4,931 research outputs found
Renormalization effects on neutrino masses and mixing in a string-inspired SU(4) X SU(2)_L X SU(2)_R X U(1)_X model
We discuss renormalization effects on neutrino masses and mixing angles in a
supersymmetric string-inspired SU(4) X SU(2)_L X SU(2)_R X U(1)_X model, with
matter in fundamental and antisymmetric tensor representations and singlet
Higgs fields charged under the anomalous U(1)_X family symmetry. The quark,
lepton and neutrino Yukawa matrices are distinguished by different
Clebsch-Gordan coefficients. The presence of a second U(1)_X breaking singlet
with fractional charge allows a more realistic, hierarchical light neutrino
mass spectrum with bi-large mixing. By numerical investigation we find a region
in the model parameter space where the neutrino mass-squared differences and
mixing angles at low energy are consistent with experimental data.Comment: 9 pages, 7 figures; references adde
Inverted neutrino mass hierarchies from U(1) symmetries
Motivated by effective low energy models of string origin, we discuss the
neutrino masses and mixing within the context of the Minimal Supersymmetric
Standard Model supplemented by a U(1) anomalous family symmetry and additional
Higgs singlet fields charged under this extra U(1). In particular, we interpret
the solar and atmospheric neutrino data assuming that there are only three
left-handed neutrinos which acquire Majorana masses via a lepton number
violating dimension-five operator. We derive the general form of the charged
lepton and neutrino mass matrices when two different pairs of singlet Higgs
fields develop non--zero vacuum expectation values and show how the resulting
neutrino textures are related to approximate lepton flavor symmetries. We
perform a numerical analysis for one particular case and obtain solutions for
masses and mixing angles, consistent with experimental data.Comment: 15 pages, 4 figure
Running neutrino masses and mixing in a SU(4) x SU(2)^2 x U(1)_X model
In this talk, we discuss the implications of the renormalization group
equations for the neutrino masses and mixing angles in a supersymmetric
string-inspired SU(4) x SU(2)_L x SU(2)_R x U(1)_X model with matter in
fundamental and antisymmetric tensor representations only. The quark, charged
lepton and neutrino Yukawa matrices are distinguished by different
Clebsch-Gordan coefficients due to contracting over SU(4) and SU(2)_R indices.
In order to permit for a more realistic, hierarchical light neutrino mass
spectrum with bi-large mixing a second U(1)_X breaking singlet with fractional
charge is introduced. By numerical investigation we find a region in the model
parameter space where the neutrino mass-squared differences and mixing angles
at low energy are consistent with experimental data.Comment: Talk presented at the Corfu Summer Institute, Corfu-Greece, September
4-14, 200
Cost-effectiveness of intrapleural use of tissue plasminogen activator and DNase in pleural infection:Evidence from the MIST2 randomised controlled trial
The MIST2 trial showed that combined intrapleural use of tissue plasminogen activator (t-PA) and DNase was effective when compared to single agents or placebo. However, the treatment costs are significant and overall cost-effectiveness of combined therapy remains unclear.An economic evaluation of the MIST2 trial was performed to assess the cost-effectiveness of combined therapy. Costs included were those related to study medications, initial hospital stay, and subsequent hospitalisations. Outcomes were measured in terms of life-years gained. All costs were reported in Euros (€) and in 2016 prices.Mean annual costs were lowest in the tPA-DNase group (€10 605 for t-PA, €17 856 for DNase; €13 483 for placebo, €7248 for t-PA-DNase (p=0.209)). Mean 1-year life expectancy was: 0.988 for t-PA; 0.923 for DNase; and 0.969 for both placebo and t-PA-DNase (p=0.296). Both DNase and placebo were less effective, in terms of life-years gained, and more costly than t-PA. When t-PA-DNase was compared to placebo, the incremental cost per life-year gained of t-PA-DNase was €1.6 billion, with a probability of 0.85 of t-PA-DNase being cost-effective.This study demonstrates that combined t-PA-DNase is likely to be highly cost-effective. In light of this evidence, a definitive trial designed to facilitate a thorough economic evaluation is warranted to provide further evidence on cost-effectiveness of this promising combined intervention
Majorana Neutrino Masses from Anomalous U(1) Symmetries
We explore the possibility of interpreting the solar and atmospheric neutrino
data within the context of the Minimal Supersymmetric Standard Model augmented
by a single U(1) anomalous family symmetry spontaneously broken by non-zero
vacuum expectation values of a pair of singlet fields. The symmetry retains a
dimension-five operator which provides Majorana masses for left-handed neutrino
states. Assuming symmetric lepton mass matrices, the model predicts inverse
hierarchical neutrino mass spectrum, theta_{13}=0 and large mixing while at the
same time it provides acceptable mass matrices for the charged fermions.Comment: 14 pages, no figure
Clinically important associations of pleurodesis success in malignant pleural effusion: Analysis of the TIME1 data set
Background and Objective:
Chemical pleurodesis is performed for patients with MPE with a published success rate of around 80%. It has been postulated that inflammation is key in achieving successful pleural symphysis, as evidenced by higher amounts of pain or detected inflammatory response. Patients with mesothelioma are postulated to have a lower rate of successful pleurodesis due to lack of normal pleural tissue enabling an inflammatory response.
Methods:
The TIME1 trial data set, in which pleurodesis success and pain were co‐primary outcome measures, was used to address a number of these assumptions. Pain score, systemic inflammatory parameters as a marker of pleural inflammation and cancer type were analysed in relation to pleurodesis success.
Results:
In total, 285 patients were included with an overall success rate of 81.4%. There was a significantly higher rise in CRP in the Pleurodesis Success group compared with the Pleurodesis Failure group (mean difference: 19.2, 95% CI of the difference: 6.2–32.0, P = 0.004) but no significant change in WCC. There was no significant difference in pain scores or analgesia requirements between the groups. Patients with mesothelioma had a lower rate of pleurodesis success than non‐mesothelioma patients (73.3% vs 84.9%, χ2 = 5.1, P = 0.023).
Conclusion:
Change in CRP during pleurodesis is associated with successful pleurodesis but higher levels of pain are not associated. Patients with mesothelioma appear less likely to undergo successful pleurodesis than patients with other malignancies, but there is still a significant rise in systemic inflammatory markers. The mechanisms of these findings are unclear but warrant further investigation
Vamsa: Automated Provenance Tracking in Data Science Scripts
There has recently been a lot of ongoing research in the areas of fairness,
bias and explainability of machine learning (ML) models due to the self-evident
or regulatory requirements of various ML applications. We make the following
observation: All of these approaches require a robust understanding of the
relationship between ML models and the data used to train them. In this work,
we introduce the ML provenance tracking problem: the fundamental idea is to
automatically track which columns in a dataset have been used to derive the
features/labels of an ML model. We discuss the challenges in capturing such
information in the context of Python, the most common language used by data
scientists. We then present Vamsa, a modular system that extracts provenance
from Python scripts without requiring any changes to the users' code. Using 26K
real data science scripts, we verify the effectiveness of Vamsa in terms of
coverage, and performance. We also evaluate Vamsa's accuracy on a smaller
subset of manually labeled data. Our analysis shows that Vamsa's precision and
recall range from 90.4% to 99.1% and its latency is in the order of
milliseconds for average size scripts. Drawing from our experience in deploying
ML models in production, we also present an example in which Vamsa helps
automatically identify models that are affected by data corruption issues
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