Reoptimization of Some Maximum Weight Induced Hereditary Subgraph Problems

The reoptimization issue studied in this paper can be described as follows: given an instance I of some problem Π, an optimal solution OPT for Π in I and an instance I′ resulting from a local perturbation of I that consists of insertions or removals of a small number of data, we wish to use OPT in order to solve Π in I', either optimally or by guaranteeing an approximation ratio better than that guaranteed by an ex nihilo computation and with running time better than that needed for such a computation. We use this setting in order to study weighted versions of several representatives of a broad class of problems known in the literature as maximum induced hereditary subgraph problems. The main problems studied are max independent set, max k-colorable subgraph and max split subgraph under vertex insertions and deletion

Approximating Weighted Duo-Preservation in Comparative Genomics

Motivated by comparative genomics, Chen et al. [9] introduced the Maximum Duo-preservation String Mapping (MDSM) problem in which we are given two strings $s_1$ and $s_2$ from the same alphabet and the goal is to find a mapping $\pi$ between them so as to maximize the number of duos preserved. A duo is any two consecutive characters in a string and it is preserved in the mapping if its two consecutive characters in $s_1$ are mapped to same two consecutive characters in $s_2$. The MDSM problem is known to be NP-hard and there are approximation algorithms for this problem [3, 5, 13], but all of them consider only the "unweighted" version of the problem in the sense that a duo from $s_1$ is preserved by mapping to any same duo in $s_2$ regardless of their positions in the respective strings. However, it is well-desired in comparative genomics to find mappings that consider preserving duos that are "closer" to each other under some distance measure [19]. In this paper, we introduce a generalized version of the problem, called the Maximum-Weight Duo-preservation String Mapping (MWDSM) problem that captures both duos-preservation and duos-distance measures in the sense that mapping a duo from $s_1$ to each preserved duo in $s_2$ has a weight, indicating the "closeness" of the two duos. The objective of the MWDSM problem is to find a mapping so as to maximize the total weight of preserved duos. In this paper, we give a polynomial-time 6-approximation algorithm for this problem.Comment: Appeared in proceedings of the 23rd International Computing and Combinatorics Conference (COCOON 2017

SUCCOR Nodes: May Sentinel Node Biopsy Determine the Need for Adjuvant Treatment?

Background The SUCCOR cohort was developed to analyse the overall and disease-free survival at 5 years in women with FIGO 2009 stage IB1 cervical cancer. The aim of this study was to compare the use of adjuvant therapy in these women, depending on the method used to diagnose lymphatic node metastasis. Patients and Methods We used data from the SUCCOR cohort, which collected information from 1049 women with FIGO 2009 stage IB1 cervical cancer who were operated on between January 2013 and December 2014 in Europe. We calculated the adjusted proportion of women who received adjuvant therapy depending on the lymph node diagnosis method and compared disease free and overall survival using Cox proportional-hazards regression models. Inverse probability weighting was used to adjust for baseline potential confounders. Results The adjusted proportion of women who received adjuvant therapy was 33.8% in the sentinel node biopsy + lymphadenectomy (SNB+LA) group and 44.7% in the LA group (p = 0.02), although the proportion of positive nodal status was similar (p = 0.30). That difference was greater in women with negative nodal status and positive Sedlis criteria (difference 31.2%, p = 0.01). Here, those who underwent a SNB+LA had an increased risk of relapse [hazard ratio (HR) 2.49, 95% confidence interval (CI) 0.98–6.33, p = 0.056] and risk of death (HR 3.49, 95% CI 1.04–11.7, p = 0.042) compared with those who underwent LA. Conclusions Women in this study were less likely to receive adjuvant therapy if their nodal invasion was determined using SNB+LA compared with LA. These results suggest a lack of therapeutic measures available when a negative result is obtained by SNB+LA, which may have an impact on the risk of recurrence and survival

On the probabilistic min spanning tree Problem

We study a probabilistic optimization model for min spanning tree, where any vertex vi of the input-graph G(V,E) has some presence probability pi in the final instance G′ ⊂ G that will effectively be optimized. Suppose that when this “real” instance G′ becomes known, a spanning tree T, called anticipatory or a priori spanning tree, has already been computed in G and one can run a quick algorithm (quicker than one that recomputes from scratch), called modification strategy, that modifies the anticipatory tree T in order to fit G ′. The goal is to compute an anticipatory spanning tree of G such that, its modification for any G ′ ⊆ G is optimal for G ′. This is what we call probabilistic min spanning tree problem. In this paper we study complexity and approximation of probabilistic min spanning tree in complete graphs under two distinct modification strategies leading to different complexity results for the problem. For the first of the strategies developed, we also study two natural subproblems of probabilistic min spanning tree, namely, the probabilistic metric min spanning tree and the probabilistic min spanning tree 1,2 that deal with metric complete graphs and complete graphs with edge-weights either 1, or 2, respectively

Systematic Procedure to Avoid Unintended Polarity Mismatch in the Cascade Connection of Multiport Devices with Symmetric Feeding Lines

This paper is a postprint of a paper submitted to and accepted for publication in [journal] and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital LibraryThe traditional cascading of generalised scattering matrices (GSMs) assumes that the modal sets at the connected ports of a cascaded network are strictly equal. This implies a careful selection of the modal polarities, or the reference systems, of every port. Usually, the connection scheme of every device is known a priori. Then, the individual GSMs are pre-processed, or auxiliary devices, which correct possible modal mismatches at the ports, are included in appropriate positions among the cascade, so that the traditional cascading-by-pairs approach can be directly applied. This scheme clearly complicates the reutilisation of previously calculated GSMs, and mixes the cascading with the solution of the individual building blocks. In this study, a systematic procedure is proposed to define the polarity of the modes at the ports of a device fed with transmission lines or waveguides showing a single or double symmetry. The modified expressions to calculate the scattering parameters of the cascade of two multiport devices, incorporating the regular modal corrections to apply when this criterion is used to define the modal polarity at the ports, is also presented in this study. This strategy is more convenient from the point of view of programming, less error-prone and easier to implement.This work was supported by the Ministry of Science and Innovation, Spanish Government, under Research Projects TEC2013-47037-C05-3-R and TEC2013-47037-C05-1-R.Belenguer Martínez, Á.; Borja, A.; Díaz Caballero, E.; Esteban González, H.; Boria Esbert, VE. (2015). Systematic Procedure to Avoid Unintended Polarity Mismatch in the Cascade Connection of Multiport Devices with Symmetric Feeding Lines. IET Microwaves Antennas and Propagation. 9(11):1128-1135. https://doi.org/10.1049/iet-map.2014.0167S1128113591

5′UTR Variants of Ribosomal Protein S19 Transcript Determine Translational Efficiency: Implications for Diamond-Blackfan Anemia and Tissue Variability

Background: Diamond-Blackfan anemia (DBA) is a lineage specific and congenital erythroblastopenia. The disease is associated with mutations in genes encoding ribosomal proteins resulting in perturbed ribosomal subunit biosynthesis. The RPS19 gene is mutated in approximately 25 % of DBA patients and a variety of coding mutations have been described, all presumably leading to haploinsufficiency. A subset of patients carries rare polymorphic sequence variants within the 59untranslated region (59UTR) of RPS19. The functional significance of these variants remains unclear. Methodology/Principal Findings: We analyzed the distribution of transcriptional start sites (TSS) for RPS19 mRNAs in testis and K562 cells. Twenty-nine novel RPS19 transcripts were identified with different 59UTR length. Quantification of expressed w.t. 59UTR variants revealed that a short 59UTR correlates with high levels of RPS19. The total levels of RPS19 transcripts showed a broad variation between tissues. We also expressed three polymorphic RPS19 59UTR variants identified in DBA patients. The sequence variants include two insertions (c.-147_-146insGCCA and c.-147_-146insAGCC) and one deletion (c.-144_-141delTTTC). The three 59UTR polymorphisms are associated with a 20–30 % reduction in RPS19 protein levels when compared to the wild-type (w.t.) 59UTR of corresponding length. Conclusions: The RPS19 gene uses a broad range of TSS and a short 59UTR is associated with increased levels of RPS19. Comparisons between tissues showed a broad variation in the total amount of RPS19 mRNA and in the distribution of TS

Intention Understanding in Autism

When we observe a motor act (e.g. grasping a cup) done by another individual, we extract, according to how the motor act is performed and its context, two types of information: the goal (grasping) and the intention underlying it (e.g. grasping for drinking). Here we examined whether children with autistic spectrum disorder (ASD) are able to understand these two aspects of motor acts. Two experiments were carried out. In the first, one group of high-functioning children with ASD and one of typically developing (TD) children were presented with pictures showing hand-object interactions and asked what the individual was doing and why. In half of the “why” trials the observed grip was congruent with the function of the object (“why-use” trials), in the other half it corresponded to the grip typically used to move that object (“why-place” trials). The results showed that children with ASD have no difficulties in reporting the goals of individual motor acts. In contrast they made several errors in the why task with all errors occurring in the “why-place” trials. In the second experiment the same two groups of children saw pictures showing a hand-grip congruent with the object use, but within a context suggesting either the use of the object or its placement into a container. Here children with ASD performed as TD children, correctly indicating the agent's intention. In conclusion, our data show that understanding others' intentions can occur in two ways: by relying on motor information derived from the hand-object interaction, and by using functional information derived from the object's standard use. Children with ASD have no deficit in the second type of understanding, while they have difficulties in understanding others' intentions when they have to rely exclusively on motor cues

Territorios afines: sociocrítica y feminismo

Desde una experiencia de trabajo compartida con Pierrette Malcuzynski, las autoras se proponen revisar críticamente las categorías propuestas por la teórica polaca para desarrollar una sociocrítica feminista. La heterogeneidad del texto, qué dice, cómo lo dice, sus no dichos, fueron propuestos por Malcuzynski como las modalidades socio-críticas de base, necesarias para situar la frontera donde se articulan socialidades y subjetividades. Tomando como ejemplos algunos relatos de corte autobiográfico de Sylvia Molloy (argentina, teórica de literatura y narradora), las autoras reflexionan sobre las articulaciones texto/discurso/sociedad desde las nociones centrales de monitoring y subjetividad