55 research outputs found
Improvement to the Prediction of Fuel Cost Distributions Using ARIMA Model
Availability of a validated, realistic fuel cost model is a prerequisite to
the development and validation of new optimization methods and control tools.
This paper uses an autoregressive integrated moving average (ARIMA) model with
historical fuel cost data in development of a three-step-ahead fuel cost
distribution prediction. First, the data features of Form EIA-923 are explored
and the natural gas fuel costs of Texas generating facilities are used to
develop and validate the forecasting algorithm for the Texas example.
Furthermore, the spot price associated with the natural gas hub in Texas is
utilized to enhance the fuel cost prediction. The forecasted data is fit to a
normal distribution and the Kullback-Leibler divergence is employed to evaluate
the difference between the real fuel cost distributions and the estimated
distributions. The comparative evaluation suggests the proposed forecasting
algorithm is effective in general and is worth pursuing further.Comment: Accepted by IEEE PES 2018 General Meetin
Small intestinal mucosa expression of putative chaperone fls485
<p>Abstract</p> <p>Background</p> <p>Maturation of enterocytes along the small intestinal crypt-villus axis is associated with significant changes in gene expression profiles. <it>fls485 </it>coding a putative chaperone protein has been recently suggested as a gene involved in this process. The aim of the present study was to analyze <it>fls48</it>5 expression in human small intestinal mucosa.</p> <p>Methods</p> <p><it>fls485 </it>expression in purified normal or intestinal mucosa affected with celiac disease was investigated with a molecular approach including qRT-PCR, Western blotting, and expression strategies. Molecular data were corroborated with several <it>in situ </it>techniques and usage of newly synthesized mouse monoclonal antibodies.</p> <p>Results</p> <p>fls485 mRNA expression was preferentially found in enterocytes and chromaffine cells of human intestinal mucosa as well as in several cell lines including Rko, Lovo, and CaCo2 cells. Western blot analysis with our new anti-fls485 antibodies revealed at least two fls485 proteins. In a functional CaCo2 model, an increase in fls485 expression was paralleled by cellular maturation stage. Immunohistochemistry demonstrated fls485 as a cytosolic protein with a slightly increasing expression gradient along the crypt-villus axis which was impaired in celiac disease Marsh IIIa-c.</p> <p>Conclusions</p> <p>Expression and synthesis of fls485 are found in surface lining epithelia of normal human intestinal mucosa and deriving epithelial cell lines. An interdependence of enterocyte differentiation along the crypt-villus axis and fls485 chaperone activity might be possible.</p
Investigating Effects of Tulathromycin Metaphylaxis on the Fecal Resistome and Microbiome of Commercial Feedlot Cattle Early in the Feeding Period
The objective was to examine effects of treating commercial beef feedlot cattle with therapeutic doses of tulathromycin, a macrolide antimicrobial drug, on changes in the fecal resistome and microbiome using shotgun metagenomic sequencing. Two pens of cattle were used, with all cattle in one pen receiving metaphylaxis treatment (800 mg subcutaneous tulathromycin) at arrival to the feedlot, and all cattle in the other pen remaining unexposed to parenteral antibiotics throughout the study period. Fecal samples were collected from 15 selected cattle in each group just prior to treatment (Day 1), and again 11 days later (Day 11). Shotgun sequencing was performed on isolated metagenomic DNA, and reads were aligned to a resistance and a taxonomic database to identify alignments to antimicrobial resistance (AMR) gene accessions and microbiome content. Overall, we identified AMR genes accessions encompassing 9 classes of AMR drugs and encoding 24 unique AMR mechanisms. Statistical analysis was used to identify differences in the resistome and microbiome between the untreated and treated groups at both timepoints, as well as over time. Based on composition and ordination analyses, the resistome and microbiome were not significantly different between the two groups on Day 1 or on Day 11. However, both the resistome and microbiome changed significantly between these two sampling dates. These results indicate that the transition into the feedlot—and associated changes in diet, geography, conspecific exposure, and environment—may exert a greater influence over the fecal resistome and microbiome of feedlot cattle than common metaphylactic antimicrobial drug treatment
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
Feilke revisited : 60 Stellenbesuche
Weitere Hrsg.: Thorsten Pohl, Sara Rezat, Torsten Steinhoff, Martin SteinseiferAnlässlich des 60. Geburtstags des Linguisten und Sprachdidaktikers Helmuth Feilke wurden Wegbegleiterinnen und Wegbegleiter gebeten, einzelne Stellen in seinen wissenschaftlichen Schriften erneut zu besuchen.
Entstanden sind pointierte Kommentare, kurze wissenschaftliche Abhandlungen und Analysen, Varianten auch des kritischen und kontroversen Nach- und Weiterdenkens und Ansätze zur Neu- oder Re-Kontextualisierung.
Je nach wissenschaftlicher Vita der Autorinnen und Autoren kann es sich um Stellen handeln, deren Rezeption zeitlich weit zurückliegt, oder um Passagen, die ganz aktuelle Fragen der eigenen Forschungsarbeit tangieren. Abgesehen davon, dass ein kurzes Format für die Beiträge gewählt und die Autorinnen und Autoren gebeten wurden, die ausgewählte Stelle knapp zu verorten und zu erläutern, war die Bearbeitungsform gänzlich freigestellt.
So sind Texte in einer Bandbreite von pointierten Kommentaren, kurzen wissenschaftlichen Abhandlungen und Analysen, Varianten des Nach- und Weiterdenkens, Ansätze zur Neu- oder Re-Kontextualisierung bis hin zu Formen des kritischen Hinterfragens und der kontroversen Auseinandersetzung entstanden
Strategien zur Erhöhung der Trübung in Getränkeemulsionen
Carbonisierte Erfrischungsgetränke enthalten für ein trübes Erscheinungsbild häufig Getränkeemulsionen. Diese sogenannten „Clouds“ sollen die Natürlichkeit fruchtbasierter Getränke unterstreichen. Ziel der vorliegenden Arbeit war es, Strategien zu entwickeln, die Trübkraft von Getränkeemulsionen zu erhöhen. Um dies zu erreichen, musste zunächst eine Korrelation zwischen der optischen Wahrnehmung des Menschen und den Messwerten der Trübungsmessung hergestellt werden. Es wurde ein polynominaler Zusammenhang zwischen der menschlichen Wahrnehmung und den Trübungsmesswerten nachgewiesen. Außerdem wurden verschieden sensible Bereiche festgestellt. Aus einer systematischen Untersuchung der Einflussfaktoren auf die Trübung ließ sich ableiten, dass neben der Öltropfengröße und -konzentration, die Brechungsindexdifferenz (BID) zwischen den beiden Phasen einer Emulsion signifikante Trübungsunterschiede erzeugt. Folglich basierten die Strategien zur Trübungserhöhung auf der Erhöhung der BID zwischen kontinuierlicher und disperser Phase, was mittels Modifizierung der Grenzfläche oder der dispersen Phase erfolgen sollte. Es wurde angenommen, dass sich die Lichtbrechung an der Grenzfläche verstärkt, wenn Partikel statt Emulgatoren zur Stabilisierung der Emulsion verwendet werden. Eine ausführliche Literaturrezension ergab, dass sich sogenannte Pickering-Partikel dafür eignen. Nichtsdestotrotz kann die notwendige physikalische Stabilität, die Getränkeemulsionen mit sich bringen müssen, nicht mit Pickering-Partikeln hergestellt werden. Die herausragende Stabilität von Pickering-Emulsionen basiert auf einem 3D-Netzwerk, welches bei der Verdünnung in die Endanwendung zwangsläufig zerstört wird. Alternativ wurden mittels eines Heißemulgierverfahrens hochschmelzende Emulgatoren verwendet. Die während des Abkühlens einsetzende Kristallisation des Emulgators sollte die lichtstreuenden Eigenschaften der Emulsion erhöhen. Die Ergebnisse ließen darauf schließen, dass die getesteten Emulgatoren nicht in ausreichendem Maße kristallisierten oder die Anordnung an der Grenzfläche die Ausbildung einer Kristallstruktur verhindert haben. Im Gegensatz dazu war der Austausch der dispersen Phase mit einem hochschmelzenden Fett erfolgreich und führte zu einer signifikanten Erhöhung der BID um 0,05–0,08 und 50 % mehr Trübung. Um überprüfen zu können, ob der Trübungsanstieg mit der Kristallinität der dispersen Phase zusammen hängt, musste der Festfettgehalt (FFG) bestimmt werden. Die klassische FFG-Bestimmung mittels Niederfeld-Magnetresonanz (TD-NMR) konnte in diesem Fall nicht angewendet werden, da die Methode nur bis zu einem Wassergehalt von 15 % zuverlässig ist. Durch die Kombination von Inversion Recovery und T2-Relaxations-Experimenten – verbunden über ein probenspezifisches Inversion Delay – konnte eine Methode entwickelt werden, die es ermöglicht, in stark wasserhaltigen Proben flüssige und feste Fettanteile zu messen. Basierend auf den Ergebnissen konnte festgestellt werden, dass ein minimaler FFGkrit > 36 % notwendig ist, um signifikante Trübungsunterschiede zu erzeugen. Die Ergebnisse der vorliegenden Arbeit demonstrieren, dass eine Erhöhung der BID eine erfolgreiche Strategie darstellt, die Trübung in Getränkeemulsionen signifikant zu erhöhen, und die Verwendung von festen Fetten verursacht bei ausreichender Kristallisation eine höhere Lichtbrechung in Emulsionen.Carbonated soft drinks (CSD) often contain beverage emulsions to provide turbidity. These so-called clouds enhance the natural appearance of fruit-derived soft drinks. The aim of the present study was to develop a strategy to increase turbidity in beverage clouds. To fulfill this aim it was first necessary to understand the relation between human visual perception and instrumental turbidity measurement. A polynomial relationship between turbidity and the human perception was established. Depending on the intensity of the turbidity different ranges of sensitivity were found. In a systematic approach factors affecting turbidity were compared. It could be concluded that apart from droplet size and concentration the refractive index difference (RID) between the two phases of the emulsion accounts for significant changes in turbidity. Therefore strategies to increase turbidity were based on the RID between continuous and dispersed phase, which may be achieved either via modification of the interface or the dispersed phase itself. Scattering of light at the interface was expected to increase when particles are used for stabilization of an emulsion. Based on an extensive review RID may be modified via Pickering particles. However, it was concluded that physical stability in Pickering emulsion as a prerequisite for beverage emulsions is not provided. Superior stability of Pickering emulsions is based on 3D network formation which is destabilized upon dilution when preparing beverages with near water viscosity. As an alternative, high melting emulsifiers (HME) were investigated performing a hot homogenization procedure. Crystallization of the emulsifier upon cooling was expected to increase the scattering efficiency at the interface. The results indicated that crystallization of the tested emulsifiers did not occur to a sufficient degree or conformational changes at the interface inhibit the formation of a crystal network. In contrast, modification of the dispersed phase with high melting lipids (HML) resulted in a significant increase of the RID by 0.05-0.08 and a significant increase in turbidity of 50 %. To prove that this effect must be attributed to the crystallinity of the dispersed phase, the solid fat content (SFC) in dispersion had to be determined. Classical SFC measurement by TD-NMR is not suitable in the present study, since it only allows maximum water content of 15 %. A new procedure was established by combining an inversion recovery and T2-relaxation with a customized inversion delay and dedicated data processing. Based on this method it was shown that a minimum SFCcrit > 36 % is required for significantly more turbid samples. Therefore, results of the present study clearly demonstrate that an increase in the RID of an emulsion is a suitable strategy to increase turbidity and, in case of adequate crystallinity, solid lipids enable to achieve more scattering efficiency
Bacillus thuringiensis CbpA is a collagen binding cell surface protein under c-di-GMP control
Cyclic diguanylate (c-di-GMP) signalling affects several cellular processes in Bacillus cereus group bacteria including biofilm formation and motility, and CdgF was previously identified as a diguanylate cyclase promoting biofilm formation in B. thuringiensis. C-di-GMP can exert its function as a second messenger via riboswitch binding, and a functional c-di-GMP-responsive riboswitch has been found upstream of cbpA in various B. cereus group strains. Protein signature recognition predicted CbpA to be a cell wall-anchored surface protein with a fibrinogen or collagen binding domain. The aim of this study was to identify the binding ligand of CbpA and the function of CbpA in cellular processes that are part of the B. cereus group c-di-GMP regulatory network. By global gene expression profiling cbpA was found to be down-regulated in a cdgF deletion mutant, and cbpA exhibited maximum expression in early exponential growth. Contrary to the wild type, a ΔcbpA deletion mutant showed no binding to collagen in a cell adhesion assay, while a CbpA overexpression strain exhibited slightly increased collagen binding compared to the control. For both fibrinogen and fibronectin there was however no change in binding activity compared to controls, and CbpA did not appear to contribute to binding to abiotic surfaces (polystyrene, glass, steel). Also, the CbpA overexpression strain appeared to be less motile and showed a decrease in biofilm formation compared to the control. This study provides the first experimental proof that the binding ligand of the c-di-GMP regulated adhesin CbpA is collagen
Long-Term Kinetics of Serum Galactomannan during Treatment of Complicated Invasive Pulmonary Aspergillosis
Several studies have evaluated the serum galactomannan (GM) antigen assay in pediatric patients, and there is convincing evidence for its usefulness as a diagnostic tool for invasive Aspergillus infections in patients with acute leukemias or post allogeneic hematopoietic cell transplantation (HCT). Less is known about the utility of the assay in monitoring responses to treatment in patients with established invasive aspergillosis (IA). Here, we present the long-term kinetics of serum galactomannan in two severely immunocompromised adolescents with invasive pulmonary aspergillosis (IPA) who were cured after complicated clinical courses. We also review the utility of the GM antigen assay in serum as a prognostic tool around the time of diagnosis of IA and as a biomarker to monitor disease activity in patients with established IA and assess responses to systemic antifungal therapy
Epidemiology, utilisation of healthcare resources and outcome of invasive fungal diseases following paediatric allogeneic haematopoietic stem cell transplantation
Summary
Background
Epidemiology and management practices of invasive fungal diseases (IFD) after allogeneic haematopoietic stem cell transplantation (HSCT) are a subject of constant change. We investigated the contemporary incidence, diagnostics, antifungal management and outcome at a major paediatric transplant centre in Germany.
Methods
The single‐centre retrospective observational study included all paediatric allogeneic HSCT patients (pts) transplanted between 2005 and 2015. Patient‐related data were assessed up to 365 days post‐transplant. The primary endpoint was the incidence of possible, probable and proven IFDs. Secondary endpoints included diagnostics and antifungal treatment; analysis of risk factors; and overall survival with the last follow‐up in January 2017.
Results
A total of 221 first (196), second (21) or third (4) procedures were performed in 200 pts (median age: 9 years, range, 0.5‐22) for leukaemia/lymphoma (149) and non‐malignant disorders (72). Prophylaxis was administered in 208 HSCT procedures (94%; fluconazole, 116, mould‐active agents, 92). At least one computed tomography scan of the chest was performed in 146, and at least one galactomannan antigen assay in 60 procedures. There were 15 cases of proven (candidemia, 4; aspergillosis, 4) or probable (aspergillosis, 7) IFDs, accounting for an incidence rate of 6.8%. Overall mortality at last follow‐up was 30%; the occurrence of proven/probable IFDs was associated with a reduced survival probability (P < .001).
Conclusion
Morbidity and mortality from IFDs at our institution were consistent with data reported from other centres. Utilisation of healthcare resources for prevention, diagnosis and management of IFDs was considerable
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