A simulated annealing algorithm for router nodes placement problem in Wireless Mesh Networks

Mesh router nodes placement is a central problem in Wireless Mesh Networks (WMNs). An efficient placement of mesh router nodes is indispensable for achieving network performance in terms of both network connectivity and user coverage. Unfortunately the problem is computationally hard to solve to optimality even for small deployment areas and a small number of mesh router nodes. As WMNs are becoming an important networking infrastructure for providing cost-efficient broadband wireless connectivity, researchers are paying attention to the resolution of the mesh router placement problem through heuristic approaches in order to achieve near optimal, yet high quality solutions in reasonable time. In this work we propose and evaluate a simulated annealing (SA) approach to placement of mesh router nodes in WMNs. The optimization model uses two maximization objectives, namely, the size of the giant component in the network and user coverage. Both objectives are important to deployment of WMNs; the former is crucial to achieve network connectivity while the later is an indicator of the QoS in WMNs. The SA approach distinguishes for its simplicity yet its policy of neighborhood exploration allows to reach promising areas of the solution space where quality solutions could be found. We have experimentally evaluated the SA algorithm through a benchmark of generated instances, varying from small to large size, and capturing different characteristics of WMNs such as topological placements of mesh clients. The experimental results showed the efficiency of the annealing approach for the placement of mesh router nodes in WMNs.Peer ReviewedPostprint (author's final draft

Genetic algorithms for efficient placement of router nodes in wireless mesh networks

In Wireless Mesh Networks (WMNs) the meshing architecture, consisting of a grid of mesh routers, provides connectivity services to different mesh client nodes. The good performance and operability of WMNs largely depends on placement of mesh routers nodes in the geographical area to achieve network connectivity and stability. Thus, finding optimal or near-optimal mesh router nodes placement is crucial to such networks. In this work we propose and evaluate Genetic Algorithms (GAs) for near-optimally solving the problem. In our approach we seek a two-fold optimization, namely, the maximization of the size of the giant component in the network and that of user coverage. The size of the giant component is considered here as a criteria for measuring network connectivity. GAs explore the solution space by means of a population of individuals, which are evaluated, selected, crossed and mutated to reproduce new individuals of better quality. The fitness of individuals is measured with respect to network connectivity and user coverage being the former a primary objective and the later a secondary one. Several genetic operators have been considered in implementing GAs in order to find the configuration that works best for the problem. We have experimentally evaluated the proposed GAs using a benchmark of generated instances varying from small to large size. In order to evaluate the quality of achieved solutions for different possible client distributions, instances have been generated using different distributions of mesh clients (Uniform, Normal, Exponential and Weibull). The experimental results showed the efficiency of the GAs for computing high quality solutions of mesh router nodes placement in WMNs.Peer ReviewedPostprint (published version

Solving mesh router nodes placement problem in Wireless Mesh Networks by Tabu Search algorithm

Wireless Mesh Networks (WMNs) are an important networking paradigm that offer cost effective Internet connectivity. The performance and operability of WMNs depend, among other factors, on the placement of network nodes in the area. Among the most important objectives in designing a WMN is the formation of a mesh backbone to achieve high user coverage. Given a number of router nodes to deploy, a deployment area and positions of client nodes in the area, an optimization problem can be formulated aiming to find the placement of router nodes so as to maximize network connectivity and user coverage. This optimization problem belongs to facility location problems, which are computationally hard to solve to optimality. In this paper we present the implementation and evaluation of Tabu Search (TS) for the problem of mesh router node placement in WMNs. The experimental evaluation showed the efficiency of TS in solving a benchmark of instances.Peer ReviewedPostprint (author's final draft

Deamidation drives molecular aging of the SARS-CoV-2 spike protein receptor-binding motif

The spike protein is the main protein component of the SARS-CoV-2 virion surface. The spike receptor-binding motif mediates recognition of the human angiotensin-converting enzyme 2 (hACE2) receptor, a critical step in infection, and is the preferential target for spikeneutralizing antibodies. Post-translational modifications of the spike receptor-binding motif have been shown to modulate viral infectivity and host immune response, but these modifications are still being explored. Here we studied asparagine deamidation of the spike protein, a spontaneous event that leads to the appearance of aspartic and isoaspartic residues, which affect both the protein backbone and its charge. We used computational prediction and biochemical experiments to identify five deamidation hotspots in the SARS-CoV-2 spike protein. Asparagine residues 481 and 501 in the receptor-binding motif deamidate with a half-life of 16.5 and 123 days at 37°C, respectively. Deamidation is significantly slowed at 4°C, indicating a strong dependence of spike protein molecular aging on environmental conditions. Deamidation of the spike receptor-binding motif decreases the equilibrium constant for binding to the hACE2 receptor more than 3.5-fold, yet its high conservation pattern suggests some positive effect on viral fitness. We propose a model for deamidation of the full SARS-CoV-2 virion illustrating how deamidation of the spike receptor-binding motif could lead to the accumulation on the virion surface of a nonnegligible chemically diverse spike population in a timescale of days. Our findings provide a potential mechanism for molecular aging of the spike protein with significant consequences for understanding virus infectivity and vaccine development.Fil: Lorenzo Lopez, Juan Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Defelipe, Lucas Alfredo. European Molecular Biology Laboratory; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Aliperti Car, Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Niebling, Stephan. European Molecular Biology Laboratory; Alemania. Centre for Structural Systems Biology; AlemaniaFil: Custódio, Tânia F.. European Molecular Biology Laboratory; Alemania. Centre for Structural Systems Biology; AlemaniaFil: Löw, Christian. European Molecular Biology Laboratory; Alemania. Centre for Structural Systems Biology; AlemaniaFil: Schwarz, Jennifer J.. European Molecular Biology Laboratory; AlemaniaFil: Remans, Kim. European Molecular Biology Laboratory; AlemaniaFil: Craig, Patricio Oliver. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Otero, Lisandro Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Klinke, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: García Alai, María. European Molecular Biology Laboratory; Alemania. Centre for Structural Systems Biology; AlemaniaFil: Sánchez Miguel, Ignacio Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Alonso, Leonardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; Argentin

A 0/1h-algorithm using cardiac myosin-binding protein C for early diagnosis of myocardial infarction.

AIMS Cardiac myosin-binding protein C (cMyC) demonstrated high diagnostic accuracy for the early detection of non-ST-elevation myocardial infarction (NSTEMI). Its dynamic release kinetics may enable a 0/1h-decision algorithm that is even more effective than the ESC hs-cTnT/I 0/1 h rule-in/rule-out algorithm. METHODS AND RESULTS In a prospective international diagnostic study enrolling patients presenting with suspected NSTEMI to the emergency department, cMyC was measured at presentation and after 1 h in a blinded fashion. Modelled on the ESC hs-cTnT/I 0/1h-algorithms, we derived a 0/1h-cMyC-algorithm. Final diagnosis of NSTEMI was centrally adjudicated according to the 4th Universal Definition of Myocardial Infarction. Among 1495 patients, the prevalence of NSTEMI was 17%. The optimal derived 0/1h-algorithm ruled-out NSTEMI with cMyC 0 h concentration below 10 ng/L (irrespective of chest pain onset) or 0 h cMyC concentrations below 18 ng/L and 0/1 h increase <4 ng/L. Rule-in occurred with 0 h cMyC concentrations of at least 140 ng/L or 0/1 h increase ≥15 ng/L. In the validation cohort (n = 663), the 0/1h-cMyC-algorithm classified 347 patients (52.3%) as 'rule-out', 122 (18.4%) as 'rule-in', and 194 (29.3%) as 'observe'. Negative predictive value for NSTEMI was 99.6% [95% confidence interval (CI) 98.9-100%]; positive predictive value 71.1% (95% CI 63.1-79%). Direct comparison with the ESC hs-cTnT/I 0/1h-algorithms demonstrated comparable safety and even higher triage efficacy using the 0h-sample alone (48.1% vs. 21.2% for ESC hs-cTnT-0/1 h and 29.9% for ESC hs-cTnI-0/1 h; P < 0.001). CONCLUSION The cMyC 0/1h-algorithm provided excellent safety and identified a greater proportion of patients suitable for direct rule-out or rule-in based on a single measurement than the ESC 0/1h-algorithm using hs-cTnT/I. TRIAL REGISTRATION ClinicalTrials.gov number, NCT00470587

Characteristics of undergraduate dental theses defended in Peruvian licensed universities and factors associated with their publication

IntroductionIn Peru, the defense of a university thesis allow to obtain a professional degree and demonstrate the research skills of the aspirant.ObjectivesTo characterize the undergraduate dental theses defended in Peruvian universities and those published in scientific journals, as well as to identify the factors associated with their publication.MethodsA cross-sectional, analytical and observational study was conducted using a search strategy in Google Scholar. We ascertained whether the theses defended between 2015-2018 had been published in scientific journals. Prevalence ratios (aPR), 95% confidence intervals (CI 95%) and p-values were obtained using generalized linear models.ResultsMost of the theses were defended in private universities (65.9%), located in the provinces (76.7%), in 2017 (32.1%). The most studied line of research was Dental Education (n = 418; 18.4%). Of the total number of defended theses (n = 2,267), only 130 (5.7%) were published, in a total of 41 scientific journals, of which 22 are specialized in the dental field. The 130 articles received 443 citations, with an average of 3.4 citations per document. The Universidad Católica Santa María was the institution that defended the most theses (n = 372); however, the Universidad Científica del Sur presented the highest percentage of published theses (36.4%). Theses with case-control (aPR: 2.74; CI 95%: 1.07-7.01; p = 0.036) and cohort (aPR: 3.51; CI 95%: 2.02-6.11; p  &lt; 0.001) methodological design had a higher frequency of publication; on the contrary, those executed in the community were less frequently published (aPR: 0.39; CI 95%: 0.17-0.93; p = 0.033), as well as, those with two researchers (aPR: 0.41; CI 95%: 0.18-0.92; p = 0.031), adjusted for two variables.ConclusionOnly one in twenty theses was published. Publication was associated with the type of methodological design, the place of execution and the number of researchers

Add-on inhaled budesonide in the treatment of hospitalised patients with COVID-19 : a randomised clinical trial

SARS-CoV-2 vaccines have been extremely effective to reduce the incidence of severe COVID19 [1-3], but effective and safe treatments of the acute infection are still limited [4, 5]. An uncontrolled pulmonary inflammatory response to SARS-CoV-2 is considered a key pathogenic mechanism of COVID19 progression [6], so systemic dexamethasone is recommended in severe cases [5, 7]. On the other hand, in very mild patients at home inhaled corticosteroids (ICS) may prevent disease progression [8-11]. Whether ICS prevent disease progression too in patients hospitalised because of COVID19 has not been explored before. Accordingly, we designed an investigator-initiated, open-label, randomised clinical trial (RCT) to explore the efficacy of adding inhaled budesonide to usual care to prevent disease progression in patients hospitalised because of COVID19 pneumonia. We also monitored carefully the safety of this intervention since there are concerns about the use of systemic corticosteroids in other viral (influenza) lung infections [12]

Diagnostic and prognostic value of QRS duration and QTc interval in patients with suspected myocardial infarction

Background: While prolongation of QRS duration and QTc interval during acute myocardial infarction (AMI) has been reported in animals, limited data is available for these readily available electrocardiography (ECG) markers in humans. Methods: Diagnostic and prognostic value of QRS duration and QTc interval in patients with suspected AMI in a prospective diagnostic multicentre study were prospectively assessed. Digital 12-lead ECGs were recorded at presentation. QRS duration and QTc interval were automatically calculated in a blinded fashion. Final diagnosis was adjudicated by two independent cardiologists. The prognostic endpoint was all-cause mortality during 24 months of follow-up. Results: Among 4042 patients, AMI was the final diagnosis in 19% of patients. Median QRS duration and median QTc interval were significantly greater in patients with AMI compared to those with other final diagnoses (98 ms [IQR 88–108] vs. 94 ms [IQR 86–102] and 436 ms [IQR 414–462] vs. 425 ms [IQR 407–445], p &lt; 0.001 for both comparisons). The diagnostic value of both ECG signatures however was only modest (AUC 0.56 and 0.60). Cumulative mortality rates after 2 years were 15.9% vs. 5.6% in patients with a QRS &gt; 120 ms compared to a QRS duration ≤ 120 ms (p &lt; 0.001), and 11.4% vs. 4.3% in patients with a QTc &gt; 440 ms compared to a QRS duration ≤ 440 ms (p &lt; 0.001). After adjustment for age and important ECG and clinical parameters, the QTc interval but not QRS duration remained an independent predictor of mortality. Conclusions: Prolongation of QRS duration &gt; 120 ms and QTc interval &gt; 440 ms predict mortality in patients with suspected AMI, but do not add diagnostic value

Search for a pentaquark decaying to Cascade- pi-

We present a search for a pentaquark decaying strongly to $\Xi^-\pi^-$ in $\gamma N$ collisions at a center-of-mass energy up to 25 GeV/c^2. Finding no evidence for such a state in the mass range of 1480 MeV/c^2 to 2400 MeV/c^2, we set limits on the yield and on the cross section times branching ratio relative to $\Xi^*(1530)^0$.Comment: Accepted by Physics Letters

Breast and Prostate Cancer Risks for Male BRCA1 and BRCA2 Pathogenic Variant Carriers Using Polygenic Risk Scores

Background: Recent population-based female breast cancer and prostate cancer polygenic risk scores (PRS) have been developed. We assessed the associations of these PRS with breast and prostate cancer risks for male BRCA1 and BRCA2 pathogenic variant carriers. Methods: 483 BRCA1 and 1318 BRCA2 European ancestry male carriers were available from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). A 147-single nucleotide polymorphism (SNP) prostate cancer PRS (PRSPC) and a 313-SNP breast cancer PRS were evaluated. There were 3 versions of the breast cancer PRS, optimized to predict overall (PRSBC), estrogen receptor (ER)-negative (PRSER-), or ER-positive (PRSER+) breast cancer risk. Results: PRSER+ yielded the strongest association with breast cancer risk. The odds ratios (ORs) per PRSER+ standard deviation estimates were 1.40 (95% confidence interval [CI] =1.07 to 1.83) for BRCA1 and 1.33 (95% CI = 1.16 to 1.52) for BRCA2 carriers. PRSPC was associated with prostate cancer risk for BRCA1 (OR = 1.73, 95% CI = 1.28 to 2.33) and BRCA2 (OR = 1.60, 95% CI = 1.34 to 1.91) carriers. The estimated breast cancer odds ratios were larger after adjusting for female relative breast cancer family history. By age 85 years, for BRCA2 carriers, the breast cancer risk varied from 7.7% to 18.4% and prostate cancer risk from 34.1% to 87.6% between the 5th and 95th percentiles of the PRS distributions. Conclusions: Population-based prostate and female breast cancer PRS are associated with a wide range of absolute breast and prostate cancer risks for male BRCA1 and BRCA2 carriers. These findings warrant further investigation aimed at providing personalized cancer risks for male carriers and informing clinical management.Peer reviewe