291 research outputs found
Thematic mapper design parameter investigation
This study simulated the multispectral data sets to be expected from three different Thematic Mapper configurations, and the ground processing of these data sets by three different resampling techniques. The simulated data sets were then evaluated by processing them for multispectral classification, and the Thematic Mapper configuration, and resampling technique which provided the best classification accuracy were identified
Recommended from our members
Winter 1972
The Mode of Action of Arsenicals in the Soil by Cecil F. Kerr (page 3) The Golf Course Superintendent: A Job Description (5) Factors Affecting Carbohydrate Reserves of Cool Season Turfgrasses by L.J. Zanoni, L. F. Michelson, W.G. COlby, and M. Drake (6) Turf Bulletin\u27s Photo Quiz by Frederick G. Cheney (9) A Close Look at TCDD (10) Environmental News--Environmental Protection Agency Cancels Registration of Herbicide Amitrole (11) Homeowner\u27s Section--Crabgrass in Perspective by R.A. Peters (12) Merion Tees--Maintenance Suggestions (14) Use of Ammonium Sulfate in Fluid Fertilizers by Frank P. Achorn and W.C. Scott, Jr. (15) River Ecology and the Impact on Man (17) To Roll or Not to Roll (18) Editorial--Talkin\u27 Turfie (24
Recommended from our members
1963
Trees for a Beautiful Golf Course by Philip Scott (page 1) The Golf Course\u27s Worst Enemy by Charles Amorim and Hal Haskell (2) Message from the President by James f. Gilligan (2) Turf Management Club News (3) Quotes from 1962 Freshman (4) When I consider How my Night is Spent Leonard Mailloux(5) Protection of a Golf Course by Pay Lucas Jr. (6) Safety - The Superintendents\u27 Responsibility by Gerald Peters (7) Picture - Senior Stockbridge Turf Majors (8) Picture - Freshmen Stockbridge Turf Majors (9) Kansas - In the Transition Zone by Carl Beer (10 Seeds by Don Daigle (11) Picture - Dean F. P. Jeffrey, Dr. W.G. Colby and Director J. R. Beattie (12) Picture - Graduates of Winter School for Turf Managers - 1963 (13) The Effect of Last Year\u27s Weather Upon This Year\u27s Incidence of Turf Insects by John C. Schread (A-1) Labor-Management Relations by Mortimer H. Gavin S.J. (A-4) Massachusetts Labor Laws by Andrew C. SInclair (A-7) Golf Course Budget by John Espey (A-10) Golf Course Budgets by Robert St. Thomas (A-12) Purpose & Method of Budgeting by Leon St. Pierre (A-13) The Committee Chairman, His Duties by Charles Connelly (A-16) Long-range vs. Short-range Planning by George Farber (A-18) The Golf Course Superintendent, His Duties by Sherwood Moore (A-20) The Budget by Leo Kowalski (A-25) Public Relations by Leon St. Pierre (A-26) A Study of WIlt by Harry Meusal (A-28) Specifications for a Method of Putting Green Construction by Alexander Radko (A-33) Management of Kentucky Bluegrass & Grass Mixtures for Turf by F.V. Juska (A-38) What\u27s New in Fertilizers by Geoffrey S. Cornish (A-40) Methylene Ureas by Harvey Stangel (A-42) Plastic Coated Fertilizers by Louis I. Hansen (A-44) The Role of Sewage Sludge by James Latham Jr. (A-49) The Role of Ureaforms in the Turf Fertilizer Industry by Robert T. Miller (A-51) Why Low Phosphorus & Higher Potassium by L. J. Sullivan (A-55) Uptake of Potassium by Evangel Bredakis (A-59) Responsibility of Industry & Community in Land Usage & Plantings by Joseph L. Beasley (A-61) Turf & Other Planting Problems by H. Thurston Handley Jr. (A-65) Weeds & Diseases by Dominic Marini (A-67) General Maintenacne & Equipment by Lewis Hodgkinson (A-68) Fertilizer Problems by William J. Bennett (A-70) Lawn Construction & Insect Problems by herbert C. Fordham (A-71
Adolescent brain maturation and cortical folding: evidence for reductions in gyrification
Evidence from anatomical and functional imaging studies have highlighted major modifications of cortical circuits during adolescence. These include reductions of gray matter (GM), increases in the myelination of cortico-cortical connections and changes in the architecture of large-scale cortical networks. It is currently unclear, however, how the ongoing developmental processes impact upon the folding of the cerebral cortex and how changes in gyrification relate to maturation of GM/WM-volume, thickness and surface area. In the current study, we acquired high-resolution (3 Tesla) magnetic resonance imaging (MRI) data from 79 healthy subjects (34 males and 45 females) between the ages of 12 and 23 years and performed whole brain analysis of cortical folding patterns with the gyrification index (GI). In addition to GI-values, we obtained estimates of cortical thickness, surface area, GM and white matter (WM) volume which permitted correlations with changes in gyrification. Our data show pronounced and widespread reductions in GI-values during adolescence in several cortical regions which include precentral, temporal and frontal areas. Decreases in gyrification overlap only partially with changes in the thickness, volume and surface of GM and were characterized overall by a linear developmental trajectory. Our data suggest that the observed reductions in GI-values represent an additional, important modification of the cerebral cortex during late brain maturation which may be related to cognitive development
Self-assembled amyloid fibrils with controllable conformational heterogeneity
Amyloid fibrils are a hallmark of neurodegenerative diseases and exhibit a conformational diversity that governs their pathological functions. Despite recent findings concerning the pathological role of their conformational diversity, the way in which the heterogeneous conformations of amyloid fibrils can be formed has remained elusive. Here, we show that microwave-assisted chemistry affects the self-assembly process of amyloid fibril formation, which results in their conformational heterogeneity. In particular, microwave-assisted chemistry allows for delicate control of the thermodynamics of the self-assembly process, which enabled us to tune the molecular structure of ??-lactoglobulin amyloid fibrils. The heterogeneous conformations of amyloid fibrils, which can be tuned with microwave-assisted chemistry, are attributed to the microwave-driven thermal energy affecting the electrostatic interaction during the self-assembly process. Our study demonstrates how microwave-assisted chemistry can be used to gain insight into the origin of conformational heterogeneity of amyloid fibrils as well as the design principles showing how the molecular structures of amyloid fibrils can be controlledopen0
Recommended from our members
Spring 1959
Seed testing - A Service for You by Miss Jessie L. Anderson (page 1) Increased Interest in Two-Year Turf Course by Fred P. Jeffrey - Director of Stockbridge (4) From the Editor (4) Message From Winter School President of 1959 (5) Turf club News (6) Number One Graduate (8) Liquid Fertilization by A.B. Longo (9) Public School Grounds by James Woodhouse (12) Comments on the 1959 Winter School (14) Picture - Stockbridge Turf Majors (16) Picture - Honorary Members of Turf Management Club (17) Letter on Chemical Compatibility (18) The Most Outstanding Turf Senior for 1958 (19) What it Means to be a Turf Manager by R. Russell (20) 10 Steps to a Better Lawn by P. Pedrazzi (24) A Scene to Remember (25) I switched from Hots to Cools by J. Spodnik (26) Why Attend Turfgrass Conferences (27) Picture - Winter School for Turf Managers - 1959 (29) Picture - University of Masssachusetts Annual Turfgrass Conference (30) Organic Fertilizers by O.J. Noer (A-1) Inorganic Fertilizers by Charles Winchell (A-1) Urea Formaldehyde by G.F. Stewart (A-2) Phosphorus and Potash Fertilization by Raph Donaldson (A-3) Questions on Fertilization to the Panel (A-4) Cemetery Maintenance by S.E. Robbins (A-6) Lime by Anson Brewer (A-6) Limited Budgets by R.W. Sharkey (A-7) Fertilization of Park Turf by E.J. Pyle (A-7) Disease and Insect Control by Orlando Capizzi (A-8) Cost of Establishing Turf by Victor Taricano (A-9) Question and Answers (A-10) Control of Pests of Ornamentals and Turf Occuring on Golf Courses by John C. Schread (A-12) Behind the Scenes in Soil Testing and What it Means to You Bertram Gersten and Wm. G. Colby (A-19) Lessons Learned from the 1958 Season as Applied to Golf Course Maintenance by A.M. Radko (A-21) The Outlook in Chemical Weed Control on Fine Turf by John Gallagher (A-24) New Developments in Turfgrass Disease Diagnosis and Control by Frank Howard (A-26
Rapid End-Point Quantitation of Prion Seeding Activity with Sensitivity Comparable to Bioassays
A major problem for the effective diagnosis and management of prion diseases is the lack of rapid high-throughput assays to measure low levels of prions. Such measurements have typically required prolonged bioassays in animals. Highly sensitive, but generally non-quantitative, prion detection methods have been developed based on prions' ability to seed the conversion of normally soluble protease-sensitive forms of prion protein to protease-resistant and/or amyloid fibrillar forms. Here we describe an approach for estimating the relative amount of prions using a new prion seeding assay called real-time quaking induced conversion assay (RT-QuIC). The underlying reaction blends aspects of the previously described quaking-induced conversion (QuIC) and amyloid seeding assay (ASA) methods and involves prion-seeded conversion of the alpha helix-rich form of bacterially expressed recombinant PrPC to a beta sheet-rich amyloid fibrillar form. The RT-QuIC is as sensitive as the animal bioassay, but can be accomplished in 2 days or less. Analogous to end-point dilution animal bioassays, this approach involves testing of serial dilutions of samples and statistically estimating the seeding dose (SD) giving positive responses in 50% of replicate reactions (SD50). Brain tissue from 263K scrapie-affected hamsters gave SD50 values of 1011-1012/g, making the RT-QuIC similar in sensitivity to end-point dilution bioassays. Analysis of bioassay-positive nasal lavages from hamsters affected with transmissible mink encephalopathy gave SD50 values of 103.5–105.7/ml, showing that nasal cavities release substantial prion infectivity that can be rapidly detected. Cerebral spinal fluid from 263K scrapie-affected hamsters contained prion SD50 values of 102.0–102.9/ml. RT-QuIC assay also discriminated deer chronic wasting disease and sheep scrapie brain samples from normal control samples. In principle, end-point dilution quantitation can be applied to many types of prion and amyloid seeding assays. End point dilution RT-QuIC provides a sensitive, rapid, quantitative, and high throughput assay of prion seeding activity
Detection of Prion Protein Particles in Blood Plasma of Scrapie Infected Sheep
Prion diseases are transmissible neurodegenerative diseases affecting humans and animals. The agent of the disease is the prion consisting mainly, if not solely, of a misfolded and aggregated isoform of the host-encoded prion protein (PrP). Transmission of prions can occur naturally but also accidentally, e.g. by blood transfusion, which has raised serious concerns about blood product safety and emphasized the need for a reliable diagnostic test. In this report we present a method based on surface-FIDA (fluorescence intensity distribution analysis), that exploits the high state of molecular aggregation of PrP as an unequivocal diagnostic marker of the disease, and show that it can detect infection in blood. To prepare PrP aggregates from blood plasma we introduced a detergent and lipase treatment to separate PrP from blood lipophilic components. Prion protein aggregates were subsequently precipitated by phosphotungstic acid, immobilized on a glass surface by covalently bound capture antibodies, and finally labeled with fluorescent antibody probes. Individual PrP aggregates were visualized by laser scanning microscopy where signal intensity was proportional to aggregate size. After signal processing to remove the background from low fluorescence particles, fluorescence intensities of all remaining PrP particles were summed. We detected PrP aggregates in plasma samples from six out of ten scrapie-positive sheep with no false positives from uninfected sheep. Applying simultaneous intensity and size discrimination, ten out of ten samples from scrapie sheep could be differentiated from uninfected sheep. The implications for ante mortem diagnosis of prion diseases are discussed
The non-octarepeat copper binding site of the prion protein is a key regulator of prion conversion
The conversion of the prion protein (PrP(C)) into prions plays a key role in transmissible spongiform encephalopathies. Despite the importance for pathogenesis, the mechanism of prion formation has escaped detailed characterization due to the insoluble nature of prions. PrP(C) interacts with copper through octarepeat and non-octarepeat binding sites. Copper coordination to the non-octarepeat region has garnered interest due to the possibility that this interaction may impact prion conversion. We used X-ray absorption spectroscopy to study copper coordination at pH 5.5 and 7.0 in human PrP(C) constructs, either wild-type (WT) or carrying pathological mutations. We show that mutations and pH cause modifications of copper coordination in the non-octarepeat region. In the WT at pH 5.5, copper is anchored to His96 and His111, while at pH 7 it is coordinated by His111. Pathological point mutations alter the copper coordination at acidic conditions where the metal is anchored to His111. By using in vitro approaches, cell-based and computational techniques, we propose a model whereby PrP(C) coordinating copper with one His in the non-octarepeat region converts to prions at acidic condition. Thus, the non-octarepeat region may act as the long-sought-after prion switch, critical for disease onset and propagation
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