Voices of girls with disabilities in rural Iran

This paper investigates the interaction of gender, disability and education in rural Iran, which is a relatively unexplored field of research. The responses of 10 female students with disabilities from Isfahan indicated that the obstacles they faced included marginalization, difficulties in getting from home to school, difficulties within the school building itself, and discrimination by teachers, classmates and school authorities. The data collected for the study contain a wide range of conservative gendered discourses, and show how traditional gender beliefs interact with disability to aggravate the problems faced in education by young women with disabilities. It is hoped that the findings will raise awareness among policy-makers of the many formidable obstacles that make it difficult for young women with disabilities to achieve their full potential in education

Advances in atomic force microscopy

This article reviews the progress of atomic force microscopy (AFM) in ultra-high vacuum, starting with its invention and covering most of the recent developments. Today, dynamic force microscopy allows to image surfaces of conductors \emph{and} insulators in vacuum with atomic resolution. The mostly used technique for atomic resolution AFM in vacuum is frequency modulation AFM (FM-AFM). This technique, as well as other dynamic AFM methods, are explained in detail in this article. In the last few years many groups have expanded the empirical knowledge and deepened the theoretical understanding of FM-AFM. Consequently, the spatial resolution and ease of use have been increased dramatically. Vacuum AFM opens up new classes of experiments, ranging from imaging of insulators with true atomic resolution to the measurement of forces between individual atoms.Comment: In press (Reviews of Modern Physics, scheduled for July 2003), 86 pages, 44 figure

A small erythropoietin derived non-hematopoietic peptide reduces cardiac inflammation, attenuates age associated declines in heart function and prolongs healthspan

BackgroundAging is associated with increased levels of reactive oxygen species and inflammation that disrupt proteostasis and mitochondrial function and leads to organism-wide frailty later in life. ARA290 (cibinetide), an 11-aa non-hematopoietic peptide sequence within the cardioprotective domain of erythropoietin, mediates tissue protection by reducing inflammation and fibrosis. Age-associated cardiac inflammation is linked to structural and functional changes in the heart, including mitochondrial dysfunction, impaired proteostasis, hypertrophic cardiac remodeling, and contractile dysfunction. Can ARA290 ameliorate these age-associated cardiac changes and the severity of frailty in advanced age?MethodsWe conducted an integrated longitudinal (n = 48) and cross-sectional (n = 144) 15 months randomized controlled trial in which 18-month-old Fischer 344 x Brown Norway rats were randomly assigned to either receive chronic ARA290 treatment or saline. Serial echocardiography, tail blood pressure and body weight were evaluated repeatedly at 4-month intervals. A frailty index was calculated at the final timepoint (33 months of age). Tissues were harvested at 4-month intervals to define inflammatory markers and left ventricular tissue remodeling. Mitochondrial and myocardial cell health was assessed in isolated left ventricular myocytes. Kaplan–Meier survival curves were established. Mixed ANOVA tests and linear mixed regression analysis were employed to determine the effects of age, treatment, and age-treatment interactions.ResultsChronic ARA290 treatment mitigated age-related increases in the cardiac non-myocyte to myocyte ratio, infiltrating leukocytes and monocytes, pro-inflammatory cytokines, total NF-κB, and p-NF-κB. Additionally, ARA290 treatment enhanced cardiomyocyte autophagy flux and reduced cellular accumulation of lipofuscin. The cardiomyocyte mitochondrial permeability transition pore response to oxidant stress was desensitized following chronic ARA290 treatment. Concurrently, ARA290 significantly blunted the age-associated elevation in blood pressure and preserved the LV ejection fraction. Finally, ARA290 preserved body weight and significantly reduced other markers of organism-wide frailty at the end of life.ConclusionAdministration of ARA290 reduces cell and tissue inflammation, mitigates structural and functional changes within the cardiovascular system leading to amelioration of frailty and preserved healthspan

System integration in multidatabases

This paper presents an exploratory approach to the development of a tool for integrating existing databases. The intent is to meet specific requirements and to achieve flexibility through the creation of an "open" system. The methodology assumes an integration model which captures the essential characteristics of a distributed system within a knowledge base. The model and the underlying knowledge base may be used to represent the distributed environment and to define requirements for the shared use of heterogeneous databases. An interactive method is proposed which allows the user to proceed in an iterative fashion in specifying system attributes and resolving design conflicts. The project is at present in the definition phase; current work is aimed at the identification of generic multidatabase services, and their abstraction in a form amenable for storage in the knowledge base

Microalgae on display: a microfluidic pixel-based irradiance assay for photosynthetic growth

Microalgal biofuel is an emerging sustainable energy resource. Photosynthetic growth is heavily dependent on irradiance, therefore photobioreactor design optimization requires comprehensive screening of irradiance variables, such as intensity, time variance and spectral composition. Here we present a microfluidic irradiance assay which leverages liquid crystal display technology to provide multiplexed screening of irradiance conditions on growth. An array of 238 microreactors are operated in parallel with identical chemical environments. The approach is demonstrated by performing three irradiance assays. The first assay evaluates the effect of intensity on growth, quantifying saturating intensity. The second assay quantifies the influence of time-varied intensity and the threshold frequency for growth. Lastly, the coupled influence of red-blue spectral composition and intensity is assessed. Each multiplexed assay is completed within three days. In contrast, completing the same number of experiments using conventional incubation flasks would require several years. Not only does our approach enable more rapid screening, but the short optical path avoids self-shading issues inherent to flask based systems.This work was possible through support from a Strategic Grant from the Natural Science and Engineering Research Council of Canada (NSERC), the University of Toronto Connaught Global Challenges Program in Bio-Inspired Ideas for Sustainable Energy and on-going support from the NSERC Discovery Grant Program. The authors gratefully acknowledge two individual awards received, namely the University of Toronto McLean Senior Fellowship (DS) and the NSERC Post-graduate Scholarship (PJG). Funding from the Canada Foundation for Innovation (CFI) provided infrastructure essential to this work

Optimal decision-making in discrete stochastic systems

Sequential search strategies for the determination of a minimum cost control alternative from a finite set in a stochastic environment are considered. The problem is equivalent to search of a "hill of uncertainty" in a decision space; any strategy defines a particular path descending the hill. Optimal decision strategies are identified for the two distinct cases of on-line or adaptive control, and off-line search

Integrated concurrency-coherence control in distributed shared memory

This paper presents a summary of the results of an examination of protocols produced via the integration of concurrency and coherence methods. Additionally locality of reference considerations are added to the integrating mixtures. Variants of a selected integration are simulated and a detailed analysis which clearly describes transactional behaviour within a realistically parametered distributed shared memory (DSM) environment is given. The performance tradeoffs identified through the simulation study should prove useful to designers of database systems in a DSM environment

A Queueing Network Model for Measuring Two-Phase Locking Overhead

This work investigates the effect of the explicit inclusion of queueing delays due to locking overhead in a performance study of a two phase locking concurrency control method. A mean value analysis is used to calculate the system's performance measures, response time and throughput. It is found that the locking overhead's contribution to delay depends largely on the degree of page faulting activity in the system and the degree of contention for the CPU. Even at low page faulting probabilities, it is shown that the 2PL locking overhead is not negligible and should therefore be incorporated as a parameter in two phase locking performance studies. 1. Introduction Several performance analysis models exist to evaluate the effects of two-phase locking (2PL) on Transaction Processing (TP) systems [Agrawal 85; Potier 80; Ryu 90; Thomasian 91]. Performance models usually include simplifying assumptions in order to make the analytical process tractable. One assumption which appears commonly th..