Now showing items 1-20 of 9541

    • Does capital market drive corporate investment efficiency? Evidence from equity lending supply

      Tsai, H.-J.; Wu, Yuliang; Xu, B. (2021)
      The increased equity lending supply (ELS) in the equity loan market, available for short sellers to borrow, exposes a firm to greater short selling threats. Considering short sellers’ strong incentives to uncover firm-specific information and monitor managers, we hypothesize that short selling threats, proxied by ELS, enhance corporate investment efficiency. We find that ELS significantly reduces managerial tendencies to underinvest (overinvest) especially for firms prone to underinvest (overinvest). The effect of ELS on investment efficiency is stronger for firms with higher information asymmetry and weaker corporate governance, confirming short sellers’ role in mitigating information and agency costs. However, short selling risk weakens the effect of ELS. Our evidence is robust to endogeneity checks and suggests that corporate investment can be driven by a particular capital market condition: the amount of lendable shares in the equity loan market.
    • Stressors and coping mechanisms of family care-givers of older relatives living with long-term conditions in mainland China: A scoping review of the evidence

      Bífárìn, Oládayò, O.; Quinn, Catherine; Breen, Liz; Wu, C.; Ke, M.; Yu, L.; Oyebode, Jan R. (Cambridge University Press, 2021)
      As the ageing population in China continues to grow, more people will be living with long-term health conditions and require support from family care-givers. This scoping review therefore aims to explore sources of stress and coping mechanisms adopted by care-givers of older relatives living with long-term conditions in mainland China. Literature searches were conducted in English (CINAHL, EMBASE, MEDLINE, PsycINFO and SCOPUS) and Chinese (CNKI, WANFANG DATA, CQVIP and CBM) databases between October and November 2019. The searches focused on the stressors and coping mechanisms utilised by family care-givers residing in the community. Narrative synthesis was used to identify themes within the data. Forty-six papers were included: 20 papers from English and 26 from Chinese databases. Six themes captured stressors: care-giving time (N = 22), financial resources (N = 17), role and personal strains (N = 42), preparedness (N = 4), social roles (N = 10) and lack of adequate formal support (N = 22); and one theme captured coping (N = 14). Unmet needs of care-givers of older relatives in mainland China were found to be extensive. Only a few studies had attempted to explore the causal link between stressors, coping and the influence of culture. Findings underscore the significance of adequately capturing intricacies around care-givers’ unmet needs, rather than generalising on the basis of culture. Qualitative studies are critical to providing a better understanding of the relationship between stressors, coping and resources afforded to care-givers by their cultural environment. Having such understanding is crucial to inform the development of competent care, which promotes self-efficacy and self-actualisation in care-givers in mainland China.
    • Self-efficacy, habit strength, health locus of control and response to the personalised nutrition Food4Me intervention study

      Stewart-Knox, Barbara J.; Rankin, A.; Bunting, B.P.; Frewer, L.J.; Celis-Morales, C.; Livingstone, K.M.; Fischer, A.R.H.; Poinhos, R.; Kuznesof, S.; Gibney, M.J.; et al. (Emerald, 2021)
      Purpose – Randomised controlled trials identify causal links between variables but not why an outcome has occurred. This analysis sought to determine how psychological factors assessed at baseline influenced response to personalised nutrition. Design/methodology/approach – Web-based, randomised, controlled trial (RCT) was conducted across seven European countries. Volunteers, both male and female, aged over 18 years were randomised to either a non-personalised (control) or a personalised (treatment) dietary advice condition. Linear mixed model analysis with fixed effects was used to compare associations between internal and external health locus of control (HLoC), nutrition self-efficacy (NS-E) and self-report habit index (S-RHI) at baseline (N 5 1444), with healthy eating index (HEI) and Mediterranean diet index (MDI) scores between conditions post-intervention (N 5 763). Findings – An increase in MDI scores was observed between baseline and six months in the treatment group which was associated with higher NS-E (p
    • Tranquillity trails – design, implementation and benefits for healthy leisure

      Watts, Gregory R.; Bauer, J. (Taylor and Francis, 2021)
      Tranquillity trails (TTs) are designed to provide a quiet and peaceful walk through mainly leafy lanes and roads and connect green open spaces where visitors can stop for thought and relaxation. There are numerous health benefits from being in close proximity to nature and TTs can facilitate this contact in mainly urban areas. This study involved the design of a trail in Tramore, a coastal town in south east Ireland. The trail links an old coastguard station, now converted to a cultural centre and coffee shop, with a Japanese garden. The trail includes a coastal path with fine views across a bay, wooded areas as well as leafy residential streets. The design of the trail was facilitated by the use of a previous developed tranquillity rating prediction tool (TRAPT) that involved the estimation of the level of man-made noise and the percentage of natural features in view. Participants who had completed the whole of the trail were encouraged to complete a questionnaire to gauge any benefits. As expected, it was reported that there were increased levels of relaxation and reduced stress. It was concluded that the approach can be used elsewhere to improve the well-being of residents and visitors.
    • Bond behaviors between nano-engineered concrete and steel bars

      Wang, X.; Dong, S.; Ashour, Ashraf F.; Ding, S.; Han, B. (Elsevier, 2021-09)
      This paper investigated the bond characteristics between eight types of nanofillers modified reactive powder concrete (RPC) and plain steel bars, aiming to explore the modifying mechanisms and establish a bond-slip relationship model for nanofillers modified RPC and steel bar interface. The experimental results indicated that the incorporation of nanofillers can increase the bond strength and reduce the slip between RPC and plain steel bars. It was shown that a 2.15 MPa/20.5% of absolute/relative increase in cracking bond strength, a 1.25 MPa/10.3% of absolute/relative increase in ultimate bond strength, a 2.35 MPa/22.4% of absolute/relative increase in residual bond strength, a 0.592 mm/56.5% of absolute/relative reduction in ultimate bond slip, and a 1.779 mm/52.1% of absolute/relative reduction in residual bond slip were the best achieved due to the addition of various nanofillers. The enhancement of nanofillers on RPC-steel bar interface has been mainly attributed to RPC microstructure improvement, optimization of intrinsic compositions, and elimination of defects in the interface, especially the underside near steel bar, due to the nano-core effect of nanofillers enriched in the interface. In addition, the bond-slip relationship of nanofillers modified RPC-steel bar interface can be accurately described by the proposed model considering an initial branch.
    • An exploration of the impact of SARS-CoV-2 (COVID-19) restrictions on marginalised groups in the UK

      Eshareturi, Cyril; Wareham, C.; Rattray, Marcus; Haith-Cooper, Melanie; McCarthy, R. (2021-08)
      Background: To contain the spread of COVID-19 within the UK over the past year, there have been a series of local and national lockdowns. These restrictions are likely to have impacted upon the health and well-being of marginalised groups who rely on now closed social and community support services to stay healthy. An understanding of the experiences of marginalised people is important; therefore, this study aimed to explore the impact of the COVID-19 restrictions on the health and well-being of marginalised groups in the UK. Methods: In summer 2020, a rapid telephone survey was conducted by trained, trusted volunteers with 76 participants who were from marginalised groups. As part of this survey, 64 participants consented to describe their experience of lockdown. These case studies were thematically analysed to identify patterns of meaning. Results: Findings indicate that lockdown led to the deterioration of health of participants, impacted adversely on their socio-economic positions and affected access to food and essential supplies. In addition, government public health messaging was considered confusing and inadequate. Conclusions: This study highlights the need for pathways into services which support marginalised groups to remain accessible during periods of restrictions and essential supplies and food to be mapped and protected for marginalised individuals within our local communities.
    • Digest of Evidence 9, The Human Bone

      Clark, J.; Garner-Lahire, J.; Spall, C.; Toop, N.; Curtis-Summers, Shirley (2021-06)
    • Global Security in the Post-Cold War Era and the Relevance of Nuclear Weapons

      Bluth, Christoph (2021-06)
      Are nuclear weapons still relevant to global security? Compared with the nuclear confrontation in the depths of the Cold War, nuclear weapons and deterrence appear to have lost their salience. Considering the conflicts in which the major powers engaged, the focus in strategic studies changed to counterinsurgency, counterterrorism, and subconventional conflict.2 Only recently, with the conflict in Ukraine and the increasingly confrontational relationship between the United States and China has this narrative come into question. The general perception on international security exhibits a strange paradox. On the one hand the US-led military interventions in Afghanistan, Iraq and other parts, the conflicts in the Middle East and Africa, the nuclearization of North Korea and the conflict between India and Pakistan among other regional security issues have given rise to a view that the modern world is less secure than ever, and we live in a world of chaos riven by unpredictable patterns of violence. By contrast, Steven Pinker has demonstrated the casualties from armed conflict are at their lowest point in human history, and interstate warfare has virtually ceased to exist as a phenomenon.3 The imminence of a global nuclear war in which at a minimum hundreds of millions of people would die appears to have dissipated. In some respects, it appears that war has become almost a phenomenon of the past. Most of the recent literature on nuclear weapons has focused on regional crises areas, such as South Asia (India and Pakistan) or the Korean peninsula.4 However, the modernization of arsenals by the nuclear powers, the integration of strategic conventional and nuclear weapons in strategic doctrines and the more confrontational dynamics in Great Power politics is cited as evidence that the risk of nuclear use is increasing. This paper contests the emerging narratives on an increased threat of nuclear conflict and considers the sources of insecurity in the contemporary period and in particular the risks of armed conflict between the United States, Russia, and China in order to assess the role of nuclear weapons in contemporary security.
    • Patient Perspectives on Factors Affecting Direct Oral Anticoagulant Use for Stroke Prevention in Atrial Fibrillation

      Medlinskiene, Kristina; Richardson, S.; Fylan, Beth; Stirling, K.; Rattray, Marcus; Petty, Duncan (2021-05-10)
      Introduction: Oral anticoagulant therapy choices for patients with atrial fibrillation (AF) expanded in the last decade with the introduction of direct oral anticoagulants (DOAC). However, the implementation of DOACs was slow and varied across different health economies in England. There is limited evidence on the patient role in the uptake of new medicines, including DOACs, apart from considering their demographic and clinical characteristics. Hence, this study aimed to address the gap by exploring the view of patients with AF on factors affecting DOAC use. Methods: A qualitative study using semi-structured interviews was conducted in three health economies in the North of England. Adult patients (>18 years) diagnosed with non-valvular AF, prescribed an oral anticoagulant (vitamin K antagonist or DOAC), and able to give written consent were recruited. Data were collected between August 2018 and April 2019. Audio recorded interviews were transcribed verbatim and analyzed using the framework method. Results: Four themes with eleven subthemes discussed identified factors affecting the use of DOACs. They were linked to limited healthcare financial and workforce resources, patient involvement in decision-making, patient knowledge about DOACs, safety concerns about oral anticoagulants, and oral anticoagulant therapy impact on patients' daily lives. Lack of a) opportunities to voice patient preferences and b) information on available therapy options resulted in some patients experiencing difficulties with the prescribed therapy. This was reported to cause negative impact on their daily lives, adherence, and overall satisfaction with the therapy. Conclusion: Greater patient involvement in decision-making could prevent and resolve difficulties encountered by some patients and potentially improve outcomes plus increase the uptake of DOACs.
    • Energy-harvesting concrete for smart and sustainable infrastructures

      Wang, X.; Dong, S.; Ashour, Ashraf F.; Han, B. (A Springer Nature Publication, 2021)
      Concrete with smart and functional properties (e.g., self-sensing, self-healing, and energy-harvesting) represents a transformative direction in the field of construction materials. Energy-harvesting concrete has the capability to store or convert the ambient energy (e.g., light, thermal, and mechanical energy) for feasible uses, alleviating global energy and pollution problems as well as reducing carbon footprint. The employment of energy-harvesting concrete can endow infrastructures (e.g., buildings, railways, and highways) with energy self-sufficiency, effectively promoting sustainable infrastructure development. This paper provides a systematic overview on the principles, fabrication, properties, and applications of energy-harvesting concrete (including light-emitting, thermal-storing, thermoelectric, pyroelectric, and piezoelectric concretes). The paper concludes with an outline of some future challenges and opportunities in the application of energy-harvesting concrete in sustainable infrastructures.
    • Understanding the principles of non-invasive positive pressure ventilation

      Roberts, Alexandra (2021-07)
      Non-invasive positive pressure ventilation (NPPV) provides respiratory support to patients without the need for invasive intubation. Although it has been used for several years in critical care, NPPV has come to prominence as a management option for certain patients with respiratory complications of coronavirus disease 2019 (COVID-19). This has led to increased care provision by nurses with little or no experience and expertise in critical care and NPPV. This article provides an overview of the principles of NPPV and its use in type 1 and type 2 respiratory failure. It explains the pathophysiology of several conditions that often lead to respiratory failure and how NPPV can mitigate respiratory failure and improve gas exchange. An individualised assessment of the patient’s suitability for NPPV and an evaluation of the effectiveness of the therapy are crucial to ensure its safe and effective use. Nurses also have an important role in providing explanations and support to patients.
    • Probing cytochrome P450 (CYP) bioactivation with chloromethylindoline bioprecursors derived from the duocarmycin family of compounds

      Ortuzar, N.; Karu, K.; Presa, Daniela; Morais, Goreti R.; Sheldrake, Helen M.; Shnyder, Steve D.; Barnieh, Francis M.; Loadman, Paul M.; Patterson, Laurence H.; Pors, Klaus; et al. (2021-06-15)
      The duocarmycins belong to a class of agent which has great potential for use in cancer therapy. Their exquisite potency means they are too toxic for systemic use, and targeted approaches are required to unlock their clinical potential. In this study, we have explored seco-OH-chloromethylindoline (CI) duocarmycin-based bioprecursors for their potential for cytochrome P450 (CYP)-mediated cancer cell kill. We report on synthetic and biological explorations of racemic seco-CI-MI, where MI is a 5-methoxy indole motif, and dehydroxylated analogues. We show up to a 10-fold bioactivation of de-OH CI-MI and a fluoro bioprecursor analogue in CYP1A1-transfected cells. Using CYP bactosomes, we also demonstrate that CYP1A2 but not CYP1B1 or CYP3A4 has propensity for potentiating these compounds, indicating preference for CYP1A bioactivation.
    • How can the potential of the duocarmycins be unlocked for cancer therapy?

      Jukes, Zoë; Morais, Goreti R.; Loadman, Paul M.; Pors, Klaus (2021-02)
      The duocarmycins belong to a class of agent that has fascinated scientists for over four decades. Their exquisite potency, unique mechanism of action, and efficacy in multidrug-resistant tumour models makes them attractive to medicinal chemists and drug hunters. However, despite great advances in fine-tuning biological activity through structure-activity relationship studies (SARS), no duocarmycin-based therapeutic has reached clinical approval. In this review, we provide an overview of the most promising strategies currently used and include both tumour-targeted prodrug approaches and antibody-directed technologies.
    • Luminal Bioavailability of Orally Administered ω-3 PUFAs in the Distal Small Intestine, and Associated Changes to the Ileal Microbiome, in Humans with a Temporary Ileostomy

      Nana, G.; Mitra, S.; Watson, H.; Young, C.; Wood, H.M.; Perry, S.L.; Race, Amanda D.; Quirke, P.; Toogood, G.J.; Loadman, Paul M.; et al. (2021-05)
      Background: Oral administration of purified omega-3 (ω-3) PUFAs is associated with changes to the fecal microbiome. However, it is not known whether this effect is associated with increased PUFA concentrations in the gut. Objectives: We investigated the luminal bioavailability of oral ω-3 PUFAs (daily dose 1 g EPA and 1g DHA free fatty acid equivalents as triglycerides in soft-gel capsules, twice daily) and changes to the gut microbiome, in the ileum. Methods: Ileostomy fluid (IF) and blood were obtained at baseline, after first capsule dosing (median 2 h), and at a similar time after final dosing on day 28, in 11 individuals (median age 63 y) with a temporary ileostomy. Fatty acids were measured by LC–tandem MS. The ileal microbiome was characterized by 16S rRNA PCR and Illumina sequencing. Results: There was a mean 6.0 ± 9.8-fold and 6.6 ± 9.6-fold increase in ileal EPA and DHA concentrations (primary outcome), respectively, at 28 d, which was associated with increased RBC ω-3 PUFA content (P ≤ 0.05). The first oral dose did not increase the ileal ω-3 PUFA concentration except in 4 individuals, who displayed high luminal EPA and DHA concentrations, which reduced to concentrations similar to the overall study population at day 28, suggesting physiological adaptation. Bacteroides, Clostridium, and Streptococcus were abundant bacterial genera in the ileum. Ileal microbiome variability over time and between individuals was large, with no consistent change associated with acute ω-3 PUFA dosing. However, high concentrations of EPA and DHA in IF on day 28 were associated with higher abundance of Bacteroides (r2 > 0.86, P < 0.05) and reduced abundance of other genera, including Actinomyces (r2 > 0.94, P < 0.05). Conclusions: Oral administration of ω-3 PUFAs leads to increased luminal ω-3 PUFA concentrations and changes to the microbiome, in the ileum of individuals with a temporary ileostomy.
    • The effect of photoperiod and high fat diet on the cognitive response in photoperiod-sensitive F344 rats

      McLean, Samantha L.; Yun, Haesung; Tedder, Andrew; Helfer, Gisela (2021)
      In many species, seasonal changes in day length (photoperiod) have profound effects on physiology and behavior. In humans, these include cognitive function and mood. Here we investigated the effect of photoperiod and high fat diets on cognitive deficits, as measured by novel object recognition, in the photoperiod-sensitive F344 rat, which exhibits marked natural changes in growth, body weight and food intake in response to photoperiod. 32 male juvenile F344 rats were housed in either long or short photoperiod and fed either a high fat or nutrient-matched chow diet. Rats were tested in the novel object recognition test before photoperiod and diet intervention and re-tested 28 days after intervention. In both tests during the acquisition trials there was no significant difference in exploration levels of the left and right objects in the groups. Before intervention, all groups showed a significant increase in exploration of the novel object compared to the familiar object. However, following the photoperiod and diet interventions the retention trial revealed that only rats in the long photoperiod-chow group explored the novel object significantly more than the familiar object, whereas all other groups showed no significant preference. These results suggest that changing rats to short photoperiod impairs their memory regardless of diet. The cognitive performance of rats on long photoperiod-chow remained intact, whereas the high fat diet in the long photoperiod group induced a memory impairment. These findings suggest that rats exposed to long photoperiod have different cognitive responses to rats exposed to short photoperiod and high fat diet.
    • Flow analysis of melted urea in a perforated rotating bucket

      Muhammad, A.; Rahmanian, Nejat; Pendyala, R. (2013-10)
      A comprehensive study of the internal flow field for the prilling application in a perforated rotating bucket has been carried out. Computational Fluid Dynamics (CFD) is used to investigate the flow field of urea melt inside the perforated rotating bucket. The bucket is mounted at the top of the prilling tower. In prilling process, urea melt is sprayed by the perforated rotating bucket to produce the urea droplets, which falls down due to gravity. These drops fall down through a cooling medium and solidify into prills. The velocity field in the bucket is very important to study, as it has great effect on the heat and mass transfer performance in prilling process. ANSYS 14.0 CFD package is used to simulate and Design Modeler and Catia V5 are used for geometrical model of the perforated prilling bucket. Velocity distribution on different planes are obtained and discussed.
    • Heat exchanger network optimization by differential evolution method

      Thuy, N.T.P.; Pendyala, R.; Rahmanian, Nejat; Marneni, N. (2014)
      The synthesis of heat exchanger network (HEN) is a comprehensive approach to optimize energy utilization in process industry. Recent developments in HEN synthesis (HENS) present several heuristic methods, such as Simulated Annealing (SA), Genetic Algorithm (GA), and Differential Evolution (DE). In this work, DE method for synthesis and optimization of HEN has been presented. Using DE combined with the concept of super-targeting, the ΔTmin optimization is determined. Then DE algorithm is employed to optimize the global cost function including the constraints, such as heat balance, the temperatures of process streams. A case study has been optimized using DE, generated structure of HEN and compared with networks obtained by other methods such as pinch technology or mathematical programming. Through the result, the proposed method has been illustrated that DE is able to apply in HEN optimization, with 16.7% increase in capital cost and 56.4%, 18.9% decrease in energy, global costs respectively.
    • An experimental investigation into the permeability and selectivity of PTFE membrane: a mixture of methane and carbon dioxide

      Gilassi, S.; Rahmanian, Nejat (Taylor & Francis, 2016)
      Research and technology innovations in the 1970s led to the significant commercial practice of gas separation by membranes that exists today. These advances involved developing membrane structures that could produce high fluxes and modules for packing a large amount of membrane area per unit volume (Murphy et al., 2009). At present, the share of using a polymeric membrane in the capture of CO2 is increasing and gradually the membrane technology is considered as the promising method in separation units, although the number of commercial membranes is not high. CO2 capture from natural gas is one of the controversial topics that many researchers and engineers try to find the best method satisfying both high efficiency and low capital cost. In common, chemical physical absorption towers are applied to remove CO2 from natural gas in order to prevent pipeline corrosion, even though the other component such as H2S gives rise to operating problems. The obscure angle of a conventional unit is related to the high energy consumption while the absorbent needs to be purified by the regeneration units which implement the temperature as a unique manipulating parameter for separating amine groups. The great advantages of using the membrane in gas industry are the low capital cost, easy installation and maintenance so that for this simple reason, new membranes come to the market for different types of processes. Capture of CO2 from natural gas accounts for one of the major difficulties so that the engineers try to employ membrane modules as to alter the process efficiency. However, there are only a limited number of membranes that can be used in real industry and the research still continues over this interesting topic (Burggraaf and Cot, 1996).
    • Investigation of Effect of Aluminium Oxide Nanoparticles on the Thermal Properties of Water-Based Fluids in a Double Tube Heat Exchanger

      Porgar, S.; Rahmanian, Nejat (2021-06-24)
      The thermal behavior of aluminium oxide-water nanofluid in a double pipe carbon steel heat exchanger was investigated in the present study. The overall heat transfer coefficient, Nusselt, and heat transfer coefficient of nanofluid were compared with the base fluid. The volume fraction of the nanoparticles was 1%. By adding nanoparticles to the fluid, the thermal properties of the base fluid improved significantly. The hot and cold fluid flow was considered counter-current, and the nanofluid was pumped into the inner tube and once into the outer tube, and the flow rate of each fluid was 0.05 kg/s. The convective heat transfer and the overall heat transfer coefficient enhanced 94% and 253% for the hot fluid flow in the outer tube and 308 % and 144% for the hot fluid flow in the inner tube, respectively. The pressure drop calculations also showed that the pressure drop would not change significantly when using nanofluid.
    • A Simple Subjective Evaluation of Enface OCT Reflectance Images Distinguishes Glaucoma From Healthy Eyes

      Cheloni, Riccardo; Dewsbery, S.D.; Denniss, Jonathan (2021-05-25)
      Purpose: We present a subjective approach to detecting glaucomatous defects in enface images and assess its diagnostic performance. We also test the hypothesis that if reflectivity changes precede thickness changes in glaucoma there should be reduced correlation between the modalities in glaucoma compared to controls. Methods: Twenty glaucoma participants and 20 age-matched controls underwent high-resolution OCT scans of one eye. 4 μm-thick enface slabs were constructed through the retina. Enface indices were depths of first gap in visible retinal nerve fiber bundles (RNFBs) and last visible bundle, subjectively evaluated in six sectors of a 3.5 mm circle around the optic disc. Retinal nerve fiber layer thickness (RNFLT) along the same circle was extracted at angles corresponding to enface indices. Between-group differences were tested by linear mixed models. Diagnostic performance was measured by partial receiver operating characteristic area (pAUC). Results: First gap and last visible bundle were closer to the inner limiting membrane in glaucoma eyes (both P < 0.0001). Enface indices showed excellent diagnostic perfor mance (pAUCs 0.63–1.00), similar to RNFLT (pAUCs 0.63–0.95). Correlation between enface and RNFLT parameters was strong in healthy (r = 0.81–0.92) and glaucoma eyes (r = 0.73–0.80). Conclusions: This simple subjective method reliably identifies glaucomatous defects in enface images with diagnostic performance at least as good as existing thickness indices. Thickness and reflectivity were similarly related in healthy and glaucoma eyes, providing no strong evidence of reflectivity loss preceding thinning. Objective analyses may realize further potential of enface OCT images in glaucoma. Translational Relevance: Novel enface OCT indices may aid glaucoma diagnosis.