7,745 research outputs found

    Study directed at development of an implantable biotelemetry ion detector

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    A literature search was conducted to currently update known information in the field of ion-selective electrodes. The review attempts to identify present trends in cation and anions selective electrodes pertinent to the area of bioimplantable units. An electronic circuit was designed to provide the high impedance interface between the ion-selective sensors and signal-processing equipment. The resulting design emphasized the need for low power and miniaturization. Many of the circuits were constructed and used to evaluate the ion-selective electrodes. A cuvette capable of holding the ion-selective and the reference electrodes was designed and constructed. This equipment was used to evaluate commercially available ion-selective electrodes and the electrodes designed and constructed in the study. The results of the electrode tests are included

    Rural to Urban Population Density Scaling of Crime and Property Transactions in English and Welsh Parliamentary Constituencies

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    Urban population scaling of resource use, creativity metrics, and human behaviors has been widely studied. These studies have not looked in detail at the full range of human environments which represent a continuum from the most rural to heavily urban. We examined monthly police crime reports and property transaction values across all 573 Parliamentary Constituencies in England and Wales, finding that scaling models based on population density provided a far superior framework to traditional population scaling. We found four types of scaling: i ) non-urban scaling in which a single power law explained the relationship between the metrics and population density from the most rural to heavily urban environments, ii ) accelerated scaling in which high population density was associated with an increase in the power-law exponent, iii ) inhibited scaling where the urban environment resulted in a reduction in the power-law exponent but remained positive, and iv ) collapsed scaling where transition to the high density environment resulted in a negative scaling exponent. Urban scaling transitions, when observed, took place universally between 10 and 70 people per hectare. This study significantly refines our understanding of urban scaling, making clear that some of what has been previously ascribed to urban environments may simply be the high density portion of non-urban scaling. It also makes clear that some metrics undergo specific transitions in urban environments and these transitions can include negative scaling exponents indicative of collapse. This study gives promise of far more sophisticated scale adjusted metrics and indicates that studies of urban scaling represent a high density subsection of overall scaling relationships which continue into rural environments

    Relatively Speaking: An Account of the Relationship between Language and Thought in the Color Domain

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    This chapter is divided into six sections. The first sets out the background of the debate about the relationship between language and cognition in the color domain. The second explains how recent studies of color recognition employing visual search tasks have clarified this relationship. This section also argues that these studies point to the existence of two separate systems that influence perception and categorization of color; one of which is linguistically based, and one of which is not affected by language. The third section critically evaluates recent claims that there are similarities between color terms in the world's languages that point to the existence of color universals. The fourth section examines children's color term acquisition in an attempt to trace the mechanisms bywhich color categories are acquired. It also discusses whether infants have an innate prepartitioned organization of color categories that is overridden during the learning process. The two final sections outline some outstanding questions, note some methodological constraints on the conclusions that can be drawn from the accumulated evidence, and argue that much more empirical investigation is still needed in this field

    Aquaculture in Jamaica

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    Jamaica, with its overfish marine resources, has become a major tilapia producer in Latin America led by a small number of large farms practicing tilapia culture with considerable commercial success. Across the country, however, aquaculture is typically practiced by a large number of small-scale fish farmers who own less than 1.0 ha of land. Production is constrained by lack of credit, finite land space and suitable soil type, but larger existing aquaculturists are expanding further for overseas markets. Inspired by pioneering tilapia fish culture demonstration projects funded by the USAID and the goverment of Jamaica, fish culture production rose from a few hundred kg of Oreochromis niloticus in 1977, to about 5000 t of processed fish mainly red hybrid tilapia, in 2000. Most of this quantity was exported to Europe and North America

    Aquaculture in Jamaica

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    Jamaica, with its overfish marine resources, has become a major tilapia producer in Latin America led by a small number of large farms practicing tilapia culture with considerable commercial success. Across the country, however, aquaculture is typically practiced by a large number of small-scale fish farmers who own less than 1.0 ha of land. Production is constrained by lack of credit, finite land space and suitable soil type, but larger existing aquaculturists are expanding further for overseas markets. Inspired by pioneering tilapia fish culture demonstration projects funded by the USAID and the goverment of Jamaica, fish culture production rose from a few hundred kg of Oreochromis niloticus in 1977, to about 5000 t of processed fish mainly red hybrid tilapia, in 2000. Most of this quantity was exported to Europe and North America.Aquaculture development, Aquaculture enterprises, Fish culture, Jamaica, Oreochromis niloticus, Oreochromis mossambicus, Colossoma macropomus, Macrobrachium rosenbergii

    An extension and application of the Leontief pollution model for waste generation and disposal in Scotland

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    Solid waste generation, treatment and disposal are important policy concerns for the Scottish Parliament. As a result of the Environment Act 1995, a National Waste Strategy for Scotland was introduced with the general aim of reducing the amount of waste produced and dealing with what is produced in more sustainable ways. This implies the need for an empirical framework to inform policymakers regarding the relationship between economic activity and waste generation, treatment and disposal and the likely impacts of any policy actions or other disturbances on all types of sustainability indicators. In this paper we report on a study to develop an extended input-output (IO) system of the type originally proposed in the seminal paper by Leontief (1970). This involves extending the standard IOaccounts to take account of pollution or waste generation as an additional output accompanying production and consumption activities in the economy and of the activity required to clean up (or prevent) these unwanted outputs. The extension of IO tables to take account of pollution/waste generation is relatively widespread in the literature. It is usually achieved through the introduction of physical pollution/waste-output coefficients, and has been previously applied to Scotland for the case ofair pollution (see McNicoll & Blackmore, 1993, McGregor et al, 2001). Such an approach allows us to examine the impact of the economy on the environment, in terms of the amount of pollution/waste emitted as a result of economic activity. However, it does not allow us to track the feedback from the environment to the economy in terms of the resources used in environmental cleaning. If we areinterested in this aspect, we need to identify the input structure of any pollution abatement or waste disposal activities and identify columns in the IO tables representing cleaning activities

    South American Coccinellidae (Coleoptera) : part 7, new name for Cyra Mulsant, review of Brachiacanthini genera, and systematic revision of Cleothera Mulsant, Hinda Mulsant and Serratitibia Gordon and Canepari, new genus

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    Genera of Brachiacanthini (Coleoptera: Coccinellidae: Hyperaspidinae) are discussed and a key to all recognized genera provided. Cyrea, new genus, is proposed, and Serratitibia, new genus, is erected and revised, Cleothera Mulsant and Hinda Mulsant are recognized as valid genera and revised. Helesius caseyi Sicard is transferred to Hinda and recognized as a synonym of Hinda designata Mulsant, new synonymy. Brachiacantha brethesi (Korschefsky), Cleothera abendrothi Kirsch, Cleothera ambigua Mulsant, Cleothera bisquatuorpustulata Mulsant, Cleothera decemsignata Mulsant, Cleothera gaillardi Mulsant, Cleothera humerata Mulsant, Cleothera tortuosa Mulsant, Cleothera traili Brèthes, Cleothera uncinata Mulsant, Hinda joeli Almeida and Milléo, Hinda modesta Weise, Hinda regularis Kirsch, Hyperaspis aliciae Crotch, and Hyperaspis fraudulenta Kirsch are transferred to Serratitibia, becoming new combinations. One new species of Hinda, H. ecuadorica, is described. A total of 73 new species of Serratitibia are described: Serratitibia amanda, S. andrea, S. angela, S. anna, S. ashley, S. barbara, S. barclayi, S. betty, S. beverly, S. bonnie, S. brenda, S. cheryl, S. christine, S. cynthia, S. debra, S. denise, S. donna, S. doris, S. elizabeth, S. evelyn, S. frances, S. gloria, S. heather, S. helen, S. irene, S. jacqueline, S. janet, S. janice, S. jean, S. jennifer, S. joan, S. joyce, S. judith, S. judy, S. julie, S. karen, S. katherine, S. kathleen, S. kathy, S. kelly, S. kimberly, S. laura, S. linda, S. lisa, S. loreto, S. lori, S. louise, S. margaret, S. marilyn, S. mary, S. martha, S. melissa, S. michelle, S. mildred, S. nancy, S. nicole, S. pamela, S. paprzycki, S. patricia, S. quincemil, S. rachel, S. rebecca, S. rose, S. ruby, S. ruth, S. sarah, S. satipoensis, S. shirley, S. stephanie, S. susan, S. tammy, S. teresa, and S. virginia. Lectotypes are here designated for Serratitibia lividipes, S. gaillardi, S. decemsignata, S. abendrothi, and S. ambigua

    South American Coccinellidae (Coleoptera) : part 15, systematic revision of Dilatitibialis Duverger (Coccidulinae; Hyperaspidini)

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    Dilatitibialis Duverger (61 species) (Coleoptera: Coccinelidae: Coccidulinae; Hyperaspidini) is discussed, species described, illustrations provided, and a key to all recognized taxa included. Cleothera cognata Mulsant, Cleothera cruciferae Mulsant, Cleothera fuscomaculata Mulsant, Cleothera gaynoni Mulsant, Cleothera glyphica Mulsant, Cleothera jucunda Mulsant, Cleothera luteola Mulsant, Cleothera mulsanti Kirsch, Cleothera oseryi Mulsant, Cleothera poortmanni Mulsant, Cleothera scenica Mulsant, Cleothera semicincta Weise, Cleothera tropicalis Mulsant, Hinda guttipennis Weise, Hyperaspis carolinae Crotch, Hyperaspis ceciliae Crotch, Hyperaspis dilatata Crotch, Hyperaspis florifera Vogel, Hyperaspis gravabilis Brèthes, Hyperaspis hybridula Crotch, Hyperaspis laterinotata Brèthes, Hyperaspis silvani Crotch, and Hyperaspis suzannae Crotch are transferred to Dilatitibialis, becoming new combinations. Lectotypes are designated for D. boliviana, D. cognata, D. florifera, D. fuscomaculata, D. gaynoni, D. glyphica, D. gravabilis, D. guttipennis, D. luteola, D. jucunda, D. mulsanti. D. poortmanni, D. retigera, D. scenica, D. semicincta, and D. staudingeri. A total of 38 new species of Dilatitibialis are described: Dilatitibialis annie, D. carmen, D. cindy, D. connie, D. crystal, D. dawn, D. diana, D. edith, D. edna, D. elaine, D. ellen, D. emily, D. ethel, D. fallax, D. florence, D. gladys, D. grace, D. josephine, D. kim, D. lillian, D. lois, D. marjorie, D. norma, D. paula, D. peggy, D. phyllis, D. rita, D. robin, D. rosa, D. shannon, D. sheila, D. sherry, D. sylvia, D. thelma, D. tiffany, D. tina, D. tracy, and D. wendy. Corrections are made to titles of previous Parts of this series, as follows: South American Coccinellidae, Part XII (Gordon 2007) is changed to Part XIII; South American Coccinellidae, Part XII (Gordon et al. 2013) is changed to Part XIV

    Do unbalanced data have a negative effect on LDA?

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    For two-class discrimination, Xie and Qiu [The effect of imbalanced data sets on LDA: a theoretical and empirical analysis, Pattern Recognition 40 (2) (2007) 557–562] claimed that, when covariance matrices of the two classes were unequal, a (class) unbalanced data set had a negative effect on the performance of linear discriminant analysis (LDA). Through re-balancing 10 real-world data sets, Xie and Qiu [The effect of imbalanced data sets on LDA: a theoretical and empirical analysis, Pattern Recognition 40 (2) (2007) 557–562] provided empirical evidence to support the claim using AUC (Area Under the receiver operating characteristic Curve) as the performance metric. We suggest that such a claim is vague if not misleading, there is no solid theoretical analysis presented in Xie and Qiu [The effect of imbalanced data sets on LDA: a theoretical and empirical analysis, Pattern Recognition 40 (2) (2007) 557–562], and AUC can lead to a quite different conclusion from that led to by misclassification error rate (ER) on the discrimination performance of LDA for unbalanced data sets. Our empirical and simulation studies suggest that, for LDA, the increase of the median of AUC (and thus the improvement of performance of LDA) from re-balancing is relatively small, while, in contrast, the increase of the median of ER (and thus the decline in performance of LDA) from re-balancing is relatively large. Therefore, from our study, there is no reliable empirical evidence to support the claim that a (class) unbalanced data set has a negative effect on the performance of LDA. In addition, re-balancing affects the performance of LDA for data sets with either equal or unequal covariance matrices, indicating that having unequal covariance matrices is not a key reason for the difference in performance between original and re-balanced data
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