348 research outputs found

    Social cost benefit analysis of water and sanitation improvement in a poor urban slum

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    A health-based socio-economic assessment as well as side-by-side social cost benefit analysis is depicted in this visual synopsis of research carried out in a suburban slum in Tripoli, Lebanon. 88% of reported diarrheal cases are attributed to unsafe water supply, inadequate sanitation and hygiene, with cases distributed uniformly throughout the year. The poster includes field observations, and a selection of alternative interventions with estimated costs. Installing rooftop tanks and replacing water piping at the household level are the most economically viable interventions

    Racial disparity and survival outcomes between African-American and Caucasian American men with penile cancer

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    Objective: To determine whether there is a survival difference for African-American men (AAM) versus Caucasian American men (CM) with penile squamous cell carcinoma (pSCC), particularly in locally advanced and metastatic cases where disease mortality is highest. Patients and Methods: Using the Florida Cancer Data System, we identified men with pSCC from 2005 to 2013. We compared age, follow-up, stage, race, and treatment type between AAM and CM. We performed Kaplan\u2013Meier analysis for overall survival (OS) between AAM and CM for all stages, and for those with locally advanced and metastatic disease. A multivariable model was developed to determine significant predictors of OS. Results: In all, 653 men (94 AAM and 559 CM) had pSCC and 198 (30%) had locally advanced and/or metastatic disease. A higher proportion of AAM had locally advanced and/or metastatic disease compared to CM (38 [40%] vs 160 [29%], P = 0.03). The median (interquartile range) follow-up for the entire cohort was 12.6 (5.4\u201332.0) months. For all stages, AAM had a significantly lower median OS compared to CM (26 vs 36\ua0months, P = 0.03). For locally advanced and metastatic disease, there was a consistent trend toward disparity in median OS between AAM and CM (17 vs 22\ua0months, P = 0.06). After adjusting for age, stage, grade, and treatment type, AAM with pSCC had a greater likelihood of death compared to CM (hazard ratio 1.64, P = 0.014). Conclusions: AAM have worse OS compared to CM with pSCC and this may partly be due to advanced stage at presentation. Treatment disparity may also contribute to lessened survival in AAM, but we were unable to demonstrate a significant difference in treatment utilisation between the groups

    Trees with Given Stability Number and Minimum Number of Stable Sets

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    We study the structure of trees minimizing their number of stable sets for given order nn and stability number α\alpha. Our main result is that the edges of a non-trivial extremal tree can be partitioned into nαn-\alpha stars, each of size n1nα\lceil \frac{n-1}{n-\alpha} \rceil or n1nα\lfloor \frac{n-1}{n-\alpha}\rfloor, so that every vertex is included in at most two distinct stars, and the centers of these stars form a stable set of the tree.Comment: v2: Referees' comments incorporate

    Whole exome sequencing in fetuses with isolated increased nuchal translucency: a systematic review and meta-analysis.

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    OBJECTIVE: To estimate the incremental yield of detecting pathogenic or likely pathogenic diagnostic genetic variants (DGV) by whole exome sequencing (WES) over standard karyotype and chromosomal microarray (CMA) analyses in fetuses with isolated increased nuchal translucency (NT) and normal fetal anatomy at the time of 11-14 weeks scan. MATERIALS AND METHODS: Medline and Embase databases were searched. Inclusion criteria were fetuses with NT >95th percentile, normal karyotype and CMA and no associated structural anomalies at the time of the 11-14 weeks scan. The primary outcome was to estimate the incremental yield of detecting pathogenic or likely pathogenic genetic variants by WES over standard karyotype and CMA analyses in fetuses with isolated increased nuchal translucency. The secondary outcomes were the detection of a genetic variant of unknown significance. Sub-analysis according to different NT cutoffs (between 3.0 and 5.5 mm and > 5.5 mm) and considering fetuses with isolated NT in which fetal anatomy was confirmed to be normal at the anomaly scan were also performed. Random effects model meta-analyses of proportion were used to analyze the data. RESULTS: Eight articles (324 fetuses) were included in the systematic review. Of the fetuses with negative standard karyotype and CMA analysis, the 8.07% (95% CI 5.4-11.3) had pathogenic or likely pathogenic genetic variants detected exclusively by WES. When stratifying the analysis according to NT cutoffs, genetic anomalies detected exclusively at WES analysis were found in 44.70% (95% CI 26.8-63.4) of fetuses with NT between 3.0 mm and 5.5 mm and 55.3% (95% CI 36.6-73.2) in those fetuses with NT >5.5 mm and positive WES results. The 7.84% (95% CI 1.6-18.2) had variants of unknown significance identified by WES. When considering fetuses with isolated increased NT and normal fetal anatomy at the anomaly scan, the rate of pathogenic or likely pathogenic genetic variants detected by WES was 3.87% (95% CI 1.6-7.1), while variants of unknown significance were detected in 4.27% (95% CI 2.2-7.0) of cases. CONCLUSIONS: Pathogenic and likely pathogenic genetic variants detected by WES are present in a significant proportion of fetuses with increased NT but normal standard karyotype and CMA analysis, also when no anomalies are detected at the anomaly scan. Further large studies sharing objective protocols of imaging assessment are needed to confirm these findings and to elucidate which gene panels should be assessed in fetuses with isolated increased NT to rule out associated genetic anomalies, which may potentially impact post-natal outcomes

    Acceptance Tests of more than 10 000 Photomultiplier Tubes for the multi-PMT Digital Optical Modules of the IceCube Upgrade

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    More than 10000 photomultiplier tubes (PMTs) with a diameter of 80 mm will be installed in multi-PMT Digital Optical Modules (mDOMs) of the IceCube Upgrade. These have been tested and pre-calibrated at two sites. A throughput of more than 1000 PMTs per week with both sites was achieved with a modular design of the testing facilities and highly automated testing procedures. The testing facilities can easily be adapted to other PMTs, such that they can, e.g., be re-used for testing the PMTs for IceCube-Gen2. Single photoelectron response, high voltage dependence, time resolution, prepulse, late pulse, afterpulse probabilities, and dark rates were measured for each PMT. We describe the design of the testing facilities, the testing procedures, and the results of the acceptance tests

    Improved modeling of in-ice particle showers for IceCube event reconstruction

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    The IceCube Neutrino Observatory relies on an array of photomultiplier tubes to detect Cherenkov light produced by charged particles in the South Pole ice. IceCube data analyses depend on an in-depth characterization of the glacial ice, and on novel approaches in event reconstruction that utilize fast approximations of photoelectron yields. Here, a more accurate model is derived for event reconstruction that better captures our current knowledge of ice optical properties. When evaluated on a Monte Carlo simulation set, the median angular resolution for in-ice particle showers improves by over a factor of three compared to a reconstruction based on a simplified model of the ice. The most substantial improvement is obtained when including effects of birefringence due to the polycrystalline structure of the ice. When evaluated on data classified as particle showers in the high-energy starting events sample, a significantly improved description of the events is observed

    All-sky Search for Transient Astrophysical Neutrino Emission with 10 Years of IceCube Cascade Events

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    Neutrino flares in the sky are searched for in data collected by IceCube between 2011 and 2021 May. This data set contains cascade-like events originating from charged-current electron neutrino and tau neutrino interactions and all-flavor neutral-current interactions. IceCube’s previous all-sky searches for neutrino flares used data sets consisting of track-like events originating from charged-current muon neutrino interactions. The cascade data set is statistically independent of the track data sets, and while inferior in angular resolution, the low-background nature makes it competitive and complementary to previous searches. No statistically significant flare of neutrino emission was observed in an all-sky scan. Upper limits are calculated on neutrino flares of varying duration from 1 hr to 100 days. Furthermore, constraints on the contribution of these flares to the diffuse astrophysical neutrino flux are presented, showing that multiple unresolved transient sources may contribute to the diffuse astrophysical neutrino flux

    Citizen science for IceCube: Name that Neutrino

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    Name that Neutrino is a citizen science project where volunteers aid in classification of events for the IceCube Neutrino Observatory, an immense particle detector at the geographic South Pole. From March 2023 to September 2023, volunteers did classifications of videos produced from simulated data of both neutrino signal and background interactions. Name that Neutrino obtained more than 128,000 classifications by over 1800 registered volunteers that were compared to results obtained by a deep neural network machine-learning algorithm. Possible improvements for both Name that Neutrino and the deep neural network are discussed

    Search for neutrino emission from cores of active galactic nuclei

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    The sources of the majority of the high-energy astrophysical neutrinos observed with the IceCube neutrino telescope at the South Pole are unknown. So far, only a flaring gamma-ray blazar was compellingly associated with the emission of high-energy neutrinos. However, several studies suggest that the neutrino emission from the gamma-ray blazar population only accounts for a small fraction of the total astrophysical neutrino flux. In this work we probe the production of high-energy neutrinos in the cores of active galactic nuclei (AGN), induced by accelerated cosmic rays in the accretion disk region. We present a likelihood analysis based on eight years of IceCube data, searching for a cumulative neutrino signal from three AGN samples created for this work. The neutrino emission is assumed to be proportional to the accretion disk luminosity estimated from the soft x-ray flux. Next to the observed soft x-ray flux, the objects for the three samples have been selected based on their radio emission and infrared color properties. For the largest sample in this search, an excess of high-energy neutrino events with respect to an isotropic background of atmospheric and astrophysical neutrinos is found, corresponding to a post-trial significance of 2.60σ. If interpreted as a genuine signal with the assumptions of a proportionality of x-ray and neutrino fluxes and a model for the subthreshold flux distribution, then this observation implies that at 100 TeV, 27%-100% of the observed neutrinos arise from particle acceleration in the core of AGN at 1σ confidence interval

    Searches for Neutrinos from Large High Altitude Air Shower Observatory Ultra-high-energy γ-Ray Sources Using the IceCube Neutrino Observatory

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    Galactic PeV cosmic-ray accelerators (PeVatrons) are Galactic sources theorized to accelerate cosmic rays up to PeV in energy. The accelerated cosmic rays are expected to interact hadronically with nearby ambient gas or the interstellar medium, resulting in γ-rays and neutrinos. Recently, the Large High Altitude Air Shower Observatory (LHAASO) identified 12 γ-ray sources with emissions above 100 TeV, making them candidates for PeVatrons. While at these high energies the Klein-Nishina effect exponentially suppresses leptonic emission from Galactic sources, evidence for neutrino emission would unequivocally confirm hadronic acceleration. Here, we present the results of a search for neutrinos from these γ-ray sources and stacking searches testing for excess neutrino emission from all 12 sources as well as their subcatalogs of supernova remnants and pulsar wind nebulae with 11 yr of track events from the IceCube Neutrino Observatory. No significant emissions were found. Based on the resulting limits, we place constraints on the fraction of γ-ray flux originating from the hadronic processes in the Crab Nebula and LHAASO J2226+6057
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