2,056 research outputs found
Performance Analysis of an Improved Gravity Anchor Bolt Expanded Foundation
No full textWith the continuous utilization of renewable energy, the number of onshore wind turbines is increasing. Small design improvements can save costs and facilitate the maintenance and repair of the wind turbine foundation. In this paper, an existing gravity expansion foundation with an anchor cage is improved. Our improvements further expand the space inside the foundation and reduce the length of the anchor bolt, which could reduce the costs and facilitate construction. To study the performance of the new foundation, a three-dimensional finite element model of the foundation-soil-anchor bolt was established via a finite element simulation. The damage evolution of the foundation was simulated with the concrete damage plasticity model (CDP). The separation ratio, foundation settlement, inclination ratio, reinforcement stress, foundation stress, and foundation damage of the new foundation under ultimate load conditions were analyzed. The influence of parameters h1 and b3 on the performance of the foundation was further studied. The finite element analysis results show that the tensile stress of concrete can be effectively reduced by appropriately increasing the corbel height and ring beam width of the foundation. The results also show that the improved wind turbine foundation force is reasonable and can meet the use of the actual project requirements on the level of finite element analysis
Chromosomal genotoxicity of nitrobenzene and benzonitrile
No full textIn order to investigate the chromosomal genotoxicity of nitrobenzene and benzonitrile, we studied the induction of micronuclei (MN) by these test compounds in V79 cells, as well as effects on the formation and stability of microtubules and on motor protein functions. No cytotoxicity was seen in V79 cell cultures in terms of Neutral red uptake after 18 h treatment with up to 1 mM nitrobenzene or 1 mM benzonitrile. Subsequently, a concentration range up to 100 muM was used in the experiments on induction of MN. Both test compounds exhibit a weak, but definitely positive test result compared to the solvent (DMSO) control. Minimal effect concentrations of nitrobenzene and benzonitrile appeared as low as 0.01 muM, and no-effect-concentrations were between 0.001 and 0.005 muM. Clearly enhanced MN rates were found at 0.1 muM and higher. Both, nitrobenzene and benzonitrile, induced mostly kinetochor (CREST)-positive micronuclei, thus characterising the chromosomal effects as aneugenic. In cell-free assays, a slight effect on tubulin assembly was observed at 1 mM nitrobenzene without addition of DMSO. Higher concentrations (5 mM) led to secondary effects. In presence of 1% DMSO, nitrobenzene exerted no detectable effect on tubulin assembly up to the solubility limit in water of about 15 mM. For benzonitrile in presence of DMSO, a clear dose-response of inhibition of tubulin assembly at 37degreesC was seen above the no-effect-concentration of 2 mM, with an IC50 of 13 mM and protein denaturation starting above a level of about 20 mM. The nature of the effects of nitrobenzene and benzonitrile on the association of tubulin to form microtubules was confirmed by electron microscopy. Treatment by either 5 mM nitrobenzene or 13 mM benzonitrile plus 1% DMSO left the microtubular structure intact whereas 5 mM nitrobenzene, in absence of DMSO, led to irregular cluster formations. The experiments demonstrate that both nitrobenzene and benzonitrile, in millimolar concentration ranges, may lead to interference with tubulin assembly in a cell-free system. The functionality of the tubulin-kinesin motor protein system was assessed using the microtubule gliding assay. Nitrobenzene affected the gliding velocity in a concentration-dependent manner, starting at about 7.5 muM and reaching complete inhibition of motility at 30 muM, whereas benzonitrile up to 200 muM did not affect the kinesin-driven gliding velocity. The micronucleus assay data demonstrate a chromosomal endpoint of genotoxicity of nitrobenzene and benzonitrile. Aneugenic effects of both compounds occur at remarkably low concentrations, with lowest-effect-concentrations being 0.1 muM. This points to the relevance of interactions with the cellular spindle apparatus
Genotoxicity of inorganic mercury salts based on disturbed microtubule function
No full textThis study investigated the hypothesis that the chromosomal genotoxicity of inorganic mercury results from interaction(s) with cytoskeletal proteins. Effects of Hg2+ salts on functional activities of tubulin and kinesin were investigated by determining tubulin assembly and kinesin-driven motility in cell-free systems. Hg2+ inhibits microtubule assembly at concentrations above 1 muM, and inhibition is complete at about 10 muM. In this range, the tubulin assembly is fully ( up to 6 muM) or partially (similar to 6 - 10 muM) reversible. The inhibition of tubulin assembly by mercury is independent of the anion, chloride or nitrate. The no-observed-effect-concentration for inhibition of microtubule assembly in vitro was 1 muM Hg2+, the IC50 5.8 muM. Mercury(II) salts at the IC50 concentrations partly inhibiting tubulin assembly did not cause the formation of aberrant microtubule structures. Effects of mercury salts on the functionality of the microtubule motility apparatus were studied with the motor protein kinesin. By using a gliding assay'' mimicking intracellular movement and transport processes in vitro, HgCl2 affected the gliding velocity of paclitaxel-stabilised microtubules in a clear dose-dependent manner. An apparent effect is detected at a concentration of 0.1 muM and a complete inhibition is reached at 1 muM. Cytotoxicity of mercury chloride was studied in V79 cells using neutral red uptake, showing an influence above 17 muM HgCl2. Between 15 and 20 muM HgCl2 there was a steep increase in cell toxicity. Both mercury chloride and mercury nitrate induced micronuclei concentration-dependently, starting at concentrations above 0.01 muM. CREST analyses on micronuclei formation in V79 cells demonstrated both clastogenic (CREST-negative) and aneugenic effects of Hg2+, with some preponderance of aneugenicity. A morphological effect of high Hg2+ concentrations ( 100 muM HgCl2) on the microtubule cytoskeleton was verified in V79 cells by immuno-fluorescence staining. The overall data are consistent with the concept that the chromosomal genotoxicity could be due to interaction of Hg2+ with the motor protein kinesin mediating cellular transport processes. Interactions of Hg2+ with the tubulin shown by in vitro investigations could also partly influence intracellular microtubule functions leading, together with the effects on the kinesin, to an impaired chromosome distribution as shown by the micronucleus test
An assessment of the impact of possible CAP reform scenarios on Romanian agriculture
No full textUsing a simplified model, with key-variable the prices of two different possible scenarios of CAP reform after 2013 (moderate and radical), this paper present a comparison between the price effects of implementation of each reform scenario at 2015 horizon on Romanian agriculture. This short analysis shows that, under the presented hypotheses, the net welfare effect, due to the price changes, for the selected products, is positive in both reform scenarios, yet greater in the case of the radical reform. Integrated in the large context of Romanian development, it seems that the influence of CAP reform upon agriculture and rural areas will be most likely a gradual one: an interpenetration between the two scenarios is foreseeable, starting with the moderate reform that will dominate the period around 2013, the reform measures acquiring a more radical character afterwards.CAP reform, Romania, welfare effects, Agricultural and Food Policy,
Prevalence and clinical picture of celiac disease in Turner syndrome
No full textPrevalence and clinical picture of celiac disease in Turner syndrome.
Bonamico M1, Pasquino AM, Mariani P, Danesi HM, Culasso F, Mazzanti L, Petri A, Bona G; Italian Society Of Pediatric Gastroenterology Hepatology (SIGEP); Italian Study Group for Turner Syndrom (ISGTS).
Author information 1Department of Pediatrics, University of Rome La Sapienza, 00161 Roma, Italy.
Abstract
A multicenter study of Turner syndrome (TS) patients was carried out to estimate the prevalence of celiac disease (CD) and to detect clinical characteristics and laboratory data of affected patients. Three hundred eighty-nine girls with TS were screened by IgA antigliadin antibodies and/or antiendomysial antibodies. Intestinal biopsy was offered to positive cases. CD was diagnosed in 25 patients. In celiac subjects, anemia, anorexia, and delayed growth (with respect to Italian TS curves) were frequently present; whereas distended abdomen, chronic diarrhea, constipation, and vomiting occurred more rarely. In addition, low serum iron levels, hemoglobinemia, and high values of aminotransferases were observed. Ten patients showed classic CD, 8 showed atypical symptoms, and 7 showed a silent CD. In 11 symptomatic patients, the diagnosis of CD was made at the onset of symptoms, whereas 7 of them showed a median delay of 79 months in diagnosis. Other autoimmune disorders were observed in 40% of the patients. Our study confirms the high prevalence (6.4%) of CD in a large series of TS patients. Moreover, the subclinical picture in 60% of the cases, the diagnostic delay, and the incidence of other autoimmune disorders suggest that routine screening of CD in TS is indicated
Documenting Impacts of Hydro-Meteorological Events Using Earth Observation
No full textThe ambition of H2020 OPERANDUM project is to develop and document Nature Based Solutions (NBS) to mitigate risks associated with hydro-meteorological (HM) hazards. NBS mitigate risks by reducing the vulnerability of a particular system. The aim of this work is to demonstrate the use of multisource remote sensing data in documenting the impact of extreme HM events to advance knowledge on vulnerability and exposure. In particular the focus is to document past impacts due to extreme events selected from a characterization of recent (3 0 years) HM events in 11 Open Air Laboratories (OALs) where co-design, co-development and deployment of NBS are taking place. The impacts were documented by applying a wide spectrum of satellite image data and other, close - range, remote sensing techniques. A better understanding of the consequences due to extreme HM events in a particular area (OALs) is essential to identify elements at risk and expected to provide a reference to evaluate the reduction of vulnerability and mitigation of risks past the completion of NBS.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Optical and Laser Remote SensingGeo-engineerin
The progress and outcomes of black and minority ethnic (BME) nurses through the Nursing and Midwifery Council's "Fitness to Practise" process: Final report
No full textBACKGROUND
This is the first investigation of the relationship between ethnicity and regulation of the nursing profession conducted internationally. The study was commissioned by the Nursing and Midwifery Council which is the regulator of the professions in the UK.
AIMS OF THE STUDY
“To establish whether the progress and outcomes of Black and minority ethnic (BME) nurses in relation to fitness to practice, from the point of referral to the point of case closure, is different from that of White nurses and midwives (N&M); and whether we can from the data account for any differences identified” (Call for research, NMC 2015). The study was designed to investigate whether BME N&M nurses are more likely to be referred and whether they were more likely to progress through the stages of the Fitness to Practise (FtP) process (screening, investigation or adjudication) and whether they were more likely to receive a severe penalty at the end of the process.
DATA
The NMC made available a copy of the register which had socio-demographic information on 681,258 nurses and midwives between April 2012 and December 2014 as well as data on referrals from April 2012 to December 2014 which totalled 5,851. Over that period the total number of cases that went to adjudication was 946.
VARIABLES
The main independent variable is ethnicity which we divided into Black, Asian, White, Other and Unknown. The latter category accounted for 40% of all referrals. The outcomes studied were rates of referral, the imposition of interim orders (where the referred individual is not allowed to work, progression through screening, investigation, adjudication and final outcome, which was dichotomised into “can work” or “cannot work”. The regression models also controlled for: age, gender, source of referral (9 categories), region of qualification (Africa, Asia, Europe, Other, UK), country of referral (4 counties of the UK) and whether or not the individual referred had a representative, such as a Union.
METHODS OF ANALYSIS
Descriptive statistics, cross-tabulation analysis, logistic regression and ordinal logistic regression
FINDINGS
Descriptive statistics showed that BME nurses are more likely to be referred than white nurses and to progress through the FtP process. Having trained in Africa is also a risk factor for referral. Older N&M and males are more likely to be referred. Most referrals come from employers but members of the public are also an important source of referral. Inferential statistics show that relative to Whites, being Asian, Black or of Unknown ethnicity is associated with progressing through FtP process. However, when “source of referral” is entered into the regression model only the “Unknown ethnicity” category remains significantly more likely to progress than White N&M. Males are more likely to progress through the FtP process but age, though positive, is not significant. There were few significant differences among the countries of the UK. The imposition of interim orders did not vary by ethnicity. The presence of a representative seems to reflect the stage of the FtP process rather than being a factor that contributes to the outcome. Finally, at adjudication, being Asian or Black is associated with a less severe penalty than White. Only those of Unknown ethnicity are more likely than Whites to get a severe penalty. These results are not altered by controlling for the source of referral.
STRENGTHS AND WEAKNESSES OF THE STUDY
The strengths include: the fact that this is the first study of its kind, the datasets analysed are large and the statistics are appropriate. Weakness include the fact that in 40% cases the ethnicity of the referred individual is not known. Some of the registered N&M may not be working which means that their risk of being referred to the NMC is low which could be a threat to the comparison of different ethnic groups. The administrative data which we analysed did not provide information about the specialty (e.g. mental health, maternity), job setting (care home, acute hospital) or level of seniority (staff nurse or Director of Nursing of the individuals referred were not amenable to analysis.
RECOMMENDATIONS
The analysis reported here could be enhanced in the future if the information on ethnicity, the setting in which the referred individual is working and their grade is made available. Some jobs may simply carry a higher risk of referral to the NMC and BME nurses may disproportionately occupy those positions. The main finding, which is that the relationship between ethnicity and FtP is mediated by referral by the employer, directs our attention to the need for further research to understand how the working environment leads to an over-representation of BME nurses in the FtP process. Within the NMC, further research needs to be conducted to understand why White nurses are more likely to be given a severe penalty at adjudication even though they are underrepresented in referrals and less likely to progress through the process. With the introduction of the NMC code and revalidation, the collection of data by the NMC and the FtP process will undoubtedly change. At the same time, the NHS has introduced policies to directly affect the working environment of BME nurses and midwives. This means that this study should be repeated to take account of these changes in the wider environment
Thermal characteristics of InGaP/GaAs HBT ballasted with extended ledge
No full textA InGaP/GaAs heterojunction bipolar transistor structure is proposed in which the base epi-layer underneath the extended ledge works as a base ballast resistor. The structure eliminates the critical alignment for a passivation ledge formation as well as additional process steps for external base ballast resistor. Both ballasted and unballasted devices were fabricated and compared. Small signal equivalent circuit gives us the magnitude of the effective ballast resistance. The thermal characteristics, including gain-collapsed I-V and Vb, regression curve are shown and modeled. The temperature dependency of base sheet resistance and its influence on the device performance are also discussed.The author would like to thank Dr. H. Koo and Mr. S. Cho of the
Hanmirotek Corp. for their valuable suggestions and participation in
the fabrication of devices
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