Constraints on light neutrino parameters derived from the study of neutrinoless double beta decay

The study of the neutrinoless double beta ($0 \beta\beta$) decay mode can provide us with important information on the neutrino properties, particularly on the electron neutrino absolute mass. In this work we revise the present constraints on the neutrino mass parameters derived from the $0 \beta\beta$ decay analysis of the experimentally interesting nuclei. We use the latest results for the phase space factors (PSFs) and nuclear matrix elements (NMEs), as well as for the experimental lifetimes limits. For the PSFs we use values computed with an improved method reported very recently. For the NMEs we use values chosen from literature on a case-by-case basis, taking advantage of the consensus reached by the community on several nuclear ingredients used in their calculation. Thus, we try to restrict the range of spread of the NME values calculated with different methods and, hence, to reduce the uncertainty in deriving limits for the Majorana neutrino mass parameter. Our results may be useful to have an up-date image on the present neutrino mass sensitivities associated with $0 \beta\beta$ measurements for different isotopes and to better estimate the range of values of the neutrino masses that can be explored in the future double beta decay (DBD) experiments.Comment: 11 page

Bounds for Calder\'on-Zygmund operators with matrix A2A_2 weights

It is well-known that dyadic martingale transforms are a good model for Calder\'on-Zygmund singular integral operators. In this paper we extend some results on weighted norm inequalities to vector-valued functions. We prove that, if $W$ is an $A_2$ matrix weight, then the weighted $L^2$-norm of a Calder\'on-Zygmund operator with cancellation has the same dependence on the $A_2$ characteristic of $W$ as the weighted $L^2$-norm of the martingale transform. Thus the question of the dependence of the norm of matrix-weighted Calder\'on-Zygmund operators on the $A_2$ characteristic of the weight is reduced to the case of dyadic martingales and paraproducts. We also show a slightly different proof for the special case of Calder\'on-Zygmund operators with even kernel. We conclude the paper by proving a version of the matrix-weighted Carleson Embedding Theorem. Our method uses the Bellman function technique to obtain the right estimates for the norm of dyadic Haar shift operators. We then apply the representation theorem of T. Hyt\"onen to extend the result to general Calder\'on-Zygmund operators.Comment: arXiv admin note: text overlap with arXiv:1310.786

Identifying the mechanisms driving pancreatic ductal adenocarcinoma stem cell characteristics using single-cell RNA-sequencing

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest human malignancies. Surgery, the only curative treatment, is precluded by the late stage at diagnosis in 80% of cases. Recurrence after surgery is common, and the disease does not respond well to chemotherapy and radiotherapy. Resistance to therapy and recurrence are thought to be driven by pancreatic cancer stem cells (PCSCs), a subset of cells with self-renewal and differentiation capacities. Annihilating these cells is therefore of paramount importance for treating PDAC. Identifying these cells, however, has proven challenging. Currently, there is no gene signature able to identify PCSCs. In this thesis, I employed single-cell RNA-sequencing to integrate multiple approaches towards the identification of PCSCs (experimentally-derived markers, bioinformatics-based gene sets, and computational tools to infer developmental potential from expression data), to uncover the genes and processes characterizing PCSCs, and to assess the effects of I-BRD9, an inhibitor of BRD9, a bromodomain-containing protein involved in chromatin remodelling upon the PCSCs, using two single-cell RNA-sequencing PDAC datasets. The results evidenced cell cycle abnormalities as crucial to cancer stemness in PDAC, with multiple lines of evidence converging towards the identification of clusters whose markers significantly overlapped with cell cycle-related stemness-associated gene sets as PCSCs. Traditionally-derived PCSC markers were found to be largely of low reliability. A transitional cell population distinct from both PCSCs and the bulk of the cells, and one with an advanced stage of differentiation which however regained partial stemness-like characteristics, were identified as highly drug-resistant, suggesting that greater than previously believed PDAC cell heterogeneity, not merely PCSCs, is involved in chemoresistance. I-BRD9 achieves a ~6-fold reduction of PCSCs in one dataset, likely mediated by the demonstrated downregulation of key G2/M DNA replication checkpoint-linked genes such as TOP2A and CDK1, but the effects are partially reversed by the addition of PDAC drug gemcitabine

FROM DOCUMENT MANAGEMENT TO KNOWLEDGE MANAGEMENT

Documents circulating in paper form are increasingly being substituted by itselectronic equivalent in the modern office today so that any stored document can be retrievedwhenever needed later on. The office worker is already burdened with information overload, soeffective and effcient retrieval facilities become an important factor affecting worker productivity. The key thrust of this article is to analyse the benefits and importance of interaction betweendocument management and knowledge management. Information stored in text-based documentsrepresents a valuable repository for both the individual worker and the enterprise as a whole and ithas to be tapped into as part of the knowledge generation process.document management, knowledge management, Information and communication technologies

Fast, Efficient Calculations of the Two-Body Matrix Elements of the Transition Operators for Neutrinoless Double Beta Decay

To extract information about the neutrino properties from the study of neutrinoless double-beta (0\nu\beta\beta) decay one needs a precise computation of the nuclear matrix elements (NMEs) associated with this process. Approaches based on the Shell Model (ShM) are among the nuclear structure methods used for their computation. ShM better incorporates the nucleon correlations, but have to face the problem of the large model spaces and computational resources. The goal is to develop a new, fast algorithm and the associated computing code for efficient calculation of the two-body matrix elements (TBMEs) of the 0\nu\beta{\beta} decay transition operator, which are necessary to calculate the NMEs. This would allow us to extend the ShM calculations for double-beta decays to larger model spaces, of about 9-10 major harmonic oscillator shells. The improvement of our code consists in a faster calculation of the radial matrix elements. Their computation normally requires the numerical evaluation of two-dimensional integrals: one over the coordinate space and the other over the momentum space. By rearranging the expressions of the radial matrix elements, the integration over the coordinate space can be performed analytically, thus the computation reduces to sum up a small number of integrals over momentum. Our results for the NMEs are in a good agreement with similar results from literature, while we find a significant reduction of the computation time for TBMEs, by a factor of about 30, as compared with our previous code that uses two-dimensional integrals.Comment: 6 pages, one figur