3,329 research outputs found

    The Development of the Virtual Notebook, a Wiki-Based Ready Reference Technology

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    Traditionally, library professionals have used a variety of ready reference technologies to assist in providing reference and user services. Technologies such as card files, vertical files, and reference notebooks are frequent components of library service desks. Ready reference technologies serve many purposes, most notably, helping staff to answer frequently asked questions and facilitating the sharing of information between library staff. This paper traces the development of the Virtual Notebook, a wiki-based ready reference technology, at Purdue University. The tool is placed within the historical context of ready reference technologies within the library profession and at Purdue. The authors present preliminary results from the implementation of the Virtual Notebook and discuss the tool’s future. The manuscript is an outgrowth of a presentation at the 2008 Brick and Click Symposium at Northwest Missouri State University

    Properties of PAN Fibers Solution Spun into a Chilled Coagulation Bath at High Solvent Compositions

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    In this work, multifilament, continuous polyacrylonitrile (PAN) fiber tow was solution spun mimicking industrial processing at the small pilot scale (0.5 k tow), while carefully altering the composition of the coagulation bath, in order to determine the effect on the resulting fiber shape, density, orientation, and tensile properties at varying points in the spinning process. Novel here are the abnormally high coagulation bath solvent compositions investigated, which surpass those often reported in the literature. In addition, the coagulation bath was maintained at a slightly chilled temperature, contrary to reported methods to produce round fibers. Further, by altering the composition of the bath in a step-wise fashion during a single spinning run, variations in all other process parameters were minimized. We found that with increasing solvent composition in the coagulation bath, the fibers not only became round in cross section, but also became smaller in diameter, which persisted down the spin line. With this decrease in diameter, all else equal, came an accompanying increase in apparent fiber density via a reduction in microvoid content. In addition, molecular orientation and tensile properties also increased. Therefore, it was found that inadequate understanding of the coagulation bath effects, and spinning at low coagulation bath solvent compositions, can hinder the ability of the fiber to reach optimum properties

    Surficial Geologic Map of the Constantine 7.5-Minute Quadrangle, Kentucky

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    The Constantine 7.5-minute quadrangle is located west of Elizabethtown along the boundary of Hardin and Breckinridge Counties. The quadrangle lies along the northern section of the Dripping Springs Escarpment, which separates the Mammoth Cave Plateau and Pennyroyal regions of the Mississippian Sinkhole Plain physiographic province (McFarlan, 1943). Topography is mostly characterized by high-elevation plateaus, ridges, and knobs of the Mammoth Cave Plateau (up to 919 ft), which have been intensely dissected by the Rough River and its tributaries (down to 516 ft). A small area of the Pennyroyal extends into the eastern part of the quadrangle, which is marked by a relatively low-relief, low-elevation sinkhole plain. Sable (1964) mapped the bedrock geology of the quadrangle, which was later digitized by Conley (2002). Bedrock throughout the quadrangle is mapped as Upper Mississippian. A series of northeast-trending faults through the southeastern half of the quadrangle (splays from the Rough Creek Fault System) have created a series of horst and graben structures that control bedrock exposure and stream incision. The oldest bedrock lithologic unit mapped is the Ste. Genevieve Limestone, which is overlain by the Paoli Limestone; both are exposed in the Pennyroyal region in the eastern part of the quadrangle and northwest of the fault system. The Mooretown Formation and Beaver Bend Limestone are mostly exposed along steep slopes above the Paoli Limestone; a large area of Mooretown Formation is locally exposed in a broad plain situated northwest of the fault system in the center of the quadrangle. The Sample Sandstone overlies the Beaver Bend Limestone and covers the largest portion of plateaus and ridgetops in the area, mostly northwest of the fault system. The Reelsville Limestone and Golconda Formation overlie the Sample Sandstone and are exposed in isolated knobs and ridges northwest of the fault system, and extensively in the southeastern section of the quadrangle, where they are overlain by the Hardinsburg Sandstone, the youngest unit mapped in the Constantine quadrangle.https://uknowledge.uky.edu/kgs_cr/1002/thumbnail.jp

    Intrinsic high aerobic capacity protects against lipid induced hepatic insulin resistance [abstract]

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    Hepatic steatosis is commonly linked to hepatic insulin resistance. However, recent studies have found that increased hepatic triacylglycerol (TAG) accumulation is not always associated with impaired hepatic insulin signaling, leading to a hypothesis that partitioning of lipids into TAG in the liver matched with high rates of fatty acid oxidation (FAO) under high lipid exposure conditions may protect against hepatic insulin resistance. We examined this hypothesis in the livers of high and low capacity running (HCR/LCR) rats which were created by artificial selection based on differences in intrinsic aerobic capacity

    Surficial Geologic Map of the Millerstown 7.5-Minute Quadrangle, Kentucky

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    The Millerstown 7.5-minute quadrangle is located south of Louisville and southwest of Elizabethtown along the boundaries between Hardin, Grayson, and Hart Counties and within the Mississippian Plateau physiographic region (McDowell, 1986). Topography is characterized by the low relief Pennyroyal plain that sits at altitudes below about 650 ft above sea level, the low relief Mammoth Cave plateau at altitudes above about 650 ft, and steep slopes of and isolated knobs of the incised Dripping Springs escarpment that separates the two plains. Moore (1965) mapped the bedrock geology of the quadrangle, which was later digitized by Johnson (2006). Mississippian bedrock and local areas of Pennsylvanian bedrock are exposed throughout most of the quadrangle, all, of which, are cut by several vertical faults. The Ste. Genevieve Limestone is the oldest lithology and underlies the Pennyroyal region in the northeast and southwest corners of the quadrangle, and locally along the Nolin River. The Beaver Bend Limestone, Mooretown Formation, Paoli Limestone, Sample Sandstone, and Reelsville Limestone stratigraphic sequence underlie most of the remaining Pennyroyal plain and several steep slopes of the Dripping Springs escarpment. The Beech Creek Limestone, Big Clifty Sandstone, and Haney Limestone Members of the Golconda Formation are exposed along the Dripping Springs escarpment the edges of the Mammoth Cave plateau region. Most of the Mammoth Cave plateau is underlain by the Hardinsburg Limestone, and, locally in the southwest corner of the quadrangle, the Glen Dean Limestone, Leitchfield Formation, and Pennsylvanian Caseyville Formation. Previously mapped surficial deposits include minor areas of alluvium in tributaries across the Millerstown quadrangle (Moore, 1964)

    Surficial Geologic Map of the Summit 7.5-Minute Quadrangle, Kentucky

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    The Summit 7.5-minute quadrangle is located south of Louisville and west of Elizabethtown along the boundary between Hardin and Grayson Counties and within the Mississippian Plateau physiographic region (McDowell, 1986). Topography is characterized by the low relief Pennyroyal region that sits at elevations between 560 to 650 ft above sea level, the low relief Mammoth Cave plateau at elevations between 750 to 900 ft, and the steep Dripping Springs escarpment that separates the two plains. Moore (1964) mapped the bedrock geology of the quadrangle, which was later digitized by Conley (2002). Mississippian bedrock is exposed throughout the quadrangle and is cut by several vertical faults. The St. Louis Limestone and overlying Ste. Genevieve Limestone underlie the Pennyroyal region and are the oldest bedrock units in the quadrangle. The Beaver Bend and Paoli Limestones, Sample Sandstone, Reelsville Limestone, and Beech Creek Limestone Member of the Golconda Formation are exposed along the Dripping Springs escarpment. The Mammoth Cave plateau region is underlain by the Big Clifty Sandstone and, locally, Haney Limestone Members of the Golconda Formation east of the Summit Fault, and Hardinsburg Sandstone west of the fault. Previously mapped surficial deposits include minor areas of alluvium in tributaries across the Summit quadrangle, and areas of “slumped sandstone” (colluvium) in the Pennyroyal region (Moore, 1964)

    An Adaptive Optics Survey of Stellar Variability at the Galactic Center

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    We present a 11.5\approx 11.5 year adaptive optics (AO) study of stellar variability and search for eclipsing binaries in the central 0.4\sim 0.4 pc (10\sim 10'') of the Milky Way nuclear star cluster. We measure the photometry of 563 stars using the Keck II NIRC2 imager (KK'-band, λ0=2.124 μm\lambda_0 = 2.124 \text{ } \mu \text{m}). We achieve a photometric uncertainty floor of ΔmK0.03\Delta m_{K'} \sim 0.03 (3%\approx 3\%), comparable to the highest precision achieved in other AO studies. Approximately half of our sample (50±2%50 \pm 2 \%) shows variability. 52±5%52 \pm 5\% of known early-type young stars and 43±4%43 \pm 4 \% of known late-type giants are variable. These variability fractions are higher than those of other young, massive star populations or late-type giants in globular clusters, and can be largely explained by two factors. First, our experiment time baseline is sensitive to long-term intrinsic stellar variability. Second, the proper motion of stars behind spatial inhomogeneities in the foreground extinction screen can lead to variability. We recover the two known Galactic center eclipsing binary systems: IRS 16SW and S4-258 (E60). We constrain the Galactic center eclipsing binary fraction of known early-type stars to be at least 2.4±1.7%2.4 \pm 1.7\%. We find no evidence of an eclipsing binary among the young S-stars nor among the young stellar disk members. These results are consistent with the local OB eclipsing binary fraction. We identify a new periodic variable, S2-36, with a 39.43 day period. Further observations are necessary to determine the nature of this source.Comment: 69 pages, 28 figures, 12 tables. Accepted for publication in The Astrophysical Journa

    Increased aerobic capacity reduces susceptibility to acute high‐fat diet‐induced weight gain

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134165/1/oby21564.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134165/2/oby21564_am.pd

    Local and distributed PiB accumulation associated with development of preclinical Alzheimer\u27s disease

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    Amyloid-beta plaques are a hallmark of Alzheimer\u27s disease (AD) that can be assessed by amyloid imaging (e.g., Pittsburgh B compound [PiB]) and summarized as a scalar value. Summary values may have clinical utility but are an average over many regions of interest, potentially obscuring important topography. This study investigates the longitudinal evolution of amyloid topographies in cognitively normal older adults who had normal (N = 131) or abnormal (N = 26) PiB scans at baseline. At 3 years follow-up, 16 participants with a previously normal PiB scan had conversion to PiB scans consistent with preclinical AD. We investigated the multivariate relationship (canonical correlation) between baseline and follow-up PiB topographies. Furthermore, we used penalized regression to investigate the added information derived from PiB topography compared to summary measures. PiB accumulation can be local, that is, a topography predicting the same topography in the future, and/or distributed, that is, one topography predicting another. Both local and distributed PiB accumulation was associated with conversion of PiB status. Additionally, elements of the multivariate topography, and not the commonly used summary scalar, correlated with future PiB changes. Consideration of the entire multivariate PiB topography provides additional information regarding the development of amyloid-beta pathology in very early preclinical AD
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