6,296 research outputs found
A Tone Signature Analysis of Multispectral Photography
Densitometrie analysis of separation negatives, Ektachrome and Infrared Ektachrorae film was performed to determine the tone signature from the films and to compare the respective tone signatures for reliability and use.
Three types of vegetation, coniferous and deciduous trees and grass, were used as targets for all the photography in this study.
The analysis and comparison of data used in this investigation revealed that density fluctuations within a specific spectrum band of a particular target were too great to yield a reliable and identifiable tone signature.
Analysis of the data revealed that the density differences between adjacent spectral bands remain relatively constant for a given target. The densities were graphed against the wave length and slopes of the lines connecting adjacent densities determined.
Chi-Square contingency tests indicate that Ektachrorae and Infrared Ektachrorae density slopes are significantly dependant and that the separation positive density slopes are highly independant. Therefore, it appears from the data used in this investigation that only the Ektachrorae and Infrared Ektachrorae density slope tone signatures can be used for identification of the targets utilized in the study.
It appears that the density slope method of tone signature determination compensates for error in exposure and developing procedure by eliminating the use of absolute density and relying on density differences between adjacent spectral bands
The Perceived Family and Parental Influence on African American Men Who Enroll in Community Colleges
Higher education institutions have generally been successful in increasing the number of diverse populations who attend college, especially recruiting and enrolling record numbers of Hispanic and Asian students. African American enrollments continue to lag behind these other diverse groups, with African American men being among the lowest of the multicultural groups to be enrolled in higher education today. Community colleges have been perhaps the most successful in recruiting and enrolling African American men, and the current study sought to describe how the families of these men interact and encourage or discourage enrollment. Using a series of semi-structured interviews, families were found to play a perceived important role in the decision to enroll in a community college. These families mentored the African American men in the study, created expectations for them to have successful life beyond high school, and pushed them to have positive ideas about their future and to plan for that future. These findings were consistent with modeling about college going decision-making, and also reinforced the emerging theory of community expectancy
Toward a Network Model of MHC Class II-Restricted Antigen Processing.
The standard model of Major Histocompatibility Complex class II (MHCII)-restricted antigen processing depicts a straightforward, linear pathway: internalized antigens are converted into peptides that load in a chaperone dependent manner onto nascent MHCII in the late endosome, the complexes subsequently trafficking to the cell surface for recognition by CD4(+) T cells (TCD4+). Several variations on this theme, both moderate and radical, have come to light but these alternatives have remained peripheral, the conventional pathway generally presumed to be the primary driver of TCD4+ responses. Here we continue to press for the conceptual repositioning of these alternatives toward the center while proposing that MHCII processing be thought of less in terms of discrete pathways and more in terms of a network whose major and minor conduits are variable depending upon many factors, including the epitope, the nature of the antigen, the source of the antigen, and the identity of the antigen-presenting cell
Presidential Perceptions Concerning Human Capital in College Student Enrollment and Persistence
With a declining population of traditional college aged students, institutions must find both new student groups to recruit and do a better job at retaining them. One obvious pool for institutions to consider are first-generation students who do not have family traditions of going to college. This population, along with others, require institutions to understand the personal development of young adults and the factors that might lead to their college enrollment. The purpose for conducting the study was to identify how college presidents perceive the importance of human capital capacity for college students in their decision to enroll in college. The study made use of a sample of 400 college presidents from different types of institutions, asking them to rate their agreement with different human capital variables and their perception of that variable as being a contributor to college enrollment. President had the highest mean agreement levels with the human capital variables of developing a strong work ethic, developing personal confidence, and developing resilience. They had the lowest mean agreement levels with learning how to take advice, wisdom, and understanding personal and family history and lore. An exploratory factor analysis provided clusters of responses, including larger themes such as self-determination and personal grit
Comparative value of full-fat corn germ, whole cottonseed and tallow as energy sources for lactating dairy cows
We used 24 multiparous Holstein cows in 4 x 4 Latin square design to evaluate full-fat corn germ as a replacement for whole cottonseed and tallow in total mixed diets for lactating dairy cows. Experimental diets on a dry matter basis were: 1) control 3.5% fat; 2) whole cottonseed 5.1% fat; 3) tallow 5.1% fat; 4) full-fat corn germ 5.1% fat. Diets were fed as total mixed rations typical of that fed on commercial dairy operations. Cottonseed meal and cottonseed hulls were included in the control, tallow, and full-fat corn germ diets to balance for fiber and protein fractions equal to those in the whole cottonseed diet. Dry matter intake, milk production, and energy corrected milk did not differ among the diets. Milk from cows fed full-fat corn germ contained less fat than milk from cows fed whole cottonseed but was similar to that of milk from cows fed control or tallow diets. Milk protein percentage was lower for cows fed full-fat corn germ than those fed control, but similar to cows fed whole cottonseed or tallow. Percentage milk lactose did not differ among dietary treatments. Cows fed WCS produced more pounds of milk fat than cows fed full-fat corn germ or tallow, but protein and lactose yield did not differ among the diets. Cows fed whole cottonseed produced milk more efficiently than cows fed control, tallow, or full-fat corn germ. Unexpectedly, efficiency of energy corrected milk production was not improved by tallow and tallow did not depress dry matter intake. Somatic cell count did not differ among experimental diets. Urea nitrogen concentration was lower in milk from cows fed full-fat corn germ and tallow than those fed whole cottonseed. All diets led to gains in body weight. The handling and storage characteristics of full-fat corn germ enhances its desirability as a feedstuff for dairy cattle. Full-fat corn germ supported milk production as well as whole cottonseed but not milk fat percentage or fat yield at the level fed in our diets. Additional studies need to be conducted to determine the most advantageous amount to feed full-fat corn germ and clarify the mechanisms by which it depresses milk fat production.; Dairy Day, 2002, Kansas State University, Manhattan, KS, 2002
A Regional Guidebook for Applying the Hydrogeomorphic Approach to the Functional Assessment
The Hydrogeomorphic (HGM) Approach is a method for developing and applying indices for the site-specific assessment of wetland functions. The HGM Approach was initially designed to be used in the context of the Clean Water Act Section 404 Regulatory Program permit review process to analyze project alternatives, minimize impacts, assess unavoidable impacts, determine mitigation requirements, and monitor the success of compensatory mitigation. However, a variety of other potential uses have been identified, including the design of wetland restoration projects, and management of wetlands.https://scholarworks.sfasu.edu/ebooks/1014/thumbnail.jp
Granitoid plutons of the Brookville terrane, southern New Brunswick: petrology, age, and tectonic setting
Latest Neoproterozoic and Cambrian plutons in the Brookville terrane of southern New Brunswick are termed the Golden Grove Plutonic Suite. Four groups are recognized on the basis of composition: gabbro (2 plutons), diorite - granodiorite (17 plutons), granodiorite - monzogranite (8 plutons), and syenogranite - monzogranite (7 plutons). The dioritic to granodioritic and most of the granodioritic to monzogranitic plutons form linear trends on chemical variation diagrams, suggesting that magma evolution was dominated by plagioclase and amphibole fractionation. These plutons appear to constitute a typical I-type, calc-alkaline suite characteristic of continental margin subduction zones. This interpretation is supported by U-Pb zircon ages, which show that these plutons have ages between 540 Ma and 526 Ma. A new U-Pb age of 539.6 ± 1.2 Ma from one of the gabbroic plutons shows that the gabbroic plutons are co-genetic with the dioritic to granitic plutons, although they show varied ultramafic to anorthositic and dioritic compositions as a result of crystal accumulation. The syenogranitic to monzogranitic plutons and two of the granodioritic and monzogranitic plutons, as well as felsic volcanic rocks of the Dipper Harbour volcanic unit, show chemical trends that differ from the other plutons in having A-type characteristics. A U-Pb age of 548 ± 2 Ma for the Fairville Granite, as well as similar ages for a syenogranitic pluton and the Dipper Harbour volcanic unit, suggests that these units represent early stages of magmatism in the Golden Grove Plutonic Suite.
RESUMÉ
Les plutons du Cambrien et des périodes les plus anciennes du Néoprotérozoïque à l'intérieur du terrane de Brookville dans le Sud du Nouveau-Brunswick sont désignés sous le nom de « cortège plutonique de Golden Grove ». On y distingue quatre groupes en fonction de leur composition : ceux à base de gabbro (deux plutons), de diorite - granodiorite (17 plutons), de granodiorite - monzogranite (huit plutons) et de syénogranite - monzogranite (sept plutons). Les plutons dioritiques à granodioritiques et la majorité des plutons granodioritiques à monzogranitiques forment des tracés linéaires sur les schémas de diversité de la composition chimique, ce qui laisse supposer que l'évolution magmatique a été dominée par une cristallisation fractionnée des plagioclases et des amphiboles. Ces plutons semblent constituer un cortège calco-alcalin intrusif typique, caractéristique des zones de subduction de la marge continentale. Cette interprétation est corroborée par la datation au U-Pb, obtenue à partir de zircon, qui révèle que ces plutons ont des âges entre 540 Ma et 526 Ma. Une nouvelle datation au U-Pb obtenue à partir de zircon situant à 539,6 ± 1,2 Ma l'âge de l'un des plutons gabbroïques, signale que les plutons gabbroïques sont cogénétiques avec les plutons dioritiques à granitiques, même s'ils présentent des compositions ultramafi ques à anorthositiques et dioritiques diversifi ées par suite d'une accumulation de cristaux. Les plutons syénogranitiques à monzogranitiques et deux des plutons granodioritiques et monzogranitiques, de même que les roches volcanofelsiques de l'unité volcanique de Dipper Harbour, livrent des tracés chimiques différents des autres plutons du fait qu'ils possèdent les caractéristiques des plutons de type anorogénique. L'âge au U-Pb de 548 ± 2 Ma du granite de Fairville ainsi que les âges similaires d'un pluton syénogranitique et de l'unité volcanique de Dipper Harbour permettent de supposer que ces unités représentent les stades précoces du magmatisme à l'intérieur du cortège plutonique de Golden Grove
Sidechain control of porosity closure in multiple peptide-based porous materials by cooperative folding
Porous materials find application in separation, storage and catalysis. We report a crystalline porous solid formed by coordination of metal centres with a glycylserine dipeptide. We prove experimentally that the structure evolves from a solvated porous into a non-porous state as result of ordered displacive and conformational changes of the peptide that suppress the void space in response to environmental pressure. This cooperative closure, which recalls the folding of proteins, retains order in three-dimensions and is driven by the hydroxyl groups acting as H-bond donors in the peptide sequence through the serine residue. This ordered closure is also displayed by multipeptide solid solutions in which the combination of different sequences of amino acids controls their guest response in a non-linear way. This functional control can be compared to the effect of single point mutations in proteins, where the exchange of single amino acids can radically alter structure and functio
Content-based image retrieval for brain MRI: An image-searching engine and population-based analysis to utilize past clinical data for future diagnosis
AbstractRadiological diagnosis is based on subjective judgment by radiologists. The reasoning behind this process is difficult to document and share, which is a major obstacle in adopting evidence-based medicine in radiology. We report our attempt to use a comprehensive brain parcellation tool to systematically capture image features and use them to record, search, and evaluate anatomical phenotypes. Anatomical images (T1-weighted MRI) were converted to a standardized index by using a high-dimensional image transformation method followed by atlas-based parcellation of the entire brain. We investigated how the indexed anatomical data captured the anatomical features of healthy controls and a population with Primary Progressive Aphasia (PPA). PPA was chosen because patients have apparent atrophy at different degrees and locations, thus the automated quantitative results can be compared with trained clinicians' qualitative evaluations. We explored and tested the power of individual classifications and of performing a search for images with similar anatomical features in a database using partial least squares-discriminant analysis (PLS-DA) and principal component analysis (PCA). The agreement between the automated z-score and the averaged visual scores for atrophy (r = 0.8) was virtually the same as the inter-evaluator agreement. The PCA plot distribution correlated with the anatomical phenotypes and the PLS-DA resulted in a model with an accuracy of 88% for distinguishing PPA variants. The quantitative indices captured the main anatomical features. The indexing of image data has a potential to be an effective, comprehensive, and easily translatable tool for clinical practice, providing new opportunities to mine clinical databases for medical decision support
Force-plate quantification of progressive behavioral deficits in the R6/2 mouse model of Huntington’s disease
The R6/2 mouse is a popular model of Huntington’s disease (HD) because of its rapid progression and measurable behavioral phenotype. Yet current behavioral phenotyping methods are usually univariate (e.g., latency to fall from a rotarod) and labor intensive. We used a force-plate actometer and specialized computer algorithms to partition the data into topographically specific behavioral categories that were sensitive to HD-like abnormalities. Seven R6/2 male mice and 7 wild type (WT) controls were placed in a 42 cm X 42 cm force-plate actometer for 20-min recording sessions at 6–7, 8–9, 10–11 and 12–13 weeks of age. Distance traveled, number of wall rears, and number of straight runs (traveling 175 mm or more in 1.5 s) were reduced in R6/2 relative to WT mice at all ages tested. Low mobility bouts (each defined as remaining continuously in a virtual circle of 15 mm radius for 5 s) were increased in R6/2 mice at 6–7 wk and beyond. Independent of body weight, force off-load during wall rears was reduced in R6/2 mice except at 6–7 wk. Power spectra of force variation during straight runs indicated an age-related progressive loss of rhythmicity in R6/2 compared to WT, suggesting gait dysrhythmia and dysmetria. Collectively, these data, which extend results obtained with other widely different behavioral phenotyping methods, document a multifaceted syndrome of motor abnormalities in R6/2 mice. We suggest, moreover, that the force-plate actometer offers a high-throughput tool for screening drugs that may affect symptom expression in R6/2 or other HD model mice
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