4,802 research outputs found
Farm Machinery Market in the Second Half of the XX Century
Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is an Invited Paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 4 (2002): J. Pawlak. Farm Machinery Market in the Second Half of the XX Century. Vol. IV. July 2002
Robust field-dressed spectra of diatomics in an optical lattice
The absorption spectra of the cold Na2 molecule dressed by a linearly
polarized standing laser wave is investigated. In the studied scenario the
rotational motion of the molecules is frozen while the vibrational and
translational degrees of freedom are accounted for as dynamical variables. In
such a situation a light-induced conical intersection (LICI) can be formed. To
measure the spectra a weak field is used whose propagation direction is
perpendicular to the direction of the dressing field but has identical
polarization direction. Although LICIs are present in our model, the
simulations demonstrate a very robust absorption spectrum, which is insensitive
to the intensity and the wavelength of the dressing field and which does not
reflect clear signatures of light-induced nonadiabatic phenomena related to the
strong mixing between the electronic, vibration and translational motions.
However, by widening artificially the very narrow translational energy level
gaps, the fingerprint of the LICI appears to some extent in the spectrum
Designing and Piloting a Tool for the Measurement of the Use of Pronunciation Learning Strategies
What appears to be indispensable to drive the field forward and ensure that research findings will be comparable across studies and provide a sound basis for feasible pedagogic proposals is to draw up a classification of PLS and design on that basis a valid and reliable data collection tool which could be employed to measure the use of these strategies in different groups of learners, correlate it with individual and contextual variables, and appraise the effects of training programs. In accordance with this rationale, the present paper represents an attempt to propose a tentative categorization of pronunciation learning strategies, adopting as a point of reference the existing taxonomies of strategic devices (i.e. O'Malley and Chamot 1990; Oxford 1990) and the instructional options teachers have at their disposal when dealing with elements of this language subsystem (e.g. Kelly 2000; Goodwin 2001). It also introduces a research instrument designed on the basis of the classification that shares a number of characteristics with Oxford's (1990) Strategy Inventory for Language Learning but, in contrast to it, includes both Likert-scale and open-ended items. The findings of a pilot study which involved 80 English Department students demonstrate that although the tool requires considerable refinement, it provides a useful point of departure for future research into PLS
Factors affecting outcomes of EU-supported investments in innovation among SMEs in the Greater Poland (Wielkopolska) region, Poland
Purpose The European Union offers support mechanisms to help small and medium sized enterprises (SMEs) to innovate and grow. Given the substantial contribution of SMEs to national economies, the present paper explores what factors tend to be associated with the success of EU-supported innovation by SMEs in Poland during its early post-accession period. Design/methodology/approach A conceptual model relating the type of innovation, investment purpose, funding type and financial readiness, location and collaboration possibilities, company size and sector of operation to changes in the capital base, employment, unit price and revenue is proposed. This model is operationalised and estimated as a structural equations model and estimated using a sample of 110 SMEs surveyed in 2008 in the Greater Poland (Wielkopolska) region in Poland. Findings Two approaches to the successful use of innovation support have been observed among the studied companies. The first approach implements market innovations to establish a presence in foreign markets and to move the product or service up the value chain. The second approach uses the funding to de-risk workforce expansion and increase production capacity. Originality/value The paper provides the first systematic disaggregate level analysis of an early post-accession context where impacts of EU support for SME innovation are decomposed into effects of specific investment conditions and innovation type on changes in capital base, employment, unit price and ultimately revenue. The insights provided here are valuable for managers developing business and innovation strategies on the one hand, but also for policymakers responsible for creating an entrepreneurship friendly environment in emerging economies
How is ICT use linked to household transport expenditure? A cross-national macro analysis of the influence of home broadband access
Understanding of the interactions between Information and Communication Technologies (ICT) and physical mobility is a major area of research with practical applications in a number of fields. Very little, however, is known regarding how these relationships vary on a cross-national basis, including across countries at different stages in development. To address this gap, this paper presents an analysis of household transport expenditure as a function of the available variables, with a particular focus on the ICT. This analysis is based on a cross-sectional dataset from 2010 comprising information on 33 countries including average household transport expenditure, ICT represented by the percentage of households with Internet access at home, and a number of contextual macroeconomic and infrastructural variables. Using a log-log framework we find that, in our sample of countries, household transport expenditure is negatively associated with Internet penetration with an elasticity of − 0.394. We verify this to be robust to endogeneity using presence of restrictions on foreign ownership in the Internet market as an instrumental variable. We also control for potential differences in data quality across countries using the Corruption Perceptions Index. To the best of our knowledge, this is the first attempt to quantify this relationship at a cross-national level while also controlling for endogeneity and data quality issues. Among the control variables, we observe the estimated effects to be intuitive, and consistent with existing research and microeconomic understandings of the behaviour of individuals and households
A framework for joint modelling of activity choice, duration, and productivity while travelling
Recent developments in mobile information and communication technologies (ICT), vehicle automation, and the associated debates on the implications for the operation of transport systems and for the appraisal of investment has heightened the importance of understanding how people spend travel time and how productive they are while travelling. To date, however, no approach has been proposed that incorporates the joint modelling of in-travel activity type, activity duration and productivity behaviour. To address this critical gap, we draw on a recently developed PPS framework (Pawlak et al., 2015) to develop a new joint model of activity type choice, duration and productivity. In our framework, we use copulas to provide a flexible link between a discrete choice model of activity type choice, a hazard-based model for activity duration, and a log-linear model of productivity. Our model is readily amenable to estimation, which we demonstrate using data from the 2008 UK Study of Productive Use of Rail Travel-time. We hence show how journey-, respondent-, attitude-, and ICT-related factors are related to expected in-travel time allocation to work and non-work activities, and the associated productivity. To the best of our knowledge, this is the first framework that both captures the effects of different factors on activity choice, duration and productivity, and models links between these aspects of behaviour. Furthermore, the convenient interpretation of the parameters in the form of semi-elasticities enables the comparison of effects associated with the presence of on-board facilities (e.g., workspace, connectivity) or equipment use, facilitating use of the model outputs in applied contexts
On the Development of Agricultural Mechanization to Ensure a Long- Term World Food Supply
Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is an Invited Paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 4 (2002): J. Pawlak, G. Pellizzi and M. Fiala. On the Development of Agricultural Mechanization to Ensure a Long- Term World Food Supply. Club of Bologna. Vol. IV. June 200
Cytochrome cM decreases photosynthesis under photomixotrophy in Synechocystis sp. PCC 6803
Photomixotrophy is a metabolic state that enables photosynthetic microorganisms to simultaneously perform photosynthesis and metabolism of imported organic carbon substrates. This process is complicated in cyanobacteria, since many, including Synechocystis sp. PCC 6803, conduct photosynthesis and respiration in an interlinked thylakoid membrane electron transport chain. Under photomixotrophy, the cell must therefore tightly regulate electron fluxes from photosynthetic and respiratory complexes. In this study, we demonstrate, via characterization of photosynthetic apparatus and the proteome, that photomixotrophic growth results in a gradual inhibition of QA- reoxidation in wild-type Synechocystis, which largely decreases photosynthesis over 3 d of growth. This process is circumvented by deleting the gene encoding cytochrome cM (CytM), a cryptic c-type heme protein widespread in cyanobacteria. The ΔCytM strain maintained active photosynthesis over the 3-d period, demonstrated by high photosynthetic O2 and CO2 fluxes and effective yields of PSI and PSII. Overall, this resulted in a higher growth rate compared to that of the wild type, which was maintained by accumulation of proteins involved in phosphate and metal uptake, and cofactor biosynthetic enzymes. While the exact role of CytM has not been determined, a mutant deficient in the thylakoid-localized respiratory terminal oxidases and CytM (ΔCox/Cyd/CytM) displayed a phenotype similar to that of ΔCytM under photomixotrophy. This, in combination with other physiological data, and in contrast to a previous hypothesis, suggests that CytM does not transfer electrons to these complexes. In summary, our data suggest that CytM may have a regulatory role in photomixotrophy by modulating the photosynthetic capacity of cells
An Imputation Approach to the Fusion of Travel Diary and Lifestyle Data: Application to the Analysis of the Interaction of ICT and Physical Mobility
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