51 research outputs found

    Anchoring of Little Quinnesec Falls Hydroelectric Dam

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    The Little Quinnesec Falls Hydroelectric Dam is located on Menominee River in Niagara, Wisconsin. It is owned and operated by Consolidated Papers, Inc. (Niagara Division). The dam generates about 10,200 kW of hydroelectric power. Under FERC re-licensing program extensive field investigations were performed. The field investigations involved coring through the gravity section of the dam and foundation rock, taking video of the boreholes using borehole camera and installing piezometers to monitor uplift pressure under the dam. The boreholes were between 8-m and 16-m in length. The interface between concrete dam and bedrock was found to be at a depth of 5-m to 8-m. The coring was performed up to 1.5 m into the bedrock. The bedrock was found to be Gneiss, light gray, coarse grained and massive. Complete water loss was noted in most of the boreholes through the dam. Dye tests indicated possible link between the boreholes and the upstream pool. The borehole camera also detected fine cracks and presence of timber at the interface between the concrete dam and the rock foundation. Based on these field investigations and subsequent analyses, stabilization measures were recommended. It included installation of vertical post-tensioned anchor system through the dam and the power plant. The work consisted of anchor installation, testing and stressing following successful performance testing of the anchors. Following stressing, secondary and final stage grouting was performed and the block-outs restored. This paper presents step-by-step procedure followed from field investigation to the installation of the anchors to fix the dam

    Behavior of Nailed Steep Slopes in Laboratory Shake Table Tests

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    This paper presents results of laboratory shake table tests performed to study the dynamic behavior of nailed steep slopes. The surface displacements, settlement of the crest and the acceleration responses along with the behavior of the facing wall are examined during the tests. Two 18 cm high 60° and 70° steep soil slopes reinforced with nine hollow aluminum nails placed in three rows are considered. Three strain gauges are glued to each nail to measure the tensile force developed in the nails. Four strain gauges are fixed at the center of the facing wall to measure the development of strains during shaking. The acceleration responses at the base and crest of the model slopes are monitored during the tests. The results clearly demonstrate advantage of a nailed slope over unreinforced slope. The failure surfaces observed in the shaking table tests are shallow and of rotational type. The nails oriented in horizontal direction are found to be more efficient. The nail forces and amplification of motion increase with the increase in slope angle and slope height. The amplitude of acceleration toward the outward slope direction is found to be larger than that toward the inward direction in all laboratory shaking tables tests

    Experimental Investigation Into Natural Base Isolation System for Earthquake Protection

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    This paper presents the results of experimental investigations into the performance of a well-designed layer of sand, and layer of sand mixed with shredded tire (rubber) as low cost base isolators. The building foundation is modeled by a 200 mm by 200 mm and 40 mm thick rigid plexi-glass block. The model footing is placed in the middle of a 1m by 1m tank filled with sand. The selected base isolator is placed between the footing and the sand foundation. The whole setup is mounted on the shake table and subjected to sinusoidal motion with varying amplitude and frequency. Acceleration values at the shake table, inside the isolation material, and on top of the footing are measured. The displacement of the footing is also measured. The sand is found to be effective only at very high amplitude (˃ 0.65g) of motion. Among all the different percentage of shredded tire in sand tested, the performance of a layer of 50% shredded rubber tire and sand placed under the footing is found to be most promising as a low cost effective base isolator

    Golgi localization and dynamics of hyaluronan binding protein 1 (HABP1/p32/C1QBP) during the cell cycle

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    Hyaluronan binding protein 1 (HABP1) is a negatively charged multifunctional mammalian protein with a unique structural fold. Despite the fact that HABP1 possesses mitochondrial localization signal, it has also been localized to other cellular compartments. Using indirect immunofluorescence, we examined the sub-cellular localization of HABP1 and its dynamics during mitosis. We wanted to determine whether it distributes in any distinctive manner after mitotic nuclear envelope disassembly or is dispersed randomly throughout the cell. Our results reveal the golgi localization of HABP1 and demonstrate its complete dispersion throughout the cell during mitosis. This distinctive distribution pattern of HABP1 during mitosis resembles its ligand hyaluronan, suggesting that in concert with each other the two molecules play critical roles in this dynamic process

    The dual inhibitory effect of thiostrepton on FoxM1 and EWS/FLI1 provides a novel therapeutic option for Ewing's sarcoma

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    The poor prognosis of Ewing's sarcoma (EWS), together with its high lethal recurrence rate and the side-effects of current treatments, call for novel targeted therapies with greater curative effectiveness and substantially reduced side-effects. The oncogenic chimeric protein EWS/FLI1 is the key malignancy driver in most EWSs, regulating numerous target genes, many of which influence cell cycle progression. It has often been argued that targeting proteins regulated directly or indirectly by EWS/FLI1 may provide improved therapeutic options for EWS. In this context, our study examined FoxM1, a key cell cycle regulating transcription factor, reported to be expressed in EWS and influenced by EWS/FLI1. Thiostrepton, a naturally occurring small molecule, has been shown to selectively inhibit FoxM1 expression in cancer cells. We demonstrate that in EWS, in addition to inhibiting FoxM1 expression, thiostrepton downregulates the expression of EWS/FLI1, both at the mRNA and protein levels, leading to cell cycle arrest and, ultimately, to apoptotic cell death. We also show that thiostrepton treatment reduces the tumorigenicity of EWS cells, significantly delaying the growth of nude mouse xenograft tumors. Results from this study demonstrate a novel action of thiostrepton as inhibitor of the expression of the EWS/FLI1 oncoprotein in vitro and in vivo, and that it shows greater efficacy against EWS than against other tumor types, as it is active on EWS cells and tumors at concentrations lower than those reported to have effective inhibitory activity on tumor cells derived from other cancers. Owing to the dual action of this small molecule, our findings suggest that thiostrepton may be particularly effective as a novel agent for the treatment of EWS patients

    Evaluation the results of surgical management of traumatic paraplegia in traumatic thoracolumbar fractures

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    Background: Thoracolumbar spine fractures are common injuries that can result in significant disability, deformity and neurological deficit. Aim of this study was to evaluate the results of surgical management of traumatic paraplegia, complete or incomplete as classified by Frankel scoring.Methods: A prospective study was conducted in patients attending outdoor and emergency department of Orthopedics of a tertiary care teaching institute in Kolkata, West Bengal with traumatic paraplegia involving the dorsolumbar spine. The important objectives are the time for recovery of various functions like sensory, motor and bowel and bladder function, comparison between early and late decompression, results of posterolateral fusion and time taken for solid bony fusion after operation. Total 46 cases were selected within a minimum of 6-month post-operative follow-up of which 4 cases lost in follow-up. Data collected from patient records included age, sex, time from injury to hospitalization, initial neurological status as per Frankel Score, MRI findings, surgery performed, postoperative course and neurological status at the time of discharge and latest follow up. Patients lost to follow up were not studied for outcome analysis.Results: When decompression done within 1st week in incomplete paraplegia, 80% of the patients showed return of grade 3 power. In complete paraplegia cases, 11% of the patients had return of power up to grade 3 when decompression done within 1 week, where no cases showed return of grade 3 power when decompression done after 2nd or 3rd week.Conclusions: After recovery from spinal shock, the earlier the surgical compression done, the better the neurological and bowel/bladder function recovery both in complete and incomplete paraplegic cases. Reduction is better and easy and less time consuming in early decompression than in late. Motor recovery can continue for over 6 months after decompression

    Evolutionary dynamics of eukaryotic selenoproteomes: large selenoproteomes may associate with aquatic life and small with terrestrial life

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    In silico and metabolic labeling studies of the selenoproteomes of several eukaryotes revealed distinct selenoprotein patterns as well as an ancient origin of selenoproteins and massive, independent losses in land plants, fungi, nematodes, insects and some protists, suggesting that the environment plays an important role in selenoproteome evolution

    Selenoproteins regulate macrophage invasiveness and extracellular matrix-related gene expression

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    <p>Abstract</p> <p>Background</p> <p>Selenium, a micronutrient whose deficiency in diet causes immune dysfunction and inflammatory disorders, is thought to exert its physiological effects mostly in the form of selenium-containing proteins (selenoproteins). Incorporation of selenium into the amino acid selenocysteine (Sec), and subsequently into selenoproteins is mediated by Sec tRNA<sup>[Ser]Sec</sup>.</p> <p>Results</p> <p>To define macrophage-specific selenoprotein functions, we generated mice with the Sec tRNA<sup>[Ser]Sec </sup>gene specifically deleted in myeloid cells. These mutant mice were devoid of the "selenoproteome" in macrophages, yet exhibited largely normal inflammatory responses. However, selenoprotein deficiency led to aberrant expression of extracellular matrix-related genes, and diminished migration of macrophages in a protein gel matrix.</p> <p>Conclusion</p> <p>Selenium status may affect immune defense and tissue homeostasis through its effect on selenoprotein expression and the trafficking of tissue macrophages.</p

    Selenoproteins regulate macrophage invasiveness and extracellular matrix-related gene expression

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    Background: Selenium, a micronutrient whose deficiency in diet causes immune dysfunction and inflammatory disorders, is thought to exert its physiological effects mostly in the form of selenium-containing proteins (selenoproteins). Incorporation of selenium into the amino acid selenocysteine (Sec), and subsequently into selenoproteins is mediated by Sec tRNA[Ser]Sec. Results: To define macrophage-specific selenoprotein functions, we generated mice with the Sec tRNA[Ser]Sec gene specifically deleted in myeloid cells. These mutant mice were devoid of the selenoproteome in macrophages, yet exhibited largely normal inflammatory responses. However, selenoprotein deficiency led to aberrant expression of extracellular matrix-related genes, and diminished migration of macrophages in a protein gel matrix. Conclusion: Selenium status may affect immune defense and tissue homeostasis through its effect on selenoprotein expression and the trafficking of tissue macrophages
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