Demonstration of event position reconstruction based on diffusion in the NEXT-white detector

Noble element time projection chambers are a leading technology for rare event detection in physics, such as for dark matter and neutrinoless double beta decay searches. Time projection chambers typically assign event position in the drift direction using the relative timing of prompt scintillation and delayed charge collection signals, allowing for reconstruction of an absolute position in the drift direction. In this paper, alternate methods for assigning event drift distance via quantification of electron diffusion in a pure high pressure xenon gas time projection chamber are explored. Data from the NEXT-White detector demonstrate the ability to achieve good position assignment accuracy for both high- and low-energy events. Using point-like energy deposits from 83mKr calibration electron captures (E ∼ 45  keV), the position of origin of low-energy events is determined to 2 cm precision with bias < 1 mm. A convolutional neural network approach is then used to quantify diffusion for longer tracks (E ≥ 1.5  MeV), from radiogenic electrons, yielding a precision of 3 cm on the event barycenter. The precision achieved with these methods indicates the feasibility energy calibrations of better than 1% FWHM at Qββ in pure xenon, as well as the potential for event fiducialization in large future detectors using an alternate method that does not rely on primary scintillation.

Unification of Efforts to Improve Global Access to Cancer Therapeutics: Report From the 2022/2023 Access to Essential Cancer Medicines Stakeholder Summit

PURPOSE

There is an urgent need to improve access to cancer therapy globally. Several independent initiatives have been undertaken to improve access to cancer medicines, and additional new initiatives are in development. Improved sharing of experiences and increased collaboration are needed to achieve substantial improvements in global access to essential oncology medicines.

METHODS

The inaugural Access to Essential Cancer Medicines Stakeholder Meeting was organized by ASCO and convened at the June 2022 ASCO Annual Meeting in Chicago, IL, with two subsequent meetings, Union for International Cancer Control World Cancer Congress held in Geneva, Switzerland, in October 2022 and at the ASCO Annual Meeting in June of 2023. Invited stakeholders included representatives from cancer institutes, physicians, researchers, professional societies, the pharmaceutical industry, patient advocacy organizations, funders, cancer organizations and foundations, policy makers, and regulatory bodies. The session was moderated by ASCO. Past efforts and current and upcoming initiatives were initially discussed (2022), updates on progress were provided (2023), and broad agreement on resulting action steps was achieved with participants.

RESULTS

Summit participants recognized that while much work was ongoing to enhance access to cancer therapeutics globally, communication and synergy across projects and organizations could be enhanced by providing a platform for collaboration and shared expertise.

CONCLUSION

The summit resulted in new cross-stakeholder insights and planned collaboration addressing barriers to accessing cancer medications. Specific actions and timelines for implementation and reporting were established.

Global Cancer Drug Development-A Report From the 2022 Accelerating Anticancer Agent Development and Validation Meeting

Rapidly expanding systemic treatment options, combined with improved screening, diagnostic, surgical, and radiotherapy techniques, have led to improved survival outcomes for many cancers over time. However, these overall survival gains have disproportionately benefited patients in high-income countries, whereas patients in low- and middle-income countries (LMICs) continue to experience challenges in accessing timely and guideline concordant care. In September 2022, the Accelerating Anticancer Agent Development and Validation workshop was held, focusing on global cancer drug development. Panelists discussed key barriers such as the lack of diagnostic services and human resources, drug accessibility and affordability, lack of research infrastructure, and regulatory and authorization challenges, with a particular focus on Africa and Latin America. Potential opportunities to improve access and affordability were reviewed, such as the importance of prioritizing investments in diagnostics, investing health infrastructure and work force planning, coordinated drug procurement efforts and streamlined regulatory processing, incentivized pricing through regulatory change, and the importance of developing and promoting clinical trials that can answer relevant clinical questions for patients in LMICs. As a cancer community, we must continue to advocate for and work toward equitable access to high-quality interventions for patients, regardless of their geographical location.

First Constraints on Heavy QCD Axions with a Liquid Argon Time Projection Chamber Using the ArgoNeuT Experiment

We present the results of a search for heavy QCD axions performed by the ArgoNeuT experiment at Fermilab. We search for heavy axions produced in the NuMI neutrino beam target and absorber decaying into dimuon pairs, which can be identified using the unique capabilities of ArgoNeuT and the MINOS near detector. This decay channel is motivated by a broad class of heavy QCD axion models that address the strong CP and axion quality problems with axion masses above the dimuon threshold. We obtain new constraints at a 95% confidence level for heavy axions in the previously unexplored mass range of 0.2-0.9 GeV, for axion decay constants around tens of TeV.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Point Absorber Limits to Future Gravitational-Wave Detectors

High-quality optical resonant cavities require low optical loss, typically on the scale of parts per million. However, unintended micron-scale contaminants on the resonator mirrors that absorb the light circulating in the cavity can deform the surface thermoelastically and thus increase losses by scattering light out of the resonant mode. The point absorber effect is a limiting factor in some high-power cavity experiments, for example, the Advanced LIGO gravitational-wave detector. In this Letter, we present a general approach to the point absorber effect from first principles and simulate its contribution to the increased scattering. The achievable circulating power in current and future gravitational-wave detectors is calculated statistically given different point absorber configurations. Our formulation is further confirmed experimentally in comparison with the scattered power in the arm cavity of Advanced LIGO measured by in situ photodiodes. The understanding presented here provides an important tool in the global effort to design future gravitational-wave detectors that support high optical power and thus reduce quantum noise.

New Constraints on Tau-Coupled Heavy Neutral Leptons with Masses m_{N}=280-970 MeV

A search for heavy neutral leptons has been performed with the ArgoNeuT detector exposed to the NuMI neutrino beam at Fermilab. We search for the decay signature N→νμ^{+}μ^{-}, considering decays occurring both inside ArgoNeuT and in the upstream cavern. In the data, corresponding to an exposure to 1.25×10^{20}  POT, zero passing events are observed consistent with the expected background. This measurement leads to a new constraint at 90% confidence level on the mixing angle |U_{τN}|^{2} of tau-coupled Dirac heavy neutral leptons with masses m_{N}=280-970  MeV, assuming |U_{eN}|^{2}=|U_{μN}|^{2}=0.

OS08.5.A Proteomic analysis of meningioma

BACKGROUND

Meningioma is the most common primary intracranial tumor. Although ~80% are benign some WHO grade I are clinically aggressive. Chemotherapies are ineffective and biomarkers for clinical management are lacking. Approximately 60% sporadic meningiomas harbor mutations in the NF2 gene andutations in TRAF7, KLF4, AKT1, SMO and PIK3CA have been identified in the majority NF2-positive tumors esp lower grade. However, the molecular mechanisms behind meningioma tumourigenesis is still unclear. We aim to identify novel biomarkers and therapeutic targets of meningioma by characterizing the proteomic landscape.

MATERIAL AND METHODS

We analysed grade I, II and III frozen meningioma specimens and three different mutational groups: AKT1/TRAF7, KLF4/TRAF7 and NF2 -/- using LC-MS/MS to analyse global proteins, enriched phosphoproteins and phosphopeptides. Differential expression and functional annotation of proteins was completed using Perseus, IPA® and DAVID. For mutational subtypes quantitative phosphoproteomics was performed using TMT 10plex labeling approach followed by motif analysis using motif-X algorithm. We validated differential expression of proteins and phosphoproteins by Western blot and immunohistochemistry.

RESULTS

We quantified 3888 proteins and 3074 phosphoproteins across all meningioma grades. Bioinformatics analysis revealed commonly upregulated (phospho)proteins to be enriched in Gene Ontology terms associated with RNA metabolism. Validation confirmed significant overexpression of proteins such as EGFR, CKAP4, the nuclear proto-oncogene SET, the splicing factor SF2/ASF as well as total and activated phosphorylated form of the NIMA-related kinase, NEK9, involved in mitotic progression. Hexokinase 2 was overexpressed in higher grades. For the mutation subtypes we have quantified 4162 proteins across all mutational meningioma subgroups. Analysis showed distinct proteomic profiles of mutational subgroups. Comparative analysis showed 10 proteins were commonly significantly upregulated among all mutational subtypes vs. normal meninges. 257 proteins were commonly significantly downregulated and enriched with molecular functions including aldehyde dehydrogenase and oxido-reductase. Mutational subtype-specific analysis identified 162 proteins significantly upregulated in AKT1/TRAF7 vs. remaining sample groups to be enriched in the oxidative phosphorylation pathway. 14 and 7 proteins were commonly significantly upregulated in KLF4/TRAF7 and NF2 -/- mutant meningioma subtypes respectively. Several of these up-regulated proteins including ANNEXIN-3, CRABP2, CLIC3 and Endoglin were verified via WB. Lastly, analyses of 6600 phosphosites predicted regulatory kinases

CONCLUSION

We show extensive proteomic and phospophoproteomics analysis of meningioma and suggest new therapeutic and biomarker candidates.

Cosmic Ray Background Removal With Deep Neural Networks in SBND

In liquid argon time projection chambers exposed to neutrino beams and running on or near surface levels, cosmic muons, and other cosmic particles are incident on the detectors while a single neutrino-induced event is being recorded. In practice, this means that data from surface liquid argon time projection chambers will be dominated by cosmic particles, both as a source of event triggers and as the majority of the particle count in true neutrino-triggered events. In this work, we demonstrate a novel application of deep learning techniques to remove these background particles by applying deep learning on full detector images from the SBND detector, the near detector in the Fermilab Short-Baseline Neutrino Program. We use this technique to identify, on a pixel-by-pixel level, whether recorded activity originated from cosmic particles or neutrino interactions.

Approaching the motional ground state of a 10-kg object

The motion of a mechanical object, even a human-sized object, should be governed by the rules of quantum mechanics. Coaxing them into a quantum state is, however, difficult because the thermal environment masks any quantum signature of the object's motion. The thermal environment also masks the effects of proposed modifications of quantum mechanics at large mass scales. We prepared the center-of-mass motion of a 10-kilogram mechanical oscillator in a state with an average phonon occupation of 10.8. The reduction in temperature, from room temperature to 77 nanokelvin, is commensurate with an 11 orders-of-magnitude suppression of quantum back-action by feedback and a 13 orders-of-magnitude increase in the mass of an object prepared close to its motional ground state. Our approach will enable the possibility of probing gravity on massive quantum systems.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

The threat of the COVID-19 pandemic on reversing global life-saving gains in the survival of childhood cancer: a call for collaborative action from SIOP, IPSO, PROS, WCC, CCI, St Jude Global, UICC and WHPCA

The COVID-19 pandemic poses an unprecedented health crisis in all socio-economic regions across the globe. While the pandemic has had a profound impact on access to and delivery of health care by all services, it has been particularly disruptive for the care of patients with life-threatening noncommunicable diseases (NCDs) such as the treatment of children and young people with cancer.

The reduction in child mortality from preventable causes over the last 50 years has seen childhood cancer emerge as a major unmet health care need. Whilst survival rates of 85% have been achieved in high income countries, this has not yet been translated into similar outcomes for children with cancer in resource-limited settings where survival averages 30%. Launched in 2018, by the World Health Organization (WHO), the Global Initiative for Childhood Cancer (GICC) is a pivotal effort by the international community to achieve at least 60% survival for children with cancer by 2030.

The WHO GICC is already making an impact in many countries but the disruption of cancer care during the COVID-19 pandemic threatens to set back this global effort to improve the outcome for children with cancer, wherever they may live.

As representatives of the global community committed to fostering the goals of the GICC, we applaud the WHO response to the COVID-19 pandemic, in particular we support the WHO’s call to ensure the needs of patients with life threatening NCDs including cancer are not compromised during the pandemic. Here, as collaborative partners in the GICC, we highlight specific areas of focus that need to be addressed to ensure the immediate care of children and adolescents with cancer is not disrupted during the pandemic; and measures to sustain the development of cancer care so the long-term goals of the GICC are not lost during this global health crisis.

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

Depression and cognitive impairment in the elderly: a multicentre study

The present study, conducted in collaboration between the Departments of Psychiatry in Swiss Universities and the World Health Organization, had two main goals: to develop assessment methods which could subsequently be used in the Swiss centres in a standard manner; and to make arrangements for continuing collaboration between the centres in Switzerland and the acquisition of new knowledge about the distinctions between depression and cognitive impairment. For this aim, three different groups of elderly patients of either sex were selected during the period of November 1989 to July 1991 for inclusion in the study. The first two groups included the first ten patients of either sex over 60 years of age consecutively contacting the participating institutions and showing depression with or without clinically significant symptoms of cognitive impairment; the control group included patients showing no depression or clinically significant symptoms of cognitive impairment. A total of 125 patients were included in the initial evaluation, 69 of which were reassessed at a seven-month follow up (on average). Each patient was administered a number of clinician-rated or self-report instruments for the assessment of depression, cognitive impairment, disabilities, physical status and onset of disorders. The study has shown that a variety of instruments can be used for the reliable assessment of depression or cognitive impairment in the elderly; but the instruments for the assessment of depression differentiate only poorly between patients with or without cognitive impairment. Because of the importance of identifying both depressed and cognitively impaired patients among the elderly, different assessment instruments targeted at the different symptom clusters need to be administered simultaneously.

Improved Limits on Millicharged Particles Using the ArgoNeuT Experiment at Fermilab

A search for millicharged particles, a simple extension of the standard model, has been performed with the ArgoNeuT detector exposed to the Neutrinos at the Main Injector beam at Fermilab. The ArgoNeuT liquid argon time projection chamber detector enables a search for millicharged particles through the detection of visible electron recoils. We search for an event signature with two soft hits (MeV-scale energy depositions) aligned with the upstream target. For an exposure of the detector of 1.0×10^{20} protons on target, one candidate event has been observed, compatible with the expected background. This search is sensitive to millicharged particles with charges between 10^{-3}e and 10^{-1}e and with masses in the range from 0.1 to 3 GeV. This measurement provides leading constraints on millicharged particles in this large unexplored parameter space region.

Breastfeeding is associated with reduced risk of multiple sclerosis in males, predominantly among HLA-DRB1*15:01 carriers

BACKGROUND

Breastfeeding as an infant appears protective against later development of some autoimmune diseases, but research into its influence on multiple sclerosis (MS) risk has yielded inconclusive results.

OBJECTIVE

We investigated the possible impact of breastfeeding on MS risk.

METHODS

We used two population-based case-control studies comprising 3670 cases and 6737 matched controls. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for association between MS and exposure to prolonged breastfeeding (4 months or longer) versus reduced breastfeeding (less than 4 months). A meta-analysis of case-control studies that assessed the impact of breastfeeding on MS risk among women and men was conducted.

RESULTS

Prolonged breastfeeding was associated with reduced MS risk among men (OR 0.7, 95% CI 0.5-0.9) but not among women (OR 0.9, 95% CI 0.8-1.1). Among men, a synergistic effect was observed between HLA-DRB1*15:01 carrier status and reduced breastfeeding.

CONCLUSIONS

Findings from the current study add to accumulating evidence that breastfeeding may be a modifiable protective factor for reducing the risk of MS in offspring. When possible, mothers should be supported to breastfeed their infants; however, the mechanism of a sex-specific biologic effect of breastfeeding on MS risk is unclear.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present our current best estimate of the plausible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next several years, with the intention of providing information to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals for the third (O3), fourth (O4) and fifth observing (O5) runs, including the planned upgrades of the Advanced LIGO and Advanced Virgo detectors. We study the capability of the network to determine the sky location of the source for gravitational-wave signals from the inspiral of binary systems of compact objects, that is binary neutron star, neutron star-black hole, and binary black hole systems. The ability to localize the sources is given as a sky-area probability, luminosity distance, and comoving volume. The median sky localization area (90% credible region) is expected to be a few hundreds of square degrees for all types of binary systems during O3 with the Advanced LIGO and Virgo (HLV) network. The median sky localization area will improve to a few tens of square degrees during O4 with the Advanced LIGO, Virgo, and KAGRA (HLVK) network. During O3, the median localization volume (90% credible region) is expected to be on the order of 10 5 , 10 6 , 10 7 Mpc 3 for binary neutron star, neutron star-black hole, and binary black hole systems, respectively. The localization volume in O4 is expected to be about a factor two smaller than in O3. We predict a detection count of 1 - 1 + 12 ( 10 - 10 + 52 ) for binary neutron star mergers, of 0 - 0 + 19 ( 1 - 1 + 91 ) for neutron star-black hole mergers, and 17 - 11 + 22 ( 79 - 44 + 89 ) for binary black hole mergers in a one-calendar-year observing run of the HLV network during O3 (HLVK network during O4). We evaluate sensitivity and localization expectations for unmodeled signal searches, including the search for intermediate mass black hole binary mergers.

Quantum-Enhanced Advanced LIGO Detectors in the Era of Gravitational-Wave Astronomy

The Laser Interferometer Gravitational Wave Observatory (LIGO) has been directly detecting gravitational waves from compact binary mergers since 2015. We report on the first use of squeezed vacuum states in the direct measurement of gravitational waves with the Advanced LIGO H1 and L1 detectors. This achievement is the culmination of decades of research to implement squeezed states in gravitational-wave detectors. During the ongoing O3 observation run, squeezed states are improving the sensitivity of the LIGO interferometers to signals above 50 Hz by up to 3 dB, thereby increasing the expected detection rate by 40% (H1) and 50% (L1).

Search for Subsolar Mass Ultracompact Binaries in Advanced LIGO's Second Observing Run

We present a search for subsolar mass ultracompact objects in data obtained during Advanced LIGO's second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational-wave candidates consistent with subsolar mass ultracompact binaries with at least one component between 0.2  M_{⊙}-1.0  M_{⊙}. We use the null result to constrain the binary merger rate of (0.2  M_{⊙}, 0.2  M_{⊙}) binaries to be less than 3.7×10^{5}  Gpc^{-3} yr^{-1} and the binary merger rate of (1.0  M_{⊙}, 1.0  M_{⊙}) binaries to be less than 5.2×10^{3}  Gpc^{-3} yr^{-1}. Subsolar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with subsolar masses. Assuming a particular primordial black hole (PBH) formation model, we constrain a population of merging 0.2  M_{⊙} black holes to account for less than 16% of the dark matter density and a population of merging 1.0  M_{⊙} black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict subsolar mass binaries.

Dose Reduction While Preserving Diagnostic Quality in Head CT: Advancing the Application of Iterative Reconstruction Using a Live Animal Model

BACKGROUND AND PURPOSE

Iterative reconstruction has promise in lowering the radiation dose without compromising image quality, but its full potential has not yet been realized. While phantom studies cannot fully approximate the subjective effects on image quality, live animal models afford this assessment. We characterize dose reduction in head CT by applying advanced modeled iterative reconstruction (ADMIRE) in a live ovine model while evaluating preservation of gray-white matter detectability and image texture compared with filtered back-projection.

MATERIALS AND METHODS

A live sheep was scanned on a Force CT scanner (Siemens) at 12 dose levels (82-982 effective mAs). Images were reconstructed with filtered back-projection and ADMIRE (strengths, 1-5). A total of 72 combinations (12 doses × 6 reconstructions) were evaluated qualitatively for resemblance to the reference image (highest dose with filtered back-projection) using 2 metrics: detectability of gray-white matter differentiation and noise-versus-smoothness in image texture. Quantitative analysis for noise, SNR, and contrast-to-noise was also performed across all dose-strength combinations.

RESULTS

Both qualitative and quantitative results confirm that gray-white matter differentiation suffers at a lower dose but recovers when complemented by higher iterative reconstruction strength, and image texture acquires excessive smoothness with a higher iterative reconstruction strength but recovers when complemented by dose reduction. Image quality equivalent to the reference image is achieved by a 58% dose reduction with ADMIRE-5.

CONCLUSIONS

An approximately 60% dose reduction may be possible while preserving diagnostic quality with the appropriate dose-strength combination. This in vivo study can serve as a useful guide for translating the full implementation of iterative reconstruction in clinical practice.

First Measurement of Inclusive Muon Neutrino Charged Current Differential Cross Sections on Argon at E_{ν}∼0.8 GeV with the MicroBooNE Detector

We report the first measurement of the double-differential and total muon neutrino charged current inclusive cross sections on argon at a mean neutrino energy of 0.8 GeV. Data were collected using the MicroBooNE liquid argon time projection chamber located in the Fermilab Booster neutrino beam and correspond to 1.6×10^{20} protons on target of exposure. The measured differential cross sections are presented as a function of muon momentum, using multiple Coulomb scattering as a momentum measurement technique, and the muon angle with respect to the beam direction. We compare the measured cross sections to multiple neutrino event generators and find better agreement with those containing more complete treatment of quasielastic scattering processes at low Q^{2}. The total flux integrated cross section is measured to be 0.693±0.010(stat)±0.165(syst)×10^{-38}  cm^{2}.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

"I'll look after the kids while you go and have a shower": an evaluation of a service to address mild to moderate maternal perinatal mental health problems

BACKGROUND

Perinatal mental health (PMH) problems are a major public health concern because they may impair parenting ability which potentially has an immediate and long-term impact on the physical, cognitive and emotional health of the child.

AIMS

We evaluated a Perinatal Support Service (PSS) which supports positive attachment between mothers with PMH problems and their child, to evidence its impact on maternal mental health and maternal-infant interaction.

METHOD

Using a mixed-methods approach, anonymised pre- and post-service outcomes data from 123 clients, 14 interviews and a focus group discussion were analysed.

RESULTS

We found significant improvement in anxiety (t (55) = 6.96, p < 0.01, 95% CI [3.15, 5.70]), and depression (t (55) = 6.58, p < 0.01, 95% CI [3.03, 5.68]) on the HADS, and on the GAD-7 (t (12) = 4.541, p = 0.001, 95% CI [3.48, 9.90]) after the PSS. Anxiety post service (M = 9.08, SD = 4.96) was lower than baseline anxiety (M = 15.77, SD = 4.68). Receiving emotional and practical support contributed to improvements in mental health and mother-child interaction.

CONCLUSION

Given the paucity of PMH services in the UK, it is imperative that services such as the PSS continue to receive funding to address unmet PMH needs.

WP1-22 DuraGen™ as an encapsulating material for neural stem cell delivery

Objectives

Achieving neural regeneration after spinal cord injury (SCI) represents a significant challenge. Neural stem cell (NSC) therapy offers replacement of damaged cells and delivery of pro-regenerative factors, but >95% of cells die when transplanted to sites of neural injury. Biomaterial scaffolds provide cellular protective encapsulation to improve cell survival. However, current available scaffolds are overwhelmingly not approved for human use, presenting a major barrier to clinical translation. Surgical biomaterials offer the unique benefit of being FDA-approved for human implantation. Specifically, a neurosurgical grade material, DuraGen™, used predominantly for human duraplasty has many attractive features of an ideal biomaterial scaffold. Here, we have investigated the use of DuraGen™ as a 3D cell encapsulation device for potential use in combinatorial, regenerative therapies.

Methods

Primary NSCs were seeded into optimised sheets of DuraGen™. NSC growth and fate within DuraGen™ were assessed using 3D microscopic fluorescence imaging techniques.

Results

DuraGen™ supports the survival (ca 95% viability, 12 days) and 3D growth of NSCs. NSC phenotype, proliferative capacity and differentiation into astrocytes, neurons and oligodendrocytes were unaffected by DuraGen™.

Conclusions

A ‘combinatorial therapy’, consisting of NSCs protected within a DuraGen™ matrix, offers a potential clinically translatable approach for neural cell therapy.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.