1,203,992 research outputs found
Using European travellers as an early alert to detect emerging pathogens in countries with limited laboratory resources
BACKGROUND: The volume, extent and speed of travel have dramatically increased in the past decades, providing the potential for an infectious disease to spread through the transportation network. By collecting information on the suspected place of infection, existing surveillance systems in industrialized countries may provide timely information for areas of the world without adequate surveillance currently in place. We present the results of a case study using reported cases of Shigella dysenteriae serotype 1 (Sd1) in European travellers to detect "events" of Sd1, related to either epidemic cases or endemic cases in developing countries. METHODS: We identified papers from a Medline search for reported events of Sd1 from 1940 to 2002. We requested data on shigella infections reported to the responsible surveillance entities in 17 European countries. Reports of Sd1 from the published literature were then compared with Sd1 notified cases among European travellers from 1990 to 2002. RESULTS: Prior to a large epidemic in 1999–2000, no cases of Sd1 had been identified in West Africa. However, if travellers had been used as an early warning, Sd1 could have been identified in this region as earlier as 1992. CONCLUSION: This project demonstrates that tracking diseases in European travellers could be used to detect emerging disease in developing countries. This approach should be further tested with a view to the continuous improvement of national health surveillance systems and existing European networks, and may play a significant role in aiding the international public health community to improve infectious disease control
Control, Process Facilitation, and Requirements Change in Offshore Requirements Analysis: The Provider Perspective
Process, technology, and project factors have been increasingly driving organizations to offshore early software development phases, such as requirements analysis. This emerging trend necessitates greater control and process facilitation between client and vendor sites. The effectiveness of control and facilitation has, however, not been examined within the context of requirements analysis and change. In this study, we examine the role of control and facilitation in managing changing requirements and on success of requirements gathering in the Indian offshore software development environment. Firms found that control by client-site coordinators had a positive impact on requirements analysis success while vender site-coordinators did not have similar influence. Process facilitation by client site-coordinators affected requirements phase success indirectly through control. The study concludes with recommendations for research and practice
The environment of HII galaxies
Recent morphological studies (Telles \& Terlevich 1994) of HII galaxies, i.e.
dwarf galaxies dominated by a very luminous starburst, have indicated that
luminous HII galaxies tend to show distorted morphology suggestive of tidal
interactions triggering the present starburst while low luminosity HII galaxies
tend to be instead symmetric and regular. To check the tidal origin of the
starburst in HII galaxies, we have searched for companions in the neighbourhood
of a sample of 51 HII galaxies. We found that only 12 HII galaxies have a
neighbour within a projected distance of 1 Mpc and 250 \kmsec~ in velocity
difference, and of these 12, only 4 have a luminous (M --19) neighbour.
Surprisingly, isolated HII galaxies tend to be of high luminosity and disturbed
morphology while HII galaxies with neighbours tend to be low luminosity regular
HII galaxies. Furthermore, the metal abundance and the equivalent width of the
emission lines in HII galaxies do not depend on the presence of a companion.
These results are opposed to simple expectations if interaction with a bright
companion is the main mechanism triggering the starbursts. We have also found a
loose group of HII galaxies with no luminous companion. For this, there is the
additional difficulty of understanding how these starbursts are synchronized on
time scales of less than yrs in systems separated by 1-2 Mpc.Comment: 7 pages, uuencoded, compressed, postscript file. (three figures
included). Also available via anonymous ftp from
ftp://cast0.ast.cam.ac.uk/pub/etelles/environ.ps.
Requirements modelling and formal analysis using graph operations
The increasing complexity of enterprise systems requires a more advanced
analysis of the representation of services expected than is currently possible.
Consequently, the specification stage, which could be facilitated by formal
verification, becomes very important to the system life-cycle. This paper presents
a formal modelling approach, which may be used in order to better represent
the reality of the system and to verify the awaited or existing system’s properties,
taking into account the environmental characteristics. For that, we firstly propose
a formalization process based upon properties specification, and secondly we
use Conceptual Graphs operations to develop reasoning mechanisms of verifying
requirements statements. The graphic visualization of these reasoning enables us
to correctly capture the system specifications by making it easier to determine if
desired properties hold. It is applied to the field of Enterprise modelling
"Regulating Healthcare Technologies and Medical Supplies: A Comparative Overview"
A complex relationship exists among EU regulations, current national practices and rules, institutional capacities to implement regulatory adjustments and the legacy of past health and regulatory policy and traditions. However, there is little empirical information on medical devices policy, the medical devices industry, and the assurance of medical device safety and usage. Drawing on a review of the secondary literature and on-going field work, the evidence suggests that the current mix of statecentric and self-regulatory traditions will be as important in determining the implementation and final outcomes of EU-rules as the new rules themselves. EU directives redesign rules, but they do not necessarily lead to institutional change, create institutional capacities, or alter old practices in the short term. Neither EU directives nor national regulatory adjustments determine the "man-machine/skill-experience" interface which is shaped and influenced by local medical traditions and the acceptance of these traditions by local publics
Abstract State Machines 1988-1998: Commented ASM Bibliography
An annotated bibliography of papers which deal with or use Abstract State
Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm
Re-examining the effects of verbal instructional type on early stage motor learning
The present study investigated the differential effects of analogy and explicit instructions on early stage motor learning and movement in a modified high jump task. Participants were randomly assigned to one of three experimental conditions: analogy, explicit light (reduced informational load), or traditional explicit (large informational load). During the two-day learning phase, participants learned a novel high jump technique based on the ‘scissors’ style using the instructions for their respective conditions. For the single-day testing phase, participants completed both a retention test and task-relevant pressure test, the latter of which featured a rising high-jump-bar pressure manipulation. Although analogy learners demonstrated slightly more efficient technique and reported fewer technical rules on average, the differences between the conditions were not statistically significant. There were, however, significant differences in joint variability with respect to instructional type, as variability was lowest for the analogy condition during both the learning and testing phases, and as a function of block, as joint variability decreased for all conditions during the learning phase. Findings suggest that reducing the informational volume of explicit instructions may mitigate the deleterious effects on performance previously associated with explicit learning in the literature
Properties of Very Luminous Galaxies
Recent analysis of the SSRS2 data based on cell-counts and two-point
correlation function has shown that very luminous galaxies are much more
strongly clustered than fainter galaxies. In fact, the amplitude of the
correlation function of very luminous galaxies () asymptotically
approaches that of clusters. In this paper we investigate the
properties of the most luminous galaxies, with blue absolute magnitude . We find that: 1) the population mix is comparable to that in other ranges
of absolute magnitudes; 2) only a small fraction are located in bona fide
clusters; 3) the bright galaxy-cluster cross-correlation function is
significantly higher on large scales than that measured for fainter galaxies;
4) the correlation length of galaxies brighter than \MB ,
expressed as a function of the mean interparticle distance, appears to follow
the universal dimensionless correlation function found for clusters and radio
galaxies; 5) a large fraction of the bright galaxies are in interacting pairs,
others show evidence for tidal distortions, while some appear to be surrounded
by faint satellite galaxies. We conclude that very luminous optical galaxies
differ from the normal population of galaxies both in the clustering and other
respects. We speculate that this population is highly biased tracers of mass,
being associated to dark halos with masses more comparable to clusters than
typical loose groups.Comment: 29 pages (6 figures) + 2 tables; paper with all figures and images
available at http://boas5.bo.astro.it/~cappi/papers.html; The Astronomical
Journal, in pres
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