1,333 research outputs found

    Macroeconomic Policies Interaction & the Symmetry of Financial Markets' Responses

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    This concise study analyses the symmetry of financial markets` responses to macroeconomic policy interaction in the United Kingdom. Employing the Vector Auto-regression (VAR) model on monthly data of the British financial sector and macroeconomic policies from January 1985 to August 2008, this study found that the equity and sovereign debt markets showed identical symmetry in response to macroeconomic policy interaction

    Vascular complications in adults and pediatrics live-donor renal transplantation: 3 decades of single centre experience

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    We analyzed the incidence of vascular complications in adults and pediatrics live donor renal transplantations over 3 decades and compared its impact upon patient and graft survival in both groups.Material and methods: Between March 1976 and December 2005, 1785 live-donor renal transplantswere performed in a single institute, of the 1546 adults and 239 pediatric (age ā‰¤18 years). The incidence of different types of vascular complications were determined in both groups. Long term patient and graft survival in patients with or without vascular complications and in various types of vascular complications were calculated & compared in both groups.Results: The overall incidence of vascular complications was 2.9%, it was equally 2.9% in both groups. In adults, 46 complications in 45 patients included 16 arterial, 10 renal artery thrombosis (0.6%), 2 cases of spasm in renal artery(0.1%), renal artery stenosis in 5 (0.3%), renal vein thrombosis in one (0.06%) and hemorrhagic complications in 28 patients whereas there were no thrombotic complications in the pediatric group, 6 case of hemorrhage (2.5%) and one case of renal artery stenosis (0.4%). There is steady decrease of vascular complications over the last 3 decades. The vascular complications significantly adverse patient and graft survival in both groups (p<0.001). The 5-years patient and graft survival in adults and pediatrics with or without vascular complications were 59.5 Ā± 9.2%, 89.14Ā Ā±Ā 0.89%, 57.5Ā Ā±Ā 18.7% and 90.18Ā Ā±Ā 2.2% for the patient and 40.14Ā Ā±Ā 7.75%, 97.79Ā Ā±Ā 1.14%, 28.57Ā Ā±Ā 17.07% and 77.18Ā Ā±Ā 3.02% for the graft. There is no statistical significant difference in either patient or graft survival in thrombotic, stenotic or hemorrhagic complications in adult or hemorrhagic complications in the pediatric group (p=0.22 and p=0.142 respectively).Conclusions: There is no increase in incidence of vascular complications in pediatrics than adult transplants. The survival either graft or patient is comparable between adult and pediatric with or without vascular complications and the subgroups of vascular complications

    Evaluating Social Housing Retrofit Options to Support Clients' Decision Makingā€”SIMPLER BIM Protocol

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    The UK government made significant commitments to upgrading the energy efficiency of seven million British homes by 2020, aiming at reducing carbon emissions and addressing fuel poverty. One alternative to achieve better energy performance in existing houses is retrofit. However, there are difficulties associated with retrofitting social housing. It is currently challenging to compare scenarios (retrofit options) considering costs, potential energy efficiency gains, and at the same time minimising disruption to users. This paper presents a Building Information Modelling (BIM) protocol aimed to support decision making by social housing owners. It adopts BIM to simulate alternative retrofit options, considering: (a) potential reductions in energy consumption, (b) 4D BIM for retrofit planning and reduction of usersā€™ disruption and (c) simulation of costs. A what-if scenario matrix is proposed to support decision making in the selection of social housing retrofit solutions, according to client and usersā€™ needs. A case study of the retrofit of a mid-terrace house is presented to demonstrate the workflow. The main output of the work is the BIM protocol, which can support client decision making in diverse social housing retrofit projects, considering all three elements (energy simulation, planning for reduced disruption and cost estimation) in an integrated fashion. Such an integrated approach enables clients to make better informed decisions considering diverse social housing retrofit options through a simple process using readily available BIM technology

    The role of tool geometry in process damped milling

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    The complex interaction between machining structural systems and the cutting process results in machining instability, so called chatter. In some milling scenarios, process damping is a useful phenomenon that can be exploited to mitigate chatter and hence improve productivity. In the present study, experiments are performed to evaluate the performance of process damped milling considering different tool geometries (edge radius, rake and relief angles and variable helix/pitch). The results clearly indicate that variable helix/pitch angles most significantly increase process damping performance. Additionally, increased cutting edge radius moderately improves process damping performance, while rake and relief angles have a smaller and closely coupled effect

    A general computational method for robustness analysis with applications to synthetic gene networks

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    Motivation: Robustness is the capacity of a system to maintain a function in the face of perturbations. It is essential for the correct functioning of natural and engineered biological systems. Robustness is generally defined in an ad hoc, problem-dependent manner, thus hampering the fruitful development of a theory of biological robustness, recently advocated by Kitano

    Numerical investigation of the effect of tread pattern on rotating wheel aerodynamics

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    The present work investigates the dynamic effect of wheel rotation on the aerodynamic characteristics of slick type (ST) wheel of Formula One racing cars using a computational approach. The ST wheel model was compared to experimental results as a validation case. The pressure coefficient over the ST wheel circumference at its middle plane (xy) has been considered as an experimental case from literature and the computed results showed a reasonable agreement. Furthermore, a quantitative evaluation of the numerically-determined wheel drag, local separation and stagnation angles has been also compared to those extracted experimentally from literature. The validation work served by assessing the suitability of using Moving Reference Frame (MRF) method to simulate the effect of wheel rotation, as well as defining the most reliable conditions of testing such as the optimal meshing criteria, the computational domain size, and the adopted turbulence model. According to wheel studies, all computational work was performed at a Reynolds number of 6.8Ɨ105 based on the wheel diameter. The wheels aerodynamic drag, lift, and moment coefficients were computed for each wheel model. Further parametric study on the tread design of the tread type (TT) wheel was performed by varying the tread depth, h. Besides, general schematic pictures of the flow behavior around the TT wheel are presented

    Characterization of growth and metabolism of the haloalkaliphile Natronomonas pharaonis

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    Natronomonas pharaonis is an archaeon adapted to two extreme conditions: high salt concentration and alkaline pH. It has become one of the model organisms for the study of extremophilic life. Here, we present a genome-scale, manually curated metabolic reconstruction for the microorganism. The reconstruction itself represents a knowledge base of the haloalkaliphile's metabolism and, as such, would greatly assist further investigations on archaeal pathways. In addition, we experimentally determined several parameters relevant to growth, including a characterization of the biomass composition and a quantification of carbon and oxygen consumption. Using the metabolic reconstruction and the experimental data, we formulated a constraints-based model which we used to analyze the behavior of the archaeon when grown on a single carbon source. Results of the analysis include the finding that Natronomonas pharaonis, when grown aerobically on acetate, uses a carbon to oxygen consumption ratio that is theoretically near-optimal with respect to growth and energy production. This supports the hypothesis that, under simple conditions, the microorganism optimizes its metabolism with respect to the two objectives. We also found that the archaeon has a very low carbon efficiency of only about 35%. This inefficiency is probably due to a very low P/O ratio as well as to the other difficulties posed by its extreme environment

    Birth weight and the risk of atrial fibrillation in whites and African Americans: The atherosclerosis risk in communities (ARIC) study

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    Background: Low birth weight (LBW) has been associated with an increased risk of cardiovascular disease (CVD). A previous study, however, found higher risk of atrial fibrillation (AF) in individuals with higher birth weight (BW). To further understand this apparent paradox, we examined the relationship between AF and BW in the Atherosclerosis Risk in Communities (ARIC) cohort. Methods: The analysis included 10,132 individuals free of AF at baseline (1996-1998), who provided BW information, were not born premature, and were not a twin. Self-reported BW was categorized as low (<2.5Ā kg), medium (2.5-4Ā kg), and high (>4.0Ā kg). AF incidence was ascertained from hospital discharge codes and death certificates. We used multivariable Cox proportional hazard models to determine the hazard ratios (HR) and 95% confidence intervals (CI) of AF across BW groups. Results: During an average follow-up of 10.3Ā years, we identified 882 incident AF cases. LBW was associated with higher risk of AF. Compared to individuals in the medium BW category, the HR (95% CI) of AF was 1.33 (0.99, 1.78) for LBW and 1.00 (0.81, 1.24) for high BW after adjusting for sociodemographic variables (p for trend = 0.29). Additional adjustment for CVD risk factors did not attenuate the associations (HR 1.42, 95% CI 1.06, 1.90 for LBW and HR 0.86, 95% CI 0.69-1.07 for high BW, compared to medium BW, p for trend = 0.01).Conclusion: LBW was associated with a higher risk of AF. This association was independent of known predictors of AF and is consistent with that observed for other cardiovascular diseases. Ā© 2014 Lawani et al.; licensee BioMed Central Ltd
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