Glancing incidence telescopes for space astronomy

Design optimization is reported for glancing telescopes of increased collecting areas. Considered are nested geometries for X-ray and extreme ultraviolet telescopes, each of which generates only one singular principal surface. In the case of the X-ray telescope, the field curvature of the outer telescope serves as a standard and the focus of each of the inner telescopes is made coplanar by a slight descrease in the collecting area of each of the inner telescopes. In the case of the EUV telescope, a slight change in the maximum slope angle of the inner telescope makes the field curvatures coincide. Five concentric X-ray telescopes form a collecting area of approximately 900 sq cm, and a nested EUV telescope consisting of two concentric telescopes produces a collecting area of about 45 sq cm

Implementation of Engine Control and Measurement Strategies for Biofuel Research in Compression-Ignition Engines

The global petroleum fuel supply is a limited resource that is understood to have negative influences on the environment because of its usage. In order address this issue, researchers are investigating sources of sustainable energy to offset this finite energy supply. One promising option for the transportation sector is biodiesel derived from various feedstocks. In order to perform viable research in the area of sustainable biodiesel, a multi-disciplinary effort to study the entire biodiesel spectrum from production to tailpipe emissions is underway at the University of Kansas. A critical aspect of this research includes investigating the effects of biodiesel combustion on engine operation. This includes observing engine power output, fuel consumption, and mechanical wear. In order to detect these characteristics effectively, full instrumentation of a single-cylinder compression-ignition engine is necessary. This engine serves as a test apparatus for experimental fuels and as a student-training tool. Of particular interest is the upgrade of this engine's fuel system to include electronically controlled fuel injection using an engine control unit. To aid in future research and to serve as a training reference, a detailed description of the construction, maintenance, and troubleshooting of the engine, dynamometer, auxiliary systems, and data acquisition equipment is included. Furthermore, this dissertation contains findings from biodiesel studies illustrating how fuel properties, such as fuel viscosity, play a role in injection and combustion behavior. The completed engine testing system provides the opportunity to continue into more sophisticated research venues, such as low temperature combustion and multiple injection events

Robert L. Detterman (1919-1990)

Detterman was well known for his biostratigraphic studies of the Triassic through Tertiary age sediments throughout arctic and south-central Alaska and the Alaska Peninsula. He was also considered an authority on glaciation for the North Slope and the Alaska Peninsula. He wrote or co-authored more than 113 publications and maps. Several finished manuscripts still await publication by the USGS. Because of his large bibliography, only a few of his more important publications will be mentioned here. ..

Design, Construction, and Validation of an In-Cylinder Pressure Recording System for Internal Combustion Engine Analysis

Due to an increased global interest in sustainable energy sources, it is imperative that the transportation sector find substitutes for the limited petroleum supply, such as biodiesel. This thesis contains three sections detailing the construction of a biodiesel engine testing system intended for biodiesel and engine technology research. Chapter one details the initial construction of the biodiesel test cell. In addition, the limitations of the system are individually pointed out, with solutions to these limitations discussed. Finally, the focus of this thesis is included to set the scope of the work discussed in chapters two and three. In chapter two, a biodiesel study was completed in order to investigate changes in engine performance because of the differences in fuel properties derived from various feedstock oils. The goal of this investigation was to determine which biodiesel fuel properties impact engine emissions and fuel consumption in comparison to petroleum-based diesel. The findings indicate good agreement with published works and resulted in correlations for fuel properties that were not discussed in literature. In chapter three, the design, construction, and validation of an engine cylinder pressure recording system are covered. In particular, the discussion includes the equipment selection, machining of the engine head and encoder adapter, writing of a LabVIEW program to record pressure and crank angle data, and the validation of this system. Validation was accomplished by testing three different fuels with very different combustion characteristics and directly comparing the results to literature trends and fundamental engine performance characteristics

Membrane-association of mRNA decapping factors is independent of stress in budding yeast

Recent evidence has suggested that the degradation of mRNA occurs on translating ribosomes or alternatively within RNA granules called P bodies, which are aggregates whose core constituents are mRNA decay proteins and RNA. In this study, we examined the mRNA decapping proteins, Dcp1, Dcp2, and Dhh1, using subcellular fractionation. We found that decapping factors co-sediment in the polysome fraction of a sucrose gradient and do not alter their behaviour with stress, inhibition of translation or inhibition of the P body formation. Importantly, their localisation to the polysome fraction is independent of the RNA, suggesting that these factors may be constitutively localised to the polysome. Conversely, polysomal and post-polysomal sedimentation of the decapping proteins was abolished with the addition of a detergent, which shifts the factors to the non-translating RNP fraction and is consistent with membrane association. Using a membrane flotation assay, we observed the mRNA decapping factors in the lower density fractions at the buoyant density of membrane-associated proteins. These observations provide further evidence that mRNA decapping factors interact with subcellular membranes, and we suggest a model in which the mRNA decapping factors interact with membranes to facilitate regulation of mRNA degradation

Impact of duplicate gene copies on phylogenetic analysis and divergence time estimates in butterflies

<p>Abstract</p> <p>Background</p> <p>The increase in availability of genomic sequences for a wide range of organisms has revealed gene duplication to be a relatively common event. Encounters with duplicate gene copies have consequently become almost inevitable in the context of collecting gene sequences for inferring species trees. Here we examine the effect of incorporating duplicate gene copies evolving at different rates on tree reconstruction and time estimation of recent and deep divergences in butterflies.</p> <p>Results</p> <p>Sequences from ultraviolet-sensitive (<it>UVRh</it>), blue-sensitive (<it>BRh</it>), and long-wavelength sensitive (<it>LWRh</it>) opsins,<it>EF-1α </it>and <it>COI </it>were obtained from 27 taxa representing the five major butterfly families (5535 bp total). Both <it>BRh </it>and <it>LWRh </it>are present in multiple copies in some butterfly lineages and the different copies evolve at different rates. Regardless of the phylogenetic reconstruction method used, we found that analyses of combined data sets using either slower or faster evolving copies of duplicate genes resulted in a single topology in agreement with our current understanding of butterfly family relationships based on morphology and molecules. Interestingly, individual analyses of <it>BRh </it>and <it>LWRh </it>sequences also recovered these family-level relationships. Two different relaxed clock methods resulted in similar divergence time estimates at the shallower nodes in the tree, regardless of whether faster or slower evolving copies were used, with larger discrepancies observed at deeper nodes in the phylogeny. The time of divergence between the monarch butterfly <it>Danaus plexippus </it>and the queen <it>D. gilippus </it>(15.3–35.6 Mya) was found to be much older than the time of divergence between monarch co-mimic <it>Limenitis archippus </it>and red-spotted purple <it>L. arthemis </it>(4.7–13.6 Mya), and overlapping with the time of divergence of the co-mimetic passionflower butterflies <it>Heliconius erato </it>and <it>H. melpomene </it>(13.5–26.1 Mya). Our family-level results are congruent with recent estimates found in the literature and indicate an age of 84–113 million years for the divergence of all butterfly families.</p> <p>Conclusion</p> <p>These results are consistent with diversification of the butterfly families following the radiation of angiosperms and suggest that some classes of opsin genes may be usefully employed for both phylogenetic reconstruction and divergence time estimation.</p

Influence of Fuel Injection System and Engine-Timing Adjustments on Regulated Emissions from Four Biodiesel Fuels

The use of biofuels for transportation has grown substantially in the past decade in response to federal mandates and increased concern about the use of petroleum fuels. As biofuels become more common, it is imperative to assess their influence on mobile source emissions of regulated and hazardous pollutants. This assessment cannot be done without first obtaining a basic understanding of how biofuels affect the relationship between fuel properties, engine design, and combustion conditions. Combustion studies were conducted on biodiesel fuels from four feedstocks (palm oil, soybean oil, canola oil, and coconut oil) with two injection systems, mechanical and electronic. For the electronic system, fuel injection timing was adjusted to compensate for physical changes caused by different fuels. The emissions of nitrogen oxides (NOx) and partial combustion products were compared across both engine injection systems. The analysis showed differences in NOx emissions based on hydrocarbon chain length and degree of fuel unsaturation, with little to no NOx increase compared with ultra-low sulfur diesel fuel for most conditions. Adjusting the fuel injection timing provided some improvement in biodiesel emissions for NOx and particulate matter, particularly at lower engine loads. The results indicated that the introduction of biodiesel and biodiesel blends could have widely dissimilar effects in different types of vehicle fleets, depending on typical engine design, age, and the feedstock used for biofuel production

Postoperative Atrial Fibrillation and Flutter in Liver Transplantation: An Important Predictor of Early and Late Morbidity and Mortality

Postoperative atrial fibrillation/flutter (POAF) is the most common perioperative arrhythmia and may be particularly problematic after liver transplantation (LT). This study is a single‐center retrospective analysis of POAF to determine its incidence following LT, to identify risk factors, to assess its impact on clinical outcomes, and to summarize management strategies. The records of all patients who underwent LT between 2010 and 2018 were reviewed. Extracted data included pre‐LT demographics and cardiac evaluation, in‐hospital post‐LT cardiac events, early and late complications, and survival. Among 1011 patients, the incidence of post‐LT POAF was 10%. Using binary logistic regression, pre‐LT history of atrial fibrillation was the strongest predictor of POAF (odds ratio [OR], 6.72; 95% confidence interval [CI], 2.00‐22.57; P < 0.001), followed by history of coronary artery disease (CAD; OR, 2.52; 95% CI, 1.10‐5.81; P = 0.03). Cardiac stress testing abnormality and CAD on cardiac catheterization were also associated with higher risk. Median time to POAF onset after LT was 3 days with 72% of cases resolving within 48 hours. POAF patients had greater hospital length of stay, death during the LT admission, and 90‐day and 1‐year mortality. POAF was an independent risk factor for post‐LT mortality (OR, 2.0; 95% CI, 1.3‐3.0; P < 0.01). Amiodarone was administered to 73% of POAF patients with no evidence of increased serum alanine aminotransferase levels. POAF occurred in 10% of post‐LT patients with early onset and rapid resolution in most affected patients. POAF patients, however, had significant morbidity and mortality, suggesting that POAF is an important marker for worse early and late post‐LT outcomes

Stented ureterovesical anastomosis in renal transplantation: does it influence the rate of urinary tract infections?

<p>Abstract</p> <p>Objective</p> <p>Our objective was to evaluate the impact of routine use of double-J stents on the incidence of urinary tract infection after renal transplantation.</p> <p>Methods</p> <p>We conducted a retrospective-comparative single-centre study in 310 consecutive adult deceased donor kidney recipients transplanted from 2002 to 2006. Patients were divided in two groups, with or without urinary stent implantation. To evaluate the predictive factors for UTI, donor and recipients pre- and post-transplantation data were analysed. Early urological complications and renal function within 12 months of transplantation were included as well.</p> <p>Results</p> <p>A total of 157 patients were enrolled to a stent (ST) and 153 patients to a no-stent (NST) group. The rate of urinary tract infection at three months was similar between the two groups (43.3% ST vs. 40.1% NST, p = 0.65). Of the identified pathogens Enterococcus and Escherichia coli were the most common species. In multivariate analysis neither age nor immunosuppressive agents, BMI or diabetes seemed to have influence on the rate of UTI. When compared to males, females had a significantly higher risk for UTI (54.0% vs. 33.5%).</p> <p>Conclusion</p> <p>Prophylactic stenting of the ureterovesical anastomosis does not increase the risk of urinary tract infection in the early postoperative period.</p

Pre‐Liver Transplant Cardiac Catheterization is Associated with Low Rate of Myocardial Infarction and Cardiac Mortality

Background A previous study at Indiana University demonstrated a reduction in myocardial infarction (MI) incidence with increased frequency of cardiac catheterization (CATH) in liver transplant (LT) candidates. A strict protocol for performing CATH based upon predefined risk factors, rather than non‐invasive testing alone, was applied to a subgroup (2009‐2010) from that study. CATH was followed by percutaneous coronary intervention (PCI) in cases of significant coronary artery disease (CAD; ≥50% stenosis). The current study applies this screening protocol to a larger cohort (2010‐2016) to assess post‐LT clinical outcomes. Results Among 811 LT patients, 766 underwent stress testing (94%), and 559 underwent CATH (69%) of whom 10% had CAD requiring PCI. The sensitivity of stress echocardiography in detecting significant CAD was 37%. Predictors of PCI included increasing age, male gender and personal history of CAD (p<0.05 for all). Compared to patients who had no CATH, patients who underwent CATH had higher mortality (p=0.07), and the hazard rates (HR) for mortality increased with CAD severity [normal CATH (HR: 1.35 [95% CI: 0.79, 2.33], p=0.298); non‐obstructive CAD (HR: 1.53 [95% CI: 0.84, 2.77], p=0.161); and significant CAD (HR: 1.96 [95% CI: 0.93, 4.15], p=0.080)]. Post‐LT outcomes were compared to the 2009‐2010 subgroup from the previous study and showed similar 1‐year overall mortality (8% and 6%, p=0.48); 1‐year MI incidence (<1% and <1%, p=0.8); and MI deaths as portion of all deaths (3% and 9%, p=0.35). Conclusion Stress echocardiography alone is not reliable in screening LT patients for CAD. Aggressive CAD screening with CATH is associated with low rate of MI and cardiac mortality and validates the previously published protocol when extrapolated over a larger sample and longer follow‐up period