877 research outputs found

    Classification of lung disease in HRCT scans using integral geometry measures and functional data analysis

    Get PDF
    A framework for classification of chronic lung disease from high-resolution CT scans is presented. We use a set of features which measure the local morphology and topology of the 3D voxels within the lung parenchyma and apply functional data classification to the extracted features. We introduce the measures, Minkowski functionals, which derive from integral geometry and show results of classification on lungs containing various stages of chronic lung disease: emphysema, fibrosis and honey-combing. Once trained, the presented method is shown to be efficient and specific at characterising the distribution of disease in HRCT slices

    Water discharge models, seasonal effluent mass loading, and best management practices for crawfish ponds

    Get PDF
    Nearly 35,000 ha are used to grow crawfish in southwest and south-central Louisiana, and many of these ponds discharge into impaired water bodies. In 2002, proposed guidelines were published by the United States Environmental Protection Agency (USEPA) assigning effluent limitations and standards for some aquaculture production systems and exempting others (e.g. crawfish ponds). This research had three objectives relative to crawfish ponds: develop water discharge models; final drawdown effluent quality and seasonal mass loading of solids and nutrients; and identification of Best Management Practices (BMPs) that could reduce effluent discharge and improve effluent quality. Models for south-central and southwest Louisiana with a 15 cm storage capacity showed that excess precipitation overflow (final drawdown not included) can be decreased by 28% for a high precipitation year, 61% for an average precipitation year, and 100% for a low precipitation year. The major sources of effluent from crawfish ponds are (1) overflow during winter – when precipitation exceeds evaporation, evapotranspiration, and infiltration – and (2) discharge during the summer drawdown period. Pond evaporation and evapotranspiration combined are the greatest sources of water loss (68%) during a crawfish production cycle. During final drawdown, solids were high during the first 5% of pond water discharge due to poorly consolidated sediment in and around the drain and high during the last 20% of pond water discharge due to the poorly consolidated pond bottom sediments. During final drawdown: total suspended solids were reduced over a distance of 268 m by 28% at the Aquaculture Research Station (wide, shallow, non-vegetated ditch); total suspended solids increased over a distance of 268 m by 15% at the Rice Research Station (narrow, non-vegetated ditch); and total suspended solids were reduced over a distance of 268 m by 80% at the University of Louisiana at Lafayette Model Sustainable Agricultural Complex (deep vegetated ditch). To reduce solid and nutrient mass loading in crawfish pond discharge, ponds should be slowly drained from the top of the water column and avoid draining the last 20% of the pond volume. If that is not possible, then it is recommended to treat the last 20% of the pond volume by sending the discharge through deep vegetated ditches, settling basins, or constructed wetlands with a residence time of 4 d to 14 d

    The Impacts of Foot and Mouth Disease Outbreaks on the Brazilian Meat Market

    Get PDF
    This study uses unrestricted vector autoregression method and historical decomposition with directed acyclic graphs to quantity the impacts of the foot and mouth disease outbreak on the Brazilian meat market for different levels of the industry (export, wholesale and farm). The imposition of an import ban by Russia on Brazilian meat exports is also analyzed. Results show that beef, pork, and chicken export prices all decreased after the FMD outbreak. More importantly, our findings indicate that all prices ended up recovering after the removal of the import ban by Russia in December 2007. As for the price margins in both beef and pork meat supply chains, the export-to-farm and export-to-wholesale margins were found to be very close to each other. On the other hand, the chicken price margin at the export level relative to the farm and wholesale levels had opposing directions trend movements. Finally, the historical decomposition of analysis of the export beef price revealed that the removal of the Russian ban on Brazilian meat imports had a very drastic positive influence on the beef industry supply chain in general.foot and mouth disease, Brazilian meat market, vector autoregression model, historical decomposition, directed acyclic graphs., Food Consumption/Nutrition/Food Safety, International Relations/Trade, Livestock Production/Industries,

    Expressing Distance in Graphs of Functions in the Cartesian Plane: Obstacles and Interventions

    Get PDF
    Connecting algebraic and graphical representations encompasses a large portion of mathematical activity for students in grades 8-14. In Calculus, the ability to represent distances on graphs using algebraic expressions is foundational for a wide range of results. However, research has shown that students may struggle to make such connections. In this article, we seek to answer the following questions: (1) What are the underlying conceptions critical to expressing distances on graphs of functions algebraically? and (2) What types of tasks may support students in developing this skill? We first offer a conceptual analysis of the connections between algebraic expressions and distances in graphs of functions. Next, we describe a hypothetical learning trajectory of tasks and associated learning goals we developed to support students in expressing distances. We then report the outcome of implementing the tasks with groups of Calculus students. While the results include some success in supporting students to express distances, they also pointed to some persistent obstacles as well as limitations of the tasks. We focus on two such obstacles that emerged: the role of conceptualizing symbols as variables in the algebraic register and the role of conceptualizing distances within the graphical register. We discuss directions for future research and ways to support students in connecting algebraic expressions and graphs

    Impact of Hired Foreign Labor on Milk Production and Herd Size in the United States

    Get PDF
    Foreign labor has become increasingly important component of U.S. agriculture. Disruption in the supply of agricultural labor has been argued to significantly affect agricultural production. This study analyzes the impacts of foreign labor shortages on the dairy industry using national survey data. The results suggest that a 30 percent hired foreign labor shortage will result in 10.1 billion pound decline in total U.S. milk production. This is equivalent to a loss of 458.9 thousand dairy cows. One of the key implications of this study is the need for immigration or labor policies that help maintain consistent labor availability and stability of the dairy farm workforce.Agricultural and Food Policy, Financial Economics, Productivity Analysis,

    Descriptive Mineralogy of Pugh Quarry, Northwestern Ohio: Sphalerite

    Get PDF
    Author Institution: Department of Geology, Miami UniversityThe Devonian rocks at Pugh Quarry have three distinct types of sphalerite (banded massive, spheroidal, and tiny euhedral). Occurrence of the banded massive sphalerite is restricted to the mineral zone, predominantly as blebs in marcasite. The color of banded sphalerite ranged from nearly colorless to various hues of yellow. The replacement of banded sphalerite by marcasite was observed. The spheroidal sphalerite occurred in association with marcasite of euhedral habit. The spherules were small, the largest no greater than 1 mm across. Where present in great profusion, the sphalerite spherules merged together forming botryoidal surfaces. The euhedral sphalerite occurred in the voids of the sponge-like and stromatolitic dolostone below the mineral zone, and in a layer of soft laminated mud associated with the dolostone. The euhedral sphalerite was predominantly red-brown, and no crystals larger than 1 mm in maximum dimension were observed

    Descriptive Mineralogy of Pugh Quarry, Northwestern Ohio: Barite and Celestite

    Get PDF
    Author Institution: Department of Geology, Miami UniversityTwo sulfate minerals, barite and celestite, were identified in the Devonian rocks at Pugh Quarry. The barite occurs commonly as rosette-like clusters with wide variety of colors and crystal habits. Unusual features include paired crystals and hollow crystals. The former consist of two barite crystals growing parallel with each other on the dolostone matrix, and the latter only of a thin wall of barite commonly marked by cross striations. Celestite crystals have two different colors. The grayblue and blue crystals are prismatic to blocky and occur as well-formed individuals, whereas the colorless and white crystals are tabular to bladed and occur as distinct individuals and as compact clusters
    corecore