Pure Gravitational Wave Estimation of Hubble's Constant using Neutron Star-Black Hole Mergers

Here we show how $H_0$ can be derived purely from the gravitational waves (GW) of neutron star-black hole (NSBH) mergers. This new method provides an estimate of $H_0$ spanning the redshift range, $z<0.25$ with current GW sensitivity and without the need for any afterglow detection. We utilise the inherently tight neutron star mass function together with the NSBH waveform amplitude and frequency to estimate distance and redshift respectively, thereby obtaining $H_0$ statistically. Our first estimate is $H_0 = 86^{+55}_{-46}$ km s$^{-1}$ Mpc$^{-1}$ for the secure NSBH events GW190426 and GW200115. We forecast that soon, with 10 more such NSBH events we can reach competitive precision of $\delta H_0/H_0 \lesssim 20\%$.Comment: 13 pages, 10 figure

Diphenhydramine as an adjunct to conscious sedation in bronchoscopy

Intravenous benzodiazepines are commonly used to achieve conscious sedation in outpatient bronchoscopy. Though effective, dose-dependent-adverse events may be encountered with the use of these sedatives. Diphenhydramine, a hypnotic, is sometimes used as an adjunctive agent in bronchoscopy to decrease sedative usage. However, data to support this practice is lacking. Our goal was to determine if adjunctive diphenhydramine significantly decreases doses of benzodiazepine in outpatient bronchoscopy. METHODS: We conducted a single-center retrospective analysis of all outpatient bronchoscopies from November 2013 to February 2016. Subjects included were those who each had two bronchoscopies: no diphenhydramine used (control) versus diphenhydramine used (intervention). The procedure time, total doses of midazolam and opiates (in morphine equivalence) for each procedure were collected. A multiple regression analysis was used to compare differences between bronchoscopy groups in midazolam and opiate use. RESULTS: Of 1164 patients with greater than 1 outpatient bronchoscopies, 61 unique subjects (female 56%) fulfilled the primary inclusion criteria thus resulting to 122 procedures. Mean body mass index was 32 kg/m2. Procedure time was 22.9 ± 16 mins in diphenhydramine group and 23.2 ± 17.8 mins in control group. Mean morphine equivalents administered was 5.6 ± 2.6 mg in diphenhydramine group and 6.2 ± 2.4 mg in control group. Mean midazolam use was 8.4 ± 3.2 mg in diphenhydramine group and 10.2 ± 3.8 mg in control group (difference: -1.795, p-value = 0.005). The mean dose of diphenhydramine used was 38.32 ± 15.12 mg. In a multivariate model, mean midazolam use remained less in the diphenhydramine group after adjusting for procedure time and morphine equivalents, (difference -1.28 mg, p-value = 0.005). CONCLUSIONS: Intravenous administration of diphenhydramine during outpatient bronchoscopy reduces midazolam usage, however, the absolute amount of dose reduction may not be clinically significant

Galaxy formation with Wave/Fuzzy Dark Matter: The core-halo structure

Dark matter-dominated cores have long been claimed for the well-studied local group dwarf galaxies. More recently, extended stellar halos have been uncovered around several of these dwarfs through deeper imaging and spectroscopy. Such core-halo structures are not a feature of conventional cold dark matter (CDM), based on collisionless particles where smooth, scale-free profiles are predicted. In contrast, smooth and prominent dark matter cores are predicted for Warm and Fuzzy/Wave Dark Matter (WDM/$\psi$DM) respectively. The question arises to what extent the visible stellar profiles should reflect this dark matter core structure. Here we compare cosmological hydrodynamical simulations of CDM, WDM $\&$ $\psi$DM, aiming to predict the stellar profiles for these three DM scenarios. We show that cores surrounded by extended halos are distinguishable for WDM and $\psi$DM, with the most prominent cores in the case of $\psi$DM, where the stellar density is enhanced in the core due to the presence of the relatively dense soliton. Our analysis demonstrates that such behavior does not appear in CDM, implying that the small-scale cut-off in the power spectrum present for WDM and $\psi$DM provides a core-halo transition. Consequently, we estimate the mass of the $\psi$DM particle at this core-halo transition point. Furthermore, we observe the anticipated asymmetry for $\psi$DM due to the soliton's random walk, a distinctive characteristic not found in the symmetric distributions of stars in Warm and CDM models.Comment: 17 pages and 15 figure

Recent results from the MAXIMA experiment

MAXIMA is a balloon-borne platform for measuring the anisotropy of the Cosmic Microwave Background (CMB). It has measured the CMB power spectrum with a ten-arcminute FWHM beam, corresponding to a detection of the power spectrum out to spherical harmonic multipole l~1000. The spectrum is consistent with a flat Universe with a nearly scale-invariant initial spectrum of adiabatic density fluctuations. Moreover, the MAXIMA data are free from any notable non-Gaussian contamination and from foreground dust emission. In the same region, the WMAP experiment observes the same structure as that observed by MAXIMA, as evinced by analysis of both maps and power spectra. The next step in the evolution of the MAXIMA program is MAXIPOL, which will observe the polarization of the CMB with comparable resolution and high sensitivity over a small patch of the sky.Comment: To appear in New Astronomy Reviews, Proceedings of the CMBNET Meeting, 20-21 February, 2003, Oxford, U

Primary chemo-radiotherapy in the treatment of locally advanced and inflammatory breast cancer

BACKGROUND: The best management of large, diffuse or inflammatory breast cancers is uncertain and the place of radiotherapy and/or surgery is not clearly defined. METHODS: A cohort of 123 patients with non-metastatic locally advanced or inflammatory breast cancer 3 cm or more in diameter or T4, was treated between 1989 and 2006. All patients received primary chemotherapy followed by radiotherapy, 40 Gy in 15 fractions with 10 Gy boost. Patients with ER positive tumours received Tamoxifen. Assessment was carried out 8 weeks post-treatment and surgery was reserved for residual or recurrent disease. RESULTS: For each stage there were T2/3: 63, T4b: 31 and T4d: 29 patients. 80 had complete clinical response (65%) but 18 patients were never free of inoperable local disease. 25 patients had residual operable disease at assessment and 12 patients who initially had a complete response developed operable local recurrence (LR). 37 Patients (30%) had surgery at a mean of 15 months post diagnosis. At 5 years, overall survival (OS) of the two surgical groups was not significantly different from those 68 patients who had complete remission without surgery, p=0.218, HR 1.46 (0.80-2.55). Surgery as an independent variable to predict survival was not significant on a Cox proportional hazards model (p=0.97). LR in the surgical groups was 13.5% vs 17.5% in the non-surgical patients. The median OS was 64.5 months and disease-free survival (DFS) was 52.5 months. 5-Year OS was 54% and DFS survival 43%. CONCLUSION: In patients with a complete or partial response to chemo-radiotherapy for locally advanced or inflammatory breast cancer, reserving surgery for those with residual or recurrent local disease did not appear to compromise survival. This finding would support examination of this treatment strategy by a randomised controlled trial

Antimicrobial Resistance Incidence and Risk Factors among Helicobacter pylori–Infected Persons, United States

Helicobacter pylori is the primary cause of peptic ulcer disease and an etiologic agent in the development of gastric cancer. H. pylori infection is curable with regimens of multiple antimicrobial agents, and antimicrobial resistance is a leading cause of treatment failure. The Helicobacter pylori Antimicrobial Resistance Monitoring Program (HARP) is a prospective, multicenter U.S. network that tracks national prevalence rates of H. pylori antimicrobial resistance. Of 347 clinical H. pylori isolates collected from December 1998 through 2002, 101 (29.1%) were resistant to one antimicrobial agent, and 17 (4.8%) were resistant to two or more antimicrobial agents. Eighty-seven (25.1%) isolates were resistant to metronidazole, 45 (12.9%) to clarithromycin, and 3 (0.9%) to amoxicillin. On multivariate analysis, black race was the only significant risk factor (p < 0.01, hazard ratio 2.04) for infection with a resistant H. pylori strain. Formulating pretreatment screening strategies or providing alternative therapeutic regimens for high-risk populations may be important for future clinical practice

Reinterpreting Low Frequency LIGO/Virgo Events as Magnified Stellar-Mass Black Holes at Cosmological Distances

Gravitational waves can be focussed by the gravity of an intervening galaxy, just like light, thereby magnifying binary merging events in the far Universe. High magnification by galaxies is found to be responsible for the brightest sources detected in sky surveys, but the low angular resolution of LIGO/Virgo is insufficient to check this lensing possibility directly. Here we find that the first six binary black hole (BBH) merging events reported by LIGO/Virgo show clear evidence for lensing in the plane of observed mass and source distance. The four lowest frequency events follow an apparent locus in this plane, which we can reproduce by galaxy lensing, where the higher the magnification, the generally more distant the source so the wave train is stretched more by the Universal expansion, by factors of 2-4. This revises the reported BBH distances upwards by an order of magnitude, equal to the square root of the magnification. Furthermore, the reported black hole masses must be decreased by 2-4 to counter the larger stretch factor, since the orbital frequency is used to derive the black hole masses. This lowers the masses to 5-15 solar masses, well below the puzzlingly high values of 20-35 solar masses otherwise estimated, with the attraction of finding agreement in mass with black holes orbiting stars in our own Galaxy, thereby implying a stellar origin for the low frequency events in the far Universe. We also show that the other two BBH events of higher frequency detected by LIGO/VIRGO, lie well below the lensing locus, consistent with being nearby and unlensed. If this apparent division between local and distant lensed events is reinforced by new detections then the spins and masses of stellar black holes can be compared over a timespan of 10 billion years by LIGO/Virgo

Evidence for lensing of gravitational waves from LIGO-Virgo data

International audienceRecently, the LIGO-Virgo Collaboration (LVC) has concluded there is no evidence for lensed gravitational waves (GWs) in the first half of the O3 run [LIGO Scientific Collaboration and Virgo Collaboration, Search for lensing signatures in the gravitational-wave observations from the first half of LIGO-Virgo’s third observing run], claiming “We find the observation of lensed events to be unlikely, with the fractional rate at μ&gt;2 being 3.3×10-4.” While we agree that the chance of an individual GW event being lensed at μ&gt;2 is smaller than &lt;10-3, the number of observed events depends on the product of this small probability times the rate of mergers at high redshift. Observational constraints from the stochastic GW background indicate that the rate of conventional mass binary black hole (BBH) mergers (8&lt;M/M⊙&lt;15) in the redshift range 1&lt;z&lt;2 could be as high as O(107) events per year, more than sufficient to compensate for the intrinsically low probability of lensing. To reach the LVC trigger threshold, these events require high magnification but would still produce up to 10–30 LVC observable events per year. Thus, all the LVC observed ordinary stellar mass BBH mergers from this epoch must be strongly lensed with as many as 106  yr-1 events lying below the current detection threshold. By adopting a low BBH coalescence rate at high redshift, LVC implicitly assume that lensed events are insignificant and, thus, incorrectly underestimate the distances of most BBH events and correspondingly overestimate masses by factors of 2–5. Furthermore, the LVC adopted priors on time delay for ideal circularly symmetric lenses are in tension with the known distribution of observed time delays of lensed quasars that require elliptical potentials with a broad spread of time delays. Pairs of events like GW190421_213856GW190910_112807 and GW190424_180648GW190910_112807, which are directly assigned a probability of zero by LVC, should instead be considered as candidate lensed BBH pairs, since their separation in time is typical of lensed quasars. Replacing the LVC model prior for the time delay distribution with the empirical quasar-based distribution reverses the LVC conclusions and says that a significant fraction of BBH pairs identified by LVC are viable multiply lensed events, including quadruple systems

A Distant Origin For Magnified LIGO/Virgo Black Holes Implied By Binary Component Masses

The primary and secondary masses of the binary black holes (BBH) reported by LIGO/Virgo are correlated with a narrow dispersion that appears to increase in proportion to mass. The mean binary mass ratio $1.45\pm0.07$ we show is consistent with pairs drawn randomly from the mass distribution of black holes in our Galaxy. However, BBH masses are concentrated around $\simeq 30M_\odot$, whereas black holes in our Galaxy peak at $\simeq 10M_\odot$. This mass difference can be reconciled by gravitational lensing magnification which allows distant events to be detected with typically $z\simeq 2$, so the waveform is reduced in frequency by $1+z$, and hence the measured chirp masses appear 3 times larger than their intrinsic values. This redshift enhancement also accounts for the dispersion of primary and secondary masses, both of which should increase as $1+z$, thereby appearing to scale with mass, in agreement with the data. Thus the BBH component masses provide independent support for lensing, implying most high chirp mass events have intrinsic masses like the stellar mass black holes in our Galaxy, coalescing at $z>1$, with only two low mass BBH detections, of $\simeq 10M_\odot$ as expected for unlensed events in the local Universe, $z\simeq 0.1$. This lensing solution requires a rapidly declining BBH event rate below $z1$, via efficient binary capture of stellar mass black holes with randomly oriented spins