54 research outputs found
The power of the CEO and environmental decoupling
This paper examines the impact of the power of the chief executive officer (CEO) on environmental decoupling. We define environmental decoupling as a gap between firm's claims about the environmental sustainability and actual environmental sustainability performance. Based on the managerial power theory, we argue that powerful managers are more involved in environmental decoupling and use environmental reporting in a more opportunistic manner than their less powerful peers. We analyse a dataset of 4576 firm-year observations of US-listed firms for the period 2002–2017. We find that powerful CEOs decouple firm's environmental performance from environmental reporting. These findings are robust to a battery of analyses and show that powerful CEOs do not show true commitment towards corporate environmental sustainability. The results provide important implications for investors, policymakers and fund managers. Useful future research recommendations are also provided to guide the research in the domain of environmental sustainability
Parametric Study and Optimization of Ceiling Fan Blades for Improved Aerodynamic Performance
This paper includes parametric study and optimization of non-linear ceiling fan blades by combining the techniques of Design of Experiments (DOE), Response Surface Methods (RSM) and Computational Fluid Dynamics (CFD). Specifically, the nonlinear (elliptical) planform shape of ceiling fan blade is investigated in conjunction with blade tip width, root and tip angle of attack. Sixteen cases are designed for three blade ceiling fan using two level full factorial model. The flow field is modeled using Reynolds-Averaged-Navier-Stokes approach. The performance variables used to formulate a multi-objective optimization problem are volumetric flow rate, torque and energy efficiency. Response Surface Method is used to generate the optimized design for non-linear ceiling fan blade profile. The results reveal that the interactions between the design variables play a significant role in determining the performance. It is concluded that the nonlinear forward sweep has a moderate effect on response parameters
Electronic cigarettes use and perception amongst medical students: a cross sectional survey from Sindh, Pakistan
Objective: The manufacturers of electronic cigarettes (e-cigarettes) are actively marketing their product through electronic and social media. Undergraduate medical students are expected to have better knowledge and awareness as they directly interact with patients in their training, The purpose of this study is therefore, to determine knowledge, use and perception regarding e-cigarettes among medical students from Sindh, Pakistan.
Results: A cross-sectional study was conducted between 1st July and 30th September 2016 at five different medical colleges situated in the second largest province of Sindh, Pakistan. The data was collected through a structured, self-administered questionnaire. Of the 500 students, the mean age was 21.5 ± 1.7 years and 58% were females. Over (65.6%) students were aware of e-cigarettes, 31 (6.2%) reported having used e-cigarettes, of whom 6 (1.2%) self-reported daily use. Users of conventional tobacco products were significantly more likely to have heard of e-cigarettes (87.6% vs 51.6%, p \u3c 0.001) and having used them (13.9% vs 1.3%, p \u3c 0.001). On multivariable logistic regression analysis we found a strong association of e-cigarette use with consumption of conventional cigarettes [OR: 10.6, 95% CI 3.6-30.8, p \u3c 0.001], use of smokeless tobacco products [OR: 7.9, 95% CI 2.7-23.4, p \u3c 0.001] however a weak association was observed for Shisha use [OR: 3.05, 95% CI 0.9-9.6, p = 0.05]
Modelling and analysis of the complement system signalling pathways: roles of C3, C5a and pro-inflammatory cytokines in SARS-CoV-2 infection
The complement system is an essential part of innate immunity. It is activated by invading pathogens causing inflammation, opsonization, and lysis via complement anaphylatoxins, complement opsonin’s and membrane attack complex (MAC), respectively. However, in SARS-CoV-2 infection overactivation of complement system is causing cytokine storm leading to multiple organs damage. In this study, the René Thomas kinetic logic approach was used for the development of biological regulatory network (BRN) to model SARS-CoV-2 mediated complement system signalling pathways. Betweenness centrality analysis in cytoscape was adopted for the selection of the most biologically plausible states in state graph. Among the model results, in strongly connected components (SCCs) pro-inflammatory cytokines (PICyts) oscillatory behaviour between recurrent generation and downregulation was found as the main feature of SARS-CoV-2 infection. Diversion of trajectories from the SCCs leading toward hyper-inflammatory response was found in agreement with in vivo studies that overactive innate immunity response caused PICyts storm during SARS-CoV-2 infection. The complex of negative regulators FI, CR1 and DAF in the inhibition of complement peptide (C5a) and PICyts was found desirable to increase immune responses. In modelling role of MAC and PICyts in lowering of SARS-CoV-2 titre was found coherent with experimental studies. Intervention in upregulation of C5a and PICyts by C3 was found helpful in back-and-forth variation of signalling pattern linked with the levels of PICyts. Moreover, intervention in upregulation of PICyts by C5a was found productive in downregulation of all activating factors in the normal SCCs. However, the computational model predictions require experimental studies to be validated by exploring the activation role of C3 and C5a which could change levels of PICyts at various phases of SARS-CoV-2 infection
Mesenchymal stem cells in cardiac regeneration: a detailed progress report of the last 6 years (2010–2015)
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Effect of Number of Blades on Performance of Ceiling Fans
In this paper, the effect of number of blades on ceiling fan performance is discussed. This approach helps to satisfy tradeoff between high air flow (performance) and power consumption (energy efficiency). Specifically, variation from two to six blades is considered with nonlinear forward sweep profile. Reynolds Averaged Navier-Stokes (RANS) technique is used to model the flow field induced by the ceiling fan inside a generic room. The performance is gauged through response parameters namely volumetric flow rate, mass flow rate, torque and energy efficiency. The results indicate that mass and volumetric flow rates are maximized for six blade configuration and energy efficiency is maximized for two blade configuration. The study indicates the importance of tradeoff between high air flow through ceiling fan and associated energy efficiency
Gender-diverse boards and related party transactions: What makes the difference?
Using the data of French publicly listed companies, we investigate the effect of board gender diversity on related party transactions (RPTs) by considering the role of female directors’ specific (statutory and demographic) attributes. The results of system generalized method of moments regression analysis shows that firms with gender-diverse boards engage less in RPTs. We also find that the consideration of specific (i.e., statutory and demographic) attributes of female directors in regression analysis changes the nature of the association between board gender diversity and RPTs from negative to positive, suggesting that the simple presence of female directors is a necessary but not sufficient condition for effective board decision making. With regard to the specific attributes of female directors, we find that business expertise and audit committee memberships discourage the use of RPTs. On the other hand, leadership and experience enhance the disclosure of RPTs. Our study contributes to the debate concerning the appointment of women to corporate boards, since female directors’ attributes are the primary drivers of board effectiveness
Buoyancy effects in stagnation-point flow of Maxwell fluid utilizing non-Fourier heat flux approach.
Here we utilize a non-Fourier approach to model buoyancy aiding or opposing flow of Maxwell fluid in the region of stagnation-point towards a vertical stretchable surface. Flow field is permeated by uniform transverse magnetic field. Two different heating processes namely (i) prescribed surface temperature (PST) and (ii) constant wall temperature (CWT) are analyzed. Through suitable transformations, the similarity equations are formed which are treated numerically for a broad range of magnetic interaction parameter. The obtained solutions are compared with available articles under limiting situations and such comparisons appear convincing. The structure of boundary layer depends on a parameter measuring the ratio of free stream velocity to the stretching sheet velocity. The momentum transport via stretching boundary is opposed by both fluid relaxation time and magnetic interaction parameter. Thermal boundary layer expands as the effects of transverse magnetic field and thermal relaxation time are amplified. A reduction in heat penetration depth is anticipated for increasing values of thermal relaxation time. The variation in wall slope of temperature with increasing thermal relaxation time appears similar at any assigned value of Prandtl number. A comparative study of aiding and opposition flow situations is presented and deliberated
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