A Comparison of Sensitivity Metrics for Two-Stage Ignition Behavior in Rapid Compression Machines

A rapid compression machine (RCM) multi-zone model is used to simulate the ignition of primary reference fuel (PRF) mixtures that exhibit two-stage ignition behavior. Sensitivity coefficients for each reaction in the PRF mechanism are calculated from four different metrics: (1) first-stage energy release, (2) first-stage pressure rise, (3) first-stage ignition delay time, and (4) total ignition delay time. The sensitivity coefficients are used to provide four unique rankings, and the rankings are compared using Spearman’s rank correlation coefficient. Special emphasis is given to comparing the rankings based on first-stage energy release and total ignition delay time. The level of agreement between these two rankings is shown to depend on the reaction conditions. Simulation cases with high peak heat release rates during the first stage of ignition tend to exhibit disagreement in the rankings, indicating that new kinetic information can be obtained by studying first stage energy release in addition to total ignition delay time. Simulations show that the high peak heat release rates are associated with energy release across a broad range of temperatures (range can be in excess of 100 K even for lean conditions). This distribution leads to a discrepancy between sensitivity coefficients calculated for the total ignition delay time and the first-stage energy release. Sensitivity coefficients for the total ignition delay time are characterized by reactivity at the highest temperatures in the RCM, while sensitivity coefficients for the first-stage energy release are characterized by reactivity across the full range of temperatures in the RCM

Investigating the role and regulation of human mitochondrial poly(A) polymerase

PhD ThesisPolyadenylation by the mitochondrial poly(A) polymerase (mtPAP) is a crucial step of post-transcriptional modification in mammalian gene expression. In human mitochondria, polyadenylation is required for completion of seven UAA stop codons following complete processing of the major polycistronic RNA unit. Patients homozygous for a 1432A>G mutation in the PAPD1 gene, which encodes mtPAP, suffer from symptoms consistent with mitochondrial disease including autosomal-recessive spastic ataxia and optic atrophy. The principal defect of the 1432A>G mutation is short adenylate tails on mt-mRNAs. Fibroblast lines from patients harboring the 1432A>G PAPD1 mutation were established, and analysis of mitochondrial gene expression showed non-uniform dysregulation. For mt-mRNAs and translation products, there is a mix of depletion, stabilization and no effect, leading to major deficits at steady-state protein levels and of respiratory complexes. To confirm the pathological nature of the mutation, a complementation experiment was performed, which showed that expression of the WT PAPD1 gene rescued the mutant phenotype. To assess whether catalytic activity was altered in the mutant enzyme, in vitro polyadenylation assays with WT and N478D recombinant mtPAP were undertaken. The N478D mtPAP was found to generate the short oligo(A) tails as observed in vivo. In addition, the presence of the LRPPRC/SLIRP complex increased the maximal poly(A) extensions generated by both WT and mutant mtPAP. Finally, experiments were undertaken to identify factors potential interacting with mtPAP. The major interacting factor was found to be ATAD3, a protein reported to be involved with multiple mitochondrial processes involving DNA and translation machinery in the form of nucleoids or mitoribosomes respectively. In summary, these investigations provide insights into the impact and regulation of mitochondrial polyadenylation, and contribute towards unraveling the complexities of post-transcriptional maturation in human mitochondrial gene expression.The Pathological Society of Great Britain and Ireland, and Newcastle University

Comparison of Ultrasound-Guided Vs Traditional Arterial Cannulation by Emergency Medicine Residents

Introduction: We sought to determine whether ultrasound-guided arterial cannulation (USGAC) is more successful than traditional radial artery cannulation (AC) as performed by emergency medicine (EM) residents with standard ultrasound training.Methods: We identified 60 patients age 18 years or older at a tertiary care, urban academic emergency department who required radial AC for either continuous blood pressure monitoring or frequent blood draws. Patients were randomized to receive radial AC via either USGAC or traditional AC. If there were three unsuccessful attempts, patients were crossed over to the alternative technique. All EM residents underwent standardized, general ultrasound training.Results: The USGAC group required fewer attempts as compared to the traditional AC group (mean 1.3 and 2.0, respectively; p<0.001); 29 out of 30 (96%) successful radial arterial lines were placed using USGAC, whereas 14 out of 30 (47%) successful lines were placed using traditional AC (p<0.001). There was no significant difference in length of procedure or complication rate between the two groups. There was no difference in provider experience with respect to USGAC vs traditional AC.Conclusion: EM residents were more successful and had fewer cannulation attempts with USGAC when compared to traditional AC after standard, intern-level ultrasound training.

Literature review: handpump functionality monitoring

This section provides a review of literature on handpump functionality monitoring. It seeks to highlight some of the functionality measurements used in the literature and describe the challenges that emerge from inconsistencies in the way the results of functionality studies are presented by authors

An evaluation of curriculum-related specialties in grades five and six

Thesis (Ed.M.)--Boston Universit

Impact of Cleaning Frequency on Nitrogen Balance in Open Feedlot Pens

Pen cleaning frequency of feedlot pens was evaluated during the summer of 2001 and 2002. Dry matter, organic matter and nitrogen recoveries were evaluated on a per head basis. Cleaning pens monthly compared to cleaning at the end of the feeding period resulted in significantly more DM, OM and N recovered. Cleaning pens every month increased N removal by 7.0 lb per steer (49.9% increase) above manure N removed at the end of the feeding period

Teaching Educators Basic Fruit Tree Grafting Methods

Hands-on education has proven to be successful in teaching basic grafting methods. MSU Extension developed and conducted eleven statewide workshops teaching Extension Agents and Master Gardeners preferred fruit tree grafting methods. The hands-on workshops provided specialists, agents, and Master Gardeners training on teaching fruit tree grafting classes for clientele. Each workshop consisted of a pre-test, a PowerPoint presentation, a post-test, and a grafting demonstration. Post-test scores showed a significant gain in knowledge over pre-test scores. This training can be replicated/adapted by other organizations to conduct educational outreach

Alcoholism Self Assessments, Thomas Chittenden Health Center

In the clinic we frequently see patients with self-admitted heavy drinking who are often in various stages of denial about their problems with alcohol. All the pamphlets and handouts available to patients at Thomas Chittenden Health Center and at Fletcher Allen Health Care are for patients who have admitted they have a problem with alcohol. These patients with admitted problems are the minority of patients with admitted heavy drinking. The patients who have not admitted their problem with drinking need a way to reflect on how their drinking is affecting their lives.https://scholarworks.uvm.edu/fmclerk/1013/thumbnail.jp