Evaluation of Laser Fluorescence in the Monitoring of the Initial Stage of the De-/Remineralization Process: An in vitro and in situ Study

This study aimed to evaluate laser fluorescence (LF) for monitoring the initial stage of subsurface de- and remineralization (<150 mu m depth). Ninety-six sound blocks of bovine enamel, selected according to surface hardness (SH) and LF were used in two experimental studies, in vitro and in situ. In vitro, blocks were exposed to a demineralizing solution, then remineralized by pH cycling for 6 days. In situ, 10 volunteers wore acrylic palatal appliances, each containing 4 dental enamel blocks that were demineralized for 14 days by exposure to 20% sucrose solution. Following this treatment, blocks were submitted to remineralization for 1 week with fluoride dentifrice (1,100 mu g F/g). In both experiments, SH and LH were measured after demineralization and after remineralization. Further, enamel blocks were selected after the demineralization/remineralization steps for measurement of cross-sectional hardness and integrated loss of subsurface hardness (Delta KHN). SH and Delta KHN showed significant differences among the phases in each study. LF values for sound, demineralized and remineralized enamel were: 5.2 +/- 1.1, 8.1 +/- 1.2 and 5.6 +/- 0.8, respectively, in the in vitro study, and 5.3 +/- 0.3, 16.5 +/- 4.7 and 6.5 +/- 2.5, respectively, in the in situ study, values for demineralized enamel being significantly higher than for sound and remineralized enamel in both studies. However, LF was correlated with Delta KHN only in situ. LF was capable of monitoring de- and remineralization in early lesions in situ, when bacteria are presumably present in the caries lesion body, but is not correlated with mineral changes in bacteria-free systems. Copyright (C) 2009 S. Karger AG, Basel

In vitro antibacterial and chemical properties of essential oils including native plants from Brazil against pathogenic and resistant bacteria

The antimicrobials products from plants have increased in importance due to the therapeutic potential in the treatment of infectious diseases. Therefore, we aimed to examine the chemical characterisation (GC-MS) of essential oils (EO) from seven plants and measure antibacterial activities against bacterial strains isolated from clinical human specimens (methicillin-resistant Staphylococcus aureus (MRSA) and sensitive (MSSA), Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) and foods (Salmonella Enteritidis). Assays were performed using the minimal inhibitory concentration (MIC and MIC90%) (mg/mL) by agar dilution and time kill curve methods (log CFU/mL) to aiming synergism between EO. EO chemical analysis showed a predominance of terpenes and its derivatives. The highest antibacterial activities were with Cinnamomun zeylanicum (0.25 mg/mL on almost bacteria tested) and Caryophyllus aronzaticus EO (2.40 mg/mL on Salmonella Enteritidis), and the lowest activity was with Eugenia uniflora (from 50.80 mg/mL against MSSA to 92.40 mg/mL against both Salmonella sources and P aeruginosa) EO. The time kill curve assays revealed the occurrence of bactericide synergism in combinations of C. aromaticus and C. zeylanicum with Rosmarinus. officinalis. Thus, the antibacterial activities of the EO were large and this can also be explained by complex chemical composition of the oils tested in this study and the synergistic effect of these EO, yet requires further investigation because these interactions between the various chemical compounds can increase or reduce (antagonism effect) the inhibitory effect of essential oils against bacterial strains.

Genetic diversity of EBV-encoded LMP1 in the Swiss HIV Cohort Study and implication for NF-Κb activation

Epstein-Barr virus (EBV) is associated with several types of cancers including Hodgkin's lymphoma (HL) and nasopharyngeal carcinoma (NPC). EBV-encoded latent membrane protein 1 (LMP1), a multifunctional oncoprotein, is a powerful activator of the transcription factor NF-κB, a property that is essential for EBV-transformed lymphoblastoid cell survival. Previous studies reported LMP1 sequence variations and induction of higher NF-κB activation levels compared to the prototype B95-8 LMP1 by some variants. Here we used biopsies of EBV-associated cancers and blood of individuals included in the Swiss HIV Cohort Study (SHCS) to analyze LMP1 genetic diversity and impact of sequence variations on LMP1-mediated NF-κB activation potential. We found that a number of variants mediate higher NF-κB activation levels when compared to B95-8 LMP1 and mapped three single polymorphisms responsible for this phenotype: F106Y, I124V and F144I. F106Y was present in all LMP1 isolated in this study and its effect was variant dependent, suggesting that it was modulated by other polymorphisms. The two polymorphisms I124V and F144I were present in distinct phylogenetic groups and were linked with other specific polymorphisms nearby, I152L and D150A/L151I, respectively. The two sets of polymorphisms, I124V/I152L and F144I/D150A/L151I, which were markers of increased NF-κB activation in vitro, were not associated with EBV-associated HL in the SHCS. Taken together these results highlighted the importance of single polymorphisms for the modulation of LMP1 signaling activity and demonstrated that several groups of LMP1 variants, through distinct mutational paths, mediated enhanced NF-κB activation levels compared to B95-8 LMP1.

Kérdőjelek a közgazdaságtanban és oktatásában = Challenges in economic research and education

Ez az esszé a teljesség igénye nélkül kísérli meg áttekinteni azt, hogy mire vezetett a közgazdaságtan világméretekben megindult és a 2008-2009. évi válság lezáratlansága miatt vélhetően évtizedes szinten zajló önvizsgálata. A tudományszak egészét egyszerre jellemzi egyfajta tartalmi kiüresedés és a társtudományokkal való erőteljesebb kapcsolatkeresés, a módszertanok és az iskolák egymás mellett élése - ami egyáltalán nem békés -, valamint a gyakorlat által felvetett kérdések elméleti általánosításának igénye. A magyar közgazdaságtan hagyományos követő szerepe megmaradt, viszont a képzésben szerzett negyedszázados tapasztalatok és az új globális kihívások lényegi átalakításokat indokolnának a mai, túlságosan egységesített képzésben. _____ This essay joins the soul-searching that has developed globally among economists since the financial crisis of 2008-2009, whose still open-ended outcomes make it likely that such self-critical reassessments will continue in the years to come. Economics is marked by the parallel existence of substantive hollowing and in-creased reliance on interfaces with neighbouring disciplines. So the plurality and none-too-peaceful coexistence of schools and methodologies is likely to persist. Similarly abundant are the attempts to theorize and generalize new phenomena in policy and business practices. Hungarian economics continues to be a follower - a trend-taker rather than trend-setter - as it was in the inter-war period. Experience has been accumulating for over 25 years in introducing Western-style higher education in economics. The increase of student numbers and steep decrease in public funding thereof call for major restructuring in curricula, institutions and teaching methods and styles alike.

Peak torque and rate of torque development in elderly with and without fall history

Background Falls are one of the greatest concerns among the elderly A number of studies have described peak torque as one of the best fall-related predictor. No studies have comprehensively focused on the rate of torque development of the lower limb muscles among elderly fallers. Then, the aim of this study was to determine the relationship between muscle peak torque and rate of torque development of the lower limb joints in elderly with and without fall history It was also aimed to determine whether these parameters of muscle performance (i e, peak torque and rate of torque development) are related to the number of falls. Methods: Thirty-one women volunteered to participate in the study and were assigned in one of the groups according to the number of falls over the 12 months that preceded the present Then, participants with no fall history (Cl; n = 13; 67.6[7.5] years-old), one fall (GII; n = 8, 66 0[4 91 years-old) and two or more falls (GIII, n = 10; 67.8[8.8] years-old) performed a number of lower limb maximal isometric voluntary contractions from which peak torque and rate of torque development were quantified Findings. Primary outcomes indicated no peak torque differences between experimental groups in any lower limb joint. The rate of torque development of the knee flexor muscles observed in the non-fallers (Cl) was greater than that observed in the fallers (P < 0.05) and had a significant relationship with the number of falls (P < 0 05) Interpretation. The greater knee flexor muscles` rate of torque development found in the non-fallers in comparison to the fallers indicated that the ability of the elderly to rapidly reorganise the arrangement of the lower limb may play a significant role in allowing the elderly to recover balance after a trip. Thus, training stimulus aimed to improve the rate of torque development may be more beneficial to prevent falls among the elderly than other training stimulus, which are not specifically designed to improve the ability to rapidly produce large amounts of torque (C) 2010 Published by Elsevier Ltd

Gene-disease network analysis reveals functional modules in mendelian, complex and environmental diseases

AbstractBACKGROUND: Scientists have been trying to understand the molecular mechanisms of diseases to design preventive and therapeutic strategies for a long time. For some diseases, it has become evident that it is not enough to obtain a catalogue of the disease-related genes but to uncover how disruptions of molecular networks in the cell give rise to disease phenotypes. Moreover, with the unprecedented wealth of information available, even obtaining such catalogue is extremely difficult.PRINCIPAL FINDINGS: We developed a comprehensive gene-disease association database by integrating associations from several sources that cover different biomedical aspects of diseases. In particular, we focus on the current knowledge of human genetic diseases including mendelian, complex and environmental diseases. To assess the concept of modularity of human diseases, we performed a systematic study of the emergent properties of human gene-disease networks by means of network topology and functional annotation analysis. The results indicate a highly shared genetic origin of human diseases and show that for most diseases, including mendelian, complex and environmental diseases, functional modules exist. Moreover, a core set of biological pathways is found to be associated with most human diseases. We obtained similar results when studying clusters of diseases, suggesting that related diseases might arise due to dysfunction of common biological processes in the cell.CONCLUSIONS: For the first time, we include mendelian, complex and environmental diseases in an integrated gene-disease association database and show that the concept of modularity applies for all of them. We furthermore provide a functional analysis of disease-related modules providing important new biological insights, which might not be discovered when considering each of the gene-disease association repositories independently. Hence, we present a suitable framework for the study of how genetic and environmental factors, such as drugs, contribute to diseases.AVAILABILITY: The gene-disease networks used in this study and part of the analysis are available at http://ibi.imim.es/DisGeNET/DisGeNETweb.html#Download

Progama de salud para tutorias de 1º y 2º de la E.S.O. en el colegio Nuestra Señora del Carmen de zaragoza

Este proyecto es un programa para trabajar diferentes temas de salud para alunmos/as de 1º y 2º de la E.S.O. en las tutorias del centro.

Técnicas de estudio en estudiantes de Secundaria que asisten a clases extraescolares en la provincia de Girona

Study techniques in out of school secondary education in the province of Girona. It is important to provide students with different ways to study so they can find the most appropriate method for them. Our research focuses on the study techniques used in secondary education by those students attending classes out of school time. In order to conduct this research, we have developed a general questionnaire after reviewing the existing literature on the topic. Some of the results obtained with this study are the following: adolescents attach great importance to learn study techniques, being summaries, diagrams and underlining the most well-known strategies for them, and mind maps and teamwork the least popular ones; they prefer dynamic teaching and learning methodologies, such as making interactive discussions; tutoring is the most valued element. Based on the results obtained with the study, we have developed some proposals to facilitate the work of the teacher when teaching study techniques and helping students to improve their academic performance

Simulando catástrofes : recursos para la enseñanza de los riesgos naturales

Los riesgos naturales son abordados por distintas asignaturas de ciencias naturalesa lo largo de la ESO y el bachillerato. Su tratamiento en el aula es una evidencia del interés y el carácter aplicado de muchos aspectos de las ciencias de la tierra. Para facilitar su enfoque didáctico se proponen algunas actividades prácticas

Idoneidad didáctica de un protocolo sociocultural de enseñanza y aprendizaje de las matemáticas

En este estudio se evalúa la adecuación de un protocolo para la enseñanza delconcepto de poliedro regular, destinado a alumnos de 14 y 15 años. Este protocolo se ha diseñado desde una perspectiva sociocultural y su evaluación se basa en la aplicación de los criterios deidoneidad didáctica que ofrece el enfoque ontosemiótico. La idoneidad se estudia con la revisión de sus diferentes dimensiones: matemática, cognitiva, interaccional, mediacional, emocional y ecológica. El análisis ha permitido detectar algunos factores que favorecen la validez del protocolo y la adecuación para su empleo en el aula, como el tipo de discurso, el uso de material manipulable o el trabajo cooperativo

Los Riesgos geológicos: algunas consideraciones didácticas

From the development of concepts related with Natural and Geological Hazards different exercises and activities are proposed. All of them can be used as didactic recourses in order to study such a subject for the most appropriate educative levels

Passeig per l’invisible: itinerari químic per la ciutat de Girona = A walk through the invisible: a chemical journey through Girona

The presented itinerary covers eleven sites of the city of Girona that have been chosen for their interest from a chemical point of view. Girona is a city with chemistry, and this journey allowed student to see that chemistry is present everywhere, even in everyday life and not only in classrooms and laboratories. This approach aims to motivate students to discover something that had been invisible

"Reacciona... explota!", un taller per fomentar vocacions científiques

The workshop "React... explode!" is a project of science that shows the most attractive side of chemistry to pre-university students. It consists of carrying out recreational chemical experiments. Most students have more interest in the amazing and spectacular experiments which involve changes of colour, light, noise, smoke... The names of the experiments are very attractive: "The toilet’s monster", "The pharaoh’s snake", "The world of cold", "The termite reaction" ...

Identidad y nuevas ecologías de aprendizaje: análisis de cuatro casos de 4º de la ESO

Este trabajo pretende, en primer lugar, ilustrar empíricamente las características de las nuevas ecologías de aprendizaje de los estudiantes mediante el análisis pormenorizado de cuatro alumnos de cuarto de la ESO durante una semana de sus vidas. En segundo lugar, analizar los perfiles personales de dichos alumnos desde el análisis de su identidad aprendiz; cómo integran su yo de estudiante en su vida cotidiana y qué posturas sostienen en relación a la escuela y al papel que juega tanto en su vida presente como en su proyecto de vida futura

Utilization of a Time Domain Simulator in the Technical and Economic Analysis of a Wind Turbine Electric Drive Train

The amount of installed wind power has been growing exponentially during the past ten years. As wind turbines have become a significant source of electrical energy, the interactions between the turbines and the electric power network need to be studied more thoroughly than before. Especially, the behavior of the turbines in fault situations is of prime importance; simply disconnecting all wind turbines from the network during a voltage drop is no longer acceptable, since this would contribute to a total network collapse. These requirements have been a contributor to the increased role of simulations in the study and design of the electric drive train of a wind turbine. When planning a wind power investment, the selection of the site and the turbine are crucial for the economic feasibility of the installation. Economic feasibility, on the other hand, is the factor that determines whether or not investment in wind power will continue, contributing to green electricity production and reduction of emissions. In the selection of the installation site and the turbine (siting and site matching), the properties of the electric drive train of the planned turbine have so far been generally not been taken into account. Additionally, although the loss minimization of some of the individual components of the drive train has been studied, the drive train as a whole has received less attention. Furthermore, as a wind turbine will typically operate at a power level lower than the nominal most of the time, efficiency analysis in the nominal operating point is not sufficient. This doctoral dissertation attempts to combine the two aforementioned areas of interest by studying the applicability of time domain simulations in the analysis of the economicfeasibility of a wind turbine. The utilization of a general-purpose time domain simulator, otherwise applied to the study of network interactions and control systems, in the economic analysis of the wind energy conversion system is studied. The main benefits of the simulation-based method over traditional methods based on analytic calculation of losses include the ability to reuse and recombine existing models, the ability to analyze interactions between the components and subsystems in the electric drive train (something which is impossible when considering different subsystems as independent blocks, as is commonly done in theanalytical calculation of efficiencies), the ability to analyze in a rather straightforward manner the effect of selections other than physical components, for example control algorithms, and the ability to verify assumptions of the effects of a particular design change on the efficiency of the whole system. Based on the work, it can be concluded that differences between two configurations can be seen in the economic performance with only minor modifications to the simulation models used in the network interaction and control method study. This eliminates the need ofdeveloping analytic expressions for losses and enables the study of the system as a whole instead of modeling it as series connection of independent blocks with no lossinterdependencies. Three example cases (site matching, component selection, control principle selection) are provided to illustrate the usage of the approach and analyze its performance.