Some Remarks on the Model Theory of Epistemic Plausibility Models

Classical logics of knowledge and belief are usually interpreted on Kripke models, for which a mathematically well-developed model theory is available. However, such models are inadequate to capture dynamic phenomena. Therefore, epistemic plausibility models have been introduced. Because these are much richer structures than Kripke models, they do not straightforwardly inherit the model-theoretical results of modal logic. Therefore, while epistemic plausibility structures are well-suited for modeling purposes, an extensive investigation of their model theory has been lacking so far. The aim of the present paper is to fill exactly this gap, by initiating a systematic exploration of the model theory of epistemic plausibility models. Like in 'ordinary' modal logic, the focus will be on the notion of bisimulation. We define various notions of bisimulations (parametrized by a language L) and show that L-bisimilarity implies L-equivalence. We prove a Hennesy-Milner type result, and also two undefinability results. However, our main point is a negative one, viz. that bisimulations cannot straightforwardly be generalized to epistemic plausibility models if conditional belief is taken into account. We present two ways of coping with this issue: (i) adding a modality to the language, and (ii) putting extra constraints on the models. Finally, we make some remarks about the interaction between bisimulation and dynamic model changes.Comment: 19 pages, 3 figure

Evaluation of torrefied poplar-biomass as a low-cost sorbent for lead and terbium removal from aqueous solutions and energy co-generation

Two low-cost renewable poplar-based materials were manufactured in this work for energy production and as sorbents for lead and terbium removal from aqueous effluents. Torrefaction was used as a pretreatment process for conditioning the raw biomass. Two different operating conditions were used in the multiple-hearth furnace of the torrefaction pilot-plant: i) 250¿°C; ii) 280¿°C, with residence times of 75¿min and 60¿min, respectively. The raw and torrefied biomasses have been characterized using SEM-EDX, FTIR, TGA, XRD and elemental analyses (C, H, N, S, O); an increase of the torrefaction severity, results in an increase of the carbon/oxygen ratio and in a greater mass loss (21% at 250¿°C, and 53% at 280¿°C). The torrefaction had a positive impact on the sorption of metals, it allowed the increase of lignin content of the manufactured materials, and it allowed the storage of the sorbents for longer time with reduced moisture content. The equilibrium studies were performed in batch system and the experimental data were described with the Sips equation. The maximum sorption capacity was found as 30¿mg¿g-1 for lead and 9.4¿mg¿g-1 for terbium (at pH 4). The kinetic profiles were fitted using the pseudo-second order rate equation. The regeneration of the sorbent was demonstrated by three sorption-desorption cycles using dilute HNO3 solution (0.1¿M) as eluent for metal recoveryPeer ReviewedPostprint (author's final draft

Robust, Bridge-less Ion-selective Electrodes with Significantly Reduced Need for Pre- and Post-application Handling

We are demonstrating robust, single-layer ion-selective electrode (ISE) utilizing simple Ag/AgCl electrode as solid support without the need for intermediate polymer layer. We have created and chemically linked a family of imidazolium ionic liquids (ILs) with poly (vinyl chloride) (PVC) using click chemistry, resulting in hybrid materials with tunable characteristics. The resultant material inherently contains chloride ion thus offering the ability to stabilize interfacial potential. This allowed us to construct very simple, single-layer membranes with significantly reduced need for conditioning as an added bonus compared to traditional sensors. Chemical immobilization of ISE membrane components also led to extended lifetime as the potential for material loss is reduced and detection limits are lowered. In our characterization we focused on perchlorate as a model ion. It\u27s levels of around 10−7 M could be repeatedly quantified over a 100 day period despite constant exposure of ISEs to aqueous solution over this time. Most importantly, the electrodes exhibited stable and reproducible signal with significantly simplified pre- and post-operation handling protocols. This offers potential for in situ applications as well as to advanced fabrication techniques and miniaturization. Simplicity of construction and operation, and low cost of the solid substrate allows for disposable ISE formats

Practice recommendation for the detection and diagnosis of patients with alzheimer’s disease dementia at Buenos Aires City

La Enfermedad de Alzheimer es la causa más frecuente de trastornos cognitivos y demencia en adultos mayores, y es considerada una nueva epidemia. Por sus diferentes manifestaciones cognitivas, conductuales y funcionales, la detección, diagnóstico y tratamiento de los pacientes con Demencia debida a Enfermedad de Alzheimer puede representar un desafío. En las presentes recomendaciones se dan pautas de manejo con niveles de recomendación basados en la mejor evidencia científica disponible. Asimismo, se presentan indicaciones y sugerencias de estudio, o derivación a un nivel superior de asistencia según la complejidad de cada caso. De este modo, se brinda un conjunto de recomendaciones prácticas de apoyo para la toma de decisiones por parte de los profesionales de la salud en cada nivel sanitario, desde la asistencia primaria hasta los médicos especialistas. Mediante un enfoque operativo y dinámico, estas Recomendaciones proponen un enfoque global basado en la evidencia para los pacientes, familiares y agentes de Salud involucrados en esta patología, de enorme relevancia a nivel social.Alzheimer’s disease is the most frequent cause of cognitive disorders and dementia in older adults and is considered a new epidemic. Due to its different cognitive, behavioral and functional manifestations, the detection, and diagnosis of patients with Alzheimer’s Disease Dementia can represent a challenge. In this Clinical Practice Recommendation, management are given with levels based on the best scientific evidence available. Likewise, indications for study, or referral to a higher level of sanitary assistance are presented, according to the complexity of each clinical case. In this way, a set of practical recommendations of support is provided for decision making by health professionals at each sanitary level, from primary care to medical specialists. Through an operational and dynamic approach, this recommendations proposes a global strategy based on evidence for patients, family members and health agents involved in this pathology, of great social relevance.Fil: Demey, Ignacio. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Hospital Británico de Buenos Aires; ArgentinaFil: Ollari, Juan A.. Hospital Británico de Buenos Aires; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital Municipal "José Tiburcio Borda"; ArgentinaFil: Rojas, Galeno. Hospital Británico de Buenos Aires; Argentina. Fundación Favaloro; Argentina. Ministerio de Salud. Administración Nacional de Medicamentos, Alimentos y Tecnología Médica; ArgentinaFil: Bagnati, Pablo. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Sarasola, Diego. No especifíca;Fil: Román, Fabián. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; Argentina. Universidad de la Costa.; ColombiaFil: Tarulla, Adriana. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; Argentina. Universidad de la Costa.; ColombiaFil: Blake, Andre. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; ArgentinaFil: Sevlever, Gustavo. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Caridi, Aldo. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; ArgentinaFil: Allegri, Ricardo Francisco. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; Argentina. Universidad de la Costa.; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Reduction of food phatogens prevalence in dietary S.cerevisiae-fed poultry orally challenged with S.enteritidis and C. jejuni.

The effect of yeast supplementation in broiler chickens on Salmonella enteritidis and Campylobacter jejuni contamination in faeces, cecum, breast, and neck skin was evaluated. Two groups (12 replicates/group, 20 Hubbard female chickens 1d old/replicate) were fed pre-starter (0-10d), starter (11-20d) and growing (21-38d) diets, and administered (Y) or not (C) Levucell\uae SB20 (Saccharomyces cerevisiae type boulardii I-1079; 106 CFU/g feed through a 0.05% premix). Birds were orally challenged at 10 days of life (S. enteritidis, 1x105 CFU/bird, and C. jejuni, 3x105 CFU/bird). On day 10 and 28 post-infection (PI), 10 animals/replicate were slaughtered and pooled ceca content of 5 birds/replicate was analysed for Salmonella and Campylobacter detection and enumeration together with total yeast count. Neck and breast skin were tested for Salmonella and Campylobacter presence on 1 subject/replicate. Data were analysed by a GLM procedure of SAS considering two experimental periods, from 0 to 20 days and from 20 to 38 days. Growth performance and faecal coliforms content were not affected by treatment. Higher yeast and lactobacilli (P=0.01) faecal count, and a significant decreased Salmonella enumeration and frequency in neck (-41%, P=0.03) and tendency in faeces (-25%; P=0.06), cecum (-25%; P=0.06), and breast skin (-33%; P=0.08) were found in Y group on day 38. No fecal Campylobacter was detected at 10d (P<0.01) or 28d (P=0.06) PI in Y birds, while in neck skin absence of Campylobacter was only recorded on day 10 PI (P=0.01). Campylobacter was significantly lower in Y birds in cecum (-42%; P=0.01), and breast skin (-58%; P=0.04) on 10d PI, while on day 38 it was reduced in breast skin (-42%; P=0.02), and tended to decrease in faeces (-25%; P=0.06). Saccharomyces cerevisiae (CNCM I-1079) significantly controlled Campylobacter carriage in chickens with some positive results also on Salmonella contamination, thus reducing the contamination of carcasses with both food borne pathogens

Single-spin asymmetries in semi-inclusive deep-inelastic scattering on a transversely polarized hydrogen target

Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering of positrons are measured for the first time with transverse target polarization. The asymmetry depends on the azimuthal angles of both the pion ($\phi$) and the target spin axis ($\phi_S$) about the virtual photon direction and relative to the lepton scattering plane. The extracted Fourier component \cmpi is a signal of the previously unmeasured quark transversity distribution, in conjunction with the so-called Collins fragmentation function, also unknown. The Fourier component \smpi of the asymmetry arises from a correlation between the transverse polarization of the target nucleon and the intrinsic transverse momentum of quarks, as represented by the previously unmeasured Sivers distribution function. Evidence for both signals is observed, but the Sivers asymmetry may be affected by exclusive vector meson productio

First Measurement of the Tensor Structure Function b1b_1 of the Deuteron

The \Hermes experiment has investigated the tensor spin structure of the deuteron using the 27.6 GeV/c positron beam of \Hera. The use of a tensor polarized deuteron gas target with only a negligible residual vector polarization enabled the first measurement of the tensor asymmetry \At and the tensor structure function \bd for average values of the Bj{\o}rken variable $0.01<0.45$ and of the squared four-momentum transfer $0.5 {\rm GeV^2} <5 {\rm GeV^2}$. The quantities \At and \bd are found to be non-zero. The rise of \bd for decreasing values of $x$ can be interpreted to originate from the same mechanism that leads to nuclear shadowing in unpolarized scattering

Double hadron leptoproduction in the nuclear medium

First measurement of double-hadron production in deep-inelastic scattering has been measured with the HERMES spectrometer at HERA using a 27.6 GeV positron beam with deuterium, nitrogen, krypton and xenon targets. The influence of the nuclear medium on the ratio of double-hadron to single-hadron yields has been investigated. Nuclear effects are clearly observed but with substantially smaller magnitude and reduced $A$-dependence compared to previously measured single-hadron multiplicity ratios. The data are in fair agreement with models based on partonic or pre-hadronic energy loss, while they seem to rule out a pure absorptive treatment of the final state interactions. Thus, the double-hadron ratio provides an additional tool for studying modifications of hadronization in nuclear matter

Subleading-twist effects in single-spin asymmetries in semi-inclusive deep-inelastic scattering on a longitudinally polarized hydrogen target

Single-spin asymmetries in the semi-inclusive production of charged pions in deep-inelastic scattering from transversely and longitudinally polarized proton targets are combined to evaluate the subleading-twist contribution to the longitudinal case. This contribution is significantly positive for (\pi^+) mesons and dominates the asymmetries on a longitudinally polarized target previously measured by \hermes. The subleading-twist contribution for (\pi^-) mesons is found to be small

Search for an exotic S=-2, Q=-2 baryon resonance at a mass near 1862 MeV in quasi-real photoproduction

A search for an exotic baryon resonance with $S=-2, Q=-2$ has been performed in quasi-real photoproduction on a deuterium target through the decay channel $\Xi^- \pi^- \to \Lambda \pi^- \pi^- \to p \pi^- \pi^- \pi^-$. No evidence for a previously reported $\Xi^{--}(1860)$ resonance is found in the $\Xi^- \pi^-$invariant mass spectrum. An upper limit for the photoproduction cross section of 2.1 nb is found at the 90% confidence level. The photoproduction cross section for the $\Xi^{0}(1530)$ is found to be between 9 and 24 nb