Decomposition, Reformulation, and Diving in University Course Timetabling

In many real-life optimisation problems, there are multiple interacting components in a solution. For example, different components might specify assignments to different kinds of resource. Often, each component is associated with different sets of soft constraints, and so with different measures of soft constraint violation. The goal is then to minimise a linear combination of such measures. This paper studies an approach to such problems, which can be thought of as multiphase exploitation of multiple objective-/value-restricted submodels. In this approach, only one computationally difficult component of a problem and the associated subset of objectives is considered at first. This produces partial solutions, which define interesting neighbourhoods in the search space of the complete problem. Often, it is possible to pick the initial component so that variable aggregation can be performed at the first stage, and the neighbourhoods to be explored next are guaranteed to contain feasible solutions. Using integer programming, it is then easy to implement heuristics producing solutions with bounds on their quality. Our study is performed on a university course timetabling problem used in the 2007 International Timetabling Competition, also known as the Udine Course Timetabling Problem. In the proposed heuristic, an objective-restricted neighbourhood generator produces assignments of periods to events, with decreasing numbers of violations of two period-related soft constraints. Those are relaxed into assignments of events to days, which define neighbourhoods that are easier to search with respect to all four soft constraints. Integer programming formulations for all subproblems are given and evaluated using ILOG CPLEX 11. The wider applicability of this approach is analysed and discussed.Comment: 45 pages, 7 figures. Improved typesetting of figures and table

Facing depletion. Artworks for an epistemological shift in the collapse era

This article first reports a victory of technosolutionism over the other alternatives, the degrowth for instance, to the ongoing collapse (species extinction, ecosystems depletion...). The victory is considered double: extraction can continue to increase (quantity and scope) and the devices made by technoscience are accepted as a solution to the problems caused by intensive exploitation (which they also increase). Exploitation is extended, following Achille Mbembé's proposal, to humans, non-human animals, and the earth (in a geological sense), retaining the terms fracturing, extraction, depletion. Four works are analyzed as epistemological shifts to technosolutionism. David Claerbout's “The Pure Necessity” (2016) is an animated cartoon of animals with a streamlined behavior depicted with the graphic style of Disney. The complex interlocking of eras, styles, behaviors (human and non-human) is envisaged as resistance to fracking and exploitation. “Animal Cinema” (2017) by Emilio Vavarella is a short film made from rushes produced by non-human animals. It is emphasized that the frugal production method opposes the spectacular logics of big-budget animal reporting. It adopts the animal point of view while respecting their means of production. It is also seductive by a fluid and hypnotizing editing more easily accessible to humans. Emilio Vavarella's Amazon's “Cabinet of Curiosity” (2019) is an installation with a strict protocol: the artist asks what he should order to make an artistic production. He then buys each suggestion until his budget is exhausted. By its absence, the commercial behavior of the so-called intelligent device is underlined. The artist also resists fracturing and exploitation by reducing himself to a demand. Finally, She Was Called Petra (2020) by myself is a multi-media installation. In this one, language is re-interrogated and a zone of contact is set up to cohabit with a hybrid presence.Este artículo da cuenta en primer lugar de una victoria del tecnosolucionismo frente a otras alternativas al colapso en curso (extinción de especies, agotamiento de ecosistemas...). La victoria se considera doble: la extracción puede seguir aumentando (en cantidad y alcance) y los dispositivos fabricados por la tecnociencia se aceptan como solución a los problemas causados por la explotación intensiva (que también requieren). La explotación se extiende, siguiendo la propuesta de Achille Mbembé, a los seres humanos, los animales no humanos y la tierra (en sentido geológico), conservando los términos fracturación, extracción, agotamiento. Se analizan cuatro obras como giros epistemológicos hacia el tecnosolucionismo. “The Pure Necessity” (2016), de David Claerbout, es una caricatura de animales con un estilo gráfico similar al de Disney. El complejo entrelazamiento de épocas, estilos, comportamientos (humanos y no humanos) se vislumbra como resistencia al frackingy la explotación. “Animal Cinema” (2017) de Emilio Vavarella es un cortometraje realizado a partir de juncos producidos por animales no humanos. Se hace hincapié en que el frugal método de producción se opone a la lógica espectacular de los reportajes sobre animales de gran presupuesto. Adopta el punto de vista de los animales respetando sus medios de producción. También resulta atractivo por su montaje fluido e hipnótico, más accesible a los humanos. “Amazon's Cabinet of Curiosity” (2019), de Emilio Vavarella, es una instalación con un estricto protocolo: el artista pregunta qué debería encargar para realizar una producción artística. Luego compra cada sugerencia hasta agotar su presupuesto. La fuerte retracción subraya el comportamiento comercial del llamado dispositivo inteligente. El artista también se resiste al fracking y a la explotación reduciéndose a una demanda. Por último, “She Was Called Petra” (2020), de mi autoría, es una instalación multimedia. En ella se reinterroga el lenguaje y se crea una zona de contacto/intercambio para cohabitar y pensar en una presencia híbrida

An international multicenter retrospective study of Pseudomonas aeruginosa nosocomial pneumonia: Impact of multidrug resistance

Introduction: Pseudomonas aeruginosa nosocomial pneumonia (Pa-NP) is associated with considerable morbidity, prolonged hospitalization, increased costs, and mortality. Methods: We conducted a retrospective cohort study of adult patients with Pa-NP to determine 1) risk factors for multidrug-resistant (MDR) strains and 2) whether MDR increases the risk for hospital death. Twelve hospitals in 5 countries (United States, n = 3; France, n = 2; Germany, n = 2; Italy, n = 2; and Spain, n = 3) participated. We compared characteristics of patients who had MDR strains to those who did not and derived regression models to identify predictors of MDR and hospital mortality. Results: Of 740 patients with Pa-NP, 226 patients (30.5%) were infected with MDR strains. In multivariable analyses, independent predictors of multidrug-resistance included decreasing age (adjusted odds ratio [AOR] 0.91, 95% confidence interval [CI] 0.96-0.98), diabetes mellitus (AOR 1.90, 95% CI 1.21-3.00) and ICU admission (AOR 1.73, 95% CI 1.06-2.81). Multidrug-resistance, heart failure, increasing age, mechanical ventilation, and bacteremia were independently associated with in-hospital mortality in the Cox Proportional Hazards Model analysis. Conclusions: Among patients with Pa-NP the presence of infection with a MDR strain is associated with increased in-hospital mortality. Identification of patients at risk of MDR Pa-NP could facilitate appropriate empiric antibiotic decisions that in turn could lead to improved hospital survival

Whole genome sequencing,molecular typing and in vivovirulence of OXA-48-producingEscherichia coli isolates includingST131 H30-Rx, H22 and H41subclones

Carbapenem-resistant Enterobacteriaceae, including the increasingly reported OXA-48 Escherichia coli producers, are an emerging public health threat worldwide. Due to their alarming detection in our healthcare setting and their possible presence in the community, seven OXA-48-producing, extraintestinal pathogenic E. coli were analysed by whole genome sequencing as well as conventional tools, and tested for in vivo virulence. As a result, five E. coli OXA-48-producing subclones were detected (O25:H4-ST131/PST43-fimH30-virotype E; O25:H4-ST131/PST9-fimH22-virotype D5, O16:H5-ST131/ PST506-fimH41; O25:H5-ST83/PST207 and O9:H25-ST58/PST24). Four ST131 and one ST83 isolates satisfied the ExPEC status, and all except the O16:H5 ST131 isolate were UPEC. All isolates exhibited local inflammatory response with extensive subcutaneous necrosis but low lethality when tested in a mouse sepsis model. The blaOXA-48 gene was located in MOBP131/IncL plasmids (four isolates) or within the chromosome (three ST131 H30-Rx isolates), carried by Tn1999-like elements. All, except the ST83 isolate, were multidrug-resistant, with additional plasmids acting as vehicles for the spread of various resistance genes. This is the first study to analyse the whole genome sequences of blaOXA-48-positive ST131, ST58 and ST83 E. coli isolates in conjunction with experimental data, and to evaluate the in vivo virulence of blaOXA-48 isolates, which pose an important challenge to patient management

Chemical Composition of the Essential Oil ofSatureja myrtifolia(Boiss. & Hohen.) from Lebanon

Satureja myrtifolia (Boiss. & Hohen.) Greuter & Burdeta medicinal plant belonging to the Lamiaceae family was collected from south of Lebanon and hydro-distilled by Clevenger method. Essential oil composition from aerial parts was analyzed by GC-MS technique. The odor of essential oil is characteristic, and clear yellow liquid oil was obtained after hydro-distillation. The yield of the essential oil was 1.25±0.02 % of dry matter (w/w). Thirty nine volatile components were identified in the Satureja myrtifolia oil, which shows a high amount of hydrocarbons class (57.82±0.1 %). Other classes were also identified such assesquiterpene hydrocarbons (12.96±0.1 %), oxygenated sesquiterpenes (10.65±0.2 %), phenolic compounds (10.32±0.1 %), acids (5.53±0.1 %), and monoterpenes hydrocarbons (2.21±0.1 %).In addition, a comparison with the unique study performed on Satureja myrtifolia was also carried out

Best practices for regeneration of forage and pasture legume and range genetic resources

Best practices for regeneration of forage and pasture legume and range genetic resources