University of Salford
  • Salford, Greater Manchester, United Kingdom
Recent publications
Non-Newtonian thermal processing in microchannel systems, is emerging as a major area of interest in modern thermal engineering. Motivated by these developments, in the current paper, a mathematical model is developed for laminar, steady state fully developed viscoelastic natural convection electro-magnetohydrodynamic (EMHD) flow in a microchannel containing a porous medium. Transverse magnetic field and axial electrical field are considered. A modified Darcy–Brinkman–Forchheimer model is deployed for porous media effects. Viscous dissipation and Joule heating effects are included. The primitive conservation equations are rendered into dimensionless coupled ordinary differential equations with associated boundary conditions. The nonlinear ordinary differential boundary value problem is then solved using He’s powerful homotopy perturbation method (HPM). Validation with the MATLAB bvp4c numerical scheme is included for Nusselt number. Graphical plots are presented for velocity, temperature and Nusselt number for the influence of emerging parameters. Increment in thermal Grashof number and electric field parameter enhance velocity. Increasing Brinkman number and magnetic interaction number boost temperatures and a weak elevation is also observed in temperatures with increment in third-grade non-Newtonian parameter and Forchheimer number. Nusselt number is also elevated with thermal Grashof number, Forchheimer number, third-grade fluid parameter, Darcy parameter, Brinkman number and magnetic number.
Although it is an integral part of global change, most of the research addressing the effects of climate change on forests have overlooked the role of environmental pollution. Similarly , most studies investigating effects of air pollutants on forests have generally neglected impacts of climate change. We review the current knowledge on combined air pollution and climate change effects on global forest ecosystems and identify several key research priorities as a roadmap for the future. Specifically, we recommend 1) establishment of much denser array of monitoring sites, particularly in the South Hemisphere; 2) further integration of ground and satellite monitoring; 3) generation of flux-based standards and critical levels taking into account the sensitivity of dominant forest tree species; 4) long-term monitoring of N, S, P cycles and base cations deposition together at global scale; 5) intensification of experimental studies, addressing combined effects of different abiotic factors on forests by assuring a better representation of taxonomic and functional diversity across the ~ 73,000 tree species on Earth; 6) more experimental focus on phenomics and genomics; 7) improved knowledge on key processes regulating the dynamics of radionuclides in forest systems; and 8) development of models integrating air pollution and climate change data from long-term monitoring programs.
Improved thermal management in high-temperature tribological systems requires novel developments in lubricants. Motivated by combining nanoparticle and magnetorheological plastomer features, this research paper deals with the analysis of the high-temperature magnetohydrodynamic squeeze flow of a Casson nanofluid between parallel disks with the Fourier-type boundary conditions including radiation. Rosseland’s diffusion flux and the Buongiorno nanoscale model are used. Suction and injection effects at the disks are also considered as is viscous heating. Robin (Fourier) boundary conditions are included, and the Buongiorno nanoscale model is used which enables the simulation of nanoparticle mass diffusion, Brownian motion and thermophoresis. The emerging nonlinear boundary value problem is solved with the bvp4c routine in MATLAB routine with appropriate boundary conditions at the disks. The effects of squeeze number, Hartmann number, Brownian motion parameter, Prandtl number, Eckert number, thermophoresis parameter, Casson viscoplastic rheological parameter and thermal radiation parameter for both disk suction and injection cases and also with equivalent and different Biot numbers at the disks are presented graphically. MATLAB solutions are validated with earlier published results. Drag force increases with greater magnetic field strength. Increasing squeezing parameter substantially modifies the velocity distribution, causing a deceleration near the disk surfaces but an acceleration further from the disks. Elevation in Prandtl number and Eckert number results in a significant enhancement in temperature but a strong depletion in nanoparticle concentration for both equal and unequal Biot numbers at the disk surfaces. Nanoparticle concentration is depleted at the disk surfaces with increasing Brownian motion parameter values. With an increase in the Casson viscoplastic parameter, temperature decreases, i.e., cooling is induced, whereas nanoparticle concentration increases. The simulations show that significant temperature elevation is produced with increasing Brownian diffusion, viscous dissipation and radiative flux effects and that combining nanoparticles and viscoplastic effects offers a good thermal management mechanism in squeezing lubrication.
The heligmonellid nematode Carolinensis minutus (Dujardin, 1845) Travassos, 1937 is recorded for the first time in Microtus agrestis (Linnaeus, 1761) in the United Kingdom. Small heligmosomoid specimens were recovered from a M. agrestis vole inhabiting mole ( Talpa europaea Linnaeus, 1758) tunnels in mid Wales. The identity of these specimens was confirmed as C. minutus by >99% nucleotide identity with internally transcribed spacer (ITS) 1 and ITS 2 sequences in French C. minutus .
Many factors influence how environmental DNA (eDNA) abundance varies in natural environments. One of the least studied contributors to eDNA variation is that of reproduction. Marine organisms that broadcast spawn are expected to shed increased quantities of DNA in association with the release of gametes and the elevated levels of activity associated with reproduction. To test this hypothesis at the community level, we present a year‐long eDNA time‐series of a temperate sea‐shelf fish assemblage combined with adult fish and ichthyoplankton abundance data. Our results show that eDNA is associated with species abundance estimated by conventional fish surveys at all life stages (adult, larval, and egg), and was on average 2.3‐fold more abundant during predicted fish reproductive periods.
The gut microbiota of social bees is relatively simple and dominated by a set of core taxa found consistently in individuals around the world. Yet, variation remains, and can affect host health. We characterised individual‐ and regional‐scale variation in honeybee (Apis mellifera) gut microbiota from 64 colonies in North‐West England by sequencing the V4 region of the 16S rRNA gene, and asked whether microbiota were influenced by host genotype and landscape composition. We also characterised the genotypes of individual bees and the land cover surrounding each colony. The literature‐defined core taxa dominated across the region despite the varied environments. However, there was variation in the relative abundance of core taxa, and colony membership explained much of this variation. Individuals from more genetically diverse colonies had more diverse microbiotas, but individual genetic diversity did not influence gut microbial diversity. There were weak trends for colonies in more similar landscapes to have more similar microbiota, and for bees from more urban landscapes to have less diverse microbiota. To our knowledge, this is the first report for any species that the gut bacterial communities of individuals are influenced by the genotypes of others in the population. This article is protected by copyright. All rights reserved.
Reconstruction of sediment accumulation in river deltas over the Holocene provides a basis for understanding the relationship between climate change, human activities and delta growth. However, variations in deposition rates on a centennial‐scale over the last 2000 years remain poorly studied for mega‐deltas. Based on optically stimulated luminescence and AMS ¹⁴C ages, we calculated deposited sediment volumes in the Yangtze River Delta (YRD) for 500‐year intervals over the last two millennia for the first time. Our results reveal that the 2.0–1.5 and 0.5–0 ka periods had higher sediment deposition rates than in 1.5–1.0 and 1.0–0.5 ka, with maximum value about two times that of the minimum. A comparison with historical records of flooding and drought events indicates that a wetter climate led to a higher sediment deposition, reflecting the role of fluvial discharge in delta growth. However, the highest sediment deposition (205 ± 29 × 10⁶ m³/a) over the last 500 years is not only related to the wetter conditions of the Little Ice Age, but also linked to dramatic regional population growth. We suggest that human activities have predominated over natural forcing in determining the deltaic growth over the last five centuries. Taking the Medieval Climate Anomaly with the lowest deposition volume as an analog of current climate warming, and considering the decline in sediment loads due to recent damming and soil conservation, the YRD is likely to face an even more severe deficit in sediment supply and higher risk of delta destruction in the coming centuries.
Recent studies on myoelectric-based prosthetic control have shown that surface electromyography (sEMG) can enhance prosthetic intuitiveness by improving motion detection algorithms and continuous data processing. This study aims to use a combination of feature extraction techniques and machine learning approaches to map sEMG signals to 10 upper-limb motions for real-time control. The study implements four machine learning methods (i.e., k-nearest neighbours (k-NN), artificial neural networks (ANN), support vector machines (SVM), linear discriminant analysis (LDA)) as classifiers and six time-domain features (i.e., root mean square (RMS), integrated absolute value (IAV), mean absolute value (MAV), simple square integration (SSI), waveform length (WL), average amplitude change (AAC)) to extract sEMG features to differentiate six individual fingers and four-hand griping patterns. Five subjects volunteered in the research and training datasets were recorded using seven sEMG electrodes for three static and three dynamic arm positions. The modalities were assessed with offline classification performance from the collected datasets and real-time evaluation metrics such as motion completion rate, motion detection accuracies and reach and grasp experiments. Based on the above, the control methodology differentiates independent finger motions with high accuracy, 94% completion rates with 0.23 s data processing and prediction time.
It became clear at the onset of the pandemic that radiography could play an important role in diagnosing and staging COVID-19. The key modality would be mobile chest radiography. However, at the onset of the pandemic, no literature existed to indicate whether or not chest X-ray imaging could be used effectively to diagnose or exclude COVID-19. This article explains how a website was created, at speed, during the initial phase of the COVID-19 pandemic. Containing holistic information, the website helped enable rapid redeployment of radiographers onto the frontline where chest X-ray imaging was needed. It aimed to help train radiographers take (and interpret) chest radiographs in high-risk areas that contained large numbers of COVID-19 patients. Within one year, the website had been used in 157 countries. This article documents the approach taken to create the website and suggestions are made about how, in the future, a rapid approach could be achieved to create other websites – should an international crisis occur again. This paper also outlines how stakeholders and content authors from across the world were brought together and supported to create the website. It goes on to explain the leadership style that was adopted to create the website and why that style was selected. An explanation is offered about the project management approach and how its ingredients relate to a published model. Aside from simply providing a historical account of how the website was created, we hope the narrative offers food for thought on how to respond rapidly during an international crisis to formulate and implement a unified international-level solution which addresses an urgent need.
This study aimed to investigate the effect of different set configurations on barbell trajectories during a series of power snatch sets. Ten strength-power athletes (height: 1.78 ± 0.09 m, body mass: 88.7 ± 14.3 kg, age: 28.9 ± 4.8 years) with at least 6 months of training experience performing the power snatch participated in this study. Each participant completed three experimental protocols as part of a randomized repeated measures design. The three protocols tested were a traditional, cluster, and ascending cluster set protocol where training loads were increased across the repetitions contained within each set. All protocols required each participant to perform the power snatch with three sets of five repetitions at an average load of 75% of one-repetition maximum. Three-dimensional barbell trajectories were recorded using a motion capture system during each set protocol. Participants maintained barbell trajectories within each set of both traditional and cluster protocols. This result indicates that higher intensities (>75% of one-repetition maximum) than those used in this study should be used when using cluster sets that are designed to maximize the benefits of cluster sets for maintaining barbell trajectories during a series of power snatch sets performed for five repetitions. Additionally, participants displayed an increased barbell loop at the first repetition during the ascending cluster protocol. Therefore, coaches should only use this programming strategy for highly trained athletes who have already developed proper weightlifting technique to avoid a suboptimal barbell trajectory during the power snatch training session.
Mast cells are innate immune cells found in connective tissues throughout the body, most prevalent at tissue-environment interfaces. They possess multiple cell-surface receptors which react to various stimuli and, after activation, release many mediators including histamine, heparin, cytokines, prostaglandins, leukotrienes and proteases. In mast cell activation syndrome, excessive amounts of inflammatory mediators are released in response to triggers such as foods, fragrances, stress, exercise, medications or temperature changes. Diagnostic markers may be difficult to assess because of their rapid degradation; these include urinary N-methyl histamine, urinary prostaglandins D 2 , DM and F 2α and serum tryptase (which is stable) in the UK. Self-management techniques, medications and avoiding triggers may improve quality of life. Treatments include mast cell mediator blockers, mast cell stabilisers and anti-inflammatory agents. ‘Long COVID’ describes post-COVID-19 syndrome when symptoms persist for more than 12 weeks after initial infection with no alternative diagnosis. Both mast cell activation syndrome and long COVID cause multiple symptoms. It is theorised that COVID-19 infection could lead to exaggeration of existing undiagnosed mast cell activation syndrome, or could activate normal mast cells owing to the persistence of viral particles. Other similarities include the relapse-remission cycle and improvements with similar treatments. Importantly, however, aside from mast cell disorders, long COVID could potentially be attributed to several other conditions.
This study aimed to evaluate whether lifting velocity can be used to estimate the overhead press one repetition maximum (1RM) and to explore the differences in the accuracy of the 1RM between three velocity-based methods. Twenty-seven weightlifters (16 men and 11 women) participated. The first session was used to test the overhead press 1RM. The second session consisted of an incremental loading test during the overhead press. The mean velocity was registered using a transducer attached to the barbell. A 1-way repeated-measures analysis of variance (ANOVA) with Bonferroni post hoc corrections was applied to the absolute differences between the actual and predicted 1RMs. Raw differences with 95% limits of agreement and ordinary least-products regressions were used to test the concurrent validity of the 1RM prediction methods with respect to the actual 1RM. The ANOVA did not reveal significant differences for the absolute differences respect to the actual 1RM between the three 1RM prediction methods ( F = 3.2, p = .073). The absolute errors were moderate for the Multiple-Point (6.1 ± 3.7%), Two-Point 45−75 (8.6 ± 6.2%), and Two-Point 45−90 methods (5.7 ± 4.0%). The validity analysis showed that all the 1RM prediction methods underestimated the actual 1RM (1.0–2.2 kg), but ordinary least-products regressions failed to show fixed or proportional bias. These results suggest that the Multiple-Point and Two-Point 45−90 velocity-based methods might be viable tools to predict the overhead press 1RM in weightlifters, but practitioners are encouraged to use the direct 1RM for a more accurate prescription of the training loads.
A hybrid knee prosthesis is proposed in this paper, which consists of a polycentric structure in passive mode for low-torque activities and a single-axis structure in active mode for high-torque activities. A novel mode transition mechanism controls self-holding electromagnets for switching modes between the four-bar linkage and single-axis structure. Compared with the conventional single-axis hybrid knee, the four-bar polycentric mechanism with varying instantaneous center of rotation (ICR) can enhance the geometric stability and increase the toe clearance in passive mode. For active mode, we developed a custom embedded electric system, employed torque control for stance and position control for swing. The results of bench tests indicated that the bandwidth of the controller was suitable for locomotion. The clinical test of level-ground walking without sudden buckling and stumble was validated by three subjects. Regarding climbing stairs, a typical high-torque activity in daily locomotion, all subjects reach the maximum knee torque around 0.95 Nm/kg comparable to the able-bodied.
The dynamic properties of joints, or inter-component connections, are a principal source of uncertainty when modelling complex built-up structures. In the present paper, we propose an interval-based sensitivity analysis (SA) to establish the contribution, or influence, of a structure's uncertain joint dynamics towards the uncertainty of its coupled admittance. We choose an interval SA as it overcomes the limitations of conventional local and global methods; accuracy and computation efficiency, respectively. Furthermore, it avoids the need for detailed probabilistic data to describe each joint, which is often unavailable. The proposed interval SA is based on the dual formulation of the sub-structuring problem and utilises the Sherman-Morrison formula to factor out the contribution of an individual joint. A complex interval is used to represent the uncertain joint stiffness and damping, and precise bounds on the assembly's complex admittance (also operational response) are determined following an application specific algorithm. The relative change between input (joint stiffness and damping) and output (complex admittance) interval area is chosen as a sensitivity metric and used to rank order the uncertain influence of each joint. The method is illustrated by numerical example.
Paediatric early warning systems (PEWS) to reduce in-hospital mortality have been a laudable endeavour. Evaluation of their impact has rarely examined the internal validity of the components of PEWS in achieving desired outcomes. We highlight the assumptions made regarding the mode of action of PEWS and, as PEWS become more commonplace, this paper asks whether we really understand their function, process and outcome.
Purpose Axillary staging is an important prognostic factor in breast cancer. Sentinel lymph node biopsy (SNB) is currently used to stage patients who are clinically and radiologically node-negative. Since the establishment that axillary node clearance (ANC) does not improve overall survival in breast-conserving surgery for patients with low-risk biological cancers, axillary management has become increasingly conservative. This study aims to identify and assess the clinical predictive value of variables that could play a role in the quantification of axillary burden, including the accuracy of quantifying abnormal axillary nodes on ultrasound. Methods A retrospective analysis was conducted of hospital data for female breast cancer patients receiving an ANC at our centre between January 2018 and January 2020. The reference standard for axillary burden was surgical histology following SNB and ANC, allowing categorisation of the patients under ‘low axillary burden’ (2 or fewer pathological macrometastases) or ‘high axillary burden’ (> 2). After exploratory univariate analysis, multivariate logistic regression was conducted to determine relationships between the outcome category and candidate predictor variables: patient age at diagnosis, tumour focality, tumour size on ultrasound and number of abnormal lymph nodes on axillary ultrasound. Results One hundred and thirty-five patients were included in the analysis. Logistic regression showed that the number of abnormal lymph nodes on axillary ultrasound was the strongest predictor of axillary burden and statistically significant ( P = 0.044), with a sensitivity of 66.7% and specificity of 86.8% ( P = 0.011). Conclusion Identifying the number of abnormal lymph nodes on preoperative ultrasound can help to quantify axillary nodal burden and identify patients with high axillary burden, and should be documented as standard in axillary ultrasound reports of patients with breast cancer.
Reflection is a trademark tool of social work, but if reflection tools are blunt, they will never dismantle the house of intersectional racist oppression. This provocation contends that reflective models need to decisively focus on intersections of power, privilege and position. The origins of Black feminist intersectionality determine intersectionality’s function as an efficacious tool of reflection. This article offers a model of intersectional reflection that explicitly scrutinises the interdependent interconnections of power to expose the compound injuries of intersectional racism and enables the identification of places of safety and opportunities for transformation. Located within a metanarrative for Black feminist social work, intersectional reflection identifies the criss-cross roads of social inequality, names the vehicles of power, analyses the intersectional crash and assesses bio-psychosocial injuries. If social work is to stand a chance of being fit for purpose in an intersectionally racist world, it needs to be based on Black feminist theory.
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Yeliz Prior
  • Centre for Health Sciences Research
Samia Nefti-meziani
  • School of Computing, Science and Engineering
Martin Johnson
  • School of Nursing, Midwifery, Social Work and Social Science
Mark Widdowson
  • School of Nursing, Midwifery and Social Work
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Crescent, M5 4WT, Salford, Greater Manchester, United Kingdom
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http://www.salford.ac.uk/