1,507 research outputs found

    Missing energy and the measurement of the CP-violating phase in neutrino oscillations

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    In the next generation of long-baseline neutrino oscillation experiments, aiming to determine the charge-parity violating phase δCP\delta_{CP} in the appearance channel, fine-grained time-projection chambers are expected to play an important role. In this Letter, we analyze an influence of realistic detector capabilities on the δCP\delta_{CP} sensitivity for a setup similar to that of the Deep Underground Neutrino Experiment. We find that the effect of the missing energy, carried out by undetected particles, is sizable. Although the reconstructed neutrino energy can be corrected for the missing energy, the accuracy of such procedure has to exceed 20\%, to avoid a sizable bias in the extracted δCP\delta_{CP} value.Comment: 6 pages, 2 figures. v2 matches the version published in PR

    Comparison of the calorimetric and kinematic methods of neutrino energy reconstruction in disappearance experiments

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    To be able to achieve their physics goals, future neutrino-oscillation experiments will need to reconstruct the neutrino energy with very high accuracy. In this work, we analyze how the energy reconstruction may be affected by realistic detection capabilities, such as energy resolutions, efficiencies, and thresholds. This allows us to estimate how well the detector performance needs to be determined a priori in order to avoid a sizable bias in the measurement of the relevant oscillation parameters. We compare the kinematic and calorimetric methods of energy reconstruction in the context of two muon-neutrino disappearance experiments operating in different energy regimes. For the calorimetric reconstruction method, we find that the detector performance has to be estimated with a ~10% accuracy to avoid a significant bias in the extracted oscillation parameters. On the other hand, in the case of kinematic energy reconstruction, we observe that the results exhibit less sensitivity to an overestimation of the detector capabilities.Comment: 16 pages, 14 figures, matches the version published in Phys. Rev.

    A multimodality localization technique for radio-guided surgery

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    <p>Abstract</p> <p>Background</p> <p>Intraoperative localization of image or endoscopy-detected lesions occasionally pose surgical challenges due to the small lesion size and/or difficult anatomic exposure. Identification of such lesions can be facilitated using a hand-held gamma probe with utilization of Tc-99m macroaggregate albumen (MAA) localization technique. The radiopharmaceutical injection can be performed using ultrasound (US) or endoscopy guidance.</p> <p>Case presentations</p> <p>The clinical use of the Tc-99m MAA protocol gamma probe-guided surgery was discussed in three representative cases. Surgical indication was diagnostic exploration in two patients with suspicious lymphadenopathy, and determination of extent of surgical resection in a patient with polyposis. Lesion localization with 100 microcurie (3.7 MBq) Tc-99m MAA prior to surgical exploration resulted in definitive localization of lesions intraoperatively.</p> <p>Conclusion</p> <p>The use Tc-99m MAA deposition technique at the site of surgical target is a highly efficient radio-guided surgery technique with definitive impact on the success of surgical exploration in selected indications.</p

    Strategies of Increased Protein Intake in ELBW Infants Fed by Human Milk Lead to Long Term Benefits

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    Objective: The aim of this observational study was to evaluate the effects of two different protein intake regimes on feeding tolerance, in-hospital growth, anthropometric data and psychomotor outcome up to 24 months corrected age (CA) in extremely low birth-weight (ELBW; birth weight &lt;1000 g) infants.Methods: During the period 2008–2013, 52 ELBW infants admitted at birth to two Neonatal Intensive Care Units of Emilia Romagna (Italy) were fed according to different protocols of protein fortification of human milk: an estimated protein intakes at maximum fortification levels of 3.5 gr/kg/day in the Standard Nutrition Population-SNP group (n = 26) and 4.8 g/kg/day in the Aggressive Nutrition Population-ANP group (n = 26). During hospitalization, infants' growth, biochemical indices of nutritional status, enteral intake, feeding tolerance, clinical history and morbidity were evaluated. After discharge, anthropometric data and psychomotor outcome, evaluated by Revised Griffiths Mental Development Scales (GMDS-R) 0–2 years, were assessed up to 24 months CA.Results: During hospitalization, the ANP group showed significantly higher weight (18.87 vs. 15.20 g/kg/day) and head circumference (0.70 vs. 0.52 cm/week) growth rates compared to SNP, less days of parenteral nutrition (7.36 ± 2.7 vs. 37.75 ± 29.6) and of hospitalization (60.0 ± 13.3 vs. 78.08 ± 21.32). After discharge, ANP infants had a greater head circumference compared to SNP (45.64 ± 0.29; 46.80 ± 0.31). Furthermore, the General Quotient of GMDS-R mean scores in the SNP group significantly decreased from 12 to 24 months CA, while no difference was seen in the ANP group.Conclusions: Increased protein intake may provide short and long term benefits in terms of growth and neurodevelopment in human milk-fed ELBW infants

    Paleocene/Eocene carbon feedbacks triggered by volcanic activity

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    The Paleocene–Eocene Thermal Maximum (PETM) was a period of geologically-rapid carbon release and global warming ~56 million years ago. Although modelling, outcrop and proxy records suggest volcanic carbon release occurred, it has not yet been possible to identify the PETM trigger, or if multiple reservoirs of carbon were involved. Here we report elevated levels of mercury relative to organic carbon—a proxy for volcanism—directly preceding and within the early PETM from two North Sea sedimentary cores, signifying pulsed volcanism from the North Atlantic Igneous Province likely provided the trigger and subsequently sustained elevated CO2. However, the PETM onset coincides with a mercury low, suggesting at least one other carbon reservoir released significant greenhouse gases in response to initial warming. Our results support the existence of ‘tipping points’ in the Earth system, which can trigger release of additional carbon reservoirs and drive Earth’s climate into a hotter state

    Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

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    IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P &lt; .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

    Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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    Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

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    Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| &lt; 0.03 at 95% confidence level. [Figure not available: see fulltext.
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