Converging Perturbative Solutions of the Schroedinger Equation for a Two-Level System with a Hamiltonian Depending Periodically on Time

We study the Schroedinger equation of a class of two-level systems under the action of a periodic time-dependent external field in the situation where the energy difference 2epsilon between the free energy levels is sufficiently small with respect to the strength of the external interaction. Under suitable conditions we show that this equation has a solution in terms of converging power series expansions in epsilon. In contrast to other expansion methods, like in the Dyson expansion, the method we present is not plagued by the presence of ``secular terms''. Due to this feature we were able to prove absolute and uniform convergence of the Fourier series involved in the computation of the wave functions and to prove absolute convergence of the epsilon-expansions leading to the ``secular frequency'' and to the coefficients of the Fourier expansion of the wave function

The retable of the chapel of Our Lady of Mercy in the cloister of Oporto’s Cathedral: study, conservation and restoration

The retable located in the Chapel of Our Lady of Mercy, in the cloisters of Oporto’s cathedral, dates back to the 17th century. Artistically, it belongs to a transition period between the Mannerism and the Baroque styles. The artistic value and the lack of documented information about the artwork led to the development of a project contemplating its the study. Both chemical and physical analyses - observation of the support, micro-FTIR and SEM-EDS - suggest that the retable was carved in sweet chestnut wood, accordingly to the techniques used at the time. The retable presents water-gilded areas contrasting with blue and red phytomorphic motifs. The polychromed areas were later covered with lead white paint. There were also evidences of previous conservation-restoration interventions. The frail condition of the retable’s materials testified the need to conserve and restore it. Among other procedures, the materials were consolidated and the lacunae were filled and inpainted - partially regenerating the artwork’s aesthetic unit

Necrosis of a Guinea Pig Stomach after Contact with Povidone-Iodine: a Case Report

Rodents are the most frequently used animals in surgical experimentation. It is estimated that guinea pigs in particular are the third most commonly used species in this context. To disinfect guinea pigs’ skin, either alcohol or surgical iodine are most often used. In the context of an animal research project, a Nissen operation was performed in an adult male guinea pig. Because of accidental contamination of the operative field, a 10% povidone-iodine cutaneous solution was applied to the serosa of the anterior wall of the stomach and to the gastric fundus. The guinea pig died 12 hours after surgery due to an acute necrotizing hemorrhagic gastritis. Although there have been a few reports of povidone-iodine toxicity in the guinea pig, as far as the authors could determine, this is the first time that such a serious abdominal complication is reported. The authors believe that the possibility of a similar event should be taken into consideration when planning, executing and interpreting experiments in the guinea pig

Existence of the Bogoliubov S(g) operator for the (:ϕ4:)2(:\phi^4:)_2 quantum field theory

We prove the existence of the Bogoliubov S(g) operator for the $(:\phi^4:)_2$ quantum field theory for coupling functions $g$ of compact support in space and time. The construction is nonperturbative and relies on a theorem of Kisy\'nski. It implies almost automatically the properties of unitarity and causality for disjoint supports in the time variable.Comment: LaTeX, 24 pages, minor modifications, typos correcte

Kelpie: A ROS-based multi-robot simulator for water surface and aerial vehicles

Testing and debugging real hardware is a time consuming task, in particular for the case of aquatic robots, for which it is necessary to transport and deploy the robots on the water. Performing waterborne and airborne field experiments with expensive hardware embedded in not yet fully functional prototypes is a highly risky endeavour. In this sense, physics-based 3D simulators are key for a fast paced and affordable development of such robotic systems. This paper contributes with a modular, open-source, and soon to be freely online available, ROS-based multi-robot simulator specially focused for aerial and water surface vehicles. This simulator is being developed as part of the RIVERWATCH experiment in the ECHORD european FP7 project. This experiment aims at demonstrating a multi-robot system for remote monitoring of riverine environments.info:eu-repo/semantics/acceptedVersio

Online self-reconfigurable robot navigation in heterogeneous environments

This paper presents a robot navigation system capable of online self-reconfiguration according to the needs imposed by the various contexts present in heterogeneous environments. The ability to cope with heterogeneous environments is key for a robust deployment of service robots in truly demanding scenarios. In the proposed system, flexibility is present at the several layers composing the robot's navigation system. At the lowest layer, proper locomotion modes are selected according to the environment's local context. At the highest layer, proper motion and path planning strategies are selected according to the environment's global context. While local context is obtained directly from the robot's sensory input, global context is inspected from semantic labels registered off-line on geo-referenced maps. The proposed system leverages on the well-known Robotics Operating System (ROS) framework for the implementation of the major navigation system components. The system was successfully validated over approximately 1 Km long experiments on INTROBOT, an all-terrain industrial-grade robot equipped with four independently steered wheels.info:eu-repo/semantics/acceptedVersio

Pain Intensity and Time to Death of Cancer Patients Referred to Palliative Care

Introdução: A dor é uma experiência frequente nos doentes com cancro, especialmente naqueles em fase final de vida. Com este estudo, pretendemos estudar a intensidade de dor nos doentes com cancro avançado, referenciados aos cuidados paliativos, analisar os factores associados à ocorrência de dor moderada ou intensa e avaliar a sua relação com o tempo até à morte destes doentes. Material e Métodos: Estudo prospectivo observacional que incluiu consecutivamente todos os doentes referenciados aos cuidados paliativos com tumores sólidos metastizados e sem tratamento oncológico específico. Foi considerada a intensidade de dor da escala de Edmonton, de acordo com a graduação zero a 10, onde 0 = ausência de dor e 10 = máxima dor possível. Resultados: Entre outubro de 2012 e junho de 2015, foram incluídos 301 doentes, com idade mediana de 69 anos (37 - 94), 57% homens e 64,8% dos doentes com performance status 3/4. Aproximadamente 42% dos doentes apresentaram dor ≥ 4 e cerca de 74,4% estavam medicados com analgesia opióide. A intensidade de dor esteve associada ao performance status dos doentes, de acordo com a análise multivariável (OR: 1,7; IC 95%: 1,0 - 2,7; p = 0,045). A mediana do tempo de sobrevivência foi de 37 dias (IC 95%: 28 - 46), tendo os doentes com dor moderada ou intensa (intensidade de dor ≥ 4) uma mediana de sobrevivência de 29 dias (IC 95%: 21 - 37), comparada com os 49 dias (IC 95%: 35 - 63) para os doentes sem dor ou dor ligeira (p = 0,022). Discussão: O performance status, para além de ter estado associado a uma maior intensidade de dor, esteve associado a um menor tempo até à morte dos doentes com cancro avançado referenciados aos cuidados paliativos. Também o internamento, a presença de metastização intra-abdominal e a analgesia opióide estiveram associados de forma negativa ao tempo até à morte destes doentes. Conclusão: A dor oncológica continua a ser um problema clinicamente relevante nos doentes com cancro avançado

Urine as a social signal in the Mozambique tilapia (Oreochromis mossambicus)

info:eu-repo/semantics/publishedVersio

Olfactory sensitivity to changes in environmental Ca2 in the freshwater teleost Carassius auratus: an olfactory role for the Ca2+ -sensing receptor?

Olfactory sensitivity to changes in environmental Ca2+ has been demonstrated in two teleost species; a salmonid (Oncorhynchus nerka) and a marine/estuarine perciform (Sparus aurata). To assess whether this phenomenon is restricted to species that normally experience large fluctuations in external ion concentrations (e.g. moving from sea water to fresh water) or is present in a much wider range of species, we investigated olfactory Ca2+ sensitivity in the goldfish (Carassius auratus), which is a stenohaline, non-migratory freshwater cyprinid. Extracellular recording from the olfactory bulb in vivo by electroencephalogram (EEG) demonstrated that the olfactory system is acutely sensitive to changes in external Ca2+ within the range that this species is likely to encounter in the wild (0.05–3 mmol l–1). The olfactory system responded to increases in external calcium with increasing bulbar activity in a manner that fitted a conventional Hill plot with an apparent EC50 of 0.9±0.3 mmol l–1 (close to both ambient and plasma free [Ca2+]) and an apparent Hill coefficient of 1.1±0.3 (means ± S.E.M., N=6). Thresholds of detection were below 50 mmol l–1. Some olfactory sensitivity to changes in external [Na+] was also recorded, but with a much higher threshold of detection (3.7 mmol l–1). The olfactory system of goldfish was much less sensitive to changes in [Mg2+] and [K+]. Preliminary data suggest that Ca2+ and Mg2+ are detected by the same mechanism, although with a much higher affinity for Ca2+. Olfactory sensitivity to Na+ may warn freshwater fish that they are reaching the limit of their osmotic tolerance when in an estuarine environment. Olfaction of serine, a potent odorant in fish, was not dependent on the presence of external Ca2+ or Na+. Finally, the teleost Ca2+-sensing receptor (Ca-SR) was shown to be highly expressed in a subpopulation of olfactory receptor neurones by both immunocytochemistry and in situ hybridisation. The olfactory sensitivity to Ca2+ (and Mg2+) is therefore likely to be mediated by the Ca-SR. We suggest that olfactory Ca2+ sensitivity is a widespread phenomenon in teleosts and may have an input into the physiological mechanisms regulating internal calcium homeostasis