Networks, Uncertainty, Applications and a Crusade for Optimality

In this thesis we address a collection of Network Design problems which are strongly motivated by applications from Telecommunications, Logistics and Bioinformatics. In most cases we justify the need of taking into account uncertainty in some of the problem parameters, and different Robust optimization models are used to hedge against it. Mixed integer linear programming formulations along with sophisticated algorithmic frameworks are designed, implemented and rigorously assessed for the majority of the studied problems. The obtained results yield the following observations: (i) relevant real problems can be effectively represented as (discrete) optimization problems within the framework of network design; (ii) uncertainty can be appropriately incorporated into the decision process if a suitable robust optimization model is considered; (iii) optimal, or nearly optimal, solutions can be obtained for large instances if a tailored algorithm, that exploits the structure of the problem, is designed; (iv) a systematic and rigorous experimental analysis allows to understand both, the characteristics of the obtained (robust) solutions and the behavior of the proposed algorithm

A mixed integer programming approach for multi-action planning for threat management

Planning for management actions that address threats to biodiversity is important for securing its long term persistence. However, systematic conservation planning (SCP) has traditionally overlooked this aspect and just focused on identiying priority areas without any recommendation on actions needed. This paper develops a mixed integer mathematical programming (MIP) approach for the multi-action management planning problem (MAMP), where the goal is to find an optimal combination of management actions that abate threats, in an efficent way while accounting for connectiivty. An extended version of the MAMP model (MAMP-E) is also proposed that adds an expression for minimizing fragmentation between different actions. To evaluate the efficiency of the two models, they were applied to a case study corresponding to a large area of the Mitchell River in Northern Asutralia, where 45 species of freshwater fish are exposed to the presence of four threats. The evaluation compares our exact MIP approach with the conservation planning software Marxan and the heuristic approach developed in Cattarino et al. (2015). The results obtained show that our MIP models have three advantages over their heuristic counterparts: shorter execution times, higher solutions quality, and a solution quality guarantee. Hence, the proposed MIP methodology provides a more effective framework for addressing the multi-action conservation problem.Peer ReviewedPostprint (published version

Instances for the Recoverable Robust Two-Level Network Design Problem

We provide the instances used in the paper "The Recoverable Robust Two-Level Network Design Problem", by E. Alvarez-Miranda, I. Ljubic, S. Raghavan and P. Toth, accepted for publication in the INFORMS J. on Computing, 2014 (http://dx.doi.org/10.1287/ijoc.2014.0606). This repository contains both the instances used in the paper as well as the results obtained by the proposed algorithm

Engaging Primary and Secondary School Students in Computer Science Through Computational Thinking Training

Although Computer Science has grown to become one of the most highly demanded professional careers, every year, only a small percentage of students choose a degree directly related to Computer Science. Perhaps the problem lies in the lack of information that society has about Computer Science itself, and particularly about the work computer scientists do. No one doubts the role of Mathematics or Languages as core subjects in every primary and secondary education syllabus; however, Computer Science plays a negligible role in most current syllabuses. Only in a few countries have governments paid special attention to content related to Computer Science and to learning to analyze and solve problems the way computer scientists do (Computational Thinking). In this article, we present Piens@ Computacion@ULLmente , a project that provides a methodology to promote Computer Science through Computational Thinking activities among primary and secondary education students. The results obtained from an exhaustive statistical analysis of the data we collected demonstrate that the perception of Computer Science that pre-university students have can be improved through specific training. Moreover, we can also confirm that the performance of pre-university students involving Computational Thinking skills is independent of gender, particularly at the primary education level

Mechanism of voltage sensing in Ca2+- and voltage-activated K + (BK) channels

In neurosecretion, allosteric communication between voltage sensors and C

Estabelecimento de pastagem consorciada com aplicação de calcário, fósforo e gesso

Em solo de baixa fertilidade, sob pastagem natural degradada, pertencente à Universidade Federal de Viçosa - Viçosa (MG), foi estabelecida uma pastagem de Brachiaria decumbens consorciada com Stylosanthes guianensis cv. Mineirão, para avaliar os efeitos de doses de calcário (1.175, 2.350, 3.525 e 4.700 kg/ha, referentes a 25, 50, 75 e 100% da quantidade de calcário recomendada-QC), gesso agrícola (0, 230, 940, 1.880 e 2.820 kg/ha, referentes à substituição de 0, 3,0, 12,5, 25,0 e 37,5% do CaO do calcário pelo CaO do gesso) e de P2O5 (50, 100, 150, 200 e 250 kg/ha) sobre o pH do solo; os teores de P, K e S disponíveis e de Ca2+, Mg2+, Al3+, H + Al; a soma de bases (SB); a CTC efetiva (t) e a pH 7,0 (T); o índice de saturação por bases (V) e por Al (m); a produção de matéria seca, densidade de perfilhos e a altura de plantas da braquiária; e a porcentagem da leguminosa na pastagem. A substituição do CaO do calcário pelo CaO do gesso elevou a porcentagem do estilosantes na pastagem e os teores de S-SO42- e de Al3+, nas camadas de 0-15 e de 15-30 cm, e reduziu os teores de Ca2+ e de Mg2+, na camada de 0-15 cm. As doses crescentes de P2O5 aumentaram os teores de P (Mehlich-1) na camada de 0-15 cm do solo e favoreceram o perfilhamento e a altura da gramínea, reduzindo a porcentagem da leguminosa na pastagem.At low fetility soil, in degraded natural pasture, a field trial was carried out at the Federal University of Viçosa, located at Viçosa – MG, was established the pasture of Brachiaria decumbens in mixture with Stylosanthes guianensis cv. Mineirão to evaluate the effect of limestone doses (1.175, 2.350, 3.525 and 4.700 kg/ha, equivalent 25, 50, 75 and 100% of limestone necessity), gypsum doses (0, 230, 940, 1.880 e 2.820 kg/ha equivalent the substitution of 0, 3,0, 12,5, 25,0 and 37,5% of limestone CaO by gypsum CaO) and P2O5 doses (50, 100, 150, 200 and 250 kg/ha) on the pH; availables P, S and K; exchangeables Ca2+, Mg2+, Al3+, H + Al; sum of bases (SB); effetive CEC (t) and CEC determined in pH 7,0 (T); base saturation (V); aluminum saturation (m) and dry matter production, tillers number and height of brachiaria grass and legume percent. The substitution of the limestone CaO by gypsum CaO increased the percent of stylosanthes, available S and Al3+, in 0-15 and 15-30 cm soil layer, and decreased Ca2+ and Mg2+, in 0-15 cm soil layer. The P doses increased the available P (Mehlich 1) in 0-15 cm soil layer, but decreased the legume percent in the pasture

Variable flocculation profiles of yeast strains isolated from cacha?a distilleries.

In cacha?a production, the use of yeast cells as starters with predictable flocculation behavior facilitates the cell recovery at the end of each fermentation cycle. Therefore, the aim of this work was to explain the behavior of cacha?a yeast strains in fermentation vats containing sugarcane through the determination of biochemical and molecular parameters associated with flocculation phenotypes. By analyzing thirteen cacha?a yeast strains isolated from different distilleries, our results demonstrated that neither classic biochemical measurements (e.g., percentage of flocculation, EDTA sensitivity, cell surface hydrophobicity, and sugar residues on the cell wall) nor modern molecular approaches, such as polymerase chain reaction (PCR) and real-time PCR (q-PCR), were sufficient to distinctly classify the cacha?a yeast strains according to their flocculation behavior. It seems that flocculation is indeed a strain-specific phenomenon that is difficult to explain and/or categorize by the available methodologie

Acercamiento al mundo laboral de la nueva Generación Z de estudiantes del Máster en Ingeniería Química mediante aprendizaje basado en retos y mentorías en el marco del desarrollo sostenible

Esta metodología (ABR) que se ha empleado en la parte teórica de la asignatura “Estancias en empresas y centros de investigación” del máster en Ingeniería Química: Ingeniería de Procesos en la UCM. La metodología implica el establecimiento de un panel de expertos, la definición de los retos a resolver, la configuración de los grupos de trabajo, la realización de distintas actividades para resolver el reto, y la exposición pública del mismo. La evaluación de la metodología se realizó mediante una encuesta a los alumnos cuyas conclusiones más relevantes son que, a pesar de que consideraban que era necesario mucho esfuerzo, los estudiantes pensaban que la metodología era interesante. Entre las actividades llevadas a cabo, las visitas a plantas industriales fueron las más valoradas, mientras que la preparación de un CV resultó la menos atractiva para los estudiantesDepto. de Ingeniería Química y de MaterialesFac. de Ciencias QuímicasFALSEsubmitte

Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: The ZIKAlliance consortium

Background: The European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic. Methods: Recruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS). After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1-3, 4-6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems. Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites. Substudies of ZIKV seroprevalence, transmissio