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Search Results: 1 - 10 of 26242 matches for " Martin Schlup "
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Unusual manifestation of Erdheim-Chester disease
Antony Pan, Terence Doyle, Martin Schlup, Ralf Lubcke, Michael Schultz
BMC Gastroenterology , 2011, DOI: 10.1186/1471-230x-11-77
Abstract: This case report describes the case of a 69-year-old man who presented otherwise well to the gastroenterology department with unspecific abdominal symptoms, nausea, vomiting and weight loss. ECD involving the gastrointestinal tract was confirmed clinically, radiologically and histologically.Gastroenterological manifestation of ECD is rare but should be considered in the differential diagnosis in patients presenting with evidence of multi-organ disease and typical radiological features of Erdheim-Chester disease elsewhere.Erdheim-Chester Disease (ECD) is a rare multisystem histiocytosis characterized by the xanthomatous or xanthogranulomatous infiltration of tissues with histiocytes, surrounded by fibrosis. The disease can affect multiple organs systems, but gastrointestinal involvement, is exceedingly rare. We describe here the case of a 69-year old man with ECD who presented to the gastroenterology department with unspecific abdominal symptoms, nausea, vomiting and weight loss.A previously fit and well 69-year-old man was admitted to the gastroenterology department with a short one month history of lethargy, decreased appetite, persistent vomiting, significant weight loss of six kilograms over 1 month and a dry cough. He denied abdominal pain, haematemesis, dysphagia and a change in bowel habit and described no cardiac, respiratory, neurological symptoms or bone pain. His past medical history includes appendectomy and total hip joint replacement. At the time of admission, he was not on any regular medication.Physical examination revealed that he was febrile (38.8C°) and appeared cachexic but with no peripheral stigmata of chronic liver disease. His abdominal examination revealed hepatomegaly but no other organomegaly, per rectal examination was unremarkable. His cardiopulmonary examinations were unremarkable apart from bilateral pitting edema up to his ankles. Peripheral blood analysis revealed an anaemia of chronic disease with hemoglobin of 108 g/L (norm - male 1
The role of aspirin in post-polypectomy bleeding – a retrospective survey
Pan Antony,Schlup Martin,Lubcke Ralf,Chou Annie
BMC Gastroenterology , 2012, DOI: 10.1186/1471-230x-12-138
Abstract: Background Bleeding following colonoscopic polypectomy is a common complication and has been reported to occur in up to 6.1% of patients. Several risk factors have been discussed but their overall contribution to post-polypectomy bleeding remains controversial. The aim of the study was to determine the rate of post polypectomy bleeding and to analyse the role of potential risk factors especially the role of aspirin. Methods We conducted a retrospective cohort study of all patients who underwent polypectomy at Dunedin Hospital, New Zealand between January 2007 and June 2009. Results During the study period, 514 patients underwent colonoscopy with polypectomy and a total of 1502 polyps were removed. From further analysis we excluded 21 patients; 15 patients had surgery immediately after colonoscopy for the diagnosis of colorectal carcinoma and 6 patients presented with symptoms of an acute lower gastrointestinal bleed prior to colonoscopy. Of the remaining 493 patients, 11 patients (2.2%) presented with post-polypectomy bleeding within 30 days of the investigation of which 8 were on aspirin. In total 145 patients were taking aspirin prior to colonoscopy and 348 patients were not taking aspirin. The use of aspirin was associated with an increased prevalence of post-polypectomy bleeding (OR=6.72, 95% C.I. 1.76 to 25.7). Interestingly, the use of non-steroidal anti-inflammatory drugs (NSAIDs) was not associated with risk of bleeding after polypectomy (OR=2.82, 95% C.I, 0.34 to 23.3). Conclusion Our study confirmed a significantly increased risk of lower gastrointestinal bleeding following polypectomy in patients taking aspirin. We would recommend approaching the patient on aspirin coming forward for a colonoscopy with potential polypectomy with caution.
Infrared Spectroscopic Characterization of CIT-6 and a Family of *BEA Zeolites
Sean R. Tomlinson,Tyler McGown,John R. Schlup,Jennifer L. Anthony
International Journal of Spectroscopy , 2013, DOI: 10.1155/2013/961404
Abstract: Infrared spectroscopy is known to be a useful tool for identifying local structure changes in zeolites. Infrared spectroscopy is often employed to complement X-ray diffraction data. Local structure changes in zeolite CIT-6 and its zeolite beta (*BEA) analogs caused by calcination, altering framework composition, and ion exchange have been identified with mid- and far-infrared spectroscopy. Differences in the local structures of the samples were observed in mid- and far-infrared spectra, including changes in the intratetrahedral asymmetric stretch, the double-ring mode, and the intratetrahedral bending mode regions. The infrared spectra indicate that calcination or acetic acid extraction changed the structure of CIT-6 to that of zeolite beta (*BEA). Zinc ion exchange or the substitution of aluminum into the framework structure of acetic acid extracted samples retained the CIT-6 structure. 1. Introduction Microporous molecular sieves are employed in catalytic, ion exchange and adsorption/separation processes and are, therefore, of scientific and commercial interest [1]. While “zeolite” specifically refers to aluminosilicate microporous molecular sieves, the term is often applied to compounds with similar crystalline structures. Zeolites are remarkable because of their uniform pores (which are less than 2?nm), their channel configuration, and their void space organization. Because of zeolites’ vast application potential, the characterization of chemical composition, structure, and bonding are important, leading to the use of various analytical techniques to obtain such data. Chemical composition of zeolites can be obtained with atomic absorption spectroscopy (AAS), atomic emission spectrometry (ICP-AES), and X-ray fluorescence spectrometry (XRF) [2]. Both 29Si and 27Al nuclear magnetic resonance (NMR) spectroscopies have proven to be valuable tools in understanding local environments surrounding atoms in the lattice. When NMR data are coupled with density functional theory (DFT) calculations, valuable insights into the crystalline structure of zeolites result [3]. X-ray diffraction (XRD) is also widely used to determine crystalline structure of zeolitic materials, and these data permit identification of samples by comparison with XRD results of known samples [4–6]. Vibrational spectroscopy, including both Raman and infrared (IR), is often employed to investigate the chemistry (with probe molecules) and short-range order in zeolites [7–15]. In the 1970s, Flanigen et al. proposed zeolite functional group assignments for the absorption bands between 1250 and
Phase-preserving chirped-pulse optical parametric amplification to 17.3 fs directly from a Ti:Sapphire oscillator
C. P. Hauri,P. Schlup,G. Arisholm,J. Biegert,U. Keller
Physics , 2004, DOI: 10.1364/OL.29.001369
Abstract: Phase-stabilized 12-fs, 1-nJ pulses from a commercial Ti:sapphire oscillator are directly amplified in a chirped-pulse optical parametric amplifier and recompressed to yield near-transform-limited 17.3-fs pulses. The amplification process is demonstrated to be phase preserving and leads to 85-uJ, carrier-envelope-offset phase-locked pulses at 1 kHz for 0.9 mJ of pump, corresponding to a single-pass gain of 8.5 x 10^4.
A Yield Mapping Procedure Based on Robust Fitting Paraboloid Cones on Moving Elliptical Neighborhoods and the Determination of Their Size Using a Robust Variogram  [PDF]
Martin Bachmaier
Positioning (POS) , 2010, DOI: 10.4236/pos.2010.11004
Abstract: The yield map is generated by fitting the yield surface shape of yield monitor data mainly using paraboloid cones on floating neighborhoods. Each yield map value is determined by the fit of such a cone on an elliptical neighborhood that is wider across the harvest tracks than it is along them. The coefficients of regression for modeling the paraboloid cones and the scale parameter are estimated using robust weighted M-estimators where the weights decrease quadratically from 1 in the middle to zero at the border of the selected neighborhood. The robust way of estimating the model parameters supersedes a procedure for detecting outliers. For a given neighborhood shape, this yield mapping method is implemented by the Fortran program paraboloidmapping.exe, which can be downloaded from the web. The size of the selected neighborhood is considered appropriate if the variance of the yield map values equals the variance of the true yields, which is the difference between the variance of the raw yield data and the error variance of the yield monitor. It is estimated using a robust variogram on data that have not had the trend removed.
Sources of inaccuracy when estimating economically optimum N fertilizer rates  [PDF]
Martin Bachmaier
Agricultural Sciences (AS) , 2012, DOI: 10.4236/as.2012.33037
Abstract: Nitrogen rate trials are often performed to determine the economically optimum N application rate. For this purpose, the yield is modeled as a function of the N application. The regression analysis provides an estimate of the modeled function and thus also an estimate of the economic optimum, Nopt. Obtaining the accuracy of such estimates by confidence intervals for Nopt is subject to the model assumptions. The dependence of these assumptions is a further source of inaccuracy. The Nopt estimate also strongly depends on the N level design, i.e., the area on which the model is fitted. A small area around the supposed Nopt diminishes the dependence of the model assumptions, but prolongs the confidence interval. The investigations of the impact of the mentioned sources on the inaccuracy of the Nopt estimate rely on N rate trials on the experimental field Sieblerfeld (Bavaria). The models applied are the quadratic and the linear-plus-plateau yield regression model.
Waiting for Redemption in The House of Asterion: A Stylistic Analysis  [PDF]
Martin Tilney
Open Journal of Modern Linguistics (OJML) , 2012, DOI: 10.4236/ojml.2012.22007
Abstract: The House of Asterion is a short story by Jorge Luis Borges that retells the classical myth of the Cretan Minotaur from an alternate perspective. The House of Asterion features the Minotaur, aka Asterion, who waits for “redemption” in his labyrinth. Many literary critics have suggested that the Borgesian labyrinth is a metaphor for human existence and the universe itself. Others have correctly interpreted Asterion’s ironic death at the hands of Theseus as his eagerly awaited redemption. Borges’ subversion of the reader’s expectations becomes the departure point for a systemic functional stylistic analysis of the story in one of its English translations, revealing how deeper-level meanings in the text are construed through its lexicogrammatical structure. A systemic functional stylistic reading suggests that on a higher level of reality, Asterion’s redemption is not only the freedom that death affords, but also a transformation that transcends his fictional universe. Asterion’s twofold redemption is brought about not only by the archetypal hero Theseus but also by the reader, who through the process of reading enables Asterion’s emancipation from the labyrinth.
A Macroeconomic Model of Biodiversity Protection  [PDF]
David Martin
Theoretical Economics Letters (TEL) , 2013, DOI: 10.4236/tel.2013.35A1006
Abstract:

Many biodiversity researchers have responded to the financial constraints faced by policy makers to develop models based upon the “Noah’s Ark” metaphor, implying that society can save only a limited amount of biodiversity. Unfortunately, as Herman Daly (Land Economics, 1991) pointed out, such microeconomic rules can allow an ark to sink albeit in some optimal fashion. So, I step back to look at the macroeconomic question, how big should the ark be? I start with Norgaard’s (Ecological Economics, 2010) framework, which is based upon the concept of a production possibility frontier combined with a sustainability criterion. I develop a model from that starting point by shifting to an isoquant framework while maintaining the strong sustainability criterion. I demonstrate how this model allows for identifying and addressing the key biodiversity protection policy criteria at the macroeconomic level. One key conclusion from this modeling is that Daly’s analysis remains remarkably prescient.

Analysis of the Navier-Stokes Equations  [PDF]
Helmut Martin
Journal of Applied Mathematics and Physics (JAMP) , 2014, DOI: 10.4236/jamp.2014.210106
Abstract: The Navier-Stokes equations for incompressible fluid flows with impervious boundary and free surface are analyzed by means of a perturbation procedure involving dimensionless variables and a dimensionless perturbation parameter which is composed of kinematic viscosity of fluid, the acceleration of gravity and a characteristic length. The new dimensionless variables are introduced into the equation system. In addition, the perturbation parameter is introduced into terms for deriving approximations systems of different orders. Such systems are obtained by equating coefficients of like powers of perturbation parameter for the successive coefficients in the series. In these systems several terms are analyzed with regards to size and significance. Based on those systems, suitable solutions of NS equations can be found for different boundary conditions. For example, a relation for stationary channel flow is obtained as approximation to the NS equations of the lowest order after transformation back to dimensional variables.
Accelerating Expansion in a Closed Universe  [PDF]
Martin Tamm
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.63029
Abstract: In this paper, I suggest a possible explanation for the accelerating expansion of the universe. This model does not require any dark energy or quintessence. Rather, the idea is to suggest a different view on the origin of general relativity. Since it is very difficult to say something in general, I will mainly restrict myself to the case of very low curvature. The question about the underlying reasons for the acceleration is also closely related to the question whether the universe is a finite or infinite. It is part of the purpose of this paper to argue that a phase of accelerating expansion may be very well compatible with the idea of a closed universe.
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