16 research outputs found
Integrated cell isolation and polymerase chain reaction analysis using silicon microfilter chambers.
No full textWhite blood cells are isolated from whole blood in silicon–glass 4.5-ml microchips containing a series of 3.5-mm feature-sized ‘weir-type‘ filters, formed by an etched silicon dam spanning the flow chamber. Genomic DNA targets, e.g., dystrophin gene, can be directly amplified using the polymerase chain reaction (PCR) from the white cells isolated on the filters. This dual function microchip provides a means to simplify nucleic acid analyses by integrating in a single device two key steps in the analytical procedure, namely, cell isolation and PC
From e-commerce to m-commerce : a new competitive environment for wireless vendors
No full textThesis (S.M.M.O.T.)--Massachusetts Institute of Technology, Sloan School of Management, Management of Technology Program, 2000.Also available online at the MIT Theses Online homepage .Includes bibliographical references (leaves 111-113).The Internet has created a revolution in business. It is allowing companies to connect like they have never been able to previously. Traditional companies are having to radically transform themselves as new business models become possible. These same companies are falling over themselves to cash in on the stratospheric corporate valuations brought on by the new economy, and at the same time are in a desperate battle with the same new economy companies to keep their customers, margins, and market share. However, the first shots of another revolution are being fired. Within five years, these same companies will be repeating their acts of desperation as the Web goes wireless. Today, mobile phones have become ubiquitous tools for many businesses allowing employees, customers, and suppliers to stay better connected. However, wireless voice is only the beginning. As wireless data transmission becomes possible, the Internet turns mobile, and entirely new disruptions in the business world will be created. Where the Internet changed how business was conducted, the wireless Web will change where business is conducted, and just as the Internet has become strategically important to almost every company today, so will the wireless Web be just as important to companies tomorrow. Complicating the matter, the mobile telecommunications industry is in a dramatic state of flux. Not only are handset manufacturers seeing exponential growth in mobile voice communications, but are also now beginning to grapple with the issues of data delivery over mobile devices. These next generation mobile devices will not only have to deliver voice services, but will also have to deliver data services such as email, e-commerce, and other Internet applications. This paper will address the strategic issues being faced by three mobile device manufacturers: Ericsson, Nokia, and Siemens. Furthermore, we will examine the effects the convergence of handheld and wireless devices, the multitude of standards, and the consolidation of industry players will have on an already competitive and complicated industry.by Andreas von Meyer zu Knonow and Mann A. Shoffner.S.M.M.O.T
English vocabulary teaching in Chinese junior high schools
No full textVocabulary learning is an important and indispensable part of the English language learning process. In this paper, the author tried to examine the vocabulary teaching practice in Chinese junior high schools. A questionnaire was used to investigate the problem from the perspectives of in-service teachers. Besides, the National English Curriculum (MOE, 2011) served as another important source of data in this study. The data revealed that progress has been made in English vocabulary teaching in Chinese junior high schools. Teachers are utilizing a wider range of educational resources and vocabulary teaching strategies during their instruction. The methods to assess vocabulary have also become more diversified. In addition to the enhancement in English vocabulary teaching practice, areas for further improvement were identified and pedagogical implications from the study were also discussed. Drawing on the data collected from the study and the official English curriculum (MOE, 2011), and research on vocabulary teaching, the author proposed three tentative suggestions to further improve the vocabulary teaching practice in Chinese junior high schools. The suggestions include: an emphasis on the teaching and testing of productive vocabulary; an increasing focus on the incidental acquisition of vocabulary; and construction of a comprehensive and balanced vocabulary assessment system which employs diversified assessment tools (formative/summative assessment; context-dependent/ context-independent assessment)
An examination of at-risk student's career development needs
No full textIncludes bibliographical references
Transitioning from high school to college: first-generation college students' perceptions of secondary school counselor's role in college preparation
No full textIncludes bibliographical references
Chip PCR. I. Surface passivation of microfabricated silicon-glass chips for PCR
No full textThe microreaction volumes of PCR chips (a micro-fabricated silicon chip bonded to a piece of flat glass to form a PCR reaction chamber) create a relatively high surface to volume ratio that increases the significance of the surface chemistry in the polymerase chain reaction (PCR). We investigated several surface passivations in an attempt to identify ‘PCR friendly ’ surfaces and used those surfaces to obtain amplifications comparable with those obtained in conventional PCR amplification systems using poly-ethylene tubes. Surface passivations by a silanization procedure followed by a coating of a selected protein or polynucleotide and the deposition of a nitride or oxide layer onto the silicon surface were investigated. Native silicon was found to be an inhibitor of PCR and amplification in an untreated PCR chip (i.e. native silicon) had a high failure rate. A silicon nitride (Si3N4) reaction surface also resulted in consistent inhibition of PCR. Passivating the PCR chip using a silanizing agent followed by a polymer treatment resulted in good amplification. However, amplification yields were inconsistent and were not always comparable with PCR in a conventional tube. An oxidized silicon (SiO2) surface gave consistent amplifications comparable with reactions performed in a conventional PCR tube
Biases and limitations of Global Forest Change and author-generated land cover maps in detecting deforestation in the Amazon
No full textStudying land use change in protected areas (PAs) located in tropical forests is a major conservation priority due to high conservation value (e.g., species richness and carbon storage) here, coupled with generally high deforestation rates. Land use change researchers use a variety of land cover products to track deforestation trends, including maps they produce themselves and readily available products, such as the Global Forest Change (GFC) dataset. However, all land cover maps should be critically assessed for limitations and biases to accurately communicate and interpret results. In this study, we assess deforestation in PA complexes located in agricultural frontiers in the Amazon Basin. We studied three specific sites: Amboró and Carrasco National Parks in Bolivia, Jamanxim National Forest in Brazil, and Tambopata National Reserve and Bahuaja-Sonene National Park in Peru. Within and in 20km buffer areas around each complex, we generated land cover maps using composites of Landsat imagery and supervised classification, and compared deforestation trends to data from the GFC dataset. We then performed a dissimilarity analysis to explore the discrepancies between the two remote sensing products. Both the GFC and our supervised classification showed that deforestation rates were higher in the 20km buffer than inside the PAs and that Jamanxim National Forest had the highest deforestation rate of the PAs we studied. However, GFC maps showed consistently higher rates of deforestation than our maps. Through a dissimilarity analysis, we found that many of the inconsistencies between these datasets arise from different treatment of mixed pixels or different parameters in map creation (for example, GFC does not detect reforestation after 2012). We found that our maps underestimated deforestation while GFC overestimated deforestation, and that true deforestation rates likely fall between our two estimates. We encourage users to consider limitations and biases when using or interpreting our maps, which we make publicly available, and GFC’s maps
Retirement modeling [electronic resource] : an exploration of the effects of retirement role model characteristics on retirement self-efficacy and life satisfaction in midlife workers
No full text" The purpose of this study was to examine the relationships among retirement role model characteristics, retirement self-efficacy, and current life satisfaction in midlife workers. Most of the literature related to retirement planning and to counseling workers who are preparing for retirement (e.g., Harper & Shoffner, 2004; Perkins, 2000; Quick, 1990) does not contain suggestions for assisting workers in identifying and observing retirement role models, possibly because there is little evidence as to if and how role models affect retirement self-efficacy. Considering that self-efficacy predicts later performance (Bandura, 1977a, 1997), interventions that increase retirement self-efficacy can be expected to increase later success in the tasks associated with transitioning to retirement, in addition to reducing preretirement anxiety. In this study, a proposed structural model describing the relationships among role model characteristics, retirement self-efficacy, and current life satisfaction was tested, and correlations among the model variables were examined. A model describing the relationships among two role model characteristics (success of models in retirement and similarity of abilities and resources between role models and the participants), retirement self-efficacy, and current life satisfaction was determined to be a good fit. Significant positive correlations at the p < .01 level were identified between current life satisfaction and both retirement self-efficacy (r = .52) and variety of retirement role models (r = .28) and between retirement self-efficacy and both success of models in retirement (r = .36) and variety of models (r = 18). The role model characteristic of success of models in retirement also correlated significantly (p < .01) with the other two retirement role model characteristics, variety of models (r = .20) and similarity of abilities and resources between the role models and the participants. Participants for the study were 218 University of North Carolina at Greensboro employees between the ages of 45 and 60 years. Participants completed the Personal Wellbeing Index (PWI; Australian Centre on Quality of Life, 2002), a modified version of the Retirement Self-Efficacy (RSE) Scale (Neuhs, 1991), the Retirement Observations Questionnaire (ROQ; Harper, 2004), and a demographic questionnaire." Abstract from author supplied metadata
Reassessing the mitochondrial DNA evidence for migration at the Mesolithic–Neolithic transition
No full textOxidative Stress and Mitochondrial Injury in Chronic Multisymptom Conditions: From Gulf War Illness to Autism Spectrum Disorder
No full textBackground: Overlapping chronic multisymptom illnesses (CMI) include Chronic Fatigue Syndrome (CFS), fibromyalgia, irritable bowel syndrome, multiple chemical sensitivity, and Gulf War illness (GWI), and subsets of autism spectrum disorder (ASD). GWI entails a more circumscribed set of experiences that may provide insights of relevance to overlapping conditions.
Objectives: To consolidate evidence regarding a role for oxidative stress and mitochondrial dysfunction (OSMD), as primary mediators in CMI, using GWI as a departure point.
Methods: Exposure relations, character, timecourse and multiplicity of symptoms, and objective correlates of GWI are compared to expectation for OSMD. Objective correlates of OSMD in GWI and overlapping conditions are examined. 
Discussion: OSMD is an expected consequence of known GWI exposures; is compatible with symptom characteristics observed; and accords with objective markers and health conditions linked to GWI, extending to autoimmune disease and infection. Emergent triangulating evidence directly supports OSMD in multisymptom “overlap” CMI conditions, with similarities to, and diagnosed at elevated rates in, GWI, suggesting a common role in each. 
Conclusions: GWI is compatible with a paradigm by which uncompensated exposure to oxidative/nitrative stressors accompanies and triggers mitochondrial dysfunction, cell energy compromise, and multiple downstream effects such as vulnerability to autoantibodies. This promotes a profile of protean symptoms with variable latency emphasizing but not confined to energy-demanding post-mitotic tissues, according with (and accounting for) known properties of multisystem overlap conditions. This advances understanding of GWI; health conditions attending GWI at elevated rates; and overlap conditions like CFS and ASD, providing prospects for vulnerability assessment, mitigation of progression, treatment, and future prevention – with implications germane to additive and excessive environmental oxidative stressor exposures in the civilian setting.

