Isolation and Crystal Structure of 3-Aryl-1-(2-hydroxyphenyl)-3-hydroxy- 1- propanones Derived from Claisen-Schmidt Condensation of 2- Hydroxyacetophenone with Benzaldehyde Derivatives

2-Hydroxyacetophenone reacted with benzaldehyde derivatives under alkalinic conditions followed by addition of dilute hydrochloric acid solution to afford mixtures of the known 2-hydroxychalcone derivatives and the corresponding previously undescribed 3-aryl-1-(2-hydroxyphenyl)-3-hydroxy-1-propanones. The isolation of the b-hydroxyketone derivatives depends on the work-up conditions. Their structures were established using a combination of NMR, IR and mass spectroscopic techniques. The conformation of the b-hydroxyketones was probed using 1 H NMR spectroscopy and X-ray crystallography. South African Journal of Chemistry Vol.55 2002: 97-110PDF and Supplemetry file attache

Complex critical exponents for percolation transitions in Josephson-junction arrays, antiferromagnets, and interacting bosons

We show that the critical behavior of quantum systems undergoing a percolation transition is dramatically affected by their topological Berry phase $2\pi\rho$. For irrational $\rho$, we demonstrate that the low-energy excitations of diluted Josephson-junctions arrays, quantum antiferromagnets, and interacting bosons are spinless fermions with fractal spectrum. As a result, critical properties not captured by the usual Ginzburg-Landau-Wilson description of phase transitions emerge, such as complex critical exponents, log-periodic oscillations and dynamically broken scale-invariance.Comment: revised version accepted for publication in Phys. Rev. Let

Pericarditis Due to Campylobacter Fetus Subsp. Fetus: a Case Report of an Uncommon Infection

Pericarditis is a common condition with numerous aetiologies. Bacteria other than the Mycobacterium tuberculosis complex are an exceptional cause. We present a case of subacute pericarditis highly probable due to Campylobacter fetus subsp. fetus in an immunosuppressed patient undergoing biologic therapy in relation to systemic lupus erythematosus (SLE). On admission, the patient presented with chest pain, dyspnea, and diaphoresis and has lately developed fever and a large pericardial effusion (PE) with a concomitant increase in the inflammatory parameters. The clinical presentation, along with the exclusion of a flare of the autoimmune disease and the isolation of Campylobacter fetus subsp. fetus on blood samples permitted the diagnosis. After therapy with antibiotics and colchicine, the patient showed full recovery.info:eu-repo/semantics/publishedVersio

GENDER DIFFERENCES ON LOWER LIMB COORDINATION DURING ELITEPLAYERS JUMP

The results from an experimental analysis of the jump in basketball female and male players are presented. Coordination of seventeen lower limb is analyzed in a high risk movement frequently performed by athletes during jump It is showed that on the sample studied several differences on relative phase are found entailing particularly transverse movement plane of knee. These results show that during some core moments of the jump, gender can influence the lower limb joint coordination. The comparison of relative phase shows a female propensity for moving in less synergy on jump reception. Such findings highlight the need for including on preparation program of athletes a prevention plan that is not necessarily identical on both genders

Random Spin-1 Quantum Chains

We study disordered spin-1 quantum chains with random exchange and biquadratic interactions using a real space renormalization group approach. We find that the dimerized phase of the pure biquadratic model is unstable and gives rise to a random singlet phase in the presence of weak disorder. In the Haldane region of the phase diagram we obtain a quite different behavior.Comment: 13 pages, Latex, no figures, to be published in Solid State Communication

Identifying and characterising crashes of returning riders: A new approach

Surveys have identified that many older motorcyclists are returning riders but it is difficult to draw conclusions about their crash risk because of discrepancies in definitions and the inability to identify returning riders in official crash databases. Analyses of NSW crash data were undertaken in which returning riders were defined as aged 25 and over, holding a full licence 10 years prior to the crash, and not the registered operator of one or more motorcycles during the 5-10 years prior to the crash. Based on this definition, there were 472 riders in casualty crashes in 2005-09 who were returning riders (5.5% of riders aged 25 and over in casualty crashes) and the characteristics of their crashes were similar to those involving continuing riders. In contrast, crashes of new riders were more likely to have characteristics suggestive of relatively more riding in urban areas, probably for transport rather than recreation. More work is recommended to assess the validity of the definition to allow a better understanding of the effects of long periods away from riding on riding skills and crash risk

Webexpert – tool for knowledge acquisition by web

Knowledge acquisition for systems based on knowledge can be called knowledge engineering, according to Feigenbaum (1980) who used the term to describe the reduction of a wide context of knowledge for a set of facts and rules. The term Knowledge Engineer started to be used to denote the responsible person by development of such systems. The basic function of Knowledge Engineering is to play the role of mediator between the expert and the Knowledge Base, to extract the knowledge from the expert, to codify the same in contribution with the expert to reach an acceptable performance.Eje: Sistemas inteligentesRed de Universidades con Carreras en Informática (RedUNCI

Resilience and Vulnerability of Public Transportation Fare Systems: The Case of the City of Rio De Janeiro, Brazil

Resilience is the ability of a system to adapt, persist, and transform as a reaction to threats, which may be external or internal to the system, while vulnerability is the state of being susceptible to harm from exposure to stresses associated with environmental and social change and from the inability to adapt. Based on a study of the threats that can affect urban mobility, we identified a gap regarding the analysis of the levels of resilience and vulnerability in the face of subsidy threats that can severely affect developing countries. This article measures the level of resilience and vulnerability due to the absence of public transport fare subsidies. For this purpose, we developed an approach based on fuzzy logic and applied it in 33 administrative regions (ARs) of the city of Rio de Janeiro, Brazil. We obtained four matrices of the levels of vulnerability and resilience of each of the regions as an origin and destination. The results show that areas nearest to the downtown region and those with high-capacity transportation available (commuter train and/or subway, systems with many transfer points) are more resilient, while a high level of vulnerability is associated with low income, negative socioeconomic indicators, and the predominance of road transportation to reach jobs. The contribution of this paper is the method applied to analyse the levels of vulnerability and resilience of public transport, which includes a threat that can cause a rupture that impacts routines and job accessibility in a region

Webexpert – tool for knowledge acquisition by web

Knowledge acquisition for systems based on knowledge can be called knowledge engineering, according to Feigenbaum (1980) who used the term to describe the reduction of a wide context of knowledge for a set of facts and rules. The term Knowledge Engineer started to be used to denote the responsible person by development of such systems. The basic function of Knowledge Engineering is to play the role of mediator between the expert and the Knowledge Base, to extract the knowledge from the expert, to codify the same in contribution with the expert to reach an acceptable performance.Eje: Sistemas inteligentesRed de Universidades con Carreras en Informática (RedUNCI