633 research outputs found

    Automated Wind Turbine Pitch Fault Prognosis using ANFIS

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    Many current wind turbine (WT) studies focus on improving their reliability and reducing the cost of energy, particularly when WTs are operated offshore. WT Supervisory Control and Data Acquisition (SCADA) systems contain alarms and signals that provide significant important information. A possible WT fault can be detected through a rigorous analysis of the SCADA data. This paper proposes a new method for analysing WT SCADA data by using Adaptive Neuro-Fuzzy Inference System (ANFIS) with the aim to achieve automated detection of significant pitch faults. Two existing statistical analysis approaches were applied to detect common pitch fault symptoms. Based on the findings, an ANFIS Diagnosis Procedure was proposed and trained. The trained system was then applied in a wind farm containing 26 WTs to show its prognosis ability for pitch faults. The result was compared to a SCADA Alarms approach and the comparison has demonstrated that the ANFIS approach gives prognostic warning of pitch faults ahead of pitch alarms. Finally, a Confusion Matrix analysis was made to show the accuracy of the proposed approach

    Policy options for including LULUCF in the EU reduction commitment and policy instruments for increasing GHG mitigation efforts in the LULUCF and agriculture sectors

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    Land use, land-use change and forestry (LULUCF) is an inventory sector defined by the Intergovern-mental Panel on Climate Change (IPCC) that covers anthropogenic emissions and removals of GHGs resulting from changes in terrestrial carbon stocks. The EU has committed unilaterally to reduce its overall greenhouse gas (GHG) emissions to 20 % be-low 1990 levels by 2020, and to 30 % below 1990 levels if conditions are right

    Constraints to production and preferred traits for taro (Colocasia esculenta) and new cocoyam (Xanthosoma mafaffa) in Togo, west Africa

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    Taro (Colocasia esculenta L. Schott) and tannia (new cocoyam) (Xanthosoma mafaffa L. Schott) are food crops cultivated in tropical and subtropical regions of Asia, Africa and Latin America. In cultivation, they are always vegetatively propagated and their production faces many constraints. Their corm is an important source of carbohydrates and leaves eaten as vegetable provide important minerals and vitamins. In Togo, although these crops are among the most important food crops in some rural areas, they appear at the country level as neglected and underutilized species (NUS) and should be promoted. However, adequate information related to production, constraints, farmers’ preferred traits and utilisation is lacking for the development of efficient breeding schemes and their sustainable preservation and use in Togo. In this paper, a focus group survey was conducted in all five ecological zones of the country to document farmers’ perceptions regarding constraints for production of these two crops and their preferred traits for production and utilization. Collected data were analysed through descriptive statistics (frequencies, percentages and means) using the Statistical Package for Social Scientists (SPSS 20) and Excel spreadsheets. Rainfall irregularity (or shortage of rainy seasons) (68.4% of responses), soil infertility (61.5% of responses) and inefficient marketing (58.7% of responses) were the most common production constraints reported. Farmers preferred early-maturity (73% of responses) and high-yield (65% of responses) as crop traits. Men are more involved in production of these crops in Togo (79% of respondents). However, the constraints and preferences reported were not gender dependent. This study showed that production of taro and tania faces many challenges in Togo. Morphological and molecular characterization of grown varieties is highly recommended to help select suitable varieties for breeding programmes. Improvements in food processing and accessibility of credit should be prioritized to generate more income for farmers and encourage production in Togo.Keywords: Agriculture, Colocasia esculenta, constraints, farmers, preferences, production, Togo, Xanthosoma mafaff

    TGF beta 1 and biglycan, decorin, and fibromodulin metabolism in canine cartilage

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    AbstractObjective: Small proteoglycans (PGs) may accumulate in late stage osteoarthritis even as aggrecan is lost. It is not clear what role transforming growth factor (TGF) beta has in this accumulation. Our goal was to investigate the ability of TGF beta 1 to modulate the synthesis and accumulation of decorin, biglycan, and fibromodulin in cartilage explants cultured under conditions in which aggrecan synthesis remains relatively constant.Design: Articular cartilage was cultured in the presence or absence of 4ng/ml TGF beta 1 for up to 16 days. Material extracted from cartilage was assayed for 35SO4-large and small PGs and for total endogenous decorin, biglycan and fibromodulin.Results: The synthesis of 35SO4-small PGs increased during the 16 days in culture in response to TGF beta 1, but declined in control cultures. The difference in 35SO4-decorin between TGF beta 1 and control samples reached nine-fold after 16 days, while the difference in total endogenous decorin was less than 1.5-fold. 35SO4-decorin, which was present in TGF beta 1-treated cultures had an identical core protein, but a longer glycosaminoglycan chain than that of decorin in control cultures. No significant differences in endogenous biglycan were detected, but accumulation of fibromodulin in TGF beta 1 explants exceeded fibromodulin in controls, on average, by 3.8-fold. Fibromodulin was present in cartilage in both keratan sulfate- and non-sulfated oligosaccharide-substituted forms.Conclusions: The accumulation of each of the three small PGs was affected to a different extent in response to TGF beta 1. Of the three, fibromodulin content was most rapidly augmented in response to TGF beta 1

    Solution structure of the Hop TPR2A domain and investigation of target druggability by NMR, biochemical and in silico approaches

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    Heat shock protein 90 (Hsp90) is a molecular chaperone that plays an important role in tumour biology by promoting the stabilisation and activity of oncogenic ‘client’ proteins. Inhibition of Hsp90 by small-molecule drugs, acting via its ATP hydrolysis site, has shown promise as a molecularly targeted cancer therapy. Owing to the importance of Hop and other tetratricopeptide repeat (TPR)-containing cochaperones in regulating Hsp90 activity, the Hsp90-TPR domain interface is an alternative site for inhibitors, which could result in effects distinct from ATP site binders. The TPR binding site of Hsp90 cochaperones includes a shallow, positively charged groove that poses a significant challenge for druggability. Herein, we report the apo, solution-state structure of Hop TPR2A which enables this target for NMR-based screening approaches. We have designed prototype TPR ligands that mimic key native ‘carboxylate clamp’ interactions between Hsp90 and its TPR cochaperones and show that they block binding between Hop TPR2A and the Hsp90 C-terminal MEEVD peptide. We confirm direct TPR-binding of these ligands by mapping 1H–15N HSQC chemical shift perturbations to our new NMR structure. Our work provides a novel structure, a thorough assessment of druggability and robust screening approaches that may offer a potential route, albeit difficult, to address the chemically challenging nature of the Hop TPR2A target, with relevance to other TPR domain interactors

    Enzymatic activities and functional interdependencies of Bacillus subtilis lipoteichoic acid synthesis enzymes

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    Lipoteichoic acid (LTA) is an important cell wall polymer in Gram-positive bacteria. The enzyme responsible for polyglycerolphosphate LTA synthesis is LtaS, first described in Staphylococcus aureus. Four LtaS orthologues, LtaSBS, YfnI, YqgS and YvgJ, are present in Bacillus subtilis. Using an in vitro enzyme assay, we determined that all four proteins are Mn2+-dependent metal enzymes that use phosphatidylglycerol as a substrate. We show that LtaSBS, YfnI and YqgS can produce polymers, suggesting that these three proteins are bona-fide LTA synthases while YvgJ functions as an LTA primase, as indicated by the accumulation of a GroP-Glc2-DAG glycolipid. Western blot analysis of LTA produced by ltaSBS, yfnI, yqgS and yvgJ single, triple and the quadruple mutant, showed that LTA production was only abolished in the quadruple and the YvgJ-only expressing mutant. B. subtilis strains expressing YfnI in the absence of LtaSBS produced LTA of retarded mobility, presumably caused by an increase in chain length as suggested by a structural analysis of purified LTA. Taken together, the presented results indicate that the mere presence or absence of LTA cannot account for cell division and sporulation defects observed in the absence of individual enzymes and revealed an unexpected enzymatic interdependency of LtaS-type proteins in B. subtilis

    The global diversity of taro: ethnobotany and conservation

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    Taro is a staple crop for several hundred million small farmers and planters throughout the tropical world. Often associated with Asia and Pacific, it is also important in the Americas and Africa. This book explores the diversity of taros and their uses as well as the status of taro genetic resources in all the major geographic regions where it is grown. While new market opportunities and taro's versatility are responsible for its growing popularity in markets, diseases and climate change also pose ever greater threats to its production and distribution. The current outbreak and spread of the devastating taro leaf blight in West Africa clearly highlights this vulnerability. By taking a global approach to the crop, the authors highlight ways to address new outbreaks of pathogens such as taro leaf blight. Diversity in cultivars is also important in coping and adapting to climate change especially when genetic diversity science and farmer knowledge can be brought together

    Schmidt-hammer exposure ages from periglacial patterned ground (sorted circles) in Jotunheimen, Norway, and their interpretative problems

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    © 2016 Swedish Society for Anthropology and Geography Periglacial patterned ground (sorted circles and polygons) along an altitudinal profile at Juvflya in central Jotunheimen, southern Norway, is investigated using Schmidt-hammer exposure-age dating (SHD). The patterned ground surfaces exhibit R-value distributions with platycurtic modes, broad plateaus, narrow tails, and a negative skew. Sample sites located between 1500 and 1925 m a.s.l. indicate a distinct altitudinal gradient of increasing mean R-values towards higher altitudes interpreted as a chronological function. An established regional SHD calibration curve for Jotunheimen yielded mean boulder exposure ages in the range 6910 ± 510 to 8240 ± 495 years ago. These SHD ages are indicative of the timing of patterned ground formation, representing minimum ages for active boulder upfreezing and maximum ages for the stabilization of boulders in the encircling gutters. Despite uncertainties associated with the calibration curve and the age distribution of the boulders, the early-Holocene age of the patterned ground surfaces, the apparent cessation of major activity during the Holocene Thermal Maximum (HTM) and continuing lack of late-Holocene activity clarify existing understanding of the process dynamics and palaeoclimatic significance of large-scale sorted patterned ground as an indicator of a permafrost environment. The interpretation of SHD ages from patterned ground surfaces remains challenging, however, owing to their diachronous nature, the potential for a complex history of formation, and the influence of local, non-climatic factors

    Thin accretion disc with a corona in a central magnetic field

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    We study the steady-state structure of an accretion disc with a corona surrounding a central, rotating, magnetized star. We assume that the magneto-rotational instability is the dominant mechanism of angular momentum transport inside the disc and is responsible for producing magnetic tubes above the disc. In our model, a fraction of the dissipated energy inside the disc is transported to the corona via these magnetic tubes. This energy exchange from the disc to the corona which depends on the disc physical properties is modified because of the magnetic interaction between the stellar magnetic field and the accretion disc. According to our fully analytical solutions for such a system, the existence of a corona not only increases the surface density but reduces the temperature of the accretion disc. Also, the presence of a corona enhances the ratio of gas pressure to the total pressure. Our solutions show that when the strength of the magnetic field of the central neutron star is large or the star is rotating fast enough, profiles of the physical variables of the disc significantly modify due to the existence of a corona.Comment: Accepted for publication in Astrophysics & Space Scienc

    Multifactorial discrimination, discrimination salience, and prevalent experiences of internalized homophobia in middle-aged and older MSM

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    Objectives: We sought to test whether discrimination salience and multifactorial discrimination were associated with prevalent experiences of internalized homophobia among middle-aged and older men who have sex with men (MSM). Methods: We analyzed data from 498 middle-aged and older MSM from the Multicenter AIDS Cohort Study (MACS) who reported any lifetime discrimination experience. We estimated the prevalence ratio of current internalized homophobia using multivariable Poisson regressions, accounting for discrimination salience, multifactorial discrimination, and covariates. We then assessed whether multifactorial discrimination moderated the association between discrimination salience and internalized homophobia. Results: Over half (56.4%) of our sample reported any current experience of internalized homophobia. More than two-thirds reported multifactorial discrimination (68.2%) and more than one-third (36.7%) reported moderate-to-high discrimination salience. Increases in discrimination salience (PR = 1.11; 95% CI: 1.03-1.20) were associated with any current internalized homophobia among middle-aged and older MSM. Multifactorial discrimination was not statistically associated with internalized homophobia and did not moderate the association between discrimination salience and internalized homophobia. Conclusions: Our study underscores internalized homophobia as a persisting concern among MSM in midlife and older adulthood. Our findings suggest that salience, as a characteristic of discrimination experiences, may have a greater impact on internalized homophobia compared with exposure. Future research efforts should assess facets of discrimination salience, such as severity, frequency, and chronicity, to better understand how discrimination shapes psychosocial well-being across the life course. Mental health advocates at policy, organizational, and community levels should aim to reduce intersectional stigma and address individual experiences of internalized homophobia
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