72 research outputs found

    THE POWER OF STRUCTURED DESIGNS AND MIXED MODELS IN A REAL WORLD EXPERIMENT

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    Justifications usually given for adopting an automated system pertain to a reduction in labor and an improvement in quality control. A manufacturer of a prototype instrument that automated some of the steps for culturing bacteria wanted to compare the automated system to the manual system. The manufacturer wanted to compare the two systems in 1) Total time needed to isolate the target bacteria, 2) Ability to isolate the target bacteria, 3) Amount of interference from background (non-target) bacterial growth, and 1) Extent of cross (sample to sample) contamination. This paper presents the experimental design used to make these comparisons and how the design helped discover some surprising results about laboratory quality control. The experiment presented illustrates the importance of a good experimental design, the power of current statistical tools, and that a thorough and appropriate analysis of a data set requires side-by-side good detective work by both statistician and client

    Physics of InAIAs/InGaAs Heterostructure Field-Effect Transistors

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    Contains an introduction, reports on two research projects and a list of publications and conference papers.Charles S. Draper Laboratories Contract DL-H-441694Joint Services Electronics Program Contract DAAL03-92-C-0001Texas Instruments Agreement dated 08/14/9

    Impact assessment of the biological control of the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), by the introduced parasitoid Epidinocarsis lopezi (De Santis) (Hymenoptera: Encyrtidae)

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    The impact of Phenacoccus manihoti Matile-Ferrero on growth and tuber yield of cassava, and the results of its biological control by the exotic parasitoid Epidinocarsis lopezi (De Santis) were investigated in a survey of 60 farmers' fields in Ghana and Ivory Coast over an area of 180 000 km2 of the savana and forest ecosystems. Twenty-nine variables associated with plant growth, agronomic and environmental factors, and insect populations were recorded. Densities of P. manihoti were closely correlated with stunting of the cassava shoot tips and, less so, with the rate of stunting early in the growing season. With increasing mealybug infestations, average harvest indices declined and populations of E. lopezi and of indigenous coccinellids increased, but parasitoids were found at lower host levels than were predators. The length of time E. lopezi had been present in an area was the most important factor influencing mealybug densities. Thus, P. manihoti populations were significantly lower where E. lopezi had been present for more than half the planting season than in areas where E. lopezi was lacking or had been only recently introduced. A significant proportion of the farmers in the savanna zone, where P. manihoti populations were much higher than in the forest zone, had observed this decline due to E. lopezi. Tuber yield losses due to P. manihoti in the absence of E. lopezi were tentatively estimated at 463 g/plant in the savanna zone. No significant effect was found in the forest region. When E. lopezi was present, average P. manihoti damage scores were reduced significantly, both in the savanna and forest regions. The increase in yields was 228g/plant or about 2.48 t/ha in the savanna regio

    High-Frequency InAIAs/InGaAs Metal-Insulator-Doped Semiconductor Field-Effect Transistors (MIDFETs) for Telecommunications

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    Contains an introduction, reports on two research projects and a list of publications.Charles S. Draper Laboratories Contract DL-H-441694Fujitsu LaboratoriesJoint Services Electronics Program Contract DAAL03-92-C-0001Texas Instrument

    Chemical Beam Epitaxy of Compound Semiconductors

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    Contains an introduction, reports on three research projects and a list of publications.3M Company Faculty Development GrantDefense Advanced Research Projects Agency Subcontract 216-25013Defense Advanced Research Projects Agency Subcontract 542383Joint Services Electronics Program Contract DAAL03-92-C-0001National Science Foundation Grant ECS 88-46919National Science Foundation Grant ECS 89-05909National Science Foundation Grant DMR 92-0295

    Can the internet reduce the loneliness of 50+ living alone?

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    Published online: 12 May 2020Living alone has been indicated as a key variable to explain loneliness in older adults. In contemporary society, where technology has become one of the main means of communication and personal interaction, has the internet influenced the relationship between living alone and loneliness? This paper aims to answer this research question by using a sample of 64,297 individuals who were surveyed in SHARE project wave 6 – in European countries with different welfare regimes (Portugal, Greece, Italy and Spain, Denmark, Sweden, Austria, Belgium, France, Germany, Switzerland, Luxemburg, Poland, Czech Republic; Slovenia, Estonia, and Croatia). The results of the regression analysis evidence the moderating role of the internet on the relationship between living alone and feelings of loneliness in individuals aged 50 and over, so that the impact of living alone on loneliness is diminished for internet users as compared to their peers who do not use the internet. The results therefore reinforce the importance of policies aimed at fostering e-inclusion as a way of reducing the loneliness of older adultsThis work was supported by European Commission; Fundação para a Ciência e a Tecnologia; U.S National Institute on Aging; Fundação Calouste Gulbenkian; German Ministry of Education and Researc

    'Concrete freedom' : C.L.R. James on culture and black politics

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    This article aims to provide a synoptic account of the cultural writings of the West Indian intellectual and activist C.L.R. James. I aim to make a case for greater recognition of his work among cultural sociologists. I go on to show how James’ original, historicising account of cultural forms relates closely to his wider political interventions including, specifically, his ground-breaking discussion of mid-twentieth century black politics in America
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