A Case Study of Laser Wind Sensor Performance Validation by Comparison to an Existing Gage

A case study concerning validation of wind speed measurements made by a laser wind sensor mounted on a 190 square foot floating platform in Muskegon Lake through comparison with measurements made by pre-existing cup anemometers mounted on a met tower on the shore line is presented. The comparison strategy is to examine the difference in measurements over time using the paired-t statistical method to identify intervals when the measurements were equivalent and to provide explanatory information for the intervals when the measurements were not equivalent. The data was partitioned into three sets: not windy (average wind speed measured by the cup anemometers ≤ 6.7m/s) windy but no enhanced turbulence (average wind speed measured by the cup anemometers \u3e 6.7m/s), and windy with enhanced turbulence associated with storm periods. For the not windy data set, the difference in the average wind speeds was equal in absolute value to the precision of the gages and not statistically significant. Similar results were obtained for the windy with no enhanced turbulence data set and the average difference was not statistically significant (α=0.01). The windy with enhanced turbulence data set showed significant differences between the buoy mounted laser wind sensor and the on-shore mast mounted cup anemometers. The sign of the average difference depended on the direction of the winds. Overall, validation evidence is obtained in the absence of enhanced turbulence. In addition, differences in wind speed during enhanced turbulence were isolated in time, studied and explained

Hepatocellular oxidant stress following intestinal ischemia-reperfusion injury,

Reperfusion of ischemic intestine results in acute liver dysfunction characterized by hepatocellular enzyme release into plasma, reduction in bile flow rate, and neutrophil sequestration within the liver. The pathophysiology underlying this acute hepatic injury is unknown. This study was undertaken to determine whether oxidants are associated with the hepatic injury and to determine the relative value of several indirect methods of assessing oxidant exposure in vivo. Rats were subjected to a standardized intestinal ischemia-reperfusion injury. Hepatic tissue was assayed for lipid peroxidation products and oxidized and reduced glutathione. There was no change in hepatic tissue total glutathione following intestinal ischemia--reperfusion injury. Oxidized glutathione (GSSG) increased significantly following 30 and 60 min of reperfusion. There was no increase in any of the products of lipid peroxidation associated with this injury. An increase in GSSG within hepatic tissue during intestinal reperfusion suggests exposure of hepatocytes to an oxidant stress. The lack of a significant increase in products of lipid peroxidation suggests that the oxidant stress is of insufficient magnitude to result in irreversible injury to hepatocyte cell membranes. These data also suggest that the measurement of tissue GSSG may be a more sensitive indicator of oxidant stress than measurement of products of lipid peroxidation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29014/1/0000043.pd

Redo fundoplication in infants and children with recurrent gastroesophageal reflux

The Nissen fundoplication is well established as the surgical treatment for medically refractory gastroesophageal reflux (GER) in childhood. Recurrent GER following fundoplication is a challenging problem with a reported incidence ranging from 0% to 12%. From January 1974 to January 1989, 286 children have been treated for GER with Nissen fundoplication and gastrostomy tube placement at the University of Michigan C.S. Mott Children's Hospital; 242 of these children have been followed for an average of 30 months, the remaining 44 have been lost to follow-up. Twenty-nine children (12%) have developed recurrent reflux following fundoplication. Medical management with thickened upright feelings, gastrostomy feedings, or gastrojejunostomy tube feedings has been successful for 11 children with control of reflux symptoms. Five additional children who were treated nonoperatively died of coexistant medical problems within 2 months following documentation or recurrent reflux. The remaining 13 children have required redo fundoplication for wrap disruption or herniation, and an additional six children, initially treated at other institutions, have also undergone redo fundoplications. One other child treated at this hospital required redo fundoplication for a postoperative partial gastric volvulus causing gastric outlet obstruction. Of the 20 children who have undergone a second Nissen fundoplication, 16 (80%) are doing well without recurrent GER. Four children have developed recurrent GER with wrap disruption; 1 is doing well following a third fundoplication, 2 have been managed successfully with continuous feedings via gastrojejunostomy feeding tubes, and a fourth child died of complications related to a recurrent tracheoesophageal fistula. Conservative management with gastrojejunal tube feedings should be considered in the initial management of children with recurrent GER following fundoplication. If necessary, redo Nissen fundoplication, although technically difficult, is associated with a good outcome in the majority of children and is indicated for refractory recurrent GER following a failed antireflux procedure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29266/1/0000324.pd

Long-term radiographic follow-up of the Nissen fundoplication in children

This study examined 46 children 5–9 years (mean 6.7) after Nissen fundoplication surgery for gastroesophageal reflux (GER). Eleven were deceased and ten of the 35 families declined objective evaluation. The remaining 25 children (71%) had a barium swallow examination. In 16 of the 25 patients the fundoplication was intact. In 2 patients a small portion of the fundoplication was displaced above the diaphragm. In 5 patients there was residual esophageal disease. In 3 patients (one with esophageal disease), with a hiatus hernia prior to surgery, despite immediate postoperative reduction, the barium swallow examination done for this study revealed recurrent hiatus hernia but no GER. Long-term results of the Nissen fundoplication reveal success in eliminating clinically significant gastroesophageal reflux. Those patients with esophageal disease prior to the surgery need close interval follow-up to monitor continuing problems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46689/1/247_2006_Article_BF02389563.pd

Two Plant Viral Suppressors of Silencing Require the Ethylene-Inducible Host Transcription Factor RAV2 to Block RNA Silencing

RNA silencing is a highly conserved pathway in the network of interconnected defense responses that are activated during viral infection. As a counter-defense, many plant viruses encode proteins that block silencing, often also interfering with endogenous small RNA pathways. However, the mechanism of action of viral suppressors is not well understood and the role of host factors in the process is just beginning to emerge. Here we report that the ethylene-inducible transcription factor RAV2 is required for suppression of RNA silencing by two unrelated plant viral proteins, potyvirus HC-Pro and carmovirus P38. Using a hairpin transgene silencing system, we find that both viral suppressors require RAV2 to block the activity of primary siRNAs, whereas suppression of transitive silencing is RAV2-independent. RAV2 is also required for many HC-Pro-mediated morphological anomalies in transgenic plants, but not for the associated defects in the microRNA pathway. Whole genome tiling microarray experiments demonstrate that expression of genes known to be required for silencing is unchanged in HC-Pro plants, whereas a striking number of genes involved in other biotic and abiotic stress responses are induced, many in a RAV2-dependent manner. Among the genes that require RAV2 for induction by HC-Pro are FRY1 and CML38, genes implicated as endogenous suppressors of silencing. These findings raise the intriguing possibility that HC-Pro-suppression of silencing is not caused by decreased expression of genes that are required for silencing, but instead, by induction of stress and defense responses, some components of which interfere with antiviral silencing. Furthermore, the observation that two unrelated viral suppressors require the activity of the same factor to block silencing suggests that RAV2 represents a control point that can be readily subverted by viruses to block antiviral silencing

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Individual Differences In Technology Stress

In line with this meeting theme, \u27Designing for Diversity\u27, the purpose of this panel discussion is to focus primarily on the individual differences determinants of the stress response and its consequences in computerized environments. Demographic differences that may or have been implicated in technology stress reactions include differences in age, gender, education, experience, and mental health status. Trait-based differences that have been studied in relation to technology stress include general ability, special abilities, personality, motivation, self-esteem, locus of control, tolerance of ambiguity, and cognitive style

Laser Wind Sensor Performance Validation with an Existing Gage

A new approach to laser wind sensor measurement validation is described and demonstrated. The new approach relies on the paired-t statistical method to generate a time series of differences between two sets of measurements. This series of differences is studied to help identify and explain time intervals of operationally significant differences, which is not possible with the traditional approach of relying on the squared coefficient of variation as the primary metric. The new approach includes estimating a confidence interval for the mean difference and establishing a level of meaningful difference for the mean difference, and partitioning the data set based on wind speed. To demonstrate the utility of the new approach, measurements made by a laser wind sensor mounted on a floating buoy are compared first with those made by a second laser wind sensor mounted on a nearby small island for which the co-efficient of variation is high (\u3e 99%). It was found that time intervals when high differences in wind speed occurred corresponded to high differences in wind direction supporting a hypothesis that the two laser wind sensor units are not always observing the same wind resource. Furthermore, the average difference for the 100m range gate is positive, statistically significant (α=0.01) and slightly larger than the precision of the gages, 0.1m/s. One possible cause of this difference is that the surface roughness over land is slowing the wind at 100m slightly. A second comparison was made with previously existing cup anemometers mounted on a metrological mast located on-shore. The cup anemometers are about 8m lower than the center of the lowest range gate on the laser wind sensor. The data was partitioned into three sets: not windy (average wind speed at the cup anemometers ≤ 6.7m/s) windy but no enhanced turbulence (average wind speed at the cup anemometers \u3e 6.7m/s), and windy with enhanced turbulence. Periods of enhanced turbulence are associated with the passage of a cold frontal boundary. The paired-t analysis for the not windy data set showed a difference in the average wind speeds of -0.096m/s, less in absolute value than the precision of the gages. The negative sign indicates slower wind speed over land as well as at a lower height, which is expected. Similar results were obtained for the windy with no enhanced turbulence data set. In addition, the average difference was not statistically significant (α=0.01). The windy with enhanced turbulence data set showed significant differences between the buoy mounted laser wind sensor and the on-shore mast mounted cup anemometers. The sign of the average difference depended on the direction of the winds in the periods of enhanced turbulence. Mean turbulent kinetic energy was measured to be greater when air flow into Muskegon Lake was predominantly from over land versus when air flow was predominantly from Lake Michigan. The higher mean turbulent kinetic energy for flow originating over land would likely be due to greater surface roughness experienced by the overland flow. Overall, the value of the new approach in obtaining validation evidence has been demonstrated. In this case, validation evidence is obtained in periods of no enhanced turbulence. Differences in wind speed during periods of enhanced turbulence are isolated in time, studied and are correlated in time with differences in wind direction