1.6%), 48/205 (23.4%) and 23/39 (59.0%) patients. The MEDS score for low-risk patients was 98.6% (95% CI 92.5% to 99.9%) sensitive and 26.5% (95% CI 21.0% to 32.6%) specific and for high-risk patients it was 31.9% (95% CI 21.4% to 44.0%) sensitive and 93.2% (95% CI 89.2% to 96.1%) specific for death within 28 days. Mortality rates for the low- and high-risk MEW score were 20/159 (12.6%) and 52/148 (35.1%) patients. The MEW score for high-risk patients was 72.2% (95% CI 60.4% to 82.1%) sensitive and 59.2% (95% CI 52.6% to 65.5%) specific for mortality. An NPT lactate level of > or =4 mmol/l was 49.1% (95% CI 35.1% to 63.2%) sensitive and 74.3% (95% CI 64.8% to 82.3%) specific for 28-day mortality. CONCLUSION: These results demonstrate the efficacy of the abbreviated MEDS score, the MEW score and NPT venous lactate levels in predicting 28-day mortality in ED patients with sepsis. The abbreviated MEDS score was found to be the best performing risk assessment model which, with prospective validation, may aid early clinical decision-making in ED patients with sepsis and might affect the outcome from sepsis.

Discovery of the short gamma-ray burst GRB 050709.

Gamma-ray bursts (GRBs) fall into two classes: short-hard and long-soft bursts. The latter are now known to have X-ray and optical afterglows, to occur at cosmological distances in star-forming galaxies, and to be associated with the explosion of massive stars. In contrast, the distance scale, the energy scale and the progenitors of the short bursts have remained a mystery. Here we report the discovery of a short-hard burst whose accurate localization has led to follow-up observations that have identified the X-ray afterglow and (for the first time) the optical afterglow of a short-hard burst; this in turn led to the identification of the host galaxy of the burst as a late-type galaxy at z = 0.16 (ref. 10). These results show that at least some short-hard bursts occur at cosmological distances in the outskirts of galaxies, and are likely to be caused by the merging of compact binaries.

Association of the dopamine transporter (DAT1) 10/10-repeat genotype with ADHD symptoms and response inhibition in a general population sample.

Association between attention-deficit hyperactivity disorder (ADHD) and the 10-repeat allele of the dopamine transporter gene (DAT1) has been reported in independent clinical samples using a categorical clinical definition of ADHD. The present study adopts a quantitative trait loci (QTL) approach to examine the association between DAT1 and a continuous measure of ADHD behaviours in a general-population sample, as well as to explore whether there is an independent association between DAT1 and performance on neuropsychological tests of attention, response inhibition, and working memory. From an epidemiological sample of 872 boys aged 6-11 years, we recruited 58 boys scoring above the 90th percentile for teacher reported ADHD symptoms (SWAN ADHD scale) and 68 boys scoring below 10th percentile for genotyping and neuropsychological testing. A significant association was found between the DAT1 homozygous 10/10-repeat genotype and high-scoring boys (chi(2)square=4.6, P<0.03; odds ratio=2.4, 95% CI 1.1-5.0). Using hierarchical linear regression, a significant independent association was found between the DAT1 10/10-repeat genotype and measures of selective attention and response inhibition after adjusting for age, IQ, and ADHD symptoms. There was no association between DAT1 and any component of working memory. Furthermore, performance on tasks of selective attention although associated with DAT1 was not associated with SWAN ADHD high scores after controlling for age and IQ. In contrast, impairment on tasks that tapped sustained attention and the central executive component of working memory were found in high-scoring boys after adjusting for age and IQ. The results suggest that DAT1 is a QTL for continuously distributed ADHD behaviours in the general population and the cognitive endophenotype of response inhibition.

The Mouse Genome Database (MGD): from genes to mice--a community resource for mouse biology.

The Mouse Genome Database (MGD) forms the core of the Mouse Genome Informatics (MGI) system (http://www.informatics.jax.org), a model organism database resource for the laboratory mouse. MGD provides essential integration of experimental knowledge for the mouse system with information annotated from both literature and online sources. MGD curates and presents consensus and experimental data representations of genotype (sequence) through phenotype information, including highly detailed reports about genes and gene products. Primary foci of integration are through representations of relationships among genes, sequences and phenotypes. MGD collaborates with other bioinformatics groups to curate a definitive set of information about the laboratory mouse and to build and implement the data and semantic standards that are essential for comparative genome analysis. Recent improvements in MGD discussed here include the enhancement of phenotype resources, the re-development of the International Mouse Strain Resource, IMSR, the update of mammalian orthology datasets and the electronic publication of classic books in mouse genetics.

The Mouse Genome Database (MGD): integrating biology with the genome.

The Mouse Genome Database (MGD) is one component of the Mouse Genome Informatics (MGI) system (http://www.informatics.jax.org), a community database resource for the laboratory mouse. MGD strives to provide a comprehensive knowledgebase about the mouse with experiments and data annotated from both literature and online sources. MGD curates and presents consensus and experimental data representations of genetic, genotype (sequence) and phenotype information including highly detailed reports about genes and gene products. Primary foci of integration are through representations of relationships between genes, sequences and phenotypes. MGD collaborates with other bioinformatics groups to curate a definitive set of information about the laboratory mouse and to build and implement the data and semantic standards that are essential for comparative genome analysis. Recent developments in MGD discussed here include an extensive integration of the mouse sequence data and substantial revisions in the presentation, query and visualization of sequence data.

Laparoscopic antireflux surgery in the elderly.

BACKGROUND: Laparoscopic antireflux surgery is frequently denied to older patients with gastroesophageal reflux disease (GERD) because of a perceived higher operative complication rate, a decreased impact of the intervention on quality of life, and decreased cost effectiveness. This study compares disease severity, surgical outcomes, and impact on quality of life between elderly and young patients with GERD. METHODS: Patients were selected from a prospectively maintained database of 1100 patients who underwent various laparoscopic esophageal procedures at our institution. Only patients having chronic intractable GERD and a minimum 6 months' follow-up were included in the study. Thirty elderly patients with a mean age of 71.2 years (SD +/- 5.6) were compared with a group of 30 younger patients (mean age, 43.9 +/- 12.8 years). Comparisons were made between subjective and objective outcomes, operative results, and health-related quality of life (HQRL) scores using SF-36 instruments. RESULTS: The preoperative symptom assessment scores presenting frequency of symptoms on a 0-4 scale), and preoperative pH and manometry data were comparable in the two groups. Elderly patients had significantly higher ASA (American Society of Anesthesiologists) scores. Each group demonstrated a significant improvement in the postoperative symptom assessment scores and the esophageal functional studies (p<0.05). However, no significant differences were found in terms of postoperative complications, postoperative hospital stay, postoperative symptom scores, Demeester scores, or the HRQL data. CONCLUSION: Laparoscopic antireflux surgery in elderly patients improves acid reflux and appears to be safe and effective as measured by postoperative testing in elderly and young patients.

Bother arising from urinary frequency in women.

Patients commonly express bother with the symptom of frequent urination. The relationship between actual voiding frequency and this symptom is undocumented. We reviewed records of 200 women who had completed 24-hour frequency-volume charts, and had indicated their degree of bother with urinary frequency utilizing the short form of the Urogenital Distress Inventory. The degree of bother was correlated with daytime and nighttime voiding frequency, maximum functional capacity, mean voided volume, and demographic variables. Among 200 women, 180 (90%) indicated at least a minor degree of bother with urinary frequency. A voiding frequency of eight or more times in 24 hours was reported by 166 (83%) of women. Among the 34 women voiding fewer than eight times/24 hours, 26 (76%) reported bother with urinary frequency. There was large variation in the degree of bother reported at a given voiding frequency. Postmenopausal women without hormone replacement therapy (HRT) recorded more nighttime voids than those on HRT. Among postmenopausal women without HRT, mean voided volume and maximum functional capacity were inversely related to patient age. Our study suggests that the currently utilized cutoff value of eight daily voids to define urinary frequency, may not be helpful in the management of women in this country. A racially diverse study of the voiding habits of asymptomatic North American women is mandated.