255 research outputs found

    Acoustic measurement of lubricant-film thickness distribution in ball bearings

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    An oil-film thickness monitoring system capable of providing an early warning of lubrication failure in rolling element bearings has been developed. The system is used to measure the lubricant-film thickness in a conventional deep groove ball bearing (shaft diameter 80 mm, ball diameter 12.7 mm). The measurement system comprises a 50 MHz broadband ultrasonic focused transducer mounted on the static outer raceway of the bearing. Typically the lubricant-films in rolling element bearings are between 0.1-1.0 μm in thickness and so are significantly smaller than the ultrasonic wavelength. A quasistatic spring model is used to calculate oil-film thickness from the measured reflection coefficient data. An accurate triggering system has been developed to enable multiple reflection coefficient measurements to be made as the contact ellipse sweeps over the measurement location. Experiments are described in which the loading conditions and rotational speed are varied. Lubricant-film thickness distributions measured ultrasonically are described and are shown to agree well with the predictions from classical elastohydrodynamic (EHD) lubrication theory, particularly at high radial loads and low rotary speeds. A range of parameters affecting the performance of the measurement are discussed and the limits of operation of the measurement technique defined. © 2006 Acoustical Society of America

    Model selection and prediction of outcomes in recent onset schizophrenia patients who undergo cognitive training.

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    Predicting treatment outcomes in psychiatric populations remains a challenge, but is increasingly important in the pursuit of personalized medicine. Patients with schizophrenia have deficits in cognition, and targeted cognitive training (TCT) of auditory processing and working memory has been shown to improve some of these impairments; but little is known about the baseline patient characteristics predictive of cognitive improvement. Here we use a model selection and regression approach called least absolute shrinkage and selection operator (LASSO) to examine predictors of cognitive improvement in response to TCT for patients with recent onset schizophrenia. Forty-three individuals with recent onset schizophrenia randomized to undergo TCT were assessed at baseline on measures of cognition, symptoms, functioning, illness duration, and demographic variables. We carried out 10-fold cross-validation of LASSO for model selection and regression. We followed up on these results using linear models for statistical inference. No individual variable was found to correlate with improvement in global cognition using a Pearson correlation approach, and a linear model including all variables was also found not to be significant. However, the LASSO model identified baseline global cognition, education, and gender in a model predictive of improvement on global cognition following TCT. These findings offer guidelines for personalized approaches to cognitive training for patients with schizophrenia

    Inclusion of pedagogical universities in international subject rankings: Problems and prospects

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    The present study actualizes the problem of internationalization of Russian pedagogical education, the solution to which will ensure the “recognition of universities” in the global education market and the entry of Russian and Chinese universities into the international educational market. We associate the solution to this problem with the digitalization of education, the internationalization of the national system of higher education, organization of worldclass research, participation in projects, programs and international professional associations. The study used the method of analysis of open sources of data, a survey of experts (working at the Higher School of Economics (HSE), Kazan Federal University (KFU)) and the method of semi-structured interviews. The empirical basis of the study was the analysis of data from the international rankings Quacquarelli Symonds World University Rankings (QS), Academic Ranking of World Universities (ARWU), Times Higher Education World University Rankings (THE) (including the subject ranking “Education”) and the Moscow International Ranking “Three University Missions” (MosIUR). In the experimental activities, the results of the monitoring study of the participation of Russian universities in MosIUR that have the required validity and are an adequate tool for scientific assessment of changes were used. The study identified and confirmed that international rankings use different source bases for similar indicators. In the TNE ranking, the assessment of the citation of scientific works is carried out according to the international scientometric database Web of Science, while the QS ranking uses the citation index of scientific publications of teachers from the scientometric database Scopus. A monitoring study of the effectiveness of the participation of Russian universities in the MosIUR ranking for 2018–2020 shows the high activity of universities. The analysis of strategies and programs for the development of pedagogical universities included in the MosIUR ranking showed the orientation of universities to solve intra-sectoral problems and consider regional specifics. It has been established that, for pedagogical universities, it is becoming significant to reorient from institutional rankings to subject and branch ones, which measure the international reputation of an educational institution in a particular subject branch. The results of a monitoring study in 2017–2021 showed a low probability of achieving indicators of international rankings ARWU, THE, QS (including the subject ranking “Education”) for Russian pedagogical universities. The most promising for pedagogical universities may be the Moscow International Ranking “Three University Missions”, as well as the use of the experience of leading research universities of the TOP 5–100 project, which occupy high ranks in international rankings – HSE (QS subject ranking “Education”) and KFU (THE, subject ranking “Education”)

    Auto-calibration of ultrasonic lubricant-film thickness measurements

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    The measurement of oil film thickness in a lubricated component is essential information for performance monitoring and design. It is well established that such measurements can be made ultrasonically if the lubricant film is modelled as a collection of small springs. The ultrasonic method requires that component faces are separated and a reference reflection recorded in order to obtain a reflection coefficient value from which film thickness is calculated. The novel and practically useful approach put forward in this paper and validated experimentally allows reflection coefficient measurement without the requirement for a reference. This involves simultaneously measuring the amplitude and phase of an ultrasonic pulse reflected from a layer. Provided that the acoustic properties of the substrate are known, the theoretical relationship between the two can be fitted to the data in order to yield reflection coefficient amplitude and phase for an infinitely thick layer. This is equivalent to measuring a reference signal directly, but importantly does not require the materials to be separated. The further valuable aspect of this approach, which is demonstrated experimentally, is its ability to be used as a self-calibrating routine, inherently compensating for temperature effects. This is due to the relationship between the amplitude and phase being unaffected by changes in temperature which cause unwanted changes to the incident pulse. Finally, error analysis is performed showing how the accuracy of the results can be optimized. A finding of particular significance is the strong dependence of the accuracy of the technique on the amplitude of reflection coefficient input data used. This places some limitations on the applicability of the technique. © 2008 IOP Publishing Ltd

    Aub and Ago3 Are Recruited to Nuage through Two Mechanisms to Form a Ping-Pong Complex Assembled by Krimper

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    In Drosophila, two Piwi proteins, Aubergine (Aub) and Argonaute-3 (Ago3), localize to perinuclear “nuage” granules and use guide piRNAs to target and destroy transposable element transcripts. We find that Aub and Ago3 are recruited to nuage by two different mechanisms. Aub requires a piRNA guide for nuage recruitment, indicating that its localization depends on recognition of RNA targets. Ago3 is recruited to nuage independently of a piRNA cargo and relies on interaction with Krimper, a stable component of nuage that is able to aggregate in the absence of other nuage proteins. We show that Krimper interacts directly with Aub and Ago3 to coordinate the assembly of the ping-pong piRNA processing (4P) complex. Symmetrical dimethylated arginines are required for Aub to interact with Krimper, but they are dispensable for Ago3 to bind Krimper. Our study reveals a multi-step process responsible for the assembly and function of nuage complexes in piRNA-guided transposon repression

    Phylogenetic Analysis and Characterization of a Sporadic Isolate of Equine Influenza A H3N8 from an Unvaccinated Horse in 2015

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    Equine influenza, caused by the H3N8 subtype, is a highly contagious respiratory disease affecting equid populations worldwide and has led to serious epidemics and transboundary pandemics. This study describes the phylogenetic characterization and replication kinetics of recently-isolated H3N8 virus from a nasal swab obtained from a sporadic case of natural infection in an unvaccinated horse from Montana, USA. The nasal swab tested positive for equine influenza by Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction (RT-PCR). Further, the whole genome sequencing of the virus confirmed that it was the H3N8 subtype and was designated as A/equine/Montana/9564-1/2015 (H3N8). A BLASTn search revealed that the polymerase basic protein 1 (PB1), polymerase acidic (PA), hemagglutinin (HA), nucleoprotein (NP), and matrix (M) segments of this H3N8 isolate shared the highest percentage identity to A/equine/Tennessee/29A/2014 (H3N8) and the polymerase basic protein 2 (PB2), neuraminidase (NA), and non-structural protein (NS) segments to A/equine/Malaysia/M201/2015 (H3N8). Phylogenetic characterization of individual gene segments, using currently available H3N8 viral genomes, of both equine and canine origin, further established that A/equine/Montana/9564-1/2015 belonged to the Florida Clade 1 viruses. Interestingly, replication kinetics of this H3N8 virus, using airway derived primary cells from multiple species, such as equine, swine, bovine, and human lung epithelial cells, demonstrated appreciable titers, when compared to Madin–Darby canine kidney epithelial cells. These findings indicate the broad host spectrum of this virus isolate and suggest the potential for cross-species transmissibility

    Sustainable development goals and 2030 agenda: Awareness, knowledge and attitudes in nine Italian universities, 2019

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    Sustainable Development Goals (SDGs) and 2030 Agenda represent global development programs. Education can widen the acknowledgement of their relevance and their applications. This survey aims to assess awareness, knowledge and attitudes towards SDGs and sustainability among first-year students in nine Italian Universities. A Likert scale-based online questionnaire of 70 items was compiled by students from March to July 2019. It examined knowledge and expectations referred to sustainable development concepts, indicators and documents/models accounting for sociodemographic variables. Statistical analyses performed were Chi-square test, Fisher\u2019s Exact test, Kendall\u2019s W correlation coefficient, univariate and multivariate analysis. The questionnaire was completed by 1676 students. A low percentage referred a good knowledge of SDGs and 2030 Agenda, most of them had never attended related educational activities previously. Better knowledge of SDGs and 2030 Agenda was observed in case of previous specific educational activities (p < 0.001). The expectation towards university guaranteeing an education on SDGs was high, both for personal wisdom and for usefulness in future professional context. A significant difference (p < 0.001) in such expectations was found, as healthcare students were less interested than colleagues of other areas. The results showed low knowledge but interest towards sustainable development. A scheduled implementation of academic initiatives should be considered

    Novel diagnostic cerebrospinal fluid biomarkers for pathologic subtypes of frontotemporal dementia identified by proteomics

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    Introduction: Reliable cerebrospinal fluid (CSF) biomarkers enabling identification of frontotemporal dementia (FTD) and its pathologic subtypes are lacking. Methods: Unbiased high-resolution mass spectrometry-based proteomics was applied on CSF of FTD patients with TAR DNA-binding protein 43 (TDP-43, FTD-TDP, n = 12) or tau pathology (FTD-tau, n = 8), and individuals with subjective memory complaints (SMC, n = 10). Validation was performed by applying enzyme-linked immunosorbent assay (ELISA) or enzymatic assays, when available, in a larger cohort (FTLD-TDP, n = 21, FTLD-tau, n = 10, SMC, n = 23) and in Alzheimer's disease (n = 20), dementia with Lewy bodies (DLB, n = 20), and vascular dementia (VaD, n = 18). Results: Of 1914 identified CSF proteins, 56 proteins were differentially regulated (fold change >1.2, P <.05) between the different patient groups: either between the two pathologic subtypes (10 proteins), or between at least one of these FTD subtypes and SMC (47 proteins). We confirmed the differential expression of YKL-40 by ELISA in a partly independent cohort. Furthermore, enzyme activity of catalase was decreased in FTD subtypes compared with SMC. Further validation in a larger cohort showed that the level of YKL-40 was twofold increased in both FTD pathologic subtypes compared with SMC and that the levels in FTLD-tau were higher compared to Alzheimer's dementia (AD), DLB, and VaD patients. Clinical validation furthermore showed that the catalase enzyme activity was decreased in the FTD subtypes compared to SMC, AD and DLB. Discussion: We identified promising CSF biomarkers for both FTD differential diagnosis and pathologic subtyping. YKL-40 and catalase enzyme activity should be validated further in similar pathology defined patient cohorts for their use for FTD diagnosis or treatment development
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