Fully General Relativistic Simulations of Black Hole-Neutron Star Mergers

Black hole-neutron star (BHNS) binaries are expected to be among the leading sources of gravitational waves observable by ground-based detectors, and may be the progenitors of short-hard gamma ray bursts (SGRBs) as well. Here, we discuss our new fully general relativistic calculations of merging BHNS binaries, which use high-accuracy, low-eccentricity, conformal thin-sandwich configurations as initial data. Our evolutions are performed using the moving puncture method and include a fully relativistic, high-resolution shock-capturing hydrodynamics treatment. Focusing on systems in which the neutron star is irrotational and the black hole is nonspinning with a 3:1 mass ratio, we investigate the inspiral, merger, and disk formation in the system. We find that the vast majority of material is promptly accreted and no more than 3% of the neutron star's rest mass is ejected into a tenuous, gravitationally bound disk. We find similar results for mass ratios of 2:1 and 1:1, even when we reduce the NS compaction in the 2:1 mass ratio case. These ambient disks reach temperatures suitable for triggering SGRBs, but their masses may be too small to produce the required total energy output. We measure gravitational waveforms and compute the effective strain in frequency space, finding measurable differences between our waveforms and those produced by binary black hole mergers within the advanced LIGO band. These differences appear at frequencies corresponding to the emission that occurs when the NS is tidally disrupted and accreted by the black hole. The resulting information about the radius of the neutron star may be used to constrain the neutron star equation of state.Comment: 22 pages, 14 figures, fixed a few typo

Analysis of changing statistical significance from .05 to .005 in foot and ankle randomized controlled trials

Background: Misinterpretation of p-values in RCTs is extremely problematic since they are the core basis for high levels of recommendation in clinical practice guidelines, especially Orthopaedics. Benjamin et al. proposed a universal protocol change, moving statistical significance from a p-value of .05 to .005 to combat the misinterpretation that is happening in medical literature. In this study, we are looking to evaluate the effect of the protocol suggested by Benjamin et al. on foot and ankle-related RCTs in the top 3 Foot and Ankle-related journals.Methods: We conducted a Pubmed search looking at studies published from January 1st, 2016 to November 10, 2021, in the following three journals; Foot and Ankle International, Journal of Foot and Ankle Surgery, and Foot & Ankle International. The inclusion criteria for the study were RCTs published in the above journals with specifically stated primary endpoints. If a study has multiple primary endpoints, all were included. Exclusion criteria were any study that was not prospective and randomized by design, also any study that did not state primary endpoints was excluded. Two authors extracted the data using a pilot-tested Google form, any disagreements or questions were resolved by published methodologic orthopaedic authors.Results: Of the 222 endpoints, 101 endpoints (45.5%; 101/222) were at or below the .05 threshold while 121 endpoints (54.5%; 121/222) were above the .05 threshold. We also found that 59 endpoints (26.6%; 59/222) were below .005.Conclusion: Our results suggest that changing the threshold for statistical significance from .05 to .005 in foot and ankle RCTs would heavily alter literature published in the field. By implementing this methodology, it is a promising measure to be able to increase RCT quality until a more substantial solution can be found. With that being said, caution must be taken when interpreting our results, also requiring further evaluation

TESS Reveals HD 118203 b to be a Transiting Planet

The exoplanet HD 118203 b, orbiting a bright (V = 8.05) host star, was discovered using the radial velocity method by da Silva et al., but was not previously known to transit. Transiting Exoplanet Survey Satellite (TESS) photometry has revealed that this planet transits its host star. Nine planetary transits were observed by TESS, allowing us to measure the radius of the planet to be 1.136^(+0.029)_(-0.028) R_J, and to calculate the planet mass to be 2.166^(+0.074)_(-0.079) M_J. The host star is slightly evolved with an effective temperature of T_(eff) = 5683^(+84)_(-85) K and a surface gravity of log g = 3.889^(+0.017)_(-0.018). With an orbital period of 6.134985^(+0.000029_(-0.000030) days and an eccentricity of 0.314 ± 0.017, the planet occupies a transitional regime between circularized hot Jupiters and more dynamically active planets at longer orbital periods. The host star is among the 10 brightest known to have transiting giant planets, providing opportunities for both planetary atmospheric and asteroseismic studies

Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development.

BACKGROUND: We present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development. RESULTS: The genome has been sequenced to 2 × coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements. CONCLUSIONS: Analyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution

Natural History of Very Early Onset Inflammatory Bowel Disease in North America: A Retrospective Cohort Study

Background: The incidence of very early onset inflammatory bowel disease (VEOIBD) is increasing, yet the phenotype and natural history of VEOIBD are not well described. Methods: We performed a retrospective cohort study of patients diagnosed with VEOIBD (6 years of age and younger) between 2008 and 2013 at 25 North American centers. Eligible patients at each center were randomly selected for chart review. We abstracted data at diagnosis and at 1, 3, and 5 years after diagnosis. We compared the clinical features and outcomes with VEOIBD diagnosed younger than 3 years of age with children diagnosed with VEOIBD at age 3 to 6 years. Results: The study population included 269 children (105 [39%] Crohn\u27s disease, 106 [39%] ulcerative colitis, and 58 [22%] IBD unclassified). The median age of diagnosis was 4.2 years (interquartile range 2.9-5.2). Most (94%) Crohn\u27s disease patients had inflammatory disease behavior (B1). Isolated colitis (L2) was the most common disease location (70% of children diagnosed younger than 3 years vs 43% of children diagnosed 3 years and older; P = 0.10). By the end of follow-up, stricturing/penetrating occurred in 7 (6.6%) children. The risk of any bowel surgery in Crohn\u27s disease was 3% by 1 year, 12% by 3 years, and 15% by 5 years and did not differ by age at diagnosis. Most ulcerative colitis patients had pancolitis (57% of children diagnosed younger than 3 years vs 45% of children diagnosed 3 years and older; P = 0.18). The risk of colectomy in ulcerative colitis/IBD unclassified was 0% by 1 year, 3% by 3 years, and 14% by 5 years and did not differ by age of diagnosis. Conclusions: Very early onset inflammatory bowel disease has a distinct phenotype with predominantly colonic involvement and infrequent stricturing/penetrating disease. The cumulative risk of bowel surgery in children with VEOIBD was approximately 14%-15% by 5 years. These data can be used to provide anticipatory guidance in this emerging patient population

KELT-16b: A Highly Irradiated, Ultra-short Period Hot Jupiter Nearing Tidal Disruption

We announce the discovery of KELT-16b, a highly irradiated, ultra-short period hot Jupiter transiting the relatively bright (V = 11.7) star TYC 2688-1839-1/KELT-16. A global analysis of the system shows KELT-16 to be an F7V star with K and . The planet is a relatively high-mass inflated gas giant with density g cm-3, surface gravity , and K. The best-fitting linear ephemeris is and day. KELT-16b joins WASP-18b, -19b, -43b, -103b, and HATS-18b as the only giant transiting planets with P \u3c 1 day. Its ultra-short period and high irradiation make it a benchmark target for atmospheric studies by the Hubble Space Telescope, Spitzer, and eventually the James Webb Space Telescope. For example, as a hotter, higher-mass analog of WASP-43b, KELT-16b may feature an atmospheric temperature-pressure inversion and day-to-night temperature swing extreme enough for TiO to rain out at the terminator. KELT-16b could also join WASP-43b in extending tests of the observed mass-metallicity relation of the solar system gas giants to higher masses. KELT-16b currently orbits at a mere ∼1.7 Roche radii from its host star, and could be tidally disrupted in as little as a few ×105 years (for a stellar tidal quality factor of ). Finally, the likely existence of a widely separated bound stellar companion in the KELT-16 system makes it possible that Kozai-Lidov (KL) oscillations played a role in driving KELT-16b inward to its current precarious orbit