96,030 research outputs found

    Research Agenda for Studying Open Source II: View Through the Lens of Referent Discipline Theories

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    In a companion paper [Niederman et al., 2006] we presented a multi-level research agenda for studying information systems using open source software. This paper examines open source in terms of MIS and referent discipline theories that are the base needed for rigorous study of the research agenda

    Acute Stroke Multimodal Imaging: Present and Potential Applications toward Advancing Care.

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    In the past few decades, the field of acute ischemic stroke (AIS) has experienced significant advances in clinical practice. A core driver of this success has been the utilization of acute stroke imaging with an increasing focus on advanced methods including multimodal imaging. Such imaging techniques not only provide a richer understanding of AIS in vivo, but also, in doing so, provide better informed clinical assessments in management and treatment toward achieving best outcomes. As a result, advanced stroke imaging methods are now a mainstay of routine AIS practice that reflect best practice delivery of care. Furthermore, these imaging methods hold great potential to continue to advance the understanding of AIS and its care in the future. Copyright © 2017 by Thieme Medical Publishers, Inc

    Acute neuroinflammation induces AIS structural plasticity in a NOX2-dependent manner

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    Background Chronic microglia-mediated inflammation and oxidative stress are well-characterized underlying factors in neurodegenerative disease, whereby reactive inflammatory microglia enhance ROS production and impact neuronal integrity. Recently, it has been shown that during chronic inflammation, neuronal integrity is compromised through targeted disruption of the axon initial segment (AIS), the axonal domain critical for action potential initiation. AIS disruption was associated with contact by reactive inflammatory microglia which wrap around the AIS, increasing association with disease progression. While it is clear that chronic microglial inflammation and enhanced ROS production impact neuronal integrity, little is known about how acute microglial inflammation influences AIS stability. Here, we demonstrate that acute neuroinflammation induces AIS structural plasticity in a ROS-mediated and calpain-dependent manner. Methods C57BL/6J and NOX2−/− mice were given a single injection of lipopolysaccharide (LPS; 5 mg/kg) or vehicle (0.9% saline, 10 mL/kg) and analyzed at 6 h–2 weeks post-injection. Anti-inflammatory Didox (250 mg/kg) or vehicle (0.9% saline, 10 mL/kg) was administered beginning 24 h post-LPS injection and continued for 5 days; animals were analyzed 1 week post-injection. Microglial inflammation was assessed using immunohistochemistry (IHC) and RT-qPCR, and AIS integrity was quantitatively analyzed using ankyrinG immunolabeling. Data were statistically compared by one-way or two-way ANOVA where mean differences were significant as assessed using Tukey’s post hoc analysis. Results LPS-induced neuroinflammation, characterized by enhanced microglial inflammation and increased expression of ROS-producing enzymes, altered AIS protein clustering. Importantly, inflammation-induced AIS changes were reversed following resolution of microglial inflammation. Modulation of the inflammatory response using anti-inflammatory Didox, even after significant AIS disruption occurred, increased the rate of AIS recovery. qPCR and IHC analysis revealed that expression of microglial NOX2, a ROS-producing enzyme, was significantly increased correlating with AIS disruption. Furthermore, ablation of NOX2 prevented inflammation-induced AIS plasticity, suggesting that ROS drive AIS structural plasticity. Conclusions In the presence of acute microglial inflammation, the AIS undergoes an adaptive change that is capable of spontaneous recovery. Moreover, recovery can be therapeutically accelerated. Together, these findings underscore the dynamic capabilities of this domain in the presence of a pathological insult and provide evidence that the AIS is a viable therapeutic target

    A Research Agenda for Studying Open Source I: A Multi-Level Framework

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    This paper presents a research agenda for studying information systems using open source software A multi-level research model is developed at five discrete levels of analysis: (1) the artifact; (2) the individual; (3) the team, project, and community; (4) the organization; and (5) society. Each level is discussed in terms of key issues within the level. Examples are based on prior research. In a companion paper, [Niederman, et al 2006], we view the agenda through the lens of referent discipline theories

    Assessing the Impact of Retreat Mechanisms in a Simple Antarctic Ice Sheet Model Using Bayesian Calibration

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    The response of the Antarctic ice sheet (AIS) to changing climate forcings is an important driver of sea-level changes. Anthropogenic climate change may drive a sizeable AIS tipping point response with subsequent increases in coastal flooding risks. Many studies analyzing flood risks use simple models to project the future responses of AIS and its sea-level contributions. These analyses have provided important new insights, but they are often silent on the effects of potentially important processes such as Marine Ice Sheet Instability (MISI) or Marine Ice Cliff Instability (MICI). These approximations can be well justified and result in more parsimonious and transparent model structures. This raises the question of how this approximation impacts hindcasts and projections. Here, we calibrate a previously published and relatively simple AIS model, which neglects the effects of MICI and regional characteristics, using a combination of observational constraints and a Bayesian inversion method. Specifically, we approximate the effects of missing MICI by comparing our results to those from expert assessments with more realistic models and quantify the bias during the last interglacial when MICI may have been triggered. Our results suggest that the model can approximate the process of MISI and reproduce the projected median melt from some previous expert assessments in the year 2100. Yet, our mean hindcast is roughly 3/4 of the observed data during the last interglacial period and our mean projection is roughly 1/6 and 1/10 of the mean from a model accounting for MICI in the year 2100. These results suggest that missing MICI and/or regional characteristics can lead to a low-bias during warming period AIS melting and hence a potential low-bias in projected sea levels and flood risks.Comment: v1: 16 pages, 4 figures, 7 supplementary files; v2: 15 pages, 4 figures, 7 supplementary files, corrected typos, revised title, updated according to revisions made through publication proces

    Phase I and Phase II Therapies for Acute Ischemic Stroke: An Update on Currently Studied Drugs in Clinical Research.

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    Acute ischemic stroke is a devastating cause of death and disability, consequences of which depend on the time from ischemia onset to treatment, the affected brain region, and its size. The main targets of ischemic stroke therapy aim to restore tissue perfusion in the ischemic penumbra in order to decrease the total infarct area by maintaining blood flow. Advances in research of pathological process and pathways during acute ischemia have resulted in improvement of new treatment strategies apart from restoring perfusion. Additionally, limiting the injury severity by manipulating the molecular mechanisms during ischemia has become a promising approach, especially in animal research. The purpose of this article is to review completed and ongoing phases I and II trials for the treatment of acute ischemic stroke, reviewing studies on antithrombotic, thrombolytic, neuroprotective, and antineuroinflammatory drugs that may translate into more effective treatments

    The prevalence of trunk asymmetries in the small island state of Malta

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    Background: Malta, the smallest member state of the European Union is constituted of two inhabited islands Malta and Gozo. In the Maltese islands there has not been any large population size definitive study concerning the incidence of trunk asymmetries that may indicate Adolescent Idiopathic Scoliosis (AIS) amongst the general population. Scoliosis is one of the most deforming orthopaedic conditions confronting children. To confirm the orthopaedic condition of scoliosis one has to carry out a visual examination that usually consists of the Adam’s Forward Bend test, this is followed by the measurement of trunk rotation with the use of a Bunnell Scoliometer. Should the angle of trunk rotation be more than five degrees then the positively screened student be referred for x-Rays and a 10 degree Cobb angle taken as being required to confirm the diagnosis of Scoliosis. The lack of a full scale study together with the apparent lack of awareness regarding the condition has prompted the authors to research the situation on all Gozitan children aged between 13 and 15 years of age. It was decided to measure Trunk Asymmetry and the aim of the study was to obtain statistical data on the occurrence of trunk asymmetries amongst the Gozitan population, to further analyse the ratio of distribution of trunk asymmetries between female and male students and finally to refer the positively screened students to the relevant medical authorities for x-ray to confirm a scoliosis diagnosis. Methods: This quantitative study design was carried out on all children aged between 13 to 15 years old over a five-month period. An Adam’s forward bend test and Scoliometer reading were taken for each participant consenting to this study. To minimse bias a qualified full time Physiotherapist graduated with a Bachelor of Science Honours degree in Physiotherapy since 2012, carried out these tests in the selected schools. Results: The results of the study concluded that 5.3% of the adolescent population in Gozo suffer from trunk asymmetries (13 out of 245). Prevalence of trunk asymmetry was calculated using the 95% confidence interval and the Chi square tests had a significant p-value. Further analysis showed that 69% of these were female and 31% were male. These results demonstrate that the prevalence of trunk asymmetries in Gozitan adolescents is comparable to that stated within the current literature. Conclusions: Results from the study confirms that trunk asymmetry is relatively common within the Maltese population. This might be indicative that a significant portion of the Maltese adolescent population might suffer from Adolescent Idiopathic Scoliosis. The intention of this research is to increase the general public’s awareness of the condition AIS, to make this condition more prominent to members of the allied professions, to reinforce the need for school screening projects and finally to ensure that the condition Trunk Asymmetry and Scoliosis is given the importance that it requires in the curriculum of study for physiotherapists.peer-reviewe

    Perceptions of gender balance of IS journal editorial positions

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    An analysis of 18,854 editorial positions on IS journals was undertaken to examine the perceived gender balance of those positions as an indication of their contribution towards a positive role model for females considering an IS academic career. The nature and extent of perceived gender balance is examined in terms of overall composition of editorial positions, journal prestige and the specific area within IS covered by a journal. The results indicate that perceived gender balance of editorial positions reflects that of ICT academia generally, and that female representation appears to be concentrated in journals covering areas that are traditionally seen as female occupations, e.g., health, education, librarianship. As such, little or no encouragement is given to females considering an IS academic career.<br /
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