A novel method of detecting galling and other forms of catastrophic adhesion in tribotests

Tribotests are used to evaluate the performance of lubricants and surface treatments intended for use in industrial applications. They are invaluable tools for lubricant development since many lubricant parameters can be screened in the laboratory with only the best going on to production trials. Friction force or coefficient of friction is often used as an indicator of lubricant performance with sudden increases in friction coefficient indicating failure through catastrophic adhesion. Under some conditions the identification of the point of failure can be a subjective process. This raises the question: Are there better methods for identifying lubricant failure due to catastrophic adhesion that would be beneficial in the evaluation of lubricants? The hypothesis of this research states that a combination of data from various sensors measuring the real-time response of a tribotest provides better detection of adhesive wear than the coefficient of friction alone. In this investigation an industrial tribotester (the Twist Compression Test) was instrumented with a variety of sensors to record: vibrations along two axes, acoustic emissions, electrical resistance, as well as transmitted torsional force and normal force. The signals were collected at 10 kHz for the duration of the tests. In the main study D2 tool steel annular specimens were tested on coldrolled sheet steel at 100 MPa contact pressure in flat sliding at 0.01 m/s. The effects of lubricant viscosity and lubricant chemistry on the adhesive properties of the surface were examined. Tests results were analyzed to establish the apparent point of failure based on the traditional friction criteria. Extended tests of one condition were run to various points up to and after this point and the results analyzed to correlate sensor data with the test specimen surfaces. Sensor data features were used to identify adhesive wear as a continuous process. In particular an increase “friction amplitude” related to a form of stick-slip was used as a key indicator of the occurrence of galling. The findings of this research forms a knowledge base for the development of a decision support system (DSS) to identify lubricant failure based on industrial application requirements.Doctoral These

Optimal and Efficient Searchable Encryption with Single Trapdoor for Multi-Owner Data Sharing in Federated Cloud Computing

Cloud computing, an Internet based computing model, has changed the way of data owners store and manage data. In such environment, data sharing is very important with more efficient data access control. Issuing an aggregate key to users on data enables and authorizes them to search for data of select encrypted files using trapdoor or encrypted keyword. The existing schemes defined for this purpose do have certain limitations. For instance, Cui et al. scheme is elegant but lacks in flexibility in access control in presence of multiple data owners sharing data to users. Its single trapdoor approach needs transformation into individual trapdoors to access data of specific data owner. Moreover, the existing schemes including that of Cui et al. does not support federated cloud.  In this paper we proposed an efficient key aggregate searchable encryption scheme which enables multiple featuressuch as support for truly single aggregate key to access data of many data owners, federated cloud support,query privacy, controlled search process and security against cross-pairing attack. It has algorithms for setup, keygen, encrypt, extract, aggregate, trapdoor, test and federator. In multi-user setting it is designed to serve data owners and users with secure data sharing through key aggregate searchable encryption The proposed scheme supports federated cloud. Experimental results revealed that the proposed scheme is provably secure withrelatively less computational overhead and time complexity when compared with the state of the art

Citron kinase is an essential effector of the Pbl-activated Rho signalling pathway in Drosophila melanogaster.

Copyright © 2004 The Company of Biologists LtdPebble (Pbl)-activated RhoA signalling is essential for cytokinesis in Drosophila melanogaster. Here we report that the Drosophila citron gene encodes an essential effector kinase of Pbl-RhoA signalling in vivo. Drosophila citron is expressed in proliferating tissues but is downregulated in differentiating tissues. We find that Citron can bind RhoA and that localisation of Citron to the contractile ring is dependent on the cytokinesis-specific Pbl-RhoA signalling. Phenotypic analysis of mutants showed that citron is required for cytokinesis in every tissue examined, with mutant cells exhibiting multinucleate and hyperploid phenotypes. Strong genetic interactions were observed between citron and pbl alleles and constructs. Vertebrate studies implicate at least two Rho effector kinases, Citron and Rok, in cytokinesis. By contrast, we failed to find evidence for a role for the Drosophila ortholog of Rok in cell division. We conclude that Citron plays an essential, non-redundant role in the Rho signalling pathway during Drosophila cytokinesis.Tetyana Shandala, Stephen L. Gregory, Hazel E. Dalton, Masha Smallhorn and Robert Sain

Clustering of match running and performance indicators to assess between- and within-playing position similarity in professional rugby league

This study aimed to determine the similarity between and within positions in professional rugby league in terms of technical performance and match displacement. Here, the analyses were repeated on 3 different datasets which consisted of technical features only, displacement features only, and a combined dataset including both. Each dataset contained 7617 observations from the 2018 and 2019 Super League seasons, including 366 players from 11 teams. For each dataset, feature selection was initially used to rank features regarding their importance for predicting a player’s position for each match. Subsets of 12, 11, and 27 features were retained for technical, displacement, and combined datasets for subsequent analyses. Hierarchical cluster analyses were then carried out on the positional means to find logical groupings. For the technical dataset, 3 clusters were found: (1) props, loose forwards, second-row, hooker; (2) halves; (3) wings, centres, fullback. For displacement, 4 clusters were found: (1) second-rows, halves; (2) wings, centres; (3) fullback; (4) props, loose forward, hooker. For the combined dataset, 3 clusters were found: (1) halves, fullback; (2) wings and centres; (3) props, loose forward, hooker, second-rows. These positional clusters can be used to standardise positional groups in research investigating either technical, displacement, or both constructs within rugby league.</p

Association of Prematurity and Urogenital Comorbidities with Postoperative Outcomes of Ureteroneocystostomy for Vesicoureteral Reflux

Background: It is estimated that 20-30% of congenital anomalies involve the kidney and ureter, and these rates are even higher in infants with low birth weights. Vesicoureteral reflux (VUR) occurs when there is a backflow of urine from the bladder to the kidney. Depending on severity, this condition may require surgical correction with ureteroneocystostomy (UNC). The impact of premature birth and presence of urogenital comorbidities on outcomes of UNC is not known. The objective of this study is to determine the relationship between premature birth and urogenital comorbidities with operative outcomes of UNC for VUR. Methods: The 2020 American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-P) database was analyzed for patients undergoing UNC for VUR. 1742 patients were evaluated with 1623 meeting inclusion criteria. The patients were divided into full term (\u3e37 weeks gestation at birth) and preterm (birth). Patient demographics, comorbid conditions, urogenital comorbidities, and outcomes were evaluated. Further analysis of factors associated with ectopic ureter was performed. Results: Out of 1623 UNC patients analyzed, 8.6% were preterm and 91.4% were full term. In basic statistics, bronchopulmonary dysplasia, esophageal/gastric/intestinal disease, developmental delay, structural CNS abnormality, neuromuscular disorder, nutritional support, congenital malformation, cardiac risk factors, ASA classification, gestational age, and urogenital comorbidities were significantly associated with prematurity. Univariate and multivariate analysis revealed that congenital malformation (p=0.007), major cardiac risk factors (p=0.002), and gestational age of 35-36 weeks are significantly associated with risk of ectopic ureter (p\u3c0.001). Conclusion: While prematurity alone is not associated with incidence of VUR, preterm patients undergoing UNC have a significantly higher risk of postoperative complications despite no differences in operative approach, VUR disease severity, and prior VUR procedure compared to full term patients undergoing this procedure. Preterm patients tend to have more comorbidities which may contribute to this finding. Ectopic ureter is associated with prematurity and factors such as congenital malformations and major cardiac risk factors may increase the risk for ectopic ureter in this population

Understanding how Victoria, Australia gained control of its second COVID-19 wave

During 2020, Victoria was the Australian state hardest hit by COVID-19, but was successful in controlling its second wave through aggressive policy interventions. We calibrated a detailed compartmental model of Victoria's second wave to multiple geographically-structured epidemic time-series indicators. We achieved a good fit overall and for individual health services through a combination of time-varying processes, including case detection, population mobility, school closures, physical distancing and face covering usage. Estimates of the risk of death in those aged ≥75 and of hospitalisation were higher than international estimates, reflecting concentration of cases in high-risk settings. We estimated significant effects for each of the calibrated time-varying processes, with estimates for the individual-level effect of physical distancing of 37.4% (95%CrI 7.2-56.4%) and of face coverings of 45.9% (95%CrI 32.9-55.6%). That the multi-faceted interventions led to the dramatic reversal in the epidemic trajectory is supported by our results, with face coverings likely particularly important

Variation in climate sensitivity and feedback parameters during the historical period

We investigate the climate feedback parameter α (W m−2 K−1) during the historical period (since 1871) in experiments using the HadGEM2 and HadCM3 atmosphere general circulation models (AGCMs) with constant preindustrial atmospheric composition and time-dependent observational sea surface temperature (SST) and sea ice boundary conditions. In both AGCMs, for the historical period as a whole, the effective climate sensitivity is ∼2 K (α≃1.7 W m−2 K−1), and α shows substantial decadal variation caused by the patterns of SST change. Both models agree with the AGCMs of the latest Coupled Model Intercomparison Project in showing a considerably smaller effective climate sensitivity of ∼1.5 K (α = 2.3 ± 0.7 W m−2 K−1), given the time-dependent changes in sea surface conditions observed during 1979–2008, than the corresponding coupled atmosphere-ocean general circulation models (AOGCMs) give under constant quadrupled CO2 concentration. These findings help to relieve the apparent contradiction between the larger values of effective climate sensitivity diagnosed from AOGCMs and the smaller values inferred from historical climate change

Population-Attributable Risk Estimates for Risk Factors Associated with Campylobacter Infection

In 2001-2002, a multicenter, prospective case-control study involving 1,714 participants ≥5 years of age was conducted in Australia to identify risk factors for Campylobacter infection. Adjusted population-attributable risks (PARs) were derived for eac

The HETDEX Pilot Survey. IV. The Evolution of [O II] Emitting Galaxies from z ~ 0.5 to z ~ 0

We present an analysis of the luminosities and equivalent widths of the 284 z < 0.56 [O II]-emitting galaxies found in the 169 square arcmin pilot survey for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). By combining emission-line fluxes obtained from the Mitchell spectrograph on the McDonald 2.7-m telescope with deep broadband photometry from archival data, we derive each galaxy's de-reddened [O II] 3727 luminosity and calculate its total star formation rate. We show that over the last ~5 Gyr of cosmic time there has been substantial evolution in the [O II] emission-line luminosity function, with L* decreasing by ~0.6 +/-0.2 dex in the observed function, and by ~0.9 +/-0.2 dex in the de-reddened relation. Accompanying this decline is a significant shift in the distribution of [O II] equivalent widths, with the fraction of high equivalent-width emitters declining dramatically with time. Overall, the data imply that the relative intensity of star formation within galaxies has decreased over the past ~5 Gyr, and that the star formation rate density of the universe has declined by a factor of ~2.5 between z ~ 0.5 and z ~ 0. These observations represent the first [O II]-based star formation rate density measurements in this redshift range, and foreshadow the advancements which will be generated by the main HETDEX survey.Comment: 11 pages with 9 figures and 1 table; accepted for publication in the Astrophysical Journa