A luminosity distribution for kilonovae based on short gamma-ray burst afterglows

The combined detection of a gravitational-wave signal, kilonova, and short gamma-ray burst (sGRB) from GW170817 marked a scientific breakthrough in the field of multi-messenger astronomy. But even before GW170817, there have been a number of sGRBs with possible associated kilonova detections. In this work, we re-examine these "historical" sGRB afterglows with a combination of state-of-the-art afterglow and kilonova models. This allows us to include optical/near-infrared synchrotron emission produced by the sGRB as well as ultraviolet/optical/near-infrared emission powered by the radioactive decay of $r$-process elements (i.e., the kilonova). Fitting the lightcurves, we derive the velocity and the mass distribution as well as the composition of the ejected material. The posteriors on kilonova parameters obtained from the fit were turned into distributions for the peak magnitude of the kilonova emission in different bands and the time at which this peak occurs. From the sGRB with an associated kilonova, we found that the peak magnitude in H bands falls in the range [-16.2, -13.1] ($95\%$ of confidence) and occurs within $0.8-3.6\,\rm days$ after the sGRB prompt emission. In g band instead we obtain a peak magnitude in range [-16.8, -12.3] occurring within the first $18\,\rm hr$ after the sGRB prompt. From the luminosity distributions of GW170817/AT2017gfo, kilonova candidates GRB130603B, GRB050709 and GRB060614 (with the possible inclusion of GRB150101B) and the upper limits from all the other sGRBs not associated with any kilonova detection we obtain for the first time a kilonova luminosity function in different bands.Comment: Published in MNRAS, 24 pages, 14 figure

Evaluation of delivery options for second-stage events

Cesarean delivery in the second stage of labor is common, whereas the frequency of operative vaginal delivery has been declining. However, data comparing outcomes for attempted operative vaginal delivery in the second stage versus cesarean in the second stage are scant. Previous studies that examine operative vaginal delivery have compared it to a baseline risk of complications from a spontaneous vaginal delivery and cesarean delivery. However, when a woman has a need for intervention in the second stage, spontaneous vaginal delivery is not an option she or the provider can choose. Thus, the appropriate clinical comparison is cesarean versus operative vaginal delivery

Early Spectra of the Gravitational Wave Source GW170817: Evolution of a Neutron Star Merger

On 2017 August 17, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of the binary neutron star gravitational wave event GW170817. We report time-series spectroscopy of SSS17a from 11.75 hours until 8.5 days after merger. Over the first hour of observations the ejecta rapidly expanded and cooled. Applying blackbody fits to the spectra, we measure the photosphere cooling from $11,000^{+3400}_{-900}$ K to $9300^{+300}_{-300}$ K, and determine a photospheric velocity of roughly 30% of the speed of light. The spectra of SSS17a begin displaying broad features after 1.46 days, and evolve qualitatively over each subsequent day, with distinct blue (early-time) and red (late-time) components. The late-time component is consistent with theoretical models of r-process-enriched neutron star ejecta, whereas the blue component requires high velocity, lanthanide-free material.Comment: 33 pages, 5 figures, 2 tables, Accepted to Scienc

Pregnancy-Associated Hypertension in Glucose-Intolerant Pregnancy and Subsequent Metabolic Syndrome

To evaluate whether pregnancy-associated hypertension (preeclampsia or gestational hypertension), among women with varying degrees of glucose intolerance during pregnancy is associated with maternal metabolic syndrome 5-10 years later

Light Curves of the Neutron Star Merger GW170817/SSS17a: Implications for R-Process Nucleosynthesis

On 2017 August 17, gravitational waves were detected from a binary neutron star merger, GW170817, along with a coincident short gamma-ray burst, GRB170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, optical and infrared light curves of SSS17a extending from 10.9 hours to 18 days post-merger. We constrain the radioactively-powered transient resulting from the ejection of neutron-rich material. The fast rise of the light curves, subsequent decay, and rapid color evolution are consistent with multiple ejecta components of differing lanthanide abundance. The late-time light curve indicates that SSS17a produced at least ~0.05 solar masses of heavy elements, demonstrating that neutron star mergers play a role in r-process nucleosynthesis in the Universe.Comment: Accepted to Scienc

Chemogenetic fingerprinting by analysis of cellular growth dynamics

<p>Abstract</p> <p>Background</p> <p>A fundamental goal in chemical biology is the elucidation of on- and off-target effects of drugs and biocides. To this aim chemogenetic screens that quantify drug induced changes in cellular fitness, typically taken as changes in composite growth, is commonly applied.</p> <p>Results</p> <p>Using the model organism <it>Saccharomyces cerevisiae </it>we here report that resolving cellular growth dynamics into its individual components, growth lag, growth rate and growth efficiency, increases the predictive power of chemogenetic screens. Both in terms of drug-drug and gene-drug interactions did the individual growth variables capture distinct and only partially overlapping aspects of cell physiology. In fact, the impact on cellular growth dynamics represented functionally distinct chemical fingerprints.</p> <p>Discussion</p> <p>Our findings suggest that the resolution and quantification of all facets of growth increases the informational and interpretational output of chemogenetic screening. Hence, by facilitating a physiologically more complete analysis of gene-drug and drug-drug interactions the here reported results may simplify the assignment of mode-of-action to orphan bioactive compounds.</p

A luminosity distribution for kilonovae based on short gamma-ray burst afterglows

The combined detection of a gravitational-wave signal, kilonova, and short gamma-ray burst (sGRB) from GW170817 marked a scientific breakthrough in the field of multimessenger astronomy. But even before GW170817, there have been a number of sGRBs with possible associated kilonova detections. In this work, we re-examine these ‘historical’ sGRB afterglows with a combination of state-of-the-art afterglow and kilonova models. This allows us to include optical/near-infrared synchrotron emission produced by the sGRB as well as ultraviolet/optical/near-infrared emission powered by the radioactive decay of r-process elements (i.e. the kilonova). Fitting the light curves, we derive the velocity and the mass distribution as well as the composition of the ejected material. The posteriors on kilonova parameters obtained from the fit were turned into distributions for the peak magnitude of the kilonova emission in different bands and the time at which this peak occurs. From the sGRB with an associated kilonova, we found that the peak magnitude in H bands falls in the range [−16.2, −13.1] (⁠95 per cent of confidence) and occurs within 0.8−3.6d after the sGRB prompt emission. In g band instead we obtain a peak magnitude in range [−16.8, −12.3] occurring within the first 18 h after the sGRB prompt. From the luminosity distributions of GW170817/AT2017gfo, kilonova candidates GRB130603B, GRB050709, and GRB060614 (with the possible inclusion of GRB150101B, GRB050724A, GRB061201, GRB080905A, GRB150424A, and GRB160821B) and the upper limits from all the other sGRBs not associated with any kilonova detection we obtain for the first time a kilonova luminosity distribution in different bands

Focused Ion Beam Fabrication

Contains reports on thirteen research projects and a list of publications.Defense Advanced Research Projects Agency/U.S. Army Research Office Contract DAAL03-88-K-0108National Science Foundation Grant ECS 89-21728MIT Lincoln Laboratory Innovative Research ProgramSEMATECH Contract 90-MC-503Micrion Contract M08774U.S. Army Research Office Contract DAAL03-87-K-0126IBM Corporatio

Mild Gestational Diabetes Mellitus and Long-Term Child Health

OBJECTIVETo evaluate whether treatment of mild gestational diabetes mellitus (GDM) confers sustained offspring health benefits, including a lower frequency of obesity.RESEARCH DESIGN AND METHODSFollow-up study of children (ages 5–10) of women enrolled in a multicenter trial of treatment versus no treatment of mild GDM. Height, weight, blood pressure, waist circumference, fasting glucose, fasting insulin, triglycerides, and HDL cholesterol were measured.RESULTSFive hundred of 905 eligible offspring (55%) were enrolled. Maternal baseline characteristics were similar between the follow-up treated and untreated groups. The frequencies of BMI ≥95th (20.8% and 22.9%) and 85th (32.6% and 38.6%) percentiles were not significantly different in treated versus untreated offspring (P = 0.69 and P = 0.26). No associations were observed for BMI z score, log waist circumference, log triglycerides, HDL cholesterol, blood pressure, or log HOMA-estimated insulin resistance (HOMA-IR). The effect of treatment was different by sex for fasting glucose and log HOMA-IR (P for interaction = 0.002 and 0.02, respectively) but not by age-group (5–6 and 7–10 years) for any outcomes. Female offspring of treated women had significantly lower fasting glucose levels.CONCLUSIONSAlthough treatment for mild GDM has been associated with neonatal benefits, no reduction in childhood obesity or metabolic dysfunction in the offspring of treated women was found. However, only female offspring of women treated for mild GDM had lower fasting glucose