47 research outputs found

    Application of advanced technologies to derivatives of current small transport aircraft

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    Mission requirements of the derivative design were the same as the baseline to readily identify the advanced technology benefits achieved. Advanced technologies investigated were in the areas of propulsion, structures and aerodynamics and a direct operating cost benefit analysis conducted to identify the most promising. Engine improvements appear most promising and combined with propeller, airfoil, surface coating and composite advanced technologies give a 21-25 percent DOC savings. A 17 percent higher acquisition cost is offset by a 34 percent savings in fuel used

    Colesevelam enhances the beneficial effects of brown fat activation on hyperlipidemia and atherosclerosis development

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    Aims Brown fat activation accelerates the uptake of cholesterol-enriched remnants by the liver and thereby lowers plasma cholesterol, consequently protecting against atherosclerosis development. Hepatic cholesterol is then converted into bile acids (BAs) that are secreted into the intestine and largely maintained within the enterohepatic circulation. We now aimed to evaluate the effects of prolonged brown fat activation combined with inhibition of intestinal BA reabsorption on plasma cholesterol metabolism and atherosclerosis development and results APOE∗3-Leiden.CETP mice with humanized lipoprotein metabolism were treated for 9 weeks with the selective b3-adrenergic receptor (AR) agonist CL316,243 to substantially activate brown fat. Prolonged b3-AR agonism reduced faecal BA excretion (-31%), while markedly increasing plasma levels of total BAs (258%), cholic acid-derived BAs (295%), and chenodeoxycholic acid-derived BAs (217%), and decreasing the expression of hepatic genes involved in BA production. In subsequent experiments, mice were additionally treated with the BA sequestrant Colesevelam to inhibit BA reabsorption. Concomitant intestinal BA sequestration increased faecal BA excretion, normalized plasma BA levels, and reduced hepatic cholesterol. Moreover, concomitant BA sequestration further reduced plasma total cholesterol (-49%) and non-high-density lipoprotein cholesterol (-56%), tended to further attenuate atherosclerotic lesion area (-54%). Concomitant BA sequestration further increased the proportion of lesion-free valves (34%) and decreased the relative macrophage area within the lesion (-26%), thereby further increasing the plaque stability index (44%). Conclusion BA sequestration prevents the marked accumulation of plasma BAs as induced by prolonged brown fat activation, thereby further improving cholesterol metabolism and reducing atherosclerosis development. These data suggest that combining brown fat activation with BA sequestration is a promising new therapeutic strategy to reduce hyperlipidaemia and cardiovascular diseases

    Identification of factors required for meristem function in Arabidopsis using a novel next generation sequencing fast forward genetics approach

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    <p>Abstract</p> <p>Background</p> <p>Phenotype-driven forward genetic experiments are powerful approaches for linking phenotypes to genomic elements but they still involve a laborious positional cloning process. Although sequencing of complete genomes now becomes available, discriminating causal mutations from the enormous amounts of background variation remains a major challenge.</p> <p>Method</p> <p>To improve this, we developed a universal two-step approach, named 'fast forward genetics', which combines traditional bulk segregant techniques with targeted genomic enrichment and next-generation sequencing technology</p> <p>Results</p> <p>As a proof of principle we successfully applied this approach to two Arabidopsis mutants and identified a novel factor required for stem cell activity.</p> <p>Conclusion</p> <p>We demonstrated that the 'fast forward genetics' procedure efficiently identifies a small number of testable candidate mutations. As the approach is independent of genome size, it can be applied to any model system of interest. Furthermore, we show that experiments can be multiplexed and easily scaled for the identification of multiple individual mutants in a single sequencing run.</p

    Manifesto for the future of work and organizational psychology

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    This manifesto presents 10 recommendations for a sustainable future for the field of Work and Organizational Psychology. The manifesto is the result of an emerging movement around the Future of WOP (seewww.futureofwop.com), which aims to bring together WOP-scholars committed to actively contribute to building a better future for our field. Our recommendations are intended to support both individuals and collectives to become actively engaged in co-creating the future of WOP together with us. Therefore, this manifesto is openand never“finished.”It should continuously evolve, based on an ongoing debate around our professional values and behavior. This manifesto is meant, first of all, for ourselves as an academic community. Furthermore, it is also important for managers, decision makers, and other stakeholders and interested parties,such as students, governments and organizations, as we envision what the future of WOP could look like, and it is only through our collective efforts that we will be able to realize a sustainable future for all of us

    Empirical drag closure for polydisperse gas–liquid systems in bubbly flow regime: Bubble swarm and micro-scale turbulence

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    Gas–liquid systems in the bubbly flow regime can be successfully simulated by considering that gas bubbles are polydisperse, namely a population of bubbles characterized by different sizes and velocities. Phase coupling issues can be properly overcome by considering the evolution in space and time of such distribution, which is dictated by the so-called Generalized Population Balance Equation (GPBE). Therefore, the development of reliable meso-scale models is crucial for its solution. This work focuses on meso-scale models for momentum coupling, namely the drag force coefficient, with particular attention to the so-called bubble swarm and micro-scale turbulence effects present in the turbulent bubbly flow regime.The proposed empirical methodology is here adopted for the simulation of very different gas–liquid systems, such as rectangular and circular bubble columns, as well as aerated stirred tank reactors, and simulation results are eventually compared with the available experimental data, resulting in very good agreement

    Trends in penetrating and anterior lamellar corneal grafting techniques for keratoconus : A national registry study

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    Purpose: Keratoconus is a progressive disorder and one of the primary indications for corneal transplantation. Anterior lamellar keratoplasty offers several advantages over other techniques, including endothelial preservation and longer graft survival. In this study, we examined the recent trend of using lamellar techniques for keratoconus at a national level. Methods: Data were obtained from the Dutch national organ transplant database regarding corneal transplants for keratoconus performed in 2005 through 2014. Baseline characteristics for patients undergoing various techniques were obtained, and temporal trends were analysed. Results: A total of 1041 operations were performed, including 736 penetrating keratoplasties (PKPs) and 297 anterior lamellar keratoplasties (ALKs). The mean age of the total surgical group was 37.4 ± 13.4 years, and 68% of patients were male (p = 0.0001). Preoperative patient characteristics were reported in all 1041 cases. The relative proportion of ALKs increased from 2005 (19% of cases) to 2010 (39% of cases) and remained approximately 30-40% thereafter. Descemet baring or deep anterior lamellar keratoplasty (DALK) was increasingly applied and was the predominant anterior lamellar technique performed from 2009 onwards. Conclusions: The number of corneal transplantations performed annually for keratoconus decreased during the past 10 years. Lamellar techniques were increasingly performed, accounting for approximately 35% of keratoplasties in 2010 and thereafter. Among ALK techniques, maximal depth DALK is the most prevalent keratoplasty performed for keratoconus in most recent years. Penetrating keratoplasty (PKP) is still common, with a stable frequency from 2010 onwards

    Nationwide reduction in the number of corneal transplantations for keratoconus following the implementation of cross-linking

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    PURPOSE: Keratoconus is characterized by corneal ectasia and irregular astigmatism, which can lead to diminished vision and corneal scarring. Approximately 10-20% of patients with keratoconus eventually require a corneal transplant. Corneal cross-linking (CXL) is a relatively new treatment that may help prevent the need for corneal transplantation. Here, we investigated whether the introduction of CXL has reduced the number of corneal transplants performed annually. METHODS: Data regarding the transplantation procedures performed in patients under the age of 50 years were extracted from the Dutch National Organ Transplant Registry. The number of corneal transplants performed prior to (i.e. in 2005 through 2007) and following the introduction of CXL (i.e. in 2012 through 2014) were compared. Furthermore, a trend analysis on annual keratoplasties over time was performed. RESULTS: Approximately 25% fewer corneal transplants were performed in the 3-year period following the introduction of CXL compared to the 3-year period prior to the introduction of CXL (201 versus 269 transplants, respectively; p = 0.005). Age, gender and visual acuity were similar between the patient groups in the two time periods. Trend analysis also demonstrated a significant decrease in the amount of corneal transplants (p = 0.001). CONCLUSION: Significantly fewer corneal transplants were performed for treating keratoconus following the nationwide introduction of CXL. This reduction suggests that corneal cross-linking can significantly reduce the need for corneal transplantation

    Trends in penetrating and anterior lamellar corneal grafting techniques for keratoconus : A national registry study

    No full text
    Purpose: Keratoconus is a progressive disorder and one of the primary indications for corneal transplantation. Anterior lamellar keratoplasty offers several advantages over other techniques, including endothelial preservation and longer graft survival. In this study, we examined the recent trend of using lamellar techniques for keratoconus at a national level. Methods: Data were obtained from the Dutch national organ transplant database regarding corneal transplants for keratoconus performed in 2005 through 2014. Baseline characteristics for patients undergoing various techniques were obtained, and temporal trends were analysed. Results: A total of 1041 operations were performed, including 736 penetrating keratoplasties (PKPs) and 297 anterior lamellar keratoplasties (ALKs). The mean age of the total surgical group was 37.4 ± 13.4 years, and 68% of patients were male (p = 0.0001). Preoperative patient characteristics were reported in all 1041 cases. The relative proportion of ALKs increased from 2005 (19% of cases) to 2010 (39% of cases) and remained approximately 30-40% thereafter. Descemet baring or deep anterior lamellar keratoplasty (DALK) was increasingly applied and was the predominant anterior lamellar technique performed from 2009 onwards. Conclusions: The number of corneal transplantations performed annually for keratoconus decreased during the past 10 years. Lamellar techniques were increasingly performed, accounting for approximately 35% of keratoplasties in 2010 and thereafter. Among ALK techniques, maximal depth DALK is the most prevalent keratoplasty performed for keratoconus in most recent years. Penetrating keratoplasty (PKP) is still common, with a stable frequency from 2010 onwards

    Cytokine Expression in Keratoconus and its Corneal Microenvironment : A Systematic Review

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    Keratoconus (KC) is a progressive corneal ecstasia characterized by thinning and weakening of the cornea that leads to a cone-like appearance, scarring, and decreased vision. Despite the well-described clinical signs, the cause of KC is unknown. Nevertheless, various genes, proteinases, and environmental factors (eye-rubbing, contact lens wear, tear film composition) have been implicated in its etiology. Although classically defined as a predominantly degenerative disease, with mechanically induced trauma accelerating its course, accumulating evidence suggests a pivotal role for inflammation in the pathophysiology of KC. Several reports have linked various inflammatory mediators (cytokines) with KC, but with contradictory findings. The methods and materials used in these studies vary considerably and warrant critical evaluation to decipher the role of inflammatory mediators in KC. We performed a systematic review of current literature on cytokine expression studies in KC and discuss critical soluble and cellular inflammatory mediators that are implicated in its pathogenesis
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