470 research outputs found
Distributed Access Control with Blockchain
The specification and enforcement of network-wide policies in a single
administrative domain is common in today's networks and considered as already
resolved. However, this is not the case for multi-administrative domains, e.g.
among different enterprises. In such situation, new problems arise that
challenge classical solutions such as PKIs, which suffer from scalability and
granularity concerns. In this paper, we present an extension to Group-Based
Policy -- a widely used network policy language -- for the aforementioned
scenario. To do so, we take advantage of a permissioned blockchain
implementation (Hyperledger Fabric) to distribute access control policies in a
secure and auditable manner, preserving at the same time the independence of
each organization. Network administrators specify polices that are rendered
into blockchain transactions. A LISP control plane (RFC 6830) allows routers
performing the access control to query the blockchain for authorizations. We
have implemented an end-to-end experimental prototype and evaluated it in terms
of scalability and network latency.Comment: 7 pages, 9 figures, 2 table
Pulmonary fungal infections in patients with acute myeloid leukaemia: is it the time to revise the radiological diagnostic criteria?
The definition of pulmonary fungal infections (PFI) according to the EORTC-MSG criteria may lack diagnostic sensitivity due to the possible presentation of PFI with different radiological pictures. We evaluated the hypothesis to apply less restrictive radiological criteria to define PFI in patients with acute myeloid leukaemia (AML) submitted to chemotherapy. Overall, 73 consecutive episodes of pulmonary infiltrates associated to positive serum galactomannan test or fungal isolation or galactomannan detection from respiratory specimens were considered. CT scans acquired at the onset of symptoms (time-0) and within 4 weeks (time-1) were analysed to identify specific (group A) or aspecific radiological signs (group B). Pulmonary infiltrates fulfilled the EORTC-MSG criteria in 49 patients (group A), whereas in 24 patients (group B) they did not reach the criteria due to aspecific CT findings at time-0. Eleven of 21 (52.4%) patients of the group B evaluable for the evolution of the radiological findings fulfilled EORTC-MSG criteria at time-1. All the analysed clinical and mycological characteristics, response to antifungal therapy and survival were comparable in the two groups. Our study seems to confirm the possibility to extend the radiological suspicion of PFI to less restrictive chest CT findings when supported by microbiological criteria in high-risk haematological patients
Regresión tumoral espontánea. A propósito de dos casos
Two cases of spontaneous tumor regression (STR) occurring in a patient with non Hodgkin lymphoma and in another patient with squamous carcinoma of the lung are presented. Both cases fulfill the criteria of STR defined by Everson and Cole. Recent results obtained in basic and clinical studies have indicated that immunological mechanisms could play an important role in STR. The mediator effects more frequently referred are: 1) generation of antineoplastic cytotoxic cells; 2) production of immunoregulatory cytokines by lymphocytes and monocytes, and 3) possible cross reaction between tumor and bacterial antigens. These mechanisms of action are discussed in relation to the presented case
P-06 The Transgenerational Effect of Substance Use Between Students, Parents & Grandparents
Using a survey conducted among college students at Andrews University, this study focused on substance use and sexual behaviors of students and the presence of familial substance use problems. Analysis indicated a significant association between substance use problems of fathers and their children’s substance use. There was a stronger statistical association between father’s substance use problems and male children’s alcohol use. In addition there was a significant relationship between grandparents substance use and youth sexual behavior for both genders. There is a need for further analysis of the study
The Transgenerational Effect of Substance Abuse
Using a survey conducted among college students at Andrews University, this study focused on substance use and sexual behaviors of students and the presence of familial substance use problems. Analysis indicated a significant association between substance use problems of fathers and their children\u27s substance use. There was a stronger statistical association between father\u27s substance use problems and male children\u27s alcohol use. In addition there was a significant relationship between grandparents substance use and youth sexual behavior for both genders. There is a need for further analysis of this study
A3 Approach to Sustainability: Integrating Energy-Efficient Belts in Amazon Fulfilment Centres
The current study presents a comprehensive strategy for the adoption of energy- efficient belts within Amazon Fulfilment Centres using the A3 methodology. It aims to enhance belting reliability, reduce maintenance costs and promote sustainabilty by addressing key phases of the belt lifecycle. Through strategic analysis, it was identified tht energy-efficient belts offer significant potential for cost savings and environmental impact reduction. However, challenges such as lack of product confidence, supplier selection misalignment and excessive product pricing hinder their adoption. The A3 methodology is employed to systematically address these challenges, including root cause analysis, countermeasure development and continuous improvement. Key strategies include boosting product confidence, aligning supplier preferences with energy-efficient options and negotiating pricing with suppliers. Additionally, real tests results are presented, demonstrating tangible benefits in terms of energy and cost savings. By leveraging the A3 methodology, this thesis provides a framwork to sustainable belt adoption and lays the groundwork for future advancements in belting reliability and cost reduction within Amazon FC´s.Outgoin
Immunomodulation induced by synthetic peptides derived from Staphylococcus aureus protein A
Peptides from 10 to 22 amino acids containing sequences encompassed by Staphylococcus aureus protein A were synthesized. Some of these peptides, when present in cultures of lymphomononuclear cells from healthy donors or from cancer patients (melanoma, breast carcinoma, non-Hodgkin lymphoma and renal cell carcinoma) promoted: (i) changes in the phenotype of the lymphomononuclear population, (ii) stimulation of monocytes (release of IL-1 and TNF-alpha), and (iii) an increase in cytotoxicity against K562, Daudi and HT-29 cells. Isolated monocytes responded also to those peptides with a release of IL-1 and TNF alpha and an increase of cytotoxicity against HT-29 cells. It was found that the active peptides had the following structural pattern: a length of at least 15 amino-acid residues with a proline at position 6, valine, leucine, isoleucine, glycine, alanine or lysine at position 2, and glutamic or aspartic acid at position 11. Replacement of Pro at position 6 with any other residue turned the peptide inactive. Replacement of residues at positions 2 and 11 with amino-acid residues other than those required for activity resulted in compounds with a marked decrease in the immunomodulating properties described, or lacking these properties altogether
Co-expression of inducible nitric oxide synthase and arginases in different human monocyte subsets. Apoptosis regulated by endogenous NO
Human monocyte subsets, isolated from cultures of mononuclear cells, or freshly obtained from patients with multiple sclerosis, Graves' disease or pemphigus vulgaris, differed in phenotype, apoptotic features, mRNA levels of arginase II (A-II) and the inducible form of nitric oxide synthase (iNOS). Liver-type arginase I mRNA was present in all subsets. Apoptosis was followed by the expression of T cell intracellular antigen (TIA) and the simultaneous detection of DNA stainability by propidium iodine and annexin V binding. Apoptosis was practically absent both in activated CD14(++)CD33(++)DR(++)CD25(++)CD69(++)CD71(++/+) CD16(-) cells, expressing A-II mRNA and having arginase activity, but not iNOS mRNA, and in not fully mature large CD14(++)CD16(+)CD23(+)DR(++) monocytes, expressing simultaneously both mRNAs and having both enzyme activities. However, differentiated small CD14(+/++)CD16(+)CD69(+)CD25(+/-)CD71(++)CD23(+) DR(++) monocytes, expressing high levels of iNOS mRNA, exhibited apoptotic signs. Amounts of NO synthesised by monocytes co-expressing iNOS and arginase changed with the addition of arginine or an iNOS inhibitor; in that case a correlation of NO production and apoptotic features was observed. Data suggest a regulatory role for endogenous NO in apoptosis of stimulated and differentiated monocytes, and also that iNOS and A-II, when simultaneously present, could control the production of NO as a consequence of their competition for arginine
Development of an Operational Satellite-Based Flood Monitoring Model for Tanzania
Timely information during water related disasters is of utmost importance for flood preparedness and risk reduction. Real time observation and monitoring of flooded areas is an expensive and time-consuming exercise. Satellite remote sensing is a quick and affordable approach that can be used for concurrent floods detection at different scales. This is important as it facilitates timely information for emergency response to disaster management departments, even in scarcely instrumented catchments. This study presents a novel approach for flood tracking using satellite technology to map flood affected areas. An open-source water detection algorithm is developed that employs readily available satellite images and the Google Earth Engine (GEE) platform. Dar es Salaam and Singida regions in Tanzania were used as the case study for validation of the proposed approach. Use is made of Sentinel-1 satellite images and GEE coding. The after-flood tracking GEE code was validated with the physical flood extent markers and after-event flood extent survey points of the regions provided by the Ministry of Water (MoW). The findings reveal that the approach supports mapping flood extent areas by giving promising results after the satisfaction from validated data. Relevant parameters were then coded in order to develop the flood map of Tanzania. The findings of this study demonstrate the usefulness of open-source GEE in rapid flood inundation mapping. 
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