Thermal Stability of RP-2 for Hydrocarbon Boost Regenerative Cooling

A series of tests were performed in the NASA Glenn Research Centers Heated Tube Facility to study the heat transfer and thermal stability behavior of RP-2 under conditions similar to those found in rocket engine cooling channels. It has long been known that hydrocarbon fuels, such as RP-2, can decompose at high temperature to form deposits (coke) which can adversely impact rocket engine cooling channel performance. The heated tube facility provides a simple means to study these effects. Using resistively heated copper tubes in a vacuum chamber, flowing RP-2 was heated to explore thermal effects at a range of test conditions. Wall temperature (850-1050F) and bulk fluid temperature (300-500F) were varied to define thermal decomposition and stability at each condition. Flow velocity and pressure were fixed at 75 fts and 1000 psia, respectively. Additionally, five different batches of RP-2 were tested at identical conditions to examine any thermal stability differences resulting from batch to batch compositional variation. Among these tests was one with a potential coke reducing additive known as 1,2,3,4-Tetrahydroquinoline (THQ). While copper tubes were used for the majority of tests, two exploratory tests were performed with a copper alloy known as GRCop-42. Each tube was instrumented with 15 thermocouples to examine the temperature profile, and carbon deposition at each thermocouple location was determined post-test in an oxidation furnace. In many tests, intermittent local temperature increases were observed visually and in the thermocouple data. These hot spots did not appear to correspond with a higher carbon deposition

Functional and Radiographic Long Term Outcomes of Hemiarthroplasty For Proximal Humeral Fractures

Background Hemiarthroplasty is the preferred surgical procedure for 3- and 4-part proximal humeral fractures. Our retrospective study examined functional and radiographic outcomes at 2- and 5-year follow-up in patients who received a hemiarthroplasty for 3- and 4-part proximal humeral fractures. Materials and methods Forty-seven consecutive patients of a single surgeon treated with a cemented shoulder hemiarthroplasty between 2000 and 2006 were followed up. Standard surgical technique was used in all cases. Postoperative radiographs were compared with radiographs at 2 and 5 years along with active range of motion and functional outcomes scores. Results Twenty-five patients were examined at 2 years and twenty-two at 2 and 5 years. The mean age was 61 years. The mean acromiohumeral distance decreased from 10.3 mm postoperatively to 8.5 mm at 2 years and 6.7 mm at 5 years (P ≤ .001). More patients had stem osteolysis and tuberosity reabsorption at 2 and 5 years compared with postoperatively (P = .016 and P ≤ .001, respectively). The University of California, Los Angeles score decreased from 26.0 to 22.3 (P = .045); the Constant score decreased from 61.1 to 50.1 (P = .01); the Simple Shoulder Test 12 score decreased from 7.7 to 6.2 (P = .018); and the American Shoulder and Elbow Surgeons score decreased from 70.4 to 58.8 (P = .015). Pain scores increased from 2- to 5-year follow-up (P = .018). The range-of-motion measures changed little from the 2-to 5-year follow-up. Conclusions Hemiarthroplasty has a high rate of long-term complications. Increases in acromiohumeral distance, stem osteolysis, and tuberosity reabsorption were observed between 2- and 5-year follow-up. Pain scores and functional outcomes worsened. No improvement in range of motion was observed

Functional and Radiographic Long Term Outcomes of Hemiarthroplasty For Proximal Humeral Fractures

Background Hemiarthroplasty is the preferred surgical procedure for 3- and 4-part proximal humeral fractures. Our retrospective study examined functional and radiographic outcomes at 2- and 5-year follow-up in patients who received a hemiarthroplasty for 3- and 4-part proximal humeral fractures. Materials and methods Forty-seven consecutive patients of a single surgeon treated with a cemented shoulder hemiarthroplasty between 2000 and 2006 were followed up. Standard surgical technique was used in all cases. Postoperative radiographs were compared with radiographs at 2 and 5 years along with active range of motion and functional outcomes scores. Results Twenty-five patients were examined at 2 years and twenty-two at 2 and 5 years. The mean age was 61 years. The mean acromiohumeral distance decreased from 10.3 mm postoperatively to 8.5 mm at 2 years and 6.7 mm at 5 years (P ≤ .001). More patients had stem osteolysis and tuberosity reabsorption at 2 and 5 years compared with postoperatively (P = .016 and P ≤ .001, respectively). The University of California, Los Angeles score decreased from 26.0 to 22.3 (P = .045); the Constant score decreased from 61.1 to 50.1 (P = .01); the Simple Shoulder Test 12 score decreased from 7.7 to 6.2 (P = .018); and the American Shoulder and Elbow Surgeons score decreased from 70.4 to 58.8 (P = .015). Pain scores increased from 2- to 5-year follow-up (P = .018). The range-of-motion measures changed little from the 2-to 5-year follow-up. Conclusions Hemiarthroplasty has a high rate of long-term complications. Increases in acromiohumeral distance, stem osteolysis, and tuberosity reabsorption were observed between 2- and 5-year follow-up. Pain scores and functional outcomes worsened. No improvement in range of motion was observed

Association between WASH-Related Behaviors and Knowledge with Childhood Diarrhea in Tanzania

Background: Diarrhea remains a major cause of morbidity and mortality among children in Tanzania. The purpose of this study was to explore associations between diarrheal disease and water, sanitation, and hygiene (WASH) related behaviors and determine care-seeking predictors for diarrheal disease. Methods: Data from 9996 female primary caregivers were collected as part of a larger integrated nutrition program. Logistic regression was used to measure associations between predictor and dependent variables and diarrheal and care-seeking outcomes. Results: Knowledge of the importance of handwashing after assisting a child who has defecated (OR 0.79, CI 0.72–0.87), before preparing food (OR 0.88, CI 0.80–0.97), and before feeding a child (OR 0.89, CI 0.81–0.99) were each associated with not having a child with diarrhea in the past two weeks. Fathers or male caregivers (OR 0.65, CI 0.48–0.89) were less likely to seek medical care for a child with diarrhea. No associations were found between WASH-related knowledge or behavior and seeking medical care for a child with diarrhea. Conclusions: Findings indicate that knowledge of handwashing importance was significant in washing hands after assisting a child who has defecated, before preparing food, and prior to feeding a child. These findings demonstrate the value of parental involvement to lower morbidity and mortality among children

Aerosolized microcystin-LR exacerbates chemokines and other inflammatory mediators of asthma in asthmatic primary human airway epithelium

Microcystin-LR, one of the most abundant and toxic HAB-derived cyanotoxins, has recently been detected in aerosols from HAB water. We previously reported that aerosol MC-LR exposure has a pro-inflammatory influence on the airways. Asthma, which is an extremely prevalent airway disease afflicting approximately 8% of the U.S. population, is largely driven by inflammation. However, the impact of MC-LR aerosol exposure on this at-risk population is unknown. In this study, a 3D primary human airway epithelium model was utilized, in which cells were isolated from healthy and asthmatic donors. An environmentally relevant concentration of MC-LR (1 μM) was aerosolized and delivered to the cell surface, before the cells were harvested for transcriptome analysis. Strikingly, 10% of the genes upregulated (log2FC \u3e 0.25) by asthma alone, were further upregulated by MC-LR exposure including inflammation mediators, such as CXCL11 (log2FC = 0.63); and TLR4 (log2FC = 0.31). These genes had significant associations with pathways, such as “immune cytokine binding” (FDR = 0.015). This study showed that aerosolized MC-LR amplifies the transcriptional differences between asthmatic and healthy donor airway epithelial cells, leading to the exacerbation of inflammatory mediators of asthma, such as chemokines, suggesting a potential for MC-LR exposure to worsen asthma severity

Social regulation of ageing by young workers in the honey bee, Apis mellifera

Organisms' lifespans are modulated by both genetic and environmental factors. The lifespan of eusocial insects is determined by features of the division of labor,which itself is influenced by social regulatory mechanisms. In the honey bee, Apis mellifera, the presence of brood and of old workers carrying out foraging tasks are important social drivers of ageing, but the influence of young adult workers is unknown, as it has not been experimentally teased apart from that of brood. In this study,we test the role of young workers in the ageing of their nestmates. We measured the impact of different social contexts characterized by the absence of brood and/or young adults on the lifespan ofworker nestmates in field colonies. To acquire insight into the physiological processes occurring under these contexts, we analyzed the expression of genes known to affect honey bee ageing. The data showed that young workers significantly reduced the lifespan of nestmate workers, similar to the effect of brood on its own. Differential expression of vitellogenin,major royal jelly protein-1, andmethylase transferase, but not methyl farneosate epoxidase genes suggests that young workers and brood influence ageing of adult nestmate workers via different physiological pathways.We identify young workers as an essential part of the social regulation of ageing in honey bee colonies.The Sur-La-Croix Foundation provided financial support to ME, while the Vinetum Foundation provided such support to both ME and PN.http://www.sherpa.ac.uk/romeo/issn/0531-5565/am2017Zoology and Entomolog