A System for Distributed Mechanisms: Design, Implementation and Applications

We describe here a structured system for distributed mechanism design appropriate for both Intranet and Internet applications. In our approach the players dynamically form a network in which they know neither their neighbours nor the size of the network and interact to jointly take decisions. The only assumption concerning the underlying communication layer is that for each pair of processes there is a path of neighbours connecting them. This allows us to deal with arbitrary network topologies. We also discuss the implementation of this system which consists of a sequence of layers. The lower layers deal with the operations that implement the basic primitives of distributed computing, namely low level communication and distributed termination, while the upper layers use these primitives to implement high level communication among players, including broadcasting and multicasting, and distributed decision making. This yields a highly flexible distributed system whose specific applications are realized as instances of its top layer. This design is implemented in Java. The system supports at various levels fault-tolerance and includes a provision for distributed policing the purpose of which is to exclude `dishonest' players. Also, it can be used for repeated creation of dynamically formed networks of players interested in a joint decision making implemented by means of a tax-based mechanism. We illustrate its flexibility by discussing a number of implemented examples.Comment: 36 pages; revised and expanded versio

The pattern and presentation of myathenia gravis in Al-Shaab and Omdurman Teaching Hospitals

Introduction: Myasthenia gravis (MG) is the most common acquired autoimmune disorder of neuromuscular transmission. It has different patterns of presentation.Objective: to study the pattern and mode of presentation of Myasthenia Gravis in Al-Shaab and Omdurman Teaching Hospitals, Khartoum Sudan.Methods: The demographic and clinical characteristics of 50 patients of myasthenia gravis (MG) were reviewed in Alshab and Oumdrman Teaching Hospitals for five months period from May to October 2008.Results: Out of 2400 patients attending neurology clinics 50 were found to have Myathenia Gravis [MG] with female; male ratio of 2.5:1. The age at presentation was the second decade of life in 34%. Most of the patients [42%] were from Khartoum State followed by North Kordofan State [14%]. High occurrence of late onset fatigability and weakness was seen in 92 % of our patients. Ocular muscles involvement was detected in 78%. MG was aggravated by hot weather and fever in 12% of the patients. Quinine represented the most common drug which aggravated the myasthenia symptoms in 4%. Diabetes mellitus and thyroid diseases were the most associated auto immune diseases seen in 12% and 4 % respectively. The diagnosis was made by classic history and neurological examinations in 88% and positive neostigmin test in64%. The majority of patients were treated with steroids. Thymectomy was done in 10% patients. The outcome was excellent as 82% improved and only one [2%] patient died.Discussion: Going with literature diagnosis of MG was made depending on classical history, full neurological examination and confirmed by tensilon test. Because of different reasons more sophisticated tests were not done in our patients. Only patients with malaria who were treated withquinine showed deterioration of their symptoms in our study. Strikingly, myasthenia crisis which were reported in 27% of patients were not seen in our population. Because of lack of usage of steroid sparing agents the vast majority [96%] of our patients were treated with steroids.Conclusion: Generalized myasthenia gravis with ocular involvement is common in our patients. However, pure OMG was not seen. Thymectomy was done in a small number of our patients with reference toother studies.Keywords: autoimmune, tensilon, neostigmin, thymectomy, diplopia, ptosis

A Distributed Platform for Mechanism Design

We describe a structured system for distributed mechanism design. It consists of a sequence of layers. The lower layers deal with the operations relevant for distributed computing only, while the upper layers are concerned only with communication among players, including broadcasting and multicasting, and distributed decision making. This yields a highly flexible distributed system whose specific applications are realized as instances of its top layer. This design supports fault-tolerance, prevents manipulations and makes it possible to implement distributed policing. The system is implemented in Java. We illustrate it by discussing a number of implemented examples.Comment: 6 pages. To appear in the Proc. of International Conference on Computational Intelligence for Modelling, Control and Automation, IEEE Societ

Attitude and Practice of Pharmacy Students Toward Traditional Herbal Medicines, Sudan

Ebaa I Mahmoud,1 Mariam A Yousif,1 Ahmed H Arbab2 1Faculty of Pharmacy, University of Khartoum, Khartoum, 11111, Sudan; 2Department of Pharmacognosy, Faculty of Pharmacy, University of Khartoum, Khartoum, 11111, SudanCorrespondence: Ahmed H Arbab, Department of Pharmacognosy, Faculty of Pharmacy, University of Khartoum, Al-Qasr Ave, Khartoum, 11111, Sudan, Tel +249 991893200, Email [email protected]: Traditional herbal medicines (THMs) are widely used in Sudan, but there is scarcity of research on pharmacy students’ attitudes and utilization of THMs. This study aims to assess the attitudes and practices of pharmacy students toward THM.Methods: A descriptive cross-sectional study was conducted among randomly selected undergraduate pharmacy students at the University of Khartoum (Sudan). Data were collected using a validated self-administered questionnaire adapted from previous studies. A statistical package for the social sciences was used for data analysis.Results: Among the 264 respondents, the average age was 21.8 years, and 84.8% of them were females. Nearly 85% of respondents were residents of Khartoum. The overall respondent’s attitudes towards THMs were positive, it ranged from high (19.7%), moderate (79.9%). About 87.8% of respondents are interested in learning more about THMs. In addition, 36.4%, and 50.4% of respondents strongly agreed or agreed that THMs should be officially licensed and controlled. A 17.8% and 63.3% of respondents, respectively, reported using traditional herbal remedies either always or occasionally. Supermarkets (35.2%) and friends/family (36.4%) were the main sources of THMs for the participants, and oral administration was the most used route (87.1%). More than 90% of respondents said they would suggest THMs to others, and the most common justifications for doing so were their accessibility (46.6%) and affordability (16.3%). The most widely used herbs were Mentha spicata, Zingiber officinale, Acacia nilotica, Hibiscus sabdariffa, and Syzygium aromaticum. Data revealed a significant association between attitude levels and respondents’ gender (p=0.046), year of study (p=0.000), and residence (p=0.017).Conclusion: Most undergraduate pharmacy students had a positive attitude and utilized THMs. Development of effective educational initiatives, research, and regulations are recommended to ensure the appropriate utilization of traditional herbal remedies.Keywords: traditional herbal medicines, attitude, practice, pharmacy students, Suda

A note on reactive transitions and Reo connectors

The structure of a reactive transition system can to be modi ed on the y by e.g. removing, reversing or adding new transitions. The topic has been studied by D. Gabbay and his collaborators in di erent contexts. In this paper we take their work a step further, introducing a suitable notion of bisimulation and obtaining a Hennessy-Milner theorem with respect to a hybrid logic in which transition properties can be expressed. Our motivation is to provide a characterisation of equivalence for such systems in order to exploit their possible roles in the formal description of software connectors in Reo, either from a behavioural (semantic) or spatial (syntactic) point of view.“SmartEGOV/NORTE-01-0145-FEDER-000037”, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (EFDR). Additional support was provided by the European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 and by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia within project UID/MAT/04106/2013 at CIDMA. The first author is also supported by an Individual Doctoral Grant (reference number PD/BD/114186/2016

Effects of Ferumoxides – Protamine Sulfate Labeling on Immunomodulatory Characteristics of Macrophage-like THP-1 Cells

Superparamagnetic Iron Oxide (SPIO) complexed with cationic transfection agent is used to label various mammalian cells. Labeled cells can then be utilized as an in vivo magnetic resonance imaging (MRI) probes. However, certain number of in vivo administered labeled cells may be cleared from tissues by the host's macrophages. For successful translation to routine clinical application of SPIO labeling method it is important that this mode of in vivo clearance of iron does not elicit any diverse immunological effects. The purpose of this study was to demonstrate that SPIO agent ferumoxides-protamine sulfate (FePro) incorporation into macrophages does not alter immunological properties of these cells with regard to differentiation, chemotaxis, and ability to respond to the activation stimuli and to modulate T cell response. We used THP-1 cell line as a model for studying macrophage cell type. THP-1 cells were magnetically labeled with FePro, differentiated with 100 nM of phorbol ester, 12-Myristate-13-acetate (TPA) and stimulated with 100 ng/ml of LPS. The results showed 1) FePro labeling had no effect on the changes in morphology and expression of cell surface proteins associated with TPA induced differentiation; 2) FePro labeled cells responded to LPS with slightly higher levels of NFκB pathway activation, as shown by immunobloting; TNF-α secretion and cell surface expression levels of CD54 and CD83 activation markers, under these conditions, were still comparable to the levels observed in non-labeled cells; 3) FePro labeling exhibited differential, chemokine dependent, effect on THP-1 chemotaxis with a decrease in cell directional migration to MCP-1; 4) FePro labeling did not affect the ability of THP-1 cells to down-regulate T cell expression of CD4 and CD8 and to induce T cell proliferation. Our study demonstrated that intracellular incorporation of FePro complexes does not alter overall immunological properties of THP-1 cells. The described experiments provide the model for studying the effects of in vivo clearance of iron particles via incorporation into the host's macrophages that may follow after in vivo application of any type of magnetically labeled mammalian cells. To better mimic the complex in vivo scenario, this model may be further exploited by introducing additional cellular and biological, immunologically relevant, components

In Vivo Serial MR Imaging of Magnetically Labeled Endothelial Progenitor Cells Homing to the Endothelium Injured Artery in Mice

Background: Emerging evidence of histopathological analyses suggests that endothelial progenitor cells (EPCs) play an important role in vascular diseases. Neointimal hyperplasia can be reduced by intravenous transfusion of EPCs after vascular injury in mice. Therefore, it would be advantageous to develop an in vivo technique that can explore the temporal and spatial migration of EPCs homing to the damaged endothelium noninvasively. Methodology/Principal Findings: The left carotid common artery (LCCA) was injured by removal of endothelium with a flexible wire in Kunming mice. EPCs were collected by in vitro culture of spleen-derived mouse mononuclear cells (MNCs). EPCs labeling was carried out in vitro using Fe2O3-poly-L-lysine (Fe2O3-PLL). In vivo serial MR imaging was performed to follow-up the injured artery at different time points after intravenous transfusion of EPCs. Vessel wall areas of injured artery were computed on T2WI. Larger MR signal voids of vessel wall on T2WI was revealed in all 6 mice of the labeled EPC transfusion group 15 days after LCCA injury, and it was found only in 1 mouse in the unlabeled EPC transfusion group (p = 0.015). Quantitative analyses of vessel wall areas on T2WI showed that the vessel wall areas of labeled EPC transfusion group were less than those of unlabeled EPC transfusion group and control group fifteen days after artery injury (p,0.05). Histopathological analyses confirmed accumulation and distribution of transfused EPCs at the injury site of LCCA. Conclusions/Significance: These data indicate that MR imaging might be used as an in vivo method for the tracking of EPC

MRI Tracking of FePro Labeled Fresh and Cryopreserved Long Term In Vitro Expanded Human Cord Blood AC133+ Endothelial Progenitor Cells in Rat Glioma

Background: Endothelial progenitors cells (EPCs) are important for the development of cell therapies for various diseases. However, the major obstacles in developing such therapies are low quantities of EPCs that can be generated from the patient and the lack of adequate non-invasive imaging approach for in vivo monitoring of transplanted cells. The objective of this project was to determine the ability of cord blood (CB) AC133+ EPCs to differentiate, in vitro and in vivo, toward mature endothelial cells (ECs) after long term in vitro expansion and cryopreservation and to use magnetic resonance imaging (MRI) to assess the in vivo migratory potential of ex vivo expanded and cryopreserved CB AC133+ EPCs in an orthotopic glioma rat model. Materials, Methods and Results: The primary CB AC133+ EPC culture contained mainly EPCs and long term in vitro conditions facilitated the maintenance of these cells in a state of commitment toward endothelial lineage. At days 15–20 and 25–30 of the primary culture, the cells were labeled with FePro and cryopreserved for a few weeks. Cryopreserved cells were thawed and in vitro differentiated or IV administered to glioma bearing rats. Different groups of rats also received long-term cultured, magnetically labeled fresh EPCs and both groups of animals underwent MRI 7 days after IV administration of EPCs. Fluorescent microscopy showed that in vitro differentiation of EPCs was not affected by FePro labeling and cryopreservation. MRI analysis demonstrated that in vivo accumulation of previously cryopreserved transplanted cells resulted in significantly higher R2 and R2* values indicating a higher rate of migration and incorporation into tumor neovascularization of previously cryopreserved CB AC133+ EPCs to glioma sites, compared to non-cryopreserved cells. Conclusion: Magnetically labeled CB EPCs can be in vitro expanded and cryopreserved for future use as MRI probes for monitoring the migration and incorporation to the sites of neovascularization

Impact of mediastinal, liver and lung 123I-metaiodobenzylguanidine (123I-MIBG) washout on calculated 123I-MIBG myocardial washout

PURPOSE: In planar (123)I-metaiodobenzylguanidine ((123)I-MIBG) myocardial imaging mediastinum (M) activity is often used as a background correction in calculating "washout" (WO). However, the most likely sources for counts that might produce errors in estimating myocardial (Myo) activity are lung (Lu) and liver (Li), which typically have higher counts/pixel (cpp) than M. The present study investigated the relationship between changes in Lu, Li and Myo activity between early and late planar (123)I-MIBG images, with comparison to M as the best estimator of non-specific background activity. METHODS: Studies on 98 subjects with both early (e) and late (l) planar (123)I-MIBG images were analysed. There were 68 subjects with chronic heart failure (CHF), 14 with hypertension (HTN) but no known heart disease and 16 controls (C). For each image, regions of interest (ROIs) were drawn: an irregular whole Myo, Lu, upper M and Li. For each ROI, WO was calculated as [(cpp(e)-cpp(l:decay corrected))/cpp(e)]x100%. RESULTS: Multivariable forward stepwise regression analysis showed that overall a significant proportion of the variation in Myo WO could be explained by a model containing M WO and Lu WO (37%, p < 0.001). Only in controls was M WO the sole variable explaining a significant proportion of the variation in Myo WO (27%, p = 0.023). CONCLUSION: Although increased Myo WO in CHF subjects reflects disease severity, part of the count differences measured on planar (123)I-MIBG myocardial images likely reflects changes in the adjacent and surrounding Lu tissue. The results for the controls suggest that this is the only group where a mediastinum correction alone may be appropriate for cardiac WO calculation