The static and dynamic response of SU-8 electrothermal microgrippers of varying thickness

This work presents an investigation into the effect on dynamic response of SU-8 microgrippers due to varying thickness, and subsequent validation via COMSOL Multiphysics simulations and thermal camera profiling during actuation. The tweezer-like microgrippers can easily manipulate, with a high degree of control, cells and particles with diameters as small as 10 μm, without using an impractical operating voltage or generating excessive heat. However, in order to fully exploit the versatility of the devices, their response characteristics must be fully understood as material and/or dimension parameters change. Therefore an investigation took place to determine the effects of device thickness on functionality of the device, including the drive current required to actuate the gripper and the speed of actuation. Furthermore, an infrared camera was used to characterise the thermal response of the device. Finally, a simulation of the temperature profile and deflection dimension has been developed in order to verify the findings and further investigate and predict the effects of design variations

How autocracies disrupt unsanctioned information flows: the role of state power and social capital in North Korea

What determines the flow of unsanctioned information in authoritarian regimes? To answer this question, we explore the use and circulation of illicit foreign information among citizens in North Korea. This paper focuses on how the structure of social relations among citizens determines where and with whom people acquire and disseminate politically unsanctioned and potentially illegal content offline. Based on findings from a choice‐based conjoint administered to 313 former residents of North Korea, we show that social capital and trust-related effects associated with the place where information is acquired and the person who provides it determine information flows.Asian Studie

Lack of mutations of exon 2 of the MEN1 gene in endocrine and nonendocrine sporadic tumors

In addition to the mutations that underlie most cases of the multiple endocrine neoplasia type 1 (MEN1) syndrome, somatic mutations of the MEN1 gene have also been described in sporadic tumors like gastrinomas, insulinomas and bronchial carcinoid neoplasm. We examined exon 2 of this gene, where most of the mutations have been described, in 148 endocrine and nonendocrine sporadic tumors. DNA was obtained by phenol/chloroform extraction and ethanol precipitation from 92 formalin-fixed, paraffin-embedded samples, and from 40 fresh tumor tissue samples. We used 5 pairs of primers to encompass the complete coding sequence of exon 2 of the MEN1 gene that was screened by the polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) technique in 78 sporadic thyroid cancers: 28 follicular adenomas, 35 papillary carcinomas, 14 follicular carcinomas, and 1 anaplastic thyroid carcinoma. We also examined 46 adrenal lesions (3 hyperplasias, 3 adenomas and 35 adrenocortical carcinomas, 2 pheochromocytomas, 2 ganglioneuroblastomas, and 1 lymphoma) and 24 breast cancers (6 noninvasive, 16 infiltrating ductal, and 2 invasive lobular tumors). The PCR product of 5 tumors suspected to present band shifts by SSCP was cloned. Direct sense and antisense sequencing did not identify mutations. These results suggest that the MEN1 gene is not important in breast, thyroid or adrenal sporadic tumorigenesis. Because the frequency of mutations varies significantly among tumor subgroups and allelic deletions are frequently observed at 11q13 in thyroid and adrenal cancers, another tumor suppressor gene residing in this region is likely to be involved in the tumorigenesis of these neoplasms.86186

한국인의 통일방식에 대한 숨겨진 선호: 선택형 컨조인트 분석(Choice-based Conjoint Analysis) 결과를 중심으로

본고는 통일의식 연구에서 그동안 활용되지않았던 컨조인트 분석(conjoint analysis)을통해 한국 국민의 통일방식을 더 세부적이고정밀하게 측정하는 데 목적을 둔다. 통일의식을 측정하는 기존 연구 방법론은 직접 단답형다항 선택식 문항으로 통일의 필요성, 시기, 통일관, 통일한반도의 정치체제 등 최종 체제에 관한 질문으로 측정해왔다. 그런데 각 변수 내 선택지에 대한 선호 혹은 비선호의 강도를 측정할 수 없었기에 어느 조건이 더 중요하게 여겨지는지 알 수 없었다. 따라서 기존 조사 결과를 활용한 복합적 정책 설계는 한계가존재한다. 본 연구는 컨조인트 분석이라는 실험적 조사설계를 활용하여 통일 후의 정치체제, 북한 지도부 정리, 노동당 당원 정리, 남한기업의 북한 경제참여, 북한 지역 군대 주둔문제 등 여러 차원의 속성수준으로 설문지를구성하여 실제 선호도를 도출하고자 한다. 연구 결과는 연합제보다 단일민주 정부에 대한선호, 노동당 당원에 대한 민감한 직위의 배제와 지도부의 기소 등 여러 차원에서 강한 선호가 나타났다. 본 연구는 한국 국민의 통일방안에 대한 구체적인 선호를 보여줌으로써, 통일이 갑작스럽게 이루어질 경우, 통일에 대한 정책설계를 위한 유익한 자료를 제공할 것으로 기대된다.Asian Studie

A Study of the 7-Li(p,n)7-Be Excitation Function at Intermediate Energies Using Residual Activity

This work was supported by National Science Foundation Grants PHY 76-84033A01, PHY 78-22774, and Indiana Universit

Nieuwe probabilistische methode om overstromingsrisico’s te schatten

Bij onderzoek naar toekomstige overstromingsrisico's worden vaak de resultaten op basis van klimaatsimulaties gepresenteerd en met elkaar vergeleken zonder dat iets gezegd wordt over de kans op veranderingen in het overstromingsrisico. Om zulke kansen te berekenen, is een probabilistische aanpak nodig. In 2010 en 2011 voerden de Vrije Universiteit Amsterdam, het KNMI, Wageningen Universiteit en Deltares het onderzoek 'Aandacht voor Veiligheid 2' uit, dat een demonstratie omvatte van een methode om probabilistische schattingen voor toekomstige overstromingsrisico's te maken. Die methode toont dat het mogelijk is de kans te schatten dat het toekomstige overstromingsrisico groter is dan het huidige overstromingsrisico

Childhood and the politics of scale: Descaling children's geographies?

This is the post-print version of the final published paper that is available from the link below. Copyright @ 2008 SAGE Publications.The past decade has witnessed a resurgence of interest in the geographies of children's lives, and particularly in engaging the voices and activities of young people in geographical research. Much of this growing body of scholarship is characterized by a very parochial locus of interest — the neighbourhood, playground, shopping mall or journey to school. In this paper I explore some of the roots of children's geographies' preoccupation with the micro-scale and argue that it limits the relevance of research, both politically and to other areas of geography. In order to widen the scope of children's geographies, some scholars have engaged with developments in the theorization of scale. I present these arguments but also point to their limitations. As an alternative, I propose that the notion of a flat ontology might help overcome some difficulties around scalar thinking, and provide a useful means of conceptualizing sociospatiality in material and non-hierarchical terms. Bringing together flat ontology and work in children's geographies on embodied subjectivity, I argue that it is important to examine the nature and limits of children's spaces of perception and action. While these spaces are not simply `local', they seldom afford children opportunities to comment on, or intervene in, the events, processes and decisions that shape their own lives. The implications for the substance and method of children's geographies and for geographical work on scale are considered

User-Centered Evaluation of a Discovery Layer System with Google Scholar

Discovery layer systems allow library users to obtain search results from multiple library resources and view results in a consistent format. The implementation of a discovery layer is expected to simplify users’ workflow of searching for scholarly information. Previous studies on discovery layer systems focused on functionality and content, but not quality of search results from the user’s perspective. The objective of this study was to obtain users’ assessment of search results of a discovery layer system (Ex Libris Primo®) and compare that with a widely used scholarly search tool (Google Scholar). Results showed that Primo’s search results relevancy is comparable to Google Scholar, but it received significantly lower usability and preference ratings. A number of usability issues of Primo were also identified from the study. Results of the study are used to improve the interface of Primo and adjust relevancy ranking options. The empirical method of search results assessment and feedback collection used in this study can be extended to similar user-centered system implementation and evaluation efforts

Integrin activation - the importance of a positive feedback

Integrins mediate cell adhesion and are essential receptors for the development and functioning of multicellular organisms. Integrin activation is known to require both ligand and talin binding and to correlate with cluster formation but the activation mechanism and precise roles of these processes are not yet resolved. Here mathematical modeling, with known experimental parameters, is used to show that the binding of a stabilizing factor, such as talin, is alone insufficient to enable ligand-dependent integrin activation for all observed conditions; an additional positive feedback is required.Comment: in press in Bulletin of Mathematical Biolog

Multidimensional endotyping in patients with severe asthma reveals inflammatory heterogeneity in matrix metalloproteinases and chitinase 3–like protein 1

BackgroundDisease heterogeneity in patients with severe asthma and its relationship to inflammatory mechanisms remain poorly understood.ObjectiveWe aimed to identify and replicate clinicopathologic endotypes based on analysis of blood and sputum parameters in asthmatic patients.MethodsOne hundred ninety-four asthmatic patients and 21 control subjects recruited from 2 separate centers underwent detailed clinical assessment, sputum induction, and phlebotomy. One hundred three clinical, physiologic, and inflammatory parameters were analyzed by using topological data analysis and Bayesian network analysis.ResultsSevere asthma was associated with anxiety and depression, obesity, sinonasal symptoms, decreased quality of life, and inflammatory changes, including increased sputum chitinase 3–like protein 1 (YKL-40) and matrix metalloproteinase (MMP) 1, 3, 8, and 12 levels. Topological data analysis identified 6 clinicopathobiologic clusters replicated in both geographic cohorts: young, mild paucigranulocytic; older, sinonasal disease; obese, high MMP levels; steroid resistant TH2 mediated, eosinophilic; mixed granulocytic with severe obstruction; and neutrophilic, low periostin levels, severe obstruction. Sputum IL-5 levels were increased in patients with severe particularly eosinophilic forms, whereas IL-13 was suppressed and IL-17 levels did not differ between clusters. Bayesian network analysis separated clinical features from intricately connected inflammatory pathways. YKL-40 levels strongly correlated with neutrophilic asthma and levels of myeloperoxidase, IL-8, IL-6, and IL-6 soluble receptor. MMP1, MMP3, MMP8, and MMP12 levels were associated with severe asthma and were correlated positively with sputum IL-5 levels but negatively with IL-13 levels.ConclusionIn 2 distinct cohorts we have identified and replicated 6 clinicopathobiologic clusters based on blood and induced sputum measures. Our data underline a disconnect between clinical features and underlying inflammation, suggest IL-5 production is relatively steroid insensitive, and highlight the expression of YKL-40 in patients with neutrophilic inflammation and the expression of MMPs in patients with severe asthma