MeV neutrinos in double beta decay

The effect of Majorana neutrinos in the MeV mass range on the double beta decay of various isotopes is studied on pure phenomenological arguments. By using only experimental half life data, limits on the mixing parameter $U_{eh}^2$ of the order 10$^{-7}$ can be derived. Also the possible achievements of upcoming experiments and some consequences are outlined.Comment: 7 pages, 6 uudecoded EPS-figure

Optimized Trigger for Ultra-High-Energy Cosmic-Ray and Neutrino Observations with the Low Frequency Radio Array

When an ultra-high energy neutrino or cosmic ray strikes the Lunar surface a radio-frequency pulse is emitted. We plan to use the LOFAR radio telescope to detect these pulses. In this work we propose an efficient trigger implementation for LOFAR optimized for the observation of short radio pulses.Comment: Submitted to Nuclear Instruments and Methods in Physics Research Section

Free Energies and fluctuations for the unitary Brownian motion

We show that the Laplace transforms of traces of words in independent unitary Brownian motions converge towards an analytic function on a non trivial disc. These results allow one to study the asymptotic behavior of Wilson loops under the unitary Yang--Mills measure on the plane with a potential. The limiting objects obtained are shown to be characterized by equations analogue to Schwinger--Dyson's ones, named here after Makeenko and Migdal

FLAVi: An Enhanced Annotator for Viral Genomes of Flaviviridae

Responding to the ongoing and severe public health threat of viruses of the family Flaviviridae, including dengue, hepatitis C, West Nile, yellow fever, and Zika, demands a greater understanding of how these viruses emerge and spread. Updated phylogenies are central to this understanding. Most cladograms of Flaviviridae focus on specific lineages and ignore outgroups, hampering the efficacy of the analysis to test ingroup monophyly and relationships. This is due to the lack of annotated Flaviviridae genomes, which has gene content variation among genera. This variation makes analysis without partitioning difficult. Therefore, we developed an annotation pipeline for the genera of Flaviviridae (Flavirirus, Hepacivirus, Pegivirus, and Pestivirus, named “Fast Loci Annotation of Viruses” (FLAVi; http://flavi-web.com/), that combines ab initio and homology-based strategies. FLAVi recovered 100% of the genes in Flavivirus and Hepacivirus genomes. In Pegivirus and Pestivirus, annotation efficiency was 100% except for one partition each. There were no false positives. The combined phylogenetic analysis of multiple genes made possible by annotation has clear impacts over the tree topology compared to phylogenies that we inferred without outgroups or data partitioning. The final tree is largely congruent with previous hypotheses and adds evidence supporting the close phylogenetic relationship between dengue and Zika

Improving delineation of true tumour volume with multimodal MRI in a rat model of brain metastasis

Purpose: Brain metastases are almost universally lethal with short median survival times. Despite this they are often potentially curable, with therapy failing only because of local relapse. One key reason relapse occurs is because treatment planning did not delineate metastasis margins sufficiently accurately, allowing residual tumour to regrow. The aim of this study was to determine the extent to which multimodal MRI, with a simple and automated analysis pipeline, could improve upon current clinical practice of single modality independent observer tumour delineation. Methods and Materials: We used a single rat model of brain metastasis (ENU1564 breast carcinoma cells in BD-IX rats), with and without radiotherapy. Multimodal MRI data were acquired using sequences either in current clinical use or in clinical trial, and included post gadolinium T1-weighted images and maps of blood flow, blood volume, T1 and T2 relaxation times, and apparent diffusion coefficient. Results: In all cases, independent observers underestimated the true size of metastases from single modality gadolinium-enhanced MRI (85±36µL vs. 131±40µL histological measurement), whilst multimodal MRI more accurately delineated tumour volume (132±41µL). Multimodal MRI offered increased sensitivity compared to independent observer for detecting metastasis (0.82 vs. 0.61, respectively), with only a slight decrease in specificity (0.86 vs. 0.98). Blood flow maps conferred the greatest improvements in margin detection for late-stage metastases after radiotherapy. Gadolinium-enhanced T1 weighted images conferred the greatest increase in accuracy of detection for smaller metastases. Conclusions: These findings suggest that multimodal MRI of brain metastases could significantly improve the visualisation of brain metastasis margins, beyond current clinical practice, with the potential to decrease relapse rates and increase patient survival. This finding now needs validation in additional tumour models or clinical cohorts.</p