Long time Solutions for a Burgers-Hilbert Equation via a Modified Energy Method

We consider an initial value problem for a quadratically nonlinear inviscid Burgers-Hilbert equation that models the motion of vorticity discontinuities. We use a modified energy method to prove the existence of small, smooth solutions over cubically nonlinear time-scales

A metabolomic investigation of the effects of vitamin E supplementation in humans.

RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.BACKGROUND: Vitamin E is a nutrient with both antioxidant and non-antioxidant activities and has been shown to modulate the function of a number of cell types in vitro and in human studies. However studies have also shown vitamin E to have detrimental interactions and therefore it is important to establish the extent to which this nutrient influences metabolism. Metabolomics can potentially identify nutrient-metabolism interactions and therefore the aim of this study was to use a non-targeted metabolomic approach to identify changes to the plasma metabolome following vitamin E supplementation in humans. METHODS: A relatively homogenous healthy adult male population (n = 10) provided a fasting blood sample immediately before and after a 4-week vitamin E supplementation regime (400 mg/d of RRR-α-tocopheryl acetate)) on top of their habitual diet. Plasma samples were analysed for vitamin E and clinical markers. Plasma underwent non-targeted metabolite profiling using liquid chromatography/mass spectroscopy and data was processed using multivariate statistical analysis. RESULTS: Plasma vitamin E concentrations were significantly increased following supplementation (p < 0.001). A partial least squares-discriminant analysis (PLS-DA) model was able to discriminate between samples taken pre and post vitamin E supplementation (goodness of fit R2Y = 0.82, predictive ability Q2 = 0.50). Variable influence on projection and PLS-DA loadings highlighted a number of discriminating ions that were confirmed as discriminatory through pairwise analysis. From database searches and comparison with standards these metabolites included a number of lysophosphatidylcholine species (16:0, 18:0, 18:1, 18:2, 20:3 and 22:6) that were increased in intensity post supplementation by varying degrees from 4% to 29% with the greatest changes found for lysoPC 22:6 and 20:3. CONCLUSIONS: Although a small scale study, these results potentially indicate that vitamin E supplementation influences phospholipid metabolism and induces lysoPC generation; a general pro-inflammatory response. Moreover the study identifies novel areas of vitamin E interactions and highlights the potential of metabolomics for elucidating interactions between nutrients and metabolic pathways in nutritional research

The moderating influence of user characteristics on the relationship between user involvement and perceived usefulness of information systems

This study examines the moderating effect of user characteristics on the relationship between user involvement and perceived usefulness of ISs. Thirty-two organi2:ations with 127 users have participated in this study. Results indicate that among user characteristics, feelings about the existence of procedures to handle conflicts between users and the IS staff, years with the company, and years of IS experience produce moderating effects in the planning and design stage, or in the implementation stage of IS development

Chronic Pancreatitis Progressing to Duodenal Obstruction in the Absence of Classic Symptoms

We report the case of a 34-year-old alcoholic who was initially seen in March 1985 because of acute pancreatitis. A mass was demonstrated in the head of the pancreas. Serial sonogram and computed tomography scans over 4 1/2 years revealed progressive encroachment of the duodenum without symptoms attributable to obstruction. In 1989, three separate endoscopies with multiple biopsies showed chronic inflammation and strictures. Hypotonic duodenography confirmed stricture and obstructed duodenum. Surgical intervention is being considered. Duodenal obstruction secondary to chronic pancreatitis is rare. It may proceed subclinically for several years independent of continued alcohol use. Only when obstruction became severe in our patient did the classic symptoms of postprandial nausea, emesis, and weight loss become manifest. Obstructive jaundice from chronic pancreatitis due to stricture in the pancreatic portion of the common bile duct is uncommon

Empirical estimation of the option premium for residential redevelopment

This paper presents and validates a novel empirical approach for measuring the value of the option to redevelop using a standard hedonic dataset. Our analysis generalizes the standard hedonic model to account for the option value of reconfiguring hedonic characteristics. We test this model with over 162,000 real estate transactions in 53 towns in Connecticut between 1994 and 2007 by adding a non-linear intensity variable, which increases with the aggregate value of structure and decreases with land value. A conservative estimate is that about 20% of towns have significantly positive option value, with a mean value of 29–34% for properties most similar to vacant land. Multiple tests across towns support predictions of real options theory. Positive option value towns have higher house price volatility and estimated option value varies positively with price volatility, a finding inconsistent with NPV theory. We also find positive association between option value and drift in house prices and a U-shape relation with house price adjusted for structural characteristics. Higher property taxes reduce the value of option to redevelop

Profiteering from the Dot-com Bubble, Sub-Prime Crisis and Asian Financial Crisis

This paper explores the characteristics associated with the formation of bubbles that occurred in the Hong Kong stock market in 1997 and 2007, as well as the 2000 dot-com bubble of Nasdaq. It examines the profitability of Technical Analysis (TA) strategies generating buy and sell signals with knowing and without trading rules. The empirical results show that by applying long and short strategies during the bubble formation and short strategies after the bubble burst, it not only produces returns that are significantly greater than buy and hold strategies, but also produces greater wealth compared with TA strategies without trading rules. We conclude these bubble detection signals help investors generate greater wealth from applying appropriate long and short Moving Average (MA) strategies

Runtime Assurance Protection for Advanced Turbofan Engine Control

This paper describes technical progress made in the application of run time assurance (RTA) methods to turbofan engines with advanced propulsion control algorithms that are employed to improve engine performance. It is assumed that the advanced algorithms cannot be fully certified using current verification and validation approaches and therefore need to be continually monitored by an RTA system that ensures safe operation. However, current turbofan engine control systems utilize engine protection logic for safe combustion dynamics and stable airflow through the engine. It was determined that the engine protection logic should continue to be used to provide system safety and should be considered as a part of the overall RTA system. The additional function that an RTA system provides is to perform diagnostics on anomalous conditions to determine if these conditions are being caused by errors in the advanced controller. If this is the case, the RTA system switches operation to a trusted reversionary controller. Initial studies were performed to demonstrate this benefit. The other focus was to improve the performance of the engine protection logic, which was deemed too conservative and reduced engine performance during transient operations. It was determined that the conservative response was due to poor tuning of one of the controller channels within the protection logic. An automatic tuning algorithm was implemented to optimize the protection logic control gains based on minimizing tracking error. Improved tracking responses were observed with no change to the existing protection logic control architecture

Chinese family with diffuse oesophageal leiomyomatosis: A new COL4A5/COL4A6 deletion and a case of gonosomal mosaicism

© 2015 Liu et al. Background: Diffuse oesophageal leiomyomatosis (DOL) is a rare disorder characterized by tumorous overgrowth of the muscular wall of the oesophagus. DOL is present in 5 % of Alport syndrome (AS) patients. AS is a rare hereditary disease that involves varying degrees of hearing impairment, ocular changes and progressive glomerulonephritis leading to renal failure. In DOL-AS patients, the genetic defect consists of a deletion involving the COL4A5 and COL4A6 genes on the X chromosome. Case presentation: We report a two-generation family (4 individuals; parents and two children, one male and one female) with two members (mother and son) affected with oesophageal leiomyomatosis. Signs of potential renal failure, which characterizes AS, were only apparent in the index patient (son) 2 years and three months after the initial diagnosis of DOL. Blood DNA from the four family members were submitted to exome sequencing and array genotyping to perform a genome wide screening for disease causal single nucleotide (SN) and copy number (CN) variations. Analyses revealed a new 40kb deletion encompassing from intron 2 of COL4A5 to intron 1 of COL4A6 at Xq22.3. The breakpoints were also identified. Possible confounding pathogenic exonic variants in genes known to be involved in other extracellular matrices disorders were also shared by the two affected individuals. Meticulous analysis of the maternal DNA revealed a case of gonosomal mosaicism. Conclusions: This is the first report of gonadosomal mosaicism associated to DOL-AS.published_or_final_versio