219 research outputs found

    Assessing the shallow groundwater system as a potential factor in generating storm-water runoff on a North Carolina barrier island

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    The town of Emerald Isle, located in North Carolina's Outer Banks, experiences significant storm-water runoff and flooding problems during the fall and winter months. The topography of the island influences drainage patterns as well as the position of the water table. The goal of this study was to determine if the shallow groundwater system is responsible for storm-water runoff on the island. Two hypotheses were developed to test the relationship between the water table and storm-water runoff. The first hypothesis states: the water table rises above the land surface during periods of high precipitation, which leads to storm-water runoff in the town. The second hypothesis states: low infiltration rates in the swales of the island impede water from recharging the Surficial aquifer. The first hypothesis was tested by monitoring the position of the water table in the Surficial aquifer over a 12-month period using a network of 15 shallow groundwater monitoring wells. Potentiometric surface maps of the aquifer show that the water table does breach the land surface during storm events that produce at least 25 mm of precipitation. The second hypothesis was tested by conducting infiltrometer tests to determine if low infiltration rates were retarding natural recharge to the groundwater system. These tests reveal that the soils located in small portions of the swales have the lowest infiltration rates on the island, making it more likely for storm-water runoff to be generated. A 3D finite-difference groundwater model was then used to determine if pumping water from the aquifer during extreme storm events (e.g., hurricanes) would alleviate an elevated water table. Numerical and analytical modeling results suggest that pumping water from the aquifer may be impractical for the town to employ because it is only a short-term solution to the storm-water problem. Therefore, several structural best management practices (BMP's) are presented as alternative measures to reduce storm-water runoff. These structural BMP's are ideal for the needs of the town, and they include bioretention, level spreader-vegetative filter strips, and infiltration basins/trenches.  M.S

    Status of the Michigan Ultra‐Cold Spin‐Polarized Hydrogen Jet

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    Progress on the Michigan ultra‐cold proton‐spin‐polarized atomic‐hydrogen Jet target is presented. We describe the present status of the Jet and some beam test results. © 2004 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87591/2/639_1.pd

    Polarized Atomic Hydrogen Beam Tests in the Michigan Ultra‐Cold Jet Target

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    Progress on the Michigan ultra‐cold proton‐spin‐polarized atomic hydrogen Jet target is presented. We describe the present status of the Jet and some beam test results. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87681/2/872_1.pd

    COOL-LAMPS III: Discovery of a 25".9 Separation Quasar Lensed by a Merging Galaxy Cluster

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    In the third paper from the COOL-LAMPS Collaboration, we report the discovery of COOL J0542-2125, a gravitationally lensed quasar at z=1.84z=1.84, observed as three images due to an intervening massive galaxy cluster at z=0.61z=0.61. The lensed quasar images were identified in a search for lens systems in recent public optical imaging data and have separations on the sky up to 25".9, wider than any previously known lensed quasar. The galaxy cluster acting as a strong lens appears to be in the process of merging, with two sub-clusters separated by 1\sim 1 Mpc in the plane of the sky, and their central galaxies showing a radial velocity difference of 1000\sim 1000 km/s. Both cluster cores show strongly lensed images of an assortment of background sources, as does the region between them. A preliminary strong lens model implies masses of $M(<250\ \rm{kpc}) = 1.79^{+0.16} _{-0.01} \times 10^{14} M_{\odot}and and M(<250\ \rm{kpc}) = 1.48^{+0.04}_{-0.10} \times 10^{14} M_{\odot}$ for the East and West sub-clusters, respectively. This line of sight is also coincident with a ROSAT ALL-sky Survey source, centered between the two confirmed cluster halos reminiscent of other major cluster-scale mergers.Comment: 13 pages, 6 figures. Submitted to Ap

    Anterior interosseous nerve syndrome: retrospective analysis of 14 patients

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    Introduction: The anterior interosseous nerve (AIN) is a only motor nerve innervating the deep muscles of the forearm. Its compression is rare. We present a retrospective analysis of 14 patients with an AIN syndrome with a variety of clinical manifestations who underwent operative and conservative treatment. Patients and methods: Fourteen patients (six female, eight male, mean age 48 ± 9 years) were included. In six patients, the right limb was affected, and in eight patients the left limb. Conservative treatment was started for every patient. If no signs of recovery appeared within 3 months, operative exploration was performed. Final assessment was performed between 2 and 9 years after the onset of paralysis (mean duration of follow-up 46 ± 11 months). Patients were examined clinically for return of power, range of motion, pinch and grip strengths. Also the disability of the arm, shoulder, and hand (DASH) score was calculated. Results: Seven of our 14 patients had incomplete AIN palsy with isolated total loss of function of flexor pollicis longus (FPL), five of FPL and flexor digitorum profundus (FDP)1 simultaneously, and two of FDP1. Weakness of FDP2 could be seen in four patients. Pronator teres was paralysed in two patients. Pain in the forearm was present in nine patients. Four patients had predisposing factors. Eight patients treated conservatively exhibited spontaneous recovery from their paralysis during 3-12 months after the onset. In six patients, the AIN was explored 12 weeks after the initial symptoms and released from compressing structures. Thirteen patients showed good limb function. In one patient with poor result a tendon transfer was necessary. The DASH score of patients treated conservatively and operatively presented no significant difference. Conclusion: AIN syndrome can have different clinical manifestations. If no signs of spontaneous recovery appear within 12 weeks, operative treatment should be performed

    COOL-LAMPS. IV. A Sample of Bright Strongly Lensed Galaxies at 3 < z < 4

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    We report the discovery of five bright, strong gravitationally lensed galaxies at 3 < z < 4: COOL J0101+2055 (z = 3.459), COOL J0104−0757 (z = 3.480), COOL J0145+1018 (z = 3.310), COOL J0516−2208 (z = 3.549), and COOL J1356+0339 (z = 3.753). These galaxies have magnitudes of rAB, zAB < 21.81 mag and are lensed by galaxy clusters at 0.26 < z < 1. This sample nearly doubles the number of known bright lensed galaxies with extended arcs at 3 < z < 4. We characterize the lensed galaxies using ground-based grz/giy imaging and optical spectroscopy. We report model-based magnitudes and derive stellar masses, dust content, and star formation rates via stellar population synthesis modeling. Building lens models based on ground-based imaging, we estimate source magnifications ranging from ∼29 to ∼180. Combining these analyses, we derive demagnified stellar masses in the range log10(M/M)9.6910.75{\mathrm{log}}_{10}({M}_{* }/{M}_{\odot })\sim 9.69-10.75 and star formation rates in the youngest age bin in the range log10(SFR/(Myr1))0.391.46{\mathrm{log}}_{10}(\mathrm{SFR}/({M}_{\odot }\,{\mathrm{yr}}^{-1}))\sim 0.39-1.46, placing the sample galaxies on the massive end of the star-forming main sequence in this redshift interval. In addition, three of the five galaxies have strong Lyα emissions, offering unique opportunities to study Lyα emitters at high redshift in future work

    Reversal of TGF-β1 stimulation of α-smooth muscle actin and extracellular matrix components by cyclic AMP in Dupuytren's - derived fibroblasts

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    <p>Abstract</p> <p>Background</p> <p>Myofibroblasts, a derived subset of fibroblasts especially important in scar formation and wound contraction, have been found at elevated levels in affected Dupuytren's tissues. Transformation of fibroblasts to myofibroblasts is characterized by expression of alpha- smooth muscle actin (α-SMA) and increased production of extracellular matrix (ECM) components, both events of relevance to connective tissue remodeling. We propose that increasing the activation of the cyclic AMP (cAMP)/protein kinase A signaling pathway will inhibit transforming growth factor-beta1 (TGF-β<sub>1</sub>)-induced ECM synthesis and myofibroblast formation and may provide a means to blunt fibrosis.</p> <p>Methods</p> <p>Fibroblasts derived from areas of Dupuytren's contracture cord (DC), from adjacent and phenotypically normal palmar fascia (PF), and from palmar fascia from patients undergoing carpal tunnel release (CTR; CT) were treated with TGF-β<sub>1 </sub>(2 ng/ml) and/or forskolin (10 μM) (a known stimulator of cAMP). Total RNA and protein extracted was subjected to real time RT-PCR and Western blot analysis.</p> <p>Results</p> <p>The basal mRNA expression levels of fibronectin- extra domain A (FN1-EDA), type I (COL1A2) and type III collagen (COL3A1), and connective tissue growth factor (CTGF) were all significantly increased in DC- and in PF-derived cells compared to CT-derived fibroblasts. The TGF-β<sub>1 </sub>stimulation of α-SMA, CTGF, COL1A2 and COL3A1 was greatly inhibited by concomitant treatment with forskolin, especially in DC-derived cells. In contrast, TGF-β<sub>1 </sub>stimulation of FN1-EDA showed similar levels of reduction with the addition of forskolin in all three cell types.</p> <p>Conclusion</p> <p>In sum, increasing cAMP levels show potential to inhibit the formation of myofibroblasts and accumulation of ECM components. Molecular agents that increase cAMP may therefore prove useful in mitigating DC progression or recurrence.</p

    Collagen based magnetic nanocomposites for oil removal applications

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    A stable magnetic nanocomposite of collagen and superparamagnetic iron oxide nanoparticles (SPIONs) is prepared by a simple process utilizing protein wastes from leather industry. Molecular interaction between helical collagen fibers and spherical SPIONs is proven through calorimetric, microscopic and spectroscopic techniques. This nanocomposite exhibited selective oil absorption and magnetic tracking ability, allowing it to be used in oil removal applications. The environmental sustainability of the oil adsorbed nanobiocomposite is also demonstrated here through its conversion into a bi-functional graphitic nanocarbon material via heat treatment. The approach highlights new avenues for converting bio-wastes into useful nanomaterials in scalable and inexpensive ways

    A supramolecular helix that disregards chirality

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    The functions of complex crystalline systems derived from supramolecular biological and non-biological assemblies typically emerge from homochiral programmed primary structures via first principles involving secondary, tertiary and quaternary structures. In contrast, heterochiral and racemic compounds yield disordered crystals, amorphous solids or liquids. Here, we report the self-assembly of perylene bisimide derivatives in a supramolecular helix that in turn self-organizes in columnar hexagonal crystalline domains regardless of the enantiomeric purity of the perylene bisimide. We show that both homochiral and racemic perylene bisimide compounds, including a mixture of 21 diastereomers that cannot be deracemized at the molecular level, self-organize to form single-handed helical assemblies with identical single-crystal-like order. We propose that this high crystalline order is generated via a cogwheel mechanism that disregards the chirality of the self-assembling building blocks. We anticipate that this mechanism will facilitate access to previously inaccessible complex crystalline systems from racemic and homochiral building blocks
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