A glossary for the social epidemiology of work organization. Part 3: terms from labour markets

This is part 3 of a three-part glossary on the social epidemiology of work organisation. The first two parts deal with the social psychology of work and with organisations. This concluding part presents concepts related to labour markets. These concepts are drawn from economics, business and sociology. They relate both to traditional interests in these disciplines and to contemporary ideas on post-industrialisation and globalisation, particularly the growth of employment in service industries, the development of a 24-h economy, increased participation of the female labour force and the perceived needs of employers in emerging high-tech economies.These changes are of particular interest because they are linked to increasing inequality in earnings and changes in social relationships in employment. These concepts have the potential to elucidate the pathways through which health is affected by conditions of work as an underlying cause

CMOS Receiver Front-End Architecture for High-Speed SI-POF Links

This works presents a new CMOS analog front-end for short-reach high-speed optical communications which compensates the limited bandwidth of POF channels and is suitable for the required large area photodetectorf The proposed pseudo-differential architecture, formed by a preamplifier and an equalizer, has been designed in a standard 0.18-μm CMOS process with a 1-V supply voltage targeting gigabit transmission for NRZ modulation. The preamplifier is based on the flipped voltage follower stage to attain a very low input resistance in order to handle the large phodiode capacitance (3 pF). The equalizer can adjust the high-frequency boosting and the gain, to compensate for the variation of the characteristics of the channel due to length of the fiber, connections, etc. causing subtantial changes of the fiber bandwidth. Reliable electrical models are employed for a Mitsubishi GH SI-POF with 10-m to 50-m length and for a S5972 silicon photodiode from Hamamatsu suitable for such a fiber due to its large diameter (0.8 mm) and responsivity at 650 nm (0.44A/W). The bandwidth of the received signal can be enhanced from 100 MHz to 1.4 GHz and from 300 MHz to 1.4 GHz for a 50-m and 10-m POF respectively. The proposed circuit shows a transimpedance of 41.5 dBΩ while the theoretical sensitivity from noise performance is below -7.5 dBm with a BER = 10-12. The power consumption is below 16 mW from 1-V supply voltage. In conclusion it targets 1.25 Gbps through a 1-mm SI-POF up to 50-m length with a commercial Si PIN photodiode

Combined Effects of the North Atlantic Oscillation and the Arctic Oscillation on Sea Surface Temperature in the Alborán Sea

We explored the possible effects of the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) on interannual sea surface temperature (SST) variations in the Albora´n Sea, both separately and combined. The probability of observing mean annual SST values higher than average was related to NAO and AO values of the previous year. The effect of NAO on SST was negative, while that of AO was positive. The pure effects of NAO and AO on SST are obscuring each other, due to the positive correlation between them. When decomposing SST, NAO and AO in seasonal values, we found that variation in mean annual SST and mean winter SST was significantly related to the mean autumn NAO of the previous year, while mean summer SST was related to mean autumn AO of the previous year. The one year delay in the effect of the NAO and AO on the SST could be partially related to the amount of accumulated snow, as we found a significant correlation between the total snow in the North Albora´n watershed for a year with the annual average SST of the subsequent year. A positive AO implies a colder atmosphere in the Polar Regions, which could favour occasional cold waves over the Iberian Peninsula which, when coupled with precipitations favoured by a negative NAO, may result in snow precipitation. This snow may be accumulated in the high peaks and melt down in spring-summer of the following year, which consequently increases the runoff of freshwater to the sea, which in turn causes a diminution of sea surface salinity and density, and blocks the local upwelling of colder water, resulting in a higher SST.CGL2009-11316 (Ministerio de Ciencia e Innovación, Spain, and FEDER

Application of a flipped classroom for model-based learning in electronics

This paper investigates the effectiveness of the flipped classroom methodology to build conceptual knowledge mentalmodels. In particular, it examines the learning process and outcomes of 40 students of a course on Physical Electronics inthe last year of a bachelor’s degree program in Physics, for which specific educational resources have been developed toimplement the flipped classroom. Among them, non-interactive resources are better to present topics and ideas, whereasinteractive resources are more useful to establish links between them to build and check the models. The examined dataentail grades, laboratory reports and rubrics, outcomes of learning activities, and direct observation, showing that theflipped classroom improves the construction of mental models, providing teaching resources where the topics and mainideas are presented, developed and exercised, and allowing students to establish links to build and check the models.Furthermore, this strategy increases the personal commitment of the students, fostering autonomy and cooperation withpeers, all of which makes it an effective pedagogical tool to build knowledge mental models

ICT-based didactic strategies to build knowledge models in electronics in higher education

This paper presents a didactic strategy based on information and communication technologies (ICTs) to help students build knowledge mental models in the context of Higher Education. It presents a methodology that combines the flipped classroom with other active methodologies and traditional lessons to improve the teaching/learning process of Electronics in university studies in Physics. Using the flipped classroom as the main strategy, the proposed methodology allows devoting more classroom time to active learning so that the instructor can follow the student learning process and evaluate model construction, while at the same time it increases student implication and fosters autonomy and cooperation with peers, contributing to a better construction of knowledge mental models in Electronics

Programmable low-power low-noise capacitance to voltage converter for MEMS accelerometers

In this work, we present a capacitance-to-voltage converter (CVC) for capacitive accelerometers based on microelectromechanical systems (MEMS). Based on a fully-differential transimpedance amplifier (TIA), it features a 34-dB transimpedance gain control and over one decade programmable bandwidth, from 75 kHz to 1.2 MHz. The TIA is aimed for low-cost low-power capacitive sensor applications. It has been designed in a standard 0.18-µm CMOS technology and its power consumption is only 54 µW. At the maximum transimpedance configuration, the TIA shows an equivalent input noise of 42 fA/vHz at 50 kHz, which corresponds to 100 µg/vHz

Diversification and manager autonomy in fund families: Implications for investors

This paper aims to investigate the consequences of investing in a single fund family for investors. In essence, we focus on the correlation among portfolio holdings of funds with effects in terms of under-diversification for mutual fund investors, especially, if they invest in the same fund family. We also explore the fund manager autonomy in portfolio holding allocation within families and determine the characteristics of those fund families with higher autonomy. Our results show that a higher correlation among funds not only implies that families offer a lower diversification to investors; it also has a negative effect on their performance. However, investors’ performance benefits from a higher manager autonomy. Consequently, investors who select a single fund family could obtain higher returns in smaller fund families with considerable experience that do not belong to a banking or insurance group, as in the former, diversification and manager autonomy are higher

Revisión de las colecciones de rocas riolíticas catalanas del Museu de Geologia y de la Facultat de Geologia de la Universitat de Barcelona

The Museu de Geologia de Barcelona and the Faculty of Geology of the University of Barcelona own twin collections of rhyolitic volcanic rocks from the Catalonian Pyrenees, permo-carboniferous in age. Samples of these collections are currently exposed in the museum and used for didactic purposes at the university (petrography and hand sample studies). This revision corroborates that the collections have a initial common origin in the San Miguel de la Cámara collection (1934). The university' collection consists of lavic rocks from the Gréixer-Coll de Pi sector, rhyolitic in composition, and with textural evidence (perlitic textures, skeletal phenocrysts, thermal shocked quartz, etc.) of magma-water interaction during the mise-en-place process. Despite of their age these rocks show fine preservation of the original textural features, but they seem unadequate for didactic purposes in introductory courses of petrography because of several facts (peraluminous character expressed in phenocrysts, presence of specific textures of magma-water interaction, advanced stage of devetrification and silicification, etc.). These samples seem more idoneous for advanced didactic purposes (second cycle or PhD level studies). The Museu de Geologia contains two groups of samples: the aforementioned lavic rocks, and pyroclastic rocks from several localities of the catalonian Pyrenees. The pyroclastic rocks offer evidence of their character related to explosive volcanism (shards, pumice, crystal fragments, etc.) but they are deeply transformed and therefore inadequated for didactic purposes. Most of the thin slides are in fact too thick to allow a correct study of pyroclastic textures. The petrographic features allow us to suspect not only rhyolitic terms but also rhyodacitic and dacitic ones. The available data (bibliography and this study) shows some inconsistences in the current interpretation of the lavic silicic rocks. We offer a synthetic tentative explanation that could be tested in future research. Key words: volcanic rock, Upper Paleozoic, Catalonian Pyrenees, rhyolite, subaqueous environment, didactics, Museu de Geologia de Barcelona, Universitat de Barcelona, Spain.El Museu de Geologia de Barcelona y la Facultat de Geologia de la Universitat de Barcelona poseen sendas colecciones 'gemelas' de rocas volcánicas riolíticas de edad permo-carbonífera, procedentes del Pirineo catalán. Algunas muestras forman parte de la exposición permanente del museo y muchas de las de la colección universitaria son utilizadas regularmente en la didáctica de petrología ígnea en la universidad (petrografía y muestras de mano). Esta revisión permite confirmar la inicial procedencia común de ambas colecciones en la inicial de San Miguel de la Cámara (1934). La colección universitaria está constituida por rocas lávicas del sector de Gréixer-Coll de Pi, son riolitas, y presentan evidencias texturales claras de emplazamiento en medio subacuático (texturas perlíticas, fenocristales esqueléticos, fenocristales de cuarzo afectados de choque térmico, etc.). A pesar de su edad presentan un excelente estado de conservación de sus texturas, pero algunas de sus características (carácter peralumínico expresado en los fenocristales, texturas excesivamente específicas de interacción agua-magma, avanzado estado de desvitrificación y silicificación, etc.) desaconsejan su empleo didáctico en cursos introductorios de petrología ígnea y sugieren que su desplazamiento hacia cursos más avanzados (segundo ciclo o doctorado) sería más adecuado. El Museu de Geologia posee dos tipos de muestras: las lávicas antes descritas, y un segundo grupo de tipo piroclástico procedente de diferentes localidades del Pirineo catalán. Las rocas piroclásticas ofrecen evidencias inequívocas de su carácter genético (volcanismo explosivo), tales como presencia de pumitas, shards, fragmentos de cristales, etc. Sin embargo, han sufrido transformaciones importantes que las hacen inadecuadas en usos didácticos. Por otra parte, la mayoría de las láminas estudiadas son excesivamente gruesas, lo que impide un correcto estudio de las texturas piroclásticas. Las características petrográficas sugieren que existen términos riodacíticos y dacíticos además de los riolíticos. Finalmente, el conjunto de datos disponibles al final del estudio muestra que existen inconsistencias en la interpretación comúnmente aceptada para las rocas lávicas. Se ofrece en el trabajo una solución de compromiso compatible con las evidencias conocidas, que debe ser entendida como una hipótesis a corroborar en futuras investigaciones. Palabras clave: roca volcánica, Paleozoico Superior, Pirineo catalán, riolita, ambiente subacuático, didáctica, Museu de Geologia de Barcelona, Universitat de Barcelona. España

Ferrocenyl gold complexes as efficient catalysts

More than half a century after the discovery of the ferrocene structure in 1951, it remains as a suitable building block in many research areas, including catalysis with the development of key chiral catalysts. On the other hand, gold-mediated catalysis has been raised in recent years, allowing the creation of a great variety of C-C bonds and C-heteroatom bonds. In this context, this review covers the recent advances made with the combination of these two iconic figures in the organometallic chemistry field, since the first gold catalyzed reaction using a ferrocene ligand reported in 1986. The combination of the excellent properties and versatility of this metallocene, has allowed the obtainment of a plethora of ligands for metal catalysis, although their use joined to gold catalysis is still scarcely explored