Data and performance of an active-set truncated Newton method with non-monotone line search for bound-constrained optimization

In this data article, we report data and experiments related to the research article entitled “A Two-Stage Active-Set Algorithm for Bound-Constrained Optimization”, by Cristofari et al. (2017). The method proposed in Cristofari et al. (2017), tackles optimization problems with bound constraints by properly combining an active-set estimate with a truncated Newton strategy. Here, we report the detailed numerical experience performed over a commonly used test set, namely CUTEst (Gould et al., 2015). First, the algorithm ASA-BCP proposed in Cristofari et al. (2017) is compared with the related method NMBC (De Santis et al., 2012). Then, a comparison with the renowned methods ALGENCAN (Birgin and Martínez et al., 2002) and LANCELOT B (Gould et al., 2003) is reported

A nonmonotone GRASP

A greedy randomized adaptive search procedure (GRASP) is an itera- tive multistart metaheuristic for difficult combinatorial optimization problems. Each GRASP iteration consists of two phases: a construction phase, in which a feasible solution is produced, and a local search phase, in which a local optimum in the neighborhood of the constructed solution is sought. Repeated applications of the con- struction procedure yields different starting solutions for the local search and the best overall solution is kept as the result. The GRASP local search applies iterative improvement until a locally optimal solution is found. During this phase, starting from the current solution an improving neighbor solution is accepted and considered as the new current solution. In this paper, we propose a variant of the GRASP framework that uses a new “nonmonotone” strategy to explore the neighborhood of the current solu- tion. We formally state the convergence of the nonmonotone local search to a locally optimal solution and illustrate the effectiveness of the resulting Nonmonotone GRASP on three classical hard combinatorial optimization problems: the maximum cut prob- lem (MAX-CUT), the weighted maximum satisfiability problem (MAX-SAT), and the quadratic assignment problem (QAP)

Anisotropic Anomalous Diffusion assessed in the human brain by scalar invariant indices

A new method to investigate anomalous diffusion in human brain is proposed. The method has been inspired by both the stretched-exponential model proposed by Hall and Barrick (HB) and DTI. Quantities extracted using HB method were able to discriminate different cerebral tissues on the basis of their complexity, expressed by the stretching exponent gamma and of the anisotropy of gamma across different directions. Nevertheless, these quantities were not defined as scalar invariants like mean diffusivity and fractional anisotropy, which are eigenvalues of the diffusion tensor. We hypotesize instead that the signal may be espressed as a simple stretched-exponential only along the principal axes of diffusion, while in a generic direction the signal is modeled as a combination of three different stretched-exponentials. In this way, we derived indices to quantify both the tissue anomalous diffusion and its anisotropy, independently of the reference frame of the experiment. We tested and compare our new method with DTI and HB approaches applying them to 10 healty subjects brain at 3T. Our experimental results show that our parameters are highly correlated to intrinsic local geometry when compared to HB indices. Moreover, they offer a different kind of contrast when compared to DTI outputs. Specifically, our indices show a higher capability to discriminate among different areas of the corpus callosum, which are known to be associated to different axonal densities.Comment: 21 pages, 6 figures, 2 table

Coordination defects in a-Si and a-Si:H : a characterization from first principles calculations

We study by means of first-principles pseudopotential method the coordination defects in a-Si and a-Si:H, also in their formation and their evolution upon hydrogen interaction. An accurate analysis of the valence charge distribution and of the ``electron localization function'' (ELF) allows to resolve possible ambiguities in the bonding configuration, and in particular to identify clearly three-fold (T_3) and five-fold (T_5) coordinated defects. We found that electronic states in the gap can be associated to both kind of defects, and that in both cases the interaction with hydrogen can reduce the density of states in the gap.Comment: To appear in Philos. Ma

Solar flares and their associated processes

The evolution of the solar neutrino flux which is described by the wave function $\Psi^T=(\nu_{eL},\nu_{XL}, \overline{\nu}_{eL}, \overline{\nu}_{XL})$ is examined. Our treatment of the problem holds for any standard model (SM) extensions possessing nonzero dipole magnetic and anapole moments. When the solar neutrino flux moves through the solar flare (SF) region in the preflare period, then it undergoes the additional (compared with the SM) resonance conversions. As a result, the weakening the electron neutrinos flux takes place. On the other hand, existence of the additional resonances lead to appearance of the $\overline{\nu}_{eL}$ and $\overline{\nu}_{XL}$ neutrinos that could be detected by the terrestrial detectors. The hypothesis of the $\nu_e$-induced $\beta$-decays is also discussed. According to it, before the large SF, decreasing the $\beta$-decay rate for some elements takes place. The possible influence of the electron antineutrino flux produced in the superflares on the regime of the hypothetical georeactor is considered.Comment: 11 pages. arXiv admin note: text overlap with arXiv:hep-ph/0401221 by other author

Magnetic resonance tumor regression grade (MR-TRG) to assess pathological complete response following neoadjuvant radiochemotherapy in locally advanced rectal cancer

This study aims to evaluate the feasibility of a magnetic resonance (MR) automatic method for quantitative assessment of the percentage of fibrosis developed within locally advanced rectal cancers (LARC) after neoadjuvant radiochemotherapy (RCT). A total of 65 patients were enrolled in the study and MR studies were performed on 3.0 Tesla scanner; patients were followed-up for 30 months. The percentage of fibrosis was quantified on T2-weighted images, using automatic K-Means clustering algorithm. According to the percentage of fibrosis, an optimal cut-off point for separating patients into favorable and unfavorable pathologic response groups was identified by ROC analysis and tumor regression grade (MR-TRG) classes were determined and compared to histopathologic TRG. An optimal cut-off point of 81% of fibrosis was identified to differentiate between favorable and unfavorable pathologic response groups resulting in a sensitivity of 78.26% and a specificity of 97.62% for the identification of complete responders (CRs). Interobserver agreement was good (0.85). The agreement between P-TRG and MR-TRG was excellent (0.923). Significant differences in terms of overall survival (OS) and disease free survival (DFS) were found between favorable and unfavorable pathologic response groups. The automatic quantification of fibrosis determined by MR is feasible and reproducible

Evaluating the expression of urokinase and tissue leukocyte being in benign and malignant breast disease

Introduction: Our objectives is to show that the expression of uPA leukocyte could be considered, in the future, as a marker of the expression of uPA in the malignant tissue and therefore a potential indicator of prognosis. Methods: We examined the expression of uPa in leukocytes and tissues of three groups of women: with breast cancer; with benign breast lesion and healthy women (control group). We used RT Real Time PCR assay. The expression of urokinase is significantly higher in malignant breast lumps compared to benign lesions. However, in women with carcinoma of the breast, malignant tissue expresses higher amounts of uPA than the healthy counterpart. There are no statistically significant differences in the expression of uPA, between tissues taken from women with benign lesions. The lymphocytes taken from healthy volunteers show a level of expression of uPA significantly lower than the other tested samples Lymphocytes extracted from cancer patients express higher amounts of uPA compared to lymphocytes belonging to women with benign breast lesions. The expression of uPA was compared with the clinical and biological parameters commonly used in clinical practice for the definition of the prognosis. The only exception found, concerns those tumors characterized by the simultaneous negativity for estrogen receptors, progesterone and HER2 (state of triple negative), in which the expression of uPA is very high. Results and conclusions: Our data show that uPA expressed by leukocytes of each individual patient is the mirror image of the one expressed by malignant nodular uPA.Introduction: Our objectives is to show that the expression of uPA leukocyte could be considered, in the future, as a marker of the expression of uPA in the malignant tissue and therefore a potential indicator of prognosis. Methods: We examined the expression of uPa in leukocytes and tissues of three groups of women: with breast cancer; with benign breast lesion and healthy women (control group). We used RT Real Time PCR assay. The expression of urokinase is significantly higher in malignant breast lumps compared to benign lesions. However, in women with carcinoma of the breast, malignant tissue expresses higher amounts of uPA than the healthy counterpart. There are no statistically significant differences in the expression of uPA, between tissues taken from women with benign lesions. The lymphocytes taken from healthy volunteers show a level of expression of uPA significantly lower than the other tested samples Lymphocytes extracted from cancer patients express higher amounts of uPA compared to lymphocytes belonging to women with benign breast lesions. The expression of uPA was compared with the clinical and biological parameters commonly used in clinical practice for the definition of the prognosis. The only exception found, concerns those tumors characterized by the simultaneous negativity for estrogen receptors, progesterone and HER2 (state of triple negative), in which the expression of uPA is very high. Results and conclusions: Our data show that uPA expressed by leukocytes of each individual patient is the mirror image of the one expressed by malignant nodular uPA

Female fertility and environmental pollution

A realistic picture of our world shows that it is heavily polluted everywhere. Coastal regions and oceans are polluted by farm fertilizer, manure runoff, sewage and industrial discharges, and large isles of waste plastic are floating around, impacting sea life. Terrestrial ecosystems are contaminated by heavy metals and organic chemicals that can be taken up by and accumulate in crop plants, and water tables are heavily contaminated by untreated industrial discharges. As deadly particulates can drift far, poor air quality has become a significant global problem and one that is not exclusive to major industrialized cities. The consequences are a dramatic impairment of our ecosystem and biodiversity and increases in degenerative or man-made diseases. In this respect, it has been demonstrated that environmental pollution impairs fertility in all mammalian species. The worst consequences are observed for females since the number of germ cells present in the ovary is fixed during fetal life, and the cells are not renewable. This means that any pollutant affecting hormonal homeostasis and/or the reproductive apparatus inevitably harms reproductive performance. This decline will have important social and economic consequences that can no longer be overlooked

The distance to galactic globular clusters through RR Lyrae pulsational properties

By adopting the same approach outlined in De Santis & Cassisi (1999), we evaluate the absolute bolometric magnitude of the Zero Age Horizontal Branch (ZAHB) at the level of the RR Lyrae variable instability strip in selected galactic globular clusters. This allows us to estimate the ZAHB absolute visual magnitude for these clusters and to investigate its dependence on the cluster metallicity. The derived $M_V(ZAHB) - [Fe/H]$ relation, corrected in order to account for the luminosity difference between the ZAHB and the mean RR Lyrae magnitude, has been compared with some of the most recent empirical determinations in this field, as the one provided by Baade-Wesselink analyses, RR Lyrae periods, Hipparcos data for field variables and Main Sequence fitting based on Hipparcos parallaxes for field subdwarfs. As a result, our relation provides a clear support to the "long" distance scale. We discuss also another method for measuring the distance to galactic globular clusters. This method is quite similar to the one adopted for estimating the absolute bolometric magnitude of the ZAHB but it relies only on the pulsational properties of the Lyrae variables in each cluster. The reliability and accuracy of this method has been tested by applying it to a sample of globulars for which, due to the morphology of their horizontal branch (HB), the use of the commonly adopted ZAHB fitting is a risky procedure.Comment: 7 pages, 2 postscript figures, accepted for publication on MNRA