Product Multicommodity Flow in Wireless Networks

We provide a tight approximate characterization of the $n$-dimensional product multicommodity flow (PMF) region for a wireless network of $n$ nodes. Separate characterizations in terms of the spectral properties of appropriate network graphs are obtained in both an information theoretic sense and for a combinatorial interference model (e.g., Protocol model). These provide an inner approximation to the $n^2$ dimensional capacity region. These results answer the following questions which arise naturally from previous work: (a) What is the significance of $1/\sqrt{n}$ in the scaling laws for the Protocol interference model obtained by Gupta and Kumar (2000)? (b) Can we obtain a tight approximation to the "maximum supportable flow" for node distributions more general than the geometric random distribution, traffic models other than randomly chosen source-destination pairs, and under very general assumptions on the channel fading model? We first establish that the random source-destination model is essentially a one-dimensional approximation to the capacity region, and a special case of product multi-commodity flow. Building on previous results, for a combinatorial interference model given by a network and a conflict graph, we relate the product multicommodity flow to the spectral properties of the underlying graphs resulting in computational upper and lower bounds. For the more interesting random fading model with additive white Gaussian noise (AWGN), we show that the scaling laws for PMF can again be tightly characterized by the spectral properties of appropriately defined graphs. As an implication, we obtain computationally efficient upper and lower bounds on the PMF for any wireless network with a guaranteed approximation factor.Comment: Revised version of "Capacity-Delay Scaling in Arbitrary Wireless Networks" submitted to the IEEE Transactions on Information Theory. Part of this work appeared in the Allerton Conference on Communication, Control, and Computing, Monticello, IL, 2005, and the Internation Symposium on Information Theory (ISIT), 200

It takes two (or more) to tango: Partnerships within the education sector in Timor-Leste

Recent international declarations stress the importance of partnerships between and amongst donors, the state and civil society, in order to improve service delivery and promote qualities of good governance, particularly in key sectors such as education.  However, in conditions of state fragility—where high levels of distrust between and amongst these ‘partners’ may exist; large and often ungovernable flows of assistance are common; and the capacity of state institutions is weak or non-existent—the feasibility of such partnerships must be critically examined. This paper examines these dilemmas within the context of Timor-Leste’s basic education sector, with specific attention paid to how external actors, internal service providers and the Ministry of Education have ‘partnered’ to qualify more than 8,000 teachers through in-service training. The author suggests that donors are increasingly compelled to work within a framework, which presents both practical challenges and deeper ideological conundrums.  Ultimately, the interests of teachers and children are being left behind in the drive for alignment, coordination and harmonisation

AEWG Guide to the Accelerated Education Principles

A large number of donor agencies, non-governmental organizations and governments have set up AEPs to meet the needs of over-age, out-of-school children and youth. These programs vary widely and are of differing quality and effectiveness. While there is guidance on quality education and education in emergencies generally, prior to this Guide, no AEP-specific Principles have existed to support these stakeholders in designing, implementing and evaluating their AEPs. With the goal of strengthening the quality of Accelerated Education (AE) programming through a more harmonized, standardized approach, the Accelerated Education Working Group, led by UNHCR and with representation from nine member organizations, has identified a set of 10 evidence-based Accelerated Education Principles. The Principles elaborated in this Guide help establish clear, common aspirations for AEPs globally

Development and validation of dissolution method for carvedilol compression-coated tablets

The present study describes the development and validation of a dissolution method for carvedilol compression-coated tablets. Dissolution test was performed using a TDT-06T dissolution apparatus. Based on the physiological conditions of the body, 0.1N hydrochloric acid was used as dissolution medium and release was monitored for 2 hours to verify the immediate release pattern of the drug in acidic pH, followed by pH 6.8 in citric-phosphate buffer for 22 hours, to simulate a sustained release pattern in the intestine. Influences of rotation speed and surfactant concentration in medium were evaluated. Samples were analysed by validated UV visible spectrophotometric method at 286 nm. 1% sodium lauryl sulphate (SLS) was found to be optimum for improving carvedilol solubility in pH 6.8 citric-phosphate buffer. Analysis of variance showed no significant difference between the results obtained at 50 and 100 rpm. The discriminating dissolution method was successfully developed for carvedilol compression-coated tablets. The conditions that allowed dissolution determination were USP type I apparatus at 100 rpm, containing 1000 ml of 0.1N HCl for 2 hours, followed by pH 6.8 citric-phosphate buffer with 1% SLS for 22 hours at 37.0 ± 0.5 ºC. Samples were analysed by UV spectrophotometric method and validated as per ICH guidelines.O presente estudo descreve o desenvolvimento e a validação de método de dissolução para comprimidos revestidos de carvedilol. O teste de dissolução foi efetuado utilizando-se o aparelho para dissolução TDT-06T. Com base nas condições fisiológicas do organismo, utilizou-se ácido clorídrico 0,1 N como meio de dissolução e a liberação foi monitorada por 2 horas para se verificar o padrão de liberação imediata do fármaco em condições de pH baixo, seguidas por pH 6,8 em tampão cítrico-fosfato por 22 horas, para simular o padrão de liberação controlada no intestino. Avaliou-se a influência da velocidade de rotação e a concentração de tensoativo no meio. As amostras foram analisadas por método espectrofotométrico UV-visível validado, em 286 nm. O laurilsulfato sódico a 1% (SLS) mostrou-se ótimo para aumentar a solubilidade do carvedilol em pH 6,8 em tampão cítrico-fosfato. A análise da variância não mostrou diferença significativa entre os resultados obtidos a 50 e a 100 rpm. O método da dissolução discriminante foi desenvolvido com sucesso para os comprimidos revestidos de carvedilol. As condições que permitiram a determinação da dissolução foram: aparelho USP tipo I a 100 rpm, contendo 1000 mL de HCL 0,1 N por 2 horas, seguido de pH 6,8 com tampão cítrico-fosfato, com 1% de SLS por 22 horas a 37,0 ± 0,5 ºC. Amostras foram analisadas por método espectrofotométrico e validadas pelas normas ICH

Optimized upper bound analysis of polymer coated metal rod extrusion through conical die

Extrusion is a metal forming process used extensively in industry to produce different structural, mechanical, electrical, architectural, automotive and aerospace application parts. Currently after extrusion, the rod is subjected to environmental wear due to long storage time and hence requires an additional cleaning process before further use. This cleaning process can be eliminated by extruding a polymer coated metal rod workpiece such that the polymer coating is sustained on the final product after the extrusion process. In the present research study a new upper bound analytical model is developed to predict the forces required to conduct extrusion of a polymer coated metal rod successfully. The search for the lower upper bound power functional is modeled as a non linear optimization problem. Optimizing the functional also determines the set of constraints defining the shape of rigid plastic deformation boundaries and the final coating thickness. Also an upper bound analytical model was developed to predict forces for failure of the polymer coating during the extrusion. Both the analytical models for successful and failed extrusion are compared to obtain critical die angle which can provide tooling and process design guidelines. Finite element analysis simulations were modeled using commercially available software package, ABAQUS. Predictions of FEA simulations were in good agreement with published results and with the predictions of analytical model developed in this study

COLISTIN-CARBAPENEM COMBINATION THERAPY AGAINST CARBAPENEM RESISTANT GRAM NEGATIVE BACILLI INFECTIONS: CLINICAL AND AN IN VITRO SYNERGY STUDY

Objective: Combination therapy is recommended for carbapenem resistant Gram negative bacilli (CR GNB) infections. However, limited data exists on the clinical effectiveness of antibiotic combinations. The purpose of this study was to evaluate the efficacy of colistin-carbapenem combination against CR GNB infection in a clinical study and an in vitro synergy study using Etest. Methods: A study was conducted in a tertiary care hospital to evaluate the clinical outcome of patients with CR GNB infections who were treated with colistin-carbapenemcombination between January to April, 2013. It was comprised of 33 patients with CR GNB infection. Detection of in vitro synergy was performed by Etest for colistin-meropenem combination on five isolates. These isolates were also screened for the resistant genes blaOXA-23, blaVIMand blaNDM using single target PCR. Results: 33 CR GNB included Acinetobacterspp. (19), Pseudomonas aeruginosa (7) and Enterobacteriaceae spp. (7). Overall clinical success of 60.6% was observed in patients receiving colistin-carbapenem combination therapy. In respiratory infection, the clinical success rate was only 25%, whereas in soft tissue infection it was 57.1%. In bloodstream infection 100%  clinical success was observed. All five isolates screened using PCR was carrying bla NDM gene, whereas isolate of Acinetobacter baumannii also carried blaOXA-23 and blaVIM gene. Indifferent interactions were observed between colistin and meropenem against all five isolates. Conclusion: We observed low clinical success rate for colistin-carbapenem combination therapy, probably due to indifferent interactions between colistin and meropenem against NDM producing strain. In addition, probable pharmacokinetic concern of colistin may have a role to play

A case of refractory multiple myeloma

Multiple myeloma is a plasma cell cancer in which antibody-producing plasma cells grow in an uncontrolled and invasive way. The known incidence of multiple myeloma in India ranges from 0.5 to 1.2 per 100,000 & is a rare in India. It usually occurs in persons older than 55 years and the ratio of men: women is 3:2. Multiple myeloma affects the bones, immune system, kidneys and red blood cell count. We report a case of refractory multiple myeloma