2,034 research outputs found

    Description and analysis of 890-MHz noise-measuring equipment

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    Ranger spacecraft noise measuring equipment for subsystem interference with spacecraft receive

    Ten Etudes for Solo Cello by Sofia Gubaidulina

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    Sofia Gubaidulina is regarded as one of the most original and highly respected voices in contemporary music today. Her use of the Fibonacci and its related series to structure her compositions has become a defining feature of her music and, therefore, most analysis has focused on pieces that incorporate this method, which she calls “rhythm of form.” Consequently, works written prior to her adoption of this method have garnered much less analytical attention. However, in her earlier works­––from the late 1960s through the early 80s––Gubaidulina not only explores new sounds and colors, but also found creative ways to structure these pieces. This dissertation will focus on the Ten Etudes for Solo Cello (1974), a seriously neglected piece in the solo cello repertoire. (The published name remains Ten Preludes at the suggestion of the cellist, Vladimir Tonhka.) Each etude explores multiple or single elements of cello technique (such as legato, staccato, ricochet or sul ponticello). I will discuss the various ways Gubaidulina explores and juxtaposes these elements to create structure and continuity in the work. I use a variety of analytical approaches in my analysis and include a number of musical and technical suggestions for the performer. I also include a discussion of the composer’s early life and education and a chapter on the development of her compositional style

    What goes in must come out - the small intestine modulates renal phosphate excretion

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    In a recent article in PNAS, Berndt et al. describe a novel and rapid regulation of renal phosphate excretion by phosphate instilled into the small intestine [1]. In a series of elegant experiments, renal phosphate clearance was measured before and during the infusion of a small amount of phosphate into the distal duodenum of rats. Twenty minutes after the infusion, massive phosphaturia was observed. This effect was specific for phosphate and was not seen when phosphate was instilled into the stomach or when NaCl was applied. Phosphaturia occurred without a measurable increase in serum phosphate an

    3D modeling of indoor environments by a mobile robot with a laser scanner and panoramic camera

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    We present a method to acquire a realistic, visually convincing 3D model of indoor office environments based on a mobile robot that is equipped with a laser range scanner and a panoramic camera. The data of the 2D laser scans are used to solve the SLAM problem and to extract walls. Textures for walls and floor are built from the images of a calibrated panoramic camera. Multi-resolution blending is used to hide seams in the generated textures

    Searching for Ground Truth: a stepping stone in automating genre classification

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    This paper examines genre classification of documents and its role in enabling the effective automated management of digital documents by digital libraries and other repositories. We have previously presented genre classification as a valuable step toward achieving automated extraction of descriptive metadata for digital material. Here, we present results from experiments using human labellers, conducted to assist in genre characterisation and the prediction of obstacles which need to be overcome by an automated system, and to contribute to the process of creating a solid testbed corpus for extending automated genre classification and testing metadata extraction tools across genres. We also describe the performance of two classifiers based on image and stylistic modeling features in labelling the data resulting from the agreement of three human labellers across fifteen genre classes.

    When Geometry is not Enough: Using Reflector Markers in Lidar SLAM

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    Lidar-based SLAM systems perform well in a wide range of circumstances by relying on the geometry of the environment. However, even mature and reliable approaches struggle when the environment contains structureless areas such as long hallways. To allow the use of lidar-based SLAM in such environments, we propose to add reflector markers in specific locations that would otherwise be difficult. We present an algorithm to reliably detect these markers and two approaches to fuse the detected markers with geometry-based scan matching. The performance of the proposed methods is demonstrated on real-world datasets from several industrial environments.Comment: Accepted at IROS 202

    Seagrasses in the Mississippi and Chandeleur Sounds and Problems Associated with Decadal-Scale Change Detection

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    Seagrass mapping data from a multitude of previous projects in the Mississippi and Chandeleur sounds were gathered and combined to provide information on seagrass change from 1940 to 2011. Seagrasses generally occur in three groups: (1) along the Mississippi mainland coastline dominated by Ruppia maritima, (2) on the north side of Mississippi Sound barrier islands dominated by Halodule wrightii, and (3) on the west side of the Chandeleur Islands dominated by Thalassia testudinum co-occurring with other seagrass species. The study area generally lost seagrasses over the 71-yr period, ostensibly due to loss or reduction of protective island barriers and reductions in water quality. An example of how the time series of maps generated in this project can be utilized to further investigate seagrass change was demonstrated with data from Horn Island, including problems associated with calculating change in seagrass area using data from previous investigations. Comparisons of seagrass area among various studies that used different mapping methods (seagrass extent vs. seagrass coverage vs. vegetated seagrass area) can result in overestimation of area change and misleading conclusions

    Functionally Important Residues in the Predicted 3rd Transmembrane Domain of the Type IIa Sodium-phosphate Cotransporter (NaPi-IIa)

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    The type IIa Na+/Pi, cotransporter (NaPi-IIa) mediates electrogenic transport of three Na+ and one divalent Pi ion (and one net positive charge) across the cell membrane. Sequence comparison of electrogenic NaPi-IIa and IIb isoforms with the electroneutral NaPi-IIc isoform pointed to the third transmembrane domain (TMD-3) as a possibly significant determinant of substrate binding. To elucidate the role of TMD-3 in the topology and mechanism underlying NaPi-IIa function we subjected it to cysteine scanning mutagenesis. The constructs were expressed in Xenopus oocytes and Pi transport kinetics were assayed by electrophysiology and radiotracer uptake. Cys substitution resulted in only marginally altered kinetics of Pi transport in those mutants providing sufficient current for analysis. Only one site, at the extracellular end of TMD-3, appeared to be accessible to methanethiosulfonate reagents. However, additional mutations carried out at D224 (replaced by E, G or N) and N227 (replaced by D or Q) resulted in markedly altered voltage and substrate dependencies of the Pi-dependent currents. Replacing Asp-224 (highly conserved in electrogenic a and b isoforms) with Gly (the residue found in the electroneutral c isoform) resulted in a mutant that mediated electroneutral Na+-dependent Pi transport. Since electrogenic NaPi-II transports 3 Na+/transport cycle, whereas electroneutral NaPi-IIc only transports 2, we speculate that this loss of electrogenicity might result from the loss of one of the three Na+ binding sites in NaPi-II
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