Geometric accuracy of LANDSAT-4 MSS image data

Analyses of the LANDSAT-4 MSS image data of North Georgia provided by the EDC in CCT-p formats reveal that errors of approximately + or - 30 m in the raw data can be reduced to about + or - 55 m based on rectification procedures involving the use of 20 to 30 well-distributed GCPs and 2nd or 3rd degree polynomial equations. Higher order polynomials do not appear to improve the rectification accuracy. A subscene area of 256 x 256 pixels was rectified with a 1st degree polynomial to yield an RMSE sub xy value of + or - 40 m, indicating that USGS 1:24,000 scale quadrangle-sized areas of LANDSAT-4 data can be fitted to a map base with relatively few control points and simple equations. The errors in the rectification process are caused by the spatial resolution of the MSS data, by errors in the maps and GCP digitizing process, and by displacements caused by terrain relief. Overall, due to the improved pointing and attitude control of the spacecraft, the geometric quality of the LANDSAT-4 MSS data appears much improved over that of LANDSATS -1, -2 and -3

Understanding Mechanistic Details of Neuroinflammatory Pathways Stimulated by the Alzheimer\u27s Disease Amyloid-Beta Protein

Alzheimer’s disease (AD) is characterized by neuroinflammation. Senile plaques composed of aggregated amyloid-β protein (Aβ) are found in AD patients’ brains. The Aβ is formed by the proteolytic cleavage of the amyloid precursor protein (APP) resulting in Aβ fragments that are 39-42 amino acids in length. The two most common peptides are Aβ(1-40) and Aβ(1-42), which differ by two amino acids, isoleucine and alanine. Within the brain of AD patients, Aβ monomer self-assembles to form several aggregate morphologies, including oligomers, protofibrils, and fibrils. Activated microglial cells and associated secreted proinflammatory cytokines surround these plaques producing a localized inflammatory environment in the brain. Several innate-immune pathways, including Toll-like receptors (TLRs) and the NLRP3 inflammasome, have been implicated in AD inflammation. Aβ plays a primary role in activating these pathways likely contributing to the progressive neurodegeneration in AD. In order to better understand the complexities of this interaction, I investigated the inflammatory response of microglia to Aβ(1-42) and Aβ(1-42)/Aβ(1-40) protofibrils, along with additional biophysical properties. Increased understanding of these pathological events will expand the current model of Aβ neuroinflammatory pathways and help identify new therapeutic targets for AD. My research has demonstrated that the Aβ(1-42) protofibrils triggered a time- and TLR/MyD88-dependent process that produced inflammatory cytokines tumor necrosis factor alpha (TNFα) and interleukin-1β (IL-1β) mRNA and intracellular pro and mature forms of IL-1β protein. Despite previous reports suggesting that NLRP3 activation requires two signals from two distinct molecules, my research indicated that Aβ(1-42) protofibrils alone could efficiently prime (TLR-dependent pro-IL-1β production) and activate (cleavage of pro-IL-1β to mature-IL-1β) the NLRP3 inflammasome. However, the increased intracellular mature-IL-1β did not translate into greater IL-1β secretion. Instead, we found that Aβ was able to elicit a very rapid, unsustainable, yet re-inducible quantized burst of secreted IL-1β, which occurred prior to Aβ priming of the microglia. These findings suggested a basal level of either pro- or mature-IL-1β in the cultured primary microglia yet revealed multiple sites of IL-1β regulation by Aβ(1-42) protofibrils. These sites, which are potential therapeutic targets, include TLR/MyD88-mediated priming, NLRP3 inflammasome activation, and modulation of the IL-1β secretory process

Geospatial Semantics for Topographic Data

U.S. Geological SurveyPlatinum Sponsors Gold Sponsors KU Department of Geography KU Institute for Policy & Social Research KU Libraries GIS and Data Services State of Kansas Data Access and Support Center (DASC) Silver Sponsors Bartlett & West KansasView Kansas Biological Survey U.S. Geological Survey (USGS) Bronze Sponsors AECOM Black & Veatch City of Lawrence - Utilities Department ESRI Global Information Systems KU Center for Global & International Studies KU Center for Remote Sensing of Ice Sheets (CReSIS) KU Environmental Studies Program Lucity, Inc. Wilson & Company, Engineers and Architect

Semantically Enabling Map Projections Knowledge

Kartografske projekcije područje su kartografije s čvrstim matematičkim temeljima za njihovu izradu i prikazivanje, što čini osnovu za prikazivanje znanja. Upotrebom varijacija jednog skupa podataka moguće je stvoriti besko­načno mnogo kartografskih projekcija, no manje od 100 ih se aktivno upotrebljava. S obzirom na to da su različita svojstva, poput površine, kuteva, općeg izgleda ili kombinacije svojstava, očuvana u različitim kartografskim projekcijama, razvijene su klasifikacije kartografskih projekcija koje se primjenjuju pri odabiru odgovarajuće kartografske projekcije za određenu svrhu. Te klasifikacije pomažu korisnicima odrediti točnu orijentaciju, standardne paralele i meridijane. One također pomažu korisnicima prilagoditi odabir ovisno o veličini, pružanju i geografskoj širini. Semantiku je moguće primijeniti za automatizaciju znanja o kartografskim projekcijama u bazu znanja koju mogu upotrebljavati ljudi i strojevi. U ovom se radu opisuje semantičko prikazivanje znanja o kartografskim projekcijama i daje jednostavan primjer upotrebe koji se temelji na bazi znanja.Map projections are an area of cartography with a firm mathematical foundation for their creation and display providing a basis for a knowledge representation. Using only variations on a single equation set, an infinite number of projections can be created, but less than 100 are in active use. Because each projection preserves specific characteristics, such as area, angles, global look, or a compromise of properties, classifications of map projections have been developed to aid in knowledge representation. These classifications are used for decision-making. They help select the correct projection for the map use. They assist users with determining the correct orientation, standard parallels and meridians. The classifications also inform the user how to adjust the selection based on size, extent, and latitude. Semantics can be used to automate map projections knowledge into a knowledge base that can be accessed by humans and machines. This work details a semantic representation of map projections knowledge and provides a simple example of a use case that exploits the knowledge base

Acute Ascending Muscle Weakness Secondary to Medication-Induced Hyperkalemia

Secondary hyperkalemic paralysis is an uncommon but potentially life-threatening consequence of drug-induced disease. We report a case of a 53-year-old female with history of chronic kidney disease presenting to the emergency department with a one-day history of upper and lower extremity weakness and paresthesias. Serum potassium concentration on admission was greater than 8 mEq/L, and serum creatinine was elevated above baseline. Electrocardiogram showed first-degree atrioventricular block with peaked T waves. The patient reported compliance with daily lisinopril 10 mg, spironolactone 25 mg, and 40 mEq twice daily of potassium chloride. Symptoms and electrocardiogram returned to baseline within 24 hours of presentation and serum potassium returned to 4.2 mEq/L at approximately 36 hours without the need for dialysis. This case emphasizes the importance of including such a condition in the differential diagnosis of patients with ascending paralysis and the importance of close monitoring of patients placed on potassium-elevating agents

Implications of Web Mercator and Its Use in Online Mapping

ABSTRACT Online interactive maps have become a popular means of communicating with spatial data. In most online mapping systems, Web Mercator has become the dominant projection. While the Mercator projection has a long history of discussion about its inappropriateness for general-purpose mapping, particularly at the global scale, and seems to have been virtually phased out for general-purpose global-scale print maps, it has seen a resurgence in popularity in Web Mercator form. This article theorizes on how Web Mercator came to be widely used for online maps and what this might mean in terms of data display, technical aspects of map generation and distribution, design, and cognition of spatial patterns. The authors emphasize details of where the projection excels and where it does not, as well as some of its advantages and disadvantages for cartographic communication, and conclude with some research directions that may help to develop better solutions to the problem of projections for general-purpose, multi-scale Web mapping. Keywords: online mapping, Web Mercator, map projections, GIScience, cartography RÉSUMÉ Les cartes interactives en ligne sont devenues un moyen populaire de communiquer au moyen de données spatiales. Dans la plupart des systèmes de cartographie en ligne, la projection de Mercator sur le Web est devenue la projection dominante. La projection de Mercator soulève depuis longtemps des discussions sur son caractère inapproprié en cartographie générale, particulièrement à l'échelle de la planète, et elle semble avoir à peu près disparu des cartes imprimées à l'échelle mondiale d'usage général, mais on a constaté un regain de popularité de la projection de Mercator sur le Web. Cet article présente une théorie sur la façon dont la projection de Mercator sur le Web s'est généralisée pour les cartes en ligne et sur ce que cela pourrait signifier pour l'affichage des données, les aspects techniques de la production et de la distribution de cartes, la conception et la cognition des tendances spatiales. Les auteurs mettent en évidence des détails sur les aspects où la projection excelle et sur ceux où elle n'excelle pas, ainsi que certains de ses avantages et inconvénients pour la communication cartographique. Ils concluent par des pistes de recherche qui peuvent aider à trouver une meilleure solution au problème des projections destinées à la cartographie générale à échelles multiples sur le Web

The Applications of GIS in the Analysis of the Impacts of Human Activities on South Texas Watersheds

With water resource planning assuming greater importance in environmental protection efforts, analyzing the health of agricultural watersheds using Geographic Information Systems (GIS) becomes essential for decision-makers in Southern Texas. Within the area, there exist numerous threats from conflicting land uses. These include the conversion of land formerly designated for agricultural purposes to other uses. Despite current efforts, anthropogenic factors are greatly contributing to the degradation of watersheds. Additionally, the activities of waste water facilities located in some of the counties, rising populations, and other socioeconomic variables are negatively impacting the quality of water in the agricultural watersheds. To map the location of these stressors spatially and the extent of their impacts across time, the paper adopts a mix scale method of temporal spatial analysis consisting of simple descriptive statistics. In terms of objectives, this research provides geo-spatial analysis of the effects of human activities on agricultural watersheds in Southern Texas and the factors fuelling the concerns under the purview of watershed management. The results point to growing ecosystem decline across time and a geographic cluster of counties experiencing environmental stress. Accordingly, the emergence of stressors such as rising population, increased use of fertilizer treatments on farm land, discharges of atmospheric pollutants and the large presence of municipal and industrial waste treatment facilities emitting pathogens and pesticides directly into the agricultural watersheds pose a growing threat to the quality of the watershed ecosystem