1,852 research outputs found

    Response of Two Dams in the 1987 Whittier Narrows Earthquake

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    The 1987 Whittier Narrows earthquake (ML = 5.9) shook two dams, the Puddingstone and Cogswell dams, which were instrumented as part of the California Strong Motion Instrumentation Program (CSMIP). The resulting recorded accelerograms provided a valuable opportunity to investigate and evaluate the accuracy and reliability of conventional geotechnical procedures for evaluation of dynamic response characteristics of earth and rockfill dams. This paper presents the results of these studies, which provide insight regarding current techniques for dynamic soil property evaluation and the applicability of one- and two-dimensional analytical procedures to evaluation of the dynamic response of these types of dams

    The bloodstream differentiation - division of Trypanosoma brucei studied using mitochondrial markers

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    In the bloodstream of its mammalian host, the African trypanosome Trypanosoma brucei undergoes a life cycle stage differentiation from a long, slender form to a short, stumpy form. This involves three known major events: exit from a proliferative cell cycle, morphological change and mitochondrial biogenesis. Previously, models have been proposed accounting for these events (Matthews & Gull 1994a). Refinement of, and discrimination between, these models has been hindered by a lack of stage-regulated antigens useful as markers at the single-cell level. We have now evaluated a variety of cytological markers and applied them to investigate the coordination of phenotypic differentiation and cell cycle arrest. Our studies have focused on the differential expression of the mitochondrial enzyme dihydrolipoamide dehydrogenase relative to the differentiation-division of bloodstream trypanosomes. The results implicate a temporal order of events: commitment, division, phenotypic differentiation

    miRNAs as Regulators of Antidiabetic Effects of Fucoidans

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    open access articleDiabetes mellitus is a metabolic disease with a high mortality rate worldwide. MicroRNAs (miRNAs), and other small noncoding RNAs, serve as endogenous gene regulators through binding to specific sequences in RNA and modifying gene expression toward up- or down-regulation. miRNAs have become compelling therapeutic targets and play crucial roles in regulating the process of insulin resistance. Fucoidan has shown potential function as an a-amylase inhibitor, which may be beneficial in the management of type 2 diabetes mellitus. In recent years, many studies on fucoidan focused on the decrease in blood glucose levels caused by ingesting low-glucose food or glucose-lowering components. However, the importance of miRNAs as regulators of antidiabetic effects was rarely recognized. Hence, this review emphasizes the antidiabetic mechanisms of fucoidan through regulation of miRNAs. Fucoidan exerts a vital antidiabetic effect by regulation of miRNA expression and thus provides a novel biological target for future research

    The effectiveness of decision aids for pregnancy related decision-making in women with pre-pregnancy morbidity; systematic review and meta-analysis.

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    INTRODUCTION: Women with pre-existing morbidity arising from medical conditions or previous caesarean section are at higher risk of adverse pregnancy outcomes compared to women without such morbidity. Women often face complex pregnancy-related decision-making that may be characterized by conflicting maternal and perinatal priorities. The aim of this systematic review and meta-analysis was to assess randomised controlled trials of decision aids to evaluate whether they are effective at reducing decisional conflict scores and to evaluate what type of decision aids are most effective for women with pre-existing morbidity in pregnancy. METHODS: We searched Medline (via Ovid), Embase (via Ovid), CINAHL (via EBSCO) from the earliest entries until September 2021. We selected randomised controlled trials comparing patient decision aids for women with pre-existing morbidity with usual clinical practice or a control intervention. Study characteristics and Jadad risk of bias was recorded. Meta-analysis by pre-existing morbidity type was performed using Stata 17 and the data was presented with a Forest Plot. Random effects models were used to calculate summary estimates if there was substantial clinical or statistical heterogeneity and post mean DCS scores were described in a sensitivity analysis and presented as a line graph, to improve clinical interpretation of results.. A narrative synthesis of the selected studies evaluated what type of decision aid works and for in what circumstances. RESULTS: Ten randomised controlled trials, which reported data from 4028 women, were included. Patient decision aids were evaluated in women with pre-existing morbidity who were undertaking pregnancy-related decision-making. Patient decision aids reduced decisional conflict scale scores by an additional - 3.7, 95% Confidence Interval - 5.9% to - 1.6%) compared to the control group. Women with pre-existing medical conditions were more conflicted at baseline and had greater reductions in decisional conflict scale score (mean difference vs. control group: - 6.6%; 95% CI - 9.8% to - 3.3%), in contrast to those with previous caesarean section (mean difference - 2.4%; 95% CI - 4.8% to - 0.1%). There was limited evidence on the effect of decision aids on health outcomes. Decision aids reduced unwanted variation in decision-making support across maternity settings. CONCLUSION: Patient decision aids are effective tools to support personalised care planning and informed decision-making in women with pre-existing morbidity. Women with pre-existing medical morbidity were more conflicted at baseline and were more likely to benefit from decision aids. Adoption of aids in this population may lead to improve adherence and health outcomes, warranting further research

    Use of Cyclic Simple Shear Testing in Evaluation of the Deformation Potential of Liquefiable Soils

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    In recent years, a significant research effort has been focused on assessing the performance of structures founded on potentially liquefiable materials. While significant progress has been made on predictive tools for cases in which large deformations are likely, the ability to accurately and reliably predict small to moderate lateral deformations (\u3c1m) has proven more elusive. As a result, there is a universal need for high quality, element-level laboratory test data to calibrate and validate constitutive laws and numerical models for predicting the deformation of soil with limited liquefaction potential. To address this increasingly urgent need, a comprehensive cyclic simple shear testing program on liquefiable sands has been undertaken using the UC Berkeley Bi-directional Simple Shear Device. Many of the tests performed have new and innovative aspects that can provide information and insight into the behavior of soils showing limited deformation potential. Descried in this paper are results from a Kα test series, which replicates sloping ground conditions, and a newly developed and innovative “fabric” test series, which examines the influence of previous loading history on soil fabric and behavior

    Solid Waste Landfill Performance During the 1994 Northridge Earthquake

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    The performance of 22landfills in the Los Angeles area during the January 17, 1994 Northridge earthquake has been investigated. Observations of damage at these landfills indicate that the overall performance of solid waste landfills was encouraging. None of the surveyed landfills showed any signs of major damage. However, one geosynthetic-lined landfill experienced two tears in the geomembrane liner. Most landfills within 30 km of the zone of energy release experienced some form of cracking in the soil cover. Beyond approximately 40 km from the zone of energy release, little to no damage was observed

    Attenuation of Peak Ground Acceleration with Distance of the June 15, 1999, Tehuacán, México, Earthquake

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    A seismic event of moment magnitude 7.0 struck the central region of Mexico on June 15, 1999 at 15:41 hrs (local time) between the states of Puebla and Oaxaca. The epicenter of the earthquake was located approximately 20 km to the south-southeast of the town of Tehuacán, Puebla and 55 km to the northeast of Huajuapan de León, Oaxaca. A reconnaissance team consisting of a group of researchers from the University of California at Berkeley (UCB) and the Autonomous University of Mexico (UNAM) visited the area and gathered some preliminary information on the geotechnical aspects of this earthquake. This paper briefly presents some key geotechnical observations and then focuses on the attenuation of peak ground acceleration with distance. A total of 29 strong-motion recordings over a variety of geologic site conditions were compiled and used to develop the observed attenuation of the peak ground acceleration (PGA) with distance for the main event. The results obtained were compared with estimations of PGA using North American attenuation relationships

    Reproduction in Mytilus edulis L. (Mollusca: Bivalvia) in Carlingford Lough, Northern Ireland

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    The reproductive cycles of several Mytilus populations in Carlingford Lough were investigated between November 1968 and May 1971. The annual cycle varied slightly from population to population though spawning began simultaneously at all stations in the spring months when sea temperature was rising rapidly between 7.5° and 12°C. A secondary phase of gametogenesis during the summer months was confirmed by oocyte counts and the onset of the secondary spawning period occurred from 4-8 weeks after the initial spring emission. Although no significant differences were recorded in oocyte size in the different populations immediately before spawning oocyte densities were greatest at the seaward stations. Similarly, low shore populations had higher oocyte densities than those higher in the littoral zone where feeding time is severely curtailed. Size did not seem to influence gametogenesis nor did the severely polluted conditions prevailing in Belfast Lough. Seasonal changes in glycogen and lipid content of the mantle were studied in relation to the annual reproductive cycle. Primary settlement of early plantigrades on algae occurred principally in summer and winter. Secondary settlement on artificial substrates coincided with the disappearance of early plantigrades from the algae

    Laboratory Experiments on Pumping and Filtration in 'Mytilus edulis L.using Suspensions of Colloidal Graphite

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    Pumping and filtration of colloidal graphite and shell movements of Mytilus edulis from Carlingford Lough, Northern Ireland, were recorded in the laboratory. Pumping and filtration rates fluctuated widely even in undisturbed animals. Long term recordings demonstrated an inverse relationship between pumping rate and filtration efficiency. The effects of light, tidal cycle, particle concentration, temperature and salinity on pumping rate have been examined. Periods of light and dark did not affect pumping rate nor was there evidence for any intrinsic tidal rhythm in feeding. Pumping increased to a maximum at graphite concentrations of 20-25 mg/l. The rate prior to the addition of graphite influenced the response at certain particle concentrations. Filtration was most efficient at 18.5°C and decreased above 22.5°. Pumping steadily increased to a maximum at 22.5°. Filtration of acclimated mussels was maximal at 25-34‰ whilst feeding ceased at the extreme salinities of 15 and 50‰

    Exploration and confirmation of factors associated with uncomplicated pregnancy in nulliparous women: prospective cohort study

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    Objective: To identify factors at 15 and 20 weeks’ gestation associated with a subsequent uncomplicated pregnancy. Design: Prospective international multicentre observational cohort study. Setting: Auckland, New Zealand and Adelaide, Australia (exploration and local replication dataset) and Manchester, Leeds, and London, United Kingdom, and Cork, Republic of Ireland (external confirmation dataset). Participants: 5628 healthy nulliparous women with a singleton pregnancy. Main outcome measure: Uncomplicated pregnancy, defined as a normotensive pregnancy delivered at >37 weeks’ gestation, resulting in a liveborn baby not small for gestational age, and the absence of any other significant pregnancy complications. In a stepwise logistic regression the comparison group was women with a complicated pregnancy. Results: Of the 5628 women, 3452 (61.3%) had an uncomplicated pregnancy. Factors that reduced the likelihood of an uncomplicated pregnancy included increased body mass index (relative risk 0.74, 95% confidence intervals 0.65 to 0.84), misuse of drugs in the first trimester (0.90, 0.84 to 0.97), mean diastolic blood pressure (for each 5 mm Hg increase 0.92, 0.91 to 0.94), and mean systolic blood pressure (for each 5 mm Hg increase 0.95, 0.94 to 0.96). Beneficial factors were prepregnancy fruit intake at least three times daily (1.09, 1.01 to 1.18) and being in paid employment (per eight hours’ increase 1.02, 1.01 to 1.04). Detrimental factors not amenable to alteration were a history of hypertension while using oral contraception, socioeconomic index, family history of any hypertensive complications in pregnancy, vaginal bleeding during pregnancy, and increasing uterine artery resistance index. Smoking in pregnancy was noted to be a detrimental factor in the initial two datasets but did not remain in the final model. Conclusions: This study identified factors associated with normal pregnancy through adoption of a novel hypothesis generating approach, which has shifted the emphasis away from adverse outcomes towards uncomplicated pregnancies. Although confirmation in other cohorts is necessary, this study implies that individually targeted lifestyle interventions (normalising maternal weight, increasing prepregnancy fruit intake, reducing blood pressure, stopping misuse of drugs) may increase the likelihood of normal pregnancy outcomes.Lucy C Chappell, Paul T Seed, Jenny Myers, Rennae S Taylor, Louise C Kenny, Gustaaf A Dekker, James J Walker, Lesley M E McCowan, Robyn A North, Lucilla Posto
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