The Development of Social Simulation as Reflected in the First Ten Years of JASSS: a Citation and Co-Citation Analysis

Social simulation is often described as a multidisciplinary and fast-moving field. This can make it difficult to obtain an overview of the field both for contributing researchers and for outsiders who are interested in social simulation. The Journal for Artificial Societies and Social Simulation (JASSS) completing its tenth year provides a good opportunity to take stock of what happened over this time period. First, we use citation analysis to identify the most influential publications and to verify characteristics of social simulation such as its multidisciplinary nature. Then, we perform a co-citation analysis to visualize the intellectual structure of social simulation and its development. Overall, the analysis shows social simulation both in its early stage and during its first steps towards becoming a more differentiated discipline.Citation Analysis, Co-Citation Analysis, Lines of Research, Multidisciplinary, Science Studies, Social Simulation

Relation between functional brain imaging, cognitive impairment and cognitive rehabilitation in patients with multiple sclerosis

Abstract : Cognitive impairment belongs to the core symptoms in MS affecting quality of life, self-esteem, and social as well as occupational functioning. Due to this high impact on patients' well-being efficient treatment concepts are required. Imaging studies on cognition have shown that functional reorganisation takes place spontaneously to compensate for deficits. In mildly to moderately impaired patients these processes may support coping with emerging deficits. However, these compensatory processes seem to be limited as brain activation of cognitively severely impaired patients is characterised by decreased additional recruitment of brain regions. Cognitive rehabilitation concentrates on the question whether induction of brain plasticity is possible for both the support of the spontaneous processes and the initiation of new ones. Combining cognition, brain imaging and cognitive rehabilitation in MS, an intriguing question is whether fMRI can provide further insights into the mechanisms of induced plasticity and serve as objective outcome measures for efficient cognitive interventio

Closing the gap: Sequence mining at scale

Frequent sequence mining is one of the fundamental building blocks in data mining. While the problem has been extensively studied, few of the available techniques are sufficiently scalable to handle datasets with billions of sequences; such large-scale datasets arise, for instance, in text mining and session analysis. In this article, we propose MG-FSM, a scalable algorithm for frequent sequence mining on MapReduce. MG-FSM can handle so-called “gap constraints”, which can be used to limit the output to a controlled set of frequent sequences. Both positional and temporal gap constraints, as well as appropriate maximality and closedness constraints, are supported. At its heart, MG-FSM partitions the input database in a way that allows us to mine each partition independently using any existing frequent sequence mining algorithm. We introduce the notion of ω-equivalency, which is a generalization of the notion of a “projected database” used by many frequent pattern mining algorithms. We also present a number of optimization techniques that minimize partition size, and therefore computational and communication costs, while still maintaining correctness. Our experimental study in the contexts of text mining and session analysis suggests that MG-FSM is significantly more efficient and scalable than alternative approaches

University Collaboration and ERP Competence Centres - A Golden Era or Golden Handcuffs?

During 1999, SAP formalised their University Comp etence Centre (UCC) program, whereby selected, experienced universities around the world will receive several million dollars of computer hardware, software and support from SAP and hardware partners to establish showcase service bureaus in support of ERP-related teaching and research. Through the program, university activity with SAP products will to a large extent shift from in-house installations to the UCCs. Member university staff and students will have Internet access to the most recent versions of SAP’s software including New Dimension products (e.g. Business Warehouse, Knowledge Warehouse, Customer Relationship Management, etc.). While the program suggests compelling potential for cooperation across member universities and globalisation of related curricula, it also implies substantial commitment and increasing SAP control over UCC and member activ ities and resources. Application Service Provision, Education- by-wire, Industry-University Collaboration, and virtual competence centres for knowledge management/content generation are all manifested in the UCC project. These consequences and implications of participation in the UCC program for member universities, non-members and students will be explored by this panel

Dosage calculation for intravenous thrombolysis of ischemic stroke: to weigh or to estimate?

Background: Estimation is a widely used method of assessing the weight of patients with acute stroke. Because the dosage of tissue plasminogen activator (tPA) is weight-dependent, errors in estimation lead to incorrect dosing. Methods: We installed a ground-level scale in the computed tomography (CT) suite of our hospital and also integrated a scale into the CT table of our Mobile Stroke Unit in order to prospectively assess the differences between reported, estimated, and measured weights of acute stroke patients. An independent rater asked patients to report their weight. The patients’ weights were also estimated by the treating physician and measured with a scale. Differences between reported, estimated, and measured weights were analyzed statistically. Results: For 100 consecutive patients, weighing was possible without treatment delays. Weights estimated by the physician diverged from measured weights by 10% or more for 27 patients and by 20% or more for 6 patients. Weights reported by the patient diverged from measured weights by 10% or more for 12 patients. Weights reported by the patients differed significantly less from measured weights (mean, 4.1 ± 3.1 kg) than did weights estimated by the physician (5.7 ± 4.4 kg; p = 0.003). Conclusion: This first prospective study of weight assessment in acute stroke shows that the use of an easily accessible scale makes it feasible to weigh patients with acute stroke without the treatment delay associated with additional patient transfers. Physicians’ estimates of patients’ weights demonstrated substantial aberrations from measured weights. Avoiding these deviations would improve the accuracy of tPA dosag

MeSi(CH2SnRO)3 (R = Ph, Me3SiCH2): Building blocks for triangular-shaped diorganotin oxide macrocycles

The syntheses of the novel silicon-bridged tris(tetraorganotin) compounds MeSi(CH2SnPh2R)3 (2, R=Ph; 5, R=Me3SiCH2) and their halogen-substituted derivatives MeSi(CH2SnPh(3−n)In)3 (3, n=1; 4, n=2) and MeSi(CH2SnI2R)3 (6, R=Me3SiCH2) are reported. The reaction of compound 4 with di-t-butyltin oxide (t-Bu2SnO)3 gives the oktokaideka-nuclear (18-nuclear) molecular diorganotin oxide [MeSi(CH2SnPhO)3]6 (7) while the reaction of 6 with sodium hydroxide, NaOH, provides the trikonta-nuclear (30-nuclear) molecular diorganotin oxide [MeSi(CH2SnRO)3]10 (8, R=Me3SiCH2). Both 7 and 8 show belt-like ladder-type macrocyclic structures and are by far the biggest molecular diorganotin oxides reported to date. The compounds have been characterized by elemental analyses, electrospray mass spectrometry (ESI-MS), NMR spectroscopy, 1H DOSY NMR spectroscopy (7), IR spectroscopy (7, 8), and single-crystal X-ray diffraction analysis (2, 7, 8)

Silicate limitation in a filament

We observed variations in primary nutrients and phytoplankton biomass in an upwelling event off Oman during the strong SW-monsoon 1997. A so called filament, originating in the coastal upwelling, was tracked, marked with a drifter and followed for 19 days while intensive water sampling took place. The first stations in this upwelling event showed a severe silicate limitation. With the silicate limitation a diverse diatom community vanished. Although after a couple of days new silicate became available, another phytoplankton community of smaller organisms < 20 flm) with nearly no diatoms bloomed. These results raise fundamental questions about the interactions between silicate limitation and the control of carbon export in the worlds most productive areas. It is discussed, whether these limitation events might be typical short term features of coastal upwelling ecosystems, not described as yet

Detection to Hospital Door:Gender Differences of Patients With Acute Stroke Symptoms

Although prehospital stroke management is challenging, it is a crucial part of the acute stroke chain to enable equal access to highly specialised stroke care. It involves a critical understanding of players usually not specialized in acute stroke treatments. There is contradictory information about gender inequity in prehospital stroke detection, dispatch, and delivery to hospital stroke centers. The aim of this narrative review is to summarize the knowledge of gender differences in the first three stages of acute stroke management. Information on the detection of acute stroke symptoms by patients, their relatives, and bystanders is discussed. Women seem to have a better overall knowledge about stroke, although general understanding needs to be improved. However, older age and different social situations of women could be identified as reasons for reduced and delayed help-seeking. Dispatch and delivery lie within the responsibility of the emergency medical service. Differences in clinical presentation with symptoms mainly affecting general conditions could be identified as a crucial challenge leading to gender inequity in these stages. Improvement of stroke education has to be applied to tackle this inequal management. However, specifically designed projects and analyses are needed to understand more details of sex differences in prehospital stroke management, which is a necessary first step for the potential development of substantially improving strategies

Advantages and Limitations of Direct PCR Amplification of Bacterial 16S-rDNA from Resected Heart Tissue or Swabs Followed by Direct Sequencing for Diagnosing Infective Endocarditis: A Retrospective Analysis in the Routine Clinical Setting

Infective endocarditis (IE) is a life-threatening disease that is associated with high morbidity and mortality. Its long-term prognosis strongly depends on a timely and optimized antibiotic treatment. Therefore, identification of the causative pathogen is crucial and currently based on blood cultures followed by characterization and susceptibility testing of the isolate. However, antibiotic treatment starting prior to blood sampling or IE caused by fastidious or intracellular microorganisms may cause negative culture results. Here we investigate the additional diagnostic value of broad-range PCR in combination with direct sequencing on resected heart tissue or swabs in patients with tissue or swab culture-negative IE in a routine clinical setting. Sensitivity, specificity, and positive and negative predictive values of broad-range PCR from diagnostic material in our patients were 33.3%, 76.9%, 90.9%, and 14.3%, respectively. We identified a total of 20 patients (21.5%) with tissue or culture-negative IE who profited by the additional application of broad-range PCR. We conclude that broad-range PCR on resected heart tissue or swabs is an important complementary diagnostic approach. It should be seen as an indispensable new tool for both the therapeutic and diagnostic management of culture-negative IE and we thus propose its possible inclusion in Duke’s diagnostic classification scheme

Antarctic sympagic meiofauna in winter: Comparing diversity, abundance and biomass between perennially and seasonally ice-covered regions

This study of Antarctic sympagic meiofauna in pack ice during late winter compares communities between the perennially ice-covered western Weddell Sea and the seasonally ice-covered southern Indian Ocean. Sympagic meiofauna (proto- and metazoans >20 μm) and eggs >20 μm were studied in terms of diversity, abundance and carbon biomass, and with respect to vertical distribution. Metazoan meiofauna had significantly higher abundance and biomass in the western Weddell Sea (medians: 31.1×103 m−2 and 6.53mg m−2, respectively) than in the southern Indian Ocean (medians: 1.0×10 103 m−2and 0.06 mg m−2, respectively). Metazoan diversity was also significantly higher in the western Weddell Sea. Furthermore, the two regions differed significantly in terms of meiofauna community composition, as revealed through multivariate analyses. The overall diversity of sympagic meiofauna was high, and integrated abundance and biomass of total meiofauna were also high in both regions (0.6–178.6×103 m−2 and 0.02–89.70mg m−2, respectively), mostly exceeding values reported earlier from the western Weddell Sea in winter. We attribute the differences in meiofauna communities between the two regions to the older first-year ice and multi-year ice that is present in the western Weddell Sea, but not in the southern Indian Ocean. Our study indicates the significance of perennially ice-covered regions for the establishment of diverse and abundant meiofauna communities. Furthermore, it highlights the potential importance of sympagic meiofauna for the organic matter pool and trophic interactions in sea ice