3,470 research outputs found
Assessing the Role of Technology Adoption in China's Growth Performance.
China has experienced a period of tremendous economic growth in recent years. In an attempt to explain this development, several existing growth-accounting studies reveal that impressively high rates of productivity growth have been at the heart of China's performance. This study investigates to what extent these productivity increases can be explained by technology-adoption theory. In less developed countries, the key element behind technological progress is technology adoption, the process of copying technological knowledge invented throughout the world. To uncover a measure of China's technological advances, the paper constructs a hybrid of some prominent technology-adoption models and calibrates it to reasonable parameter values. The calibrated version of the model is then combined with Chinese economic data. For the period 1978-2005, the analysis finds that the Chinese performance can be explained to a surprisingly large extent by the suggested technology-adoption framework. It can account for roughly 80% of China's productivity gains.technological progress; technology adoption; TFP; China
An analysis of perceived overqualification in the Swiss labor market
This paper takes Switzerland as a case study and examines the determinants of (perceived) overqualification in a macroeconomic setting where there is indeed excess demand for qualified labor. Our analyses show that overqualification in the Swiss labor market cannot be explained by possible rigidities and discrimination. Hence, the labor market in Switzerland must in general be considered as efficient. Hence, unobserved heterogeneity should indeed account for the phenomenon of overqualification / overeducation. Nonetheless, women's family commitments are found to restrict the full utilization of their investment in human capital. Thus, there exists some room for policy measures to improve the job – education match of women (especially of those who have children between 0 – 6 years of age) by increasing the availability of external child care facilities and / or making child care at home more affordable.Overeducation
Public Education and Growth in Developing Countries
Human capital plays a key role in fostering technology adoption, the major source of economic growth in developing countries. Consequently, enhancing the level of human capital should be a matter of public concern. The present paper studies public education incentives in an environment in which governments can invest in human capital to facilitate the adoption of new technologies invented abroad or, instead, focus on consumptive public spending. Although human capital is pivotal for growth, the model reveals that incentives to invest in public education vanish if a country is poorly endowed with human capital. Rather, governments of these poorly-endowed countries focus on consumptive public spending. As a result, while their better-endowed counterparts build up human capital thereby promoting technology adoption and growth, the growth process in poorly-endowed countries stagnates.growth; public education; human capital; technology adoption
Feeding difficulties in disabled children leads to malnutrition: experience in an Indian slum
Public funding and enrolment into higher education in Europe
In this paper we provide evidence for the impact of public funding on enrolment of students in college. We use a panel for European countries and apply instrumental variables techniques to find that public funding for schooling - regardless at what level - does increase college enrolment alike with an elasticity of about one. A second issue concerns the impact of tuition fees, which are found to reduce college enrolment.College enrolment; public funding; tuition costs
Hollow Cathode and Low-Thrust Extraction Grid Analysis for a Miniature Ion Thruster
Miniature ion thrusters are well suited for future space missions that require high efficiency, precision thrust, and low contamination in the mN to sub-mN range. JPL’s miniature xenon Ion (MiXI) thruster has demonstrated an efficient discharge and ion extraction grid assembly using filament cathodes and the internal conduction (IC) cathode. JPL is currently preparing to incorporate a miniature hollow cathode for the MiXI discharge. Computational analyses anticipate that an axially upstream hollow cathode location provides the most favorable performance and beam profile; however, the hot surfaces of the hollow cathode must be sufficiently downstream to avoid demagnetization of the cathode magnet at the back of the chamber, which can significantly reduce discharge performance. MiXI’s ion extraction grids are designed to provide >3mN of thrust; however, previous to this effort, the low-thrust characteristics had not been investigated. Experimental results obtained with the MiXI-II thruster (a near replica or the original MiXI thruster) show that sparse average discharge plasma densities of ∼5×10^15–5×10^16 m^−3 allow the use of very low beamlet focusing extraction voltages of only ∼250–500 V, thus providing thrust levels as low as 0.03 mN for focused beamlet conditions. Consequently, the thrust range thus far demonstrated by MiXI in this and other tests is 0.03–1.54 mN
Development of an assistive soft exoskeleton : a multistakeholder endeavour
Background
As in other areas, digitalization and new technologies become increasingly relevant for physiotherapy. However, often these developments are driven by technological feasibility rather than by clinical demand. In order to grant maximum acceptability and effective implementation of a technology multiple stakeholders i.e. engineers, patients and therapists need to collaborate throughout the planning and development processes. Here, we describe the design and development of three prototype-generations of a soft and modular exoskeleton.
Purpose
Development of a soft and modular exoskeleton, which incorporates the needs and requirements of future users.
Methods
Nine research groups including therapists, designers and engineers from seven European countries were involved in this project. As stakeholders we considered patients with gait limitations due to stroke, incomplete spinal cord injury or age-related weakness (primary end-users, PU), therapists with professional experience in the area of the PU’s conditions and non-professional carers (secondary end-users, SU). The perspectives of PU and SU were incorporated into the technical concepts adopting a user-centered design approach. The initial prototype was designed according to the requirements, which were derived from use-cases representing the target populations. Evaluations of all prototypes were performed using semi-structured interviews with both, PU and SU. Functions of the respective prototypes were evaluated with a predefined testing protocol. The conclusions of the evaluations were fed back to the engineers and informed the development of the consecutive prototypes. All data collection procedures were approved by the local ethics committee and participants provided written informed consent.
Results
In total eight PU and eight SU were recruited. In general, the prototypes were in an early stage of development and the operation required staff with engineering knowledge and an experimental laboratory. In general, PU and SU rated the technology positively. The individually analyzed data from the interviews and functionality tests revealed heterogeneous results indicating the diversity of the PU’s functional impairments and expectations of PU and SU.
Conclusions
Based on this project’s experience, we are convinced that future PU and SU of a technology must be involved in the development from the very beginning. However, in order to obtain adequate feedback, the choice of individuals (PU and SU) and the level of involvement must be considered carefully. For example, inadequate expectations may draw the attention to irrelevant issues. In our project, research physiotherapists played a key role by bridging PU and SU with engineers. This information exchange was partially challenging because of different areas of interest, different terminology and geographical distance.
Implications
A common understanding of the project goals among the project teams and adherence to timelines are essential for successful progress such a large project. The project should assure that all stakeholders can acquire basic knowledge and perspectives of the other involved stakeholders, especially from other disciplines. Specifically for physiotherapists, basic and continuing education should incorporate technological knowledge from engineering disciplines in order to enable physiotherapists to contribute to the development of new devices. This opens the chance to participate in the development of technology for clinical applications.
Funding acknowledgements
This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 688175 (XoSoft)
"In vitro" study of the mode of action of antidepressants in cell culture models : comparison of the effects of "Hypericum perforatum L." extracts and classical synthetic compounds on the [beta]-adrenergic signal pathway
The clinical effectiveness of the plant extract of Hypericum perforatum L. in treating mild to moderate depression is well established. The extract shows a more favourable side effect profile than other antidepressant drugs, like tricyclics and selective serotonin reuptake inhibitors. Until now, the mode of action of antidepressant drugs is not well understood and it is possible that immediate and adaptive effects contribute to their effectiveness of treating depression. Reuptake inhibition of neurotransmitters, an immediate effect of antidepressant drugs, occurs after drug exposure in minutes to hours. Adaptive effects, like changes in the number of neurotransmitter receptors, phsopholipid (PL) accumulation and alterations of cell membrane properties, need a prolonged, chronic exposure of several days to weeks to develop.
In the present work, influences of chronic exposure of Hypericum perforatum extracts to rat C6 glioblastoma cells (C6 cells) and human skin fibroblasts were investigated. Changes on the cellular level including cell shape, morphology and proliferation rate and on the β-adrenergic signal pathway including membrane properties, number of β-adrenoceptor and accumulation of the second messenger cAMP were monitored. These effects were compared with those of the selective serotonin reuptake inhibitor (SSRI) fluoxetine and the tricyclic antidepressant desipramine (DMI).
Chronic exposure of C6 cells and fibroblasts to a Hypericum extract, fluoxetine or DMI led to a change in the cell morphology. The cell body broadened and vesicular inclusions were observed. These changes were more pronounced, especially in C6 cells, after chronic exposure to fluoxetine or DMI. The effects were not due to cell hypertrophy since the DNA/protein ration remained constant under each treatment condition. In contrast to fluoxetine and DMI, Hypericum extract exposed cells showed a distinct cell growth inhibition.
Chronic exposure of fibroblasts and C6 cells to the Hypericum extract led to change in membrane properties. Fibroblasts exposed to the plant extract showed an accumulation of the total amount of PL, as observed after exposure to fluoxetine or DMI. Moreover, the membrane fluidity of C6 cells and fibroblasts was increased after Hypericum extract treatment, whereas exposure to DMI or fluoxetine did not influence the membrane fluidity.
Complex changes in the relative PL content of the cellular and plasma membrane composition were observed after chronic exposure of C6 cells to Hypericum extract or DM. The most pronounced and consistent effect was the increase of phosphatidylinositol after both treatments.
The β-adrenoceptor number and its signal pathway were affected after chronic exposure of C6 cells to Hypericum extract, fluoxetine or DMI. All treatment conditions resulted in a down-regulation of the β-adrenoceptor number at varying degrees. The cAMP accumulation ofter chronic exposure to all drugs was reduced.
Our results showed that the in vitro effects of the Hypericum extract were compareble to those of the well-established tricyclic antidepressant DMI and the SSRI antidepressant fluoxetine and they might, therefore, share a common mode of action. Hyperforin, a constituent of the Hypericum perforatum extract, ahs gained more attention in recent years. It has been shown that mainly hyperforin is responsible for interactions with co-administered drugs that may lead to severe conditions. Thus, using a hyperforin-"free" and hyperforin-rich fraction of the Hypericum extract, the sifgnificance of hyperforin on the in vitro antidepressant effects in C6 cells was investigated. Down-regulation of the β-adrenoceptor number could be observed in C6 cells after chronic exposure to the hyperforin-"free" fraction. This reduction was comparable to that obtained with the Hypericum extract. Contrarily, chronic exposure of C6 cells to a hyperforin-rich fraction did not reduce the β-adrenoceptor number. Interestingly, exposure of C6 cells to both fractions inhibited the cAMP accumulation comparable to that level observed after exposure to Hypericum extract.
It was shown that a hyperforin-"free" fraction induced changes on the β-adrenoceptor number and on the cAMP accumulation similar to a Hypericum extract, the tricyclic DMI and the SSRI fluoxetine. Consequently, it is tempting to point out that a hyperforin-free Hypericum extract might possess the same potential as a hydroalcoholic Hypericum extract in treating mild to moderate depression, but without inducing metabolic interactions with co-administered drugs
Private returns to education versus education spill-over effects: Or what co-workers account for!
In this study we test whether education spill-over effects biase private returns to education. We newly investigate for such effects within narrowly defined occupational groups of a given firm using, going thus a step further than earlier studies analysing such effects at employer level or within regions. Using panel data from a Swiss employer-based labour force survey of 1996 we find clear empirical evidence for education spill-over effects on individual wages (2%). This result proved to be robust against an alternative explanation based on imperfect substitution between highly and less educated workers. Consequently, conventionally calculated private returns to education are shown to be biased upward
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