146 research outputs found
Integrating CAA within the University of Ulster
Marking coursework is a time consuming activity, further exacerbated by the need for regular submission and timely, informative feedback. Increasing student numbers (particularly within computing and management) coupled with a decline in resources, mean that staff are unable to give formative feedback on student learning to the extent they may wish. Understandably there is concern that as the quantity of marking increases, there is a corresponding deterioration in the quality of assessment. This has led staff at the University of Ulster to investigate new ways to assess students. Computer Assisted Assessment (CAA) offers the opportunity to assess students more regularly without increasing staff workload.
This paper outlines how WebCT has been used to support computer assisted assessment throughout the Faculty of Informatics and the Faculty of Business and Management at the University of Ulster
Employee Education, Information and Communication Technology, Workplace Organization and Trade: A Comparative Analysis of Greek and Swiss Enterprises
This paper aims at investigating empirically at the firm level the effect of the use of modern information and communication technologies (ICT), and also of two other factors, the adoption of new forms of workplace organization and trade (export) activities, on the demand for employees with different levels of (vocational) education. The study is based on firm-level data collected through a common questionnaire from firms' samples of similar composition (concerning firm sizes and industries) in Greece and Switzerland; from these data econometric models of similar specification have been constructed for both countries. The results of multivariate analysis show that the intensive use of ICT correlates positively with the employment shares of high-educated personnel and negatively with the ones of the loweducated personnel. These findings are consistent with the hypothesis of skill-biased technical change. Further, the intensive use of employee voice-oriented organizational practices correlates positively with the employment shares of high-educated employees in both countries, and also negatively with the employment share of low-educated ones only for the Swiss firms. The results for the work design organizational practices are more ambiguous. Thus, there is only partial confirmation of the hypothesis of skilled-biased organizational change. Finally, we found some evidence in favour of the trade effect (export activities) only for the Swiss firms. Our results show both similarities and differences in the above aspects between Greece and Switzerland and indicate that national context characteristics affect the relationship of the demand for employees with different levels of (vocational) education with ICT use, adoption of new forms of workplace organization and trade
Axial light emission and Ar metastable densities in a parallel plate dc micro discharge in steady state and transient regimes
Axial emission profiles in a parallel plate dc micro discharge (feedgas:
argon; discharge gap d=1mm; pressure p=10Torr) were studied by means of time
resolved imaging with a fast ICCD camera. Additionally, volt-ampere (V-A)
characteristics were recorded and Ar* metastable densities were measured by
tunable diode laser absorption spectroscopy (TDLAS). Axial emission profiles in
the steady state regime are similar to corresponding profiles in standard size
discharges (d=1cm, p=1Torr). For some discharge conditions relaxation
oscillations are present when the micro discharge switches periodically between
low current Townsend-like mode and normal glow. At the same time the axial
emission profile shows transient behavior, starting with peak distribution at
the anode, which gradually moves towards the cathode during the normal glow.
The development of argon metastable densities highly correlates with the
oscillating discharge current. Gas temperatures in the low current
Townsend-like mode (T= 320-400K) and the high current glow mode (T=469-526K)
were determined by the broadening of the recorded spectral profiles as a
function of the discharge current.Comment: submitted to Plasma Sources Sci. Techno
Iron Supply and Demand in Antarctic Shelf Ecosystem
The Ross Sea sustains a rich ecosystem and is the most productive sector of the Southern Ocean. Most of this production occurs within a polynya during the November-February period, when the availability of dissolved iron (dFe) is thought to exert the major control on phytoplankton growth. Here we combine new data on the distribution of dFe, high-resolution model simulations of ice melt and regional circulation, and satellite-based estimates of primary production to quantify iron supply and demand over the Ross Sea continental shelf. Our analysis suggests that the largest sources of dFe to the euphotic zone are wintertime mixing and melting sea ice, with a lesser input from intrusions of Circumpolar Deep Water and a small amount from melting glacial ice. Together these sources are in approximate balance with the annual biological dFe demand inferred from satellite-based productivity algorithms, although both the supply and demand estimates have large uncertainties
The Role of γ-Tubulin in Centrosomal Microtubule Organization
As part of a multi-subunit ring complex, γ-tubulin has been shown to promote microtubule nucleation both in vitro and in vivo, and the structural properties of the complex suggest that it also seals the minus ends of the polymers with a conical cap. Cells depleted of γ-tubulin, however, still display many microtubules that participate in mitotic spindle assembly, suggesting that γ-tubulin is not absolutely required for microtubule nucleation in vivo, and raising questions about the function of the minus end cap. Here, we assessed the role of γ-tubulin in centrosomal microtubule organisation using three-dimensional reconstructions of γ-tubulin-depleted C. elegans embryos. We found that microtubule minus-end capping and the PCM component SPD-5 are both essential for the proper placement of microtubules in the centrosome. Our results further suggest that γ-tubulin and SPD-5 limit microtubule polymerization within the centrosome core, and we propose a model for how abnormal microtubule organization at the centrosome could indirectly affect centriole structure and daughter centriole replication
Prior knowledge transfer across transcriptional data sets and technologies using compositional statistics yields new mislabelled ovarian cell line
Here, we describe gene expression compositional assignment (GECA), a powerful, yet simple method based on compositional statistics that can validate the transfer of prior knowledge, such as gene lists, into independent data sets, platforms and technologies. Transcriptional profiling has been used to derive gene lists that stratify patients into prognostic molecular subgroups and assess biomarker performance in the pre-clinical setting. Archived public data sets are an invaluable resource for subsequent in silico validation, though their use can lead to data integration issues. We show that GECA can be used without the need for normalising expression levels between data sets and can outperform rank-based correlation methods. To validate GECA, we demonstrate its success in the cross-platform transfer of gene lists in different domains including: bladder cancer staging, tumour site of origin and mislabelled cell lines. We also show its effectiveness in transferring an epithelial ovarian cancer prognostic gene signature across technologies, from a microarray to a next-generation sequencing setting. In a final case study, we predict the tumour site of origin and histopathology of epithelial ovarian cancer cell lines. In particular, we identify and validate the commonly-used cell line OVCAR-5 as non-ovarian, being gastrointestinal in origin. GECA is available as an open-source R package
Measuring efficiency of innovation using combined Data Envelopment Analysis and Structural Equation Modeling:empirical study in EU regions
The main aim of this paper is to investigate the impact of patent applications, development level, employment level and degree of technological diversity on innovation efficiency. Innovation efficiency is derived by relating innovation inputs and innovation outputs. Expenditures in Research and Development and Human Capital stand for innovation inputs. Technological knowledge diffusion that comes from spatial and technological neighborhood stands for innovation output. We derive innovation efficiency using Data Envelopment Analysis for 192 European regions for a 12-year period (1995–2006). We also examine the impact of patents production, development and employment level and the level of technological diversity on innovation efficiency using Structural Equation Modeling. This paper contributes a method of innovation efficiency estimation in terms of regional knowledge spillovers and causal relationship of efficiency measurement criteria. The study reveals that the regions presenting high innovation activities through patents production have higher innovation efficiency. Additionally, our findings show that the regions characterized by high levels of employment achieve innovation sources exploitation efficiently. Moreover, we find that the level of regional development has both a direct and indirect effect on innovation efficiency. More accurately, transition and less developed regions in terms of per capita GDP present high levels of efficiency if they innovate in specific and limited technological fields. On the other hand, the more developed regions can achieve high innovation efficiency if they follow a more decentralized innovation policy
Age and skill bias of trade liberalisation? : heterogeneous employment effects of EU Eastern Enlargement
This study analyses the 2004 Eastern Enlargement to the European Union to
obtain evidence on the employment effects of an increase in trade liberalisation. The
Enlargement is thought to generate a trade-induced demand shock with no (or only
limited) supply effects. Besides the variation over time induced by the Enlargement,
identification of the effects is based on a Melitz (2003) type productivity term to
differentiate firms by the extent of exposure to the demand shock. The idea is that the
effects of the demand shock should be driven by differences in firm-level productivity
from the period before the new member countries actually entered the EU. German
linked employer-employee data allow to observe the relation of initial establishment
productivity with employment changes over a long panel from 1995 to 2009. The
estimates show that the Enlargement had a negative effect on establishment-level
employment growth, which is driven by increased worker separations and increased
job destruction. Besides the overall employment effect, the study focuses on effect
heterogeneity across age and skill groups of the workforce. These estimates point to a
skill bias in the effect of the Enlargement that disadvantages low- and medium-skilled
workers in terms of higher worker separation and job destruction. In addition, lowskilled
workers suffer fewer accessions by firms, where against medium-skilled workers
enjoy increased accessions and creation of new jobs. Besides this indication for a skill
bias, there are no clear indications that point to an age bias in the employment effect
of the Eastern Enlargement
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