Development that works, March 31, 2011

This repository item contains a single issue of the Pardee Conference Series, On March 31, 2011, more than 100 people participated in a conference titled “Development That Works,” sponsored by Boston University’s Frederick S. Pardee Center for the Study of the Longer-Range Future in collaboration with the BU Global Development program. In the pages that follow, four essays written by Boston University graduate students capture the salient points and overarching themes from the four sessions, each of which featured presentations by outstanding scholars and practitioners working in the field of development. The conference agenda and speakers’ biographies are included following the essays.The theme and the title of the conference—”Development That Works”—stemmed from the conference organizers’ desire to explore, from a groundlevel perspective, what programs, policies, and practices have been shown—or appear to have the potential—to achieve sustained, long-term advances in development in various parts of the world. The intent was not to simply showcase “success stories,” but rather to explore the larger concepts and opportunities that have resulted in development that is meaningful and sustainable over time. The presentations and discussions focused on critical assessments of why and how some programs take hold, and what can be learned from them. From the influence of global economic structures to innovative private sector programs and the need to evaluate development programs at the “granular” level, the expert panelists provided well-informed and often provocative perspectives on what is and isn’t working in development programs today, and what could work better in the future

PEG–Polypeptide Block Copolymers as pH-Responsive Endosome-Solubilizing Drug Nanocarriers

Herein we report the potential of click chemistry-modified polypeptide-based block copolymers for the facile fabrication of pH-sensitive nanoscale drug delivery systems. PEG–polypeptide copolymers with pendant amine chains were synthesized by combining N-carboxyanhydride-based ring-opening polymerization with post-functionalization using azide–alkyne cycloaddition. The synthesized block copolymers contain a polypeptide block with amine-functional side groups and were found to self-assemble into stable polymersomes and disassemble in a pH-responsive manner under a range of biologically relevant conditions. The self-assembly of these block copolymers yields nanometer-scale vesicular structures that are able to encapsulate hydrophilic cytotoxic agents like doxorubicin at physiological pH but that fall apart spontaneously at endosomal pH levels after cellular uptake. When drug-encapsulated copolymer assemblies were delivered systemically, significant levels of tumor accumulation were achieved, with efficacy against the triple-negative breast cancer cell line, MDA-MB-468, and suppression of tumor growth in an in vivo mouse model.Novartis Institutes of Biomedical ResearchNational Institutes of Health (U.S.) (Centers for Cancer Nanotechnology Excellence Grant P30 CA14051)National Institutes of Health (U.S.) (Centers for Cancer Nanotechnology Excellence Grant 5 U54 CA151884-02)National Science Foundation (U.S.). Graduate Research FellowshipNatural Sciences and Engineering Research Council of Canada (Postdoctoral Fellowship

Microstructure, texture and tensile properties of ultrafine/nano grained magnesium alloy processed by accumulative back extrusion

An AZ31 wrought magnesium alloy was processed by employing multipass accumulative back extrusion process. The obtained microstructure, texture and room temperature tensile properties were characterized and discussed. Ultrafine grained microstructure including nano grains were developed, where the obtained mean grain size was decreased from 8 to 0.5 µm by applying consecutive passes. The frequency of both low angle and high angle boundaries increased after processing. Strength of the experimental alloy was decreased after processing, which was attributed to the obtained texture involving the major component lying inclined to the deformation axis. Both the uniform and post uniform elongations of the processed materials were increased after processing, where a total elongation of 68 pct was obtained after six-pass deformation. The contribution of different twinning and slip mechanism was described by calculating corresponding Schmid factors. The operation of prismatic slip was considered as the major deformation contributor. The significant increase in post uniform deformation of the processed material was discussed relying on the occurrence of grain boundary sliding associated with the operation of prismatic slip.Postprint (author's final draft

Organising and representing the poor in a clientelistic democracy: the decline of radical NGOs in Bangladesh

This paper examines the political role of radical development NGOs that emerged in Bangladesh to challenge the marginalization of subordinate groups and strengthen democratic processes. After briefly introducing the political context of Bangladesh and its NGOs, the paper identifies and defines a radical NGO sub-sector. It then reviews the activities of these organizations during the pre-1990 military government era and during the subsequent period of electoral democracy. Some important achievements are identified, but also many failures that have led to decline, leaving behind an NGO sector dominated by credit and service delivery organizations. The paper then explains this decline by focusing on three inter-related factors: (i) an institutional setting dominated by clientelistic structures that have undermined efforts to build horizontal alliances among excluded groups in civil society, or links between NGOs and political parties; (ii) a shift in donor support from mobilization to market-based service delivery agencies; and (iii) internal structures that have generated legitimacy and accountability problems by encouraging elite capture, co-option and personalised leadership in the radical sub-sector. It concludes with some brief reflections on the main implications of these failures

Low stress abrasion-corrosion of high-Cr white cast iron: Combined effects of particle angularity and chloride ions

Tribo-electrochemical behavior of a high chromium white cast iron (high-Cr WCI) used in, e.g., slurry pumps in mining and mineral processing applications, was investigated using a combination of electrochemical techniques, including zero resistance amperometry as well as potentiostatic and potentiodynamic polarisation. The effects of third body particles angularity on the localised tribocorrosion response of the cast alloy was studied during and post abrasion-corrosion by round ceramic beads and semi-angular silica sand particles. Advanced characterization methods such as electron backscatter diffraction and focused-ion beam cross-sectioning of affected areas were also employed to understand the wear and corrosion interactive actions. It was found that in chloride-free solutions, the behavior of high-Cr WCI resembled that of the austenitic 316 SS studied before. In contrast, in chloride-containing electrolytes, the semi-angular silica sand particles increased interfacial (carbide/matrix) localised corrosion susceptibility during and post-abrasion as indicated by the stark increase in anodic current and the morphology of the attack. Semi-angular silica sand abrasives had a greater adverse impact on post-abrasion interfacial corrosion vulnerability, compared to round ceramic beads. The complex behavior observed indicates that any material developed for tribocorrosive conditions must account for the particles angularity and their subsequent effects on localised corrosion

Through-thickness variations in recrystallization behavior in an Al-based ARB composite sheet

A composite sheet of commercially pure aluminum and an Al-0.3 wt.% Sc alloy (in the supersaturated solid solution condition) was produced by accumulative roll bonding at 200°C. The material was then subjected to isothermal annealing at 300°C for 1-30 minutes and cold water quenched. The transverse section was investigated by electron back-scatter diffraction (EBSD) to investigate the variations in microstructure and texture within Al layers through the sheet thickness. A faster spheroidization of the highly elongated lamellar band deformation structures was observed in the surface aluminum layer as compared to the mid- and quarter-thickness layers. In the quarter thickness aluminum layer so-called continuous recrystallization occurred and, thus, the p-fiber rolling texture was retained. Further growth in this layer led to secondary recrystallization of cube orientations. In contrast, in the surface aluminum layers the recrystallization and grain growth texture were relatively random. Intermediate behavior was observed in the mid-thickness aluminum layer. © Published under licence by IOP Publishing Ltd

Effects of temperature and strain rate on the dynamic mechanical behavior of a fine grained Al-Sc alloy

A rod gravity cast aluminum alloy of nominal composition Al-3.0Mg-0.8Sc-0.08Zr has been tested at high strain rates in tension and compression using a Split Hopkinson Pressure Bar. Peak aging heat treatments were performed in an attempt to grow secondary phase Al3Sc particles at grain boundaries to strengthen the alloy under high strain rate loads and at elevated temperatures. Electron backscattering diffraction and energy dispersive x-ray spectroscopy were performed for as cast and peak aged material conditions. Preliminary characterization results indicate negligible changes to the microstructure and second phase particles from the peak aging process performed in this study. Results show that the alloy's mechanical response to compression and tension at high strain rates is less sensitive at elevated temperatures when compared to a high strength 7010 aluminum alloy, providing further evidence of scandium's high temperature strengthening effects in aluminum alloys