703 research outputs found
Relationship Between Elevated Blood Pressure/Hypertension in Military Personnel and the Stress of Combat Deployment
Few studies about elevated blood pressure in the U.S. military exist in which researchers examined exposure to combat and its association with elevated blood pressure. The purpose of this quantitative research was to describe the extent of association between those who were exposed to combat deployment, were 40 or older, and were overweight or obese and had elevated blood pressure for U.S. military personnel who deployed to an area of declared combat between 2012 and 2017. The conceptual basis of this research was best represented by the determinants of health model. Chi-square correlation revealed that being older (equal to or greater than 40 years; p = .018) and being overweight/obese (body mass index [BMI] equal to or greater than 25; p = .000) both have statistically significant relationships with elevated blood pressure (either systolic blood pressure equal to or greater than 120 mm/hg or diastolic blood pressure equal to or greater than 80 mm/hg) among military personnel, while combat deployment does not (deployment \u3e 30 days; p =. 487). However, only being overweight/obese remained significant even when controlling for exposure to combat deployment and being older. Binary logistic regression revealed that elevated blood pressure/hypertension is greater than three times more likely to occur in the presence of the overweight/obese predictor (BMI equal to or greater than 25; p =. 000) variable. The findings of this research could be used to proactively enforce medically derived appropriate medical fitness standards such as maintenance of normal BMI during deployments. Social adaptations could be instrumental in improving wellness among deployed military personnel
Determining the rheology of active lava flows from photogrammetric image sequence processing
We describe a photogrammetric approach used to determine the rheological properties of active lava flows based on stereo image sequences. Bulk rheological properties can be estimated from measurements of flow slope, velocity and dimensions and so, at flow-fronts, they can be calculated from sequential digital elevation models (DEMs) acquired as the flow advances over new ground. For useful flow parameters to be extracted, DEMs may need to be obtained at approximately minute intervals, over durations of up to multiple hours. To deliver such data, we use oblique stereo pair sequences captured by digital SLR cameras and a semi-automated DEM-generation pipeline. Although similar data could be acquired with a terrestrial laser scanner, with deployments in remote and hazardous regions the photogrammetric approach offers significant logistical advantages in terms of reduced equipment cost, bulk, weight and power requirements. We describe the application of the technique to an active lava flow on Mount Etna, Sicily, in 2006. Image sequences were acquired from two tripod-mounted cameras over a period of ~3 hours, as the flow-front advanced ~15 m. Photogrammetric control was provided by 11 targets placed in the scene, with their coordinates determined by dGPS. The cameras were synchronised by a shutter release cable and triggered by an external timer (intervalometer). Image pairs were obtained every minute with DEMs extraction carried out on every fourth epoch; 57 DEMs, with a 0.25-m resolution, were generated. We describe the challenges associated with data collection in this remote environment and the techniques required to automate the photogrammetric analysis and sequence-DEM generation
Graphical programming: A systems approach for telerobotic servicing of space assets
Satellite servicing is in many ways analogous to subsea robotic servicing in the late 1970's. A cost effective, reliable, telerobotic capability had to be demonstrated before the oil companies invested money in deep water robot serviceable production facilities. In the same sense, aeronautic engineers will not design satellites for telerobotic servicing until such a quantifiable capability has been demonstrated. New space servicing systems will be markedly different than existing space robot systems. Past space manipulator systems, including the Space Shuttle's robot arm, have used master/slave technologies with poor fidelity, slow operating speeds and most importantly, in-orbit human operators. In contrast, new systems will be capable of precision operations, conducted at higher rates of speed, and be commanded via ground-control communication links. Challenge presented by this environment include achieving a mandated level of robustness and dependability, radiation hardening, minimum weight and power consumption, and a system which accommodates the inherent communication delay between the ground station and the satellite. There is also a need for a user interface which is easy to use, ensures collision free motions, and is capable of adjusting to an unknown workcell (for repair operations the condition of the satellite may not be known in advance). This paper describes the novel technologies required to deliver such a capability
Twin Studies: Research in Genes, Teeth and Faces
This volume is about an ongoing long-term research initiative led by researchers from the School of Dentistry at the University of Adelaide. The aim of this book is to provide an overview of the studies of the teeth and faces of Australian twins and their families that have extended over more than thirty years
Techno-Economic Analysis of a Secondary Air Stripper Process
We present results of an initial techno-economic assessment on a post-combustion CO2 capture process developed by the Center for Applied Energy Research (CAER) at the University of Kentucky using Mitsubishi Hitachi Power Systems’ H3-1 aqueous amine solvent. The analysis is based on data collected at a 0.7 MWe pilot unit combined with laboratory data and process simulations. The process adds a secondary air stripper to a conventional solvent process, which increases the cyclic loading of the solvent in two ways. First, air strips additional CO2 from the solvent downstream of the conventional steam-heated thermal stripper. This extra stripping of CO2 reduces the lean loading entering the absorber. Second, the CO2-enriched air is then sent to the boiler for use as secondary air. This recycling of CO2 results in a higher concentration of CO2 in the flue gas sent to the absorber, and hence a higher rich loading of the solvent exiting the absorber. A process model was incorporated into a full-scale supercritical pulverized coal power plant model to determine the plant performance and heat and mass balances. The performance and heat and mass balance data were used to size equipment and develop cost estimates for capital and operating costs. Lifecycle costs were considered through a levelized cost of electricity (LCOE) assessment based on the capital cost estimate and modeled performance. The results of the simulations show that the CAER process yields a regeneration energy of 3.12 GJ/t CO2, a 174.59/MWh. This compares to the U.S. Department of Energy\u27s projected costs (Case 10) of regeneration energy of 3.58 GJ/t CO2, a 189.59/MWh. For H3-1, the CAER process results in a regeneration energy of 2.62 GJ/tCO2 with a stripper pressure of 5.2 bar, a capture cost of 164.33/MWh
Outcome of children with resistant and relapsed Hodgkin's disease.
During the period 1974-89, 169 children with Hodgkin's disease were treated in the Paediatric Oncology Units of the Royal Marsden and St Bartholomew's Hospitals. The overall actuarial survival for the whole group was 81% at 10 years. Thirty-five of the 169 children either did not achieve a complete remission or subsequently relapsed. The estimated actuarial survival from initial relapse or failure of primary treatment was 60% at 5 years and 45% at 10 years. Over half of the patients requiring salvage therapy had declared themselves within 2 years and only 3 relapses occurred more than 3 years from diagnosis. Very few patients remain disease free long term after failure of primary and initial salvage therapy. Patients relapsing within a year of diagnosis or not achieving a complete response to primary therapy and those with disseminated relapse had a poor response to salvage therapy. A significant subgroup of patients had prolonged survival despite multiple relapses. Neither initial histology nor stage affected survival from relapse although numbers in each subgroup were small
The Prevalence of L. monocytogenes in Cull Sows
The goal of this study was to determine the distribution of Listeria monocytogenes in cull sows and their pork. Two trials were conducted at a single packing plant in 2001 (n=179 cull sows) and in 2002 (n= 160 cull sows). Fecal samples collected antemortem (trial 1) as well as animal tissues, carcass, and environmental swabs, and meat block samples collected at the abattoir (trials 1 and 2) were analyzed. When results from both trials were combined, overall L. monocytogenes was detected in five or 0.17% of the total samples (n=2,858). Specifically, L. monocytogenes was confirmed in a tonsil sample (0.55% of tonsils positive) and in a carcass swab sample (0.56% of carcasses) before the organic acid rinse. L. monocytogenes was recovered in three (1.21%) meat block samples (n=213). These data indicate that L. monocytogenes is present in the cull sow and their pork
Global Consensus Position Statement on the Use of Testosterone Therapy for Women
The only evidence-based indication for testosterone for women is for HSDD. There are insufficient data for using testosterone for any other symptom/condition or for disease prevention
The viscosity of pāhoehoe lava: In situ syn-eruptive measurements from Kilauea, Hawaii
Viscosity is one of the most important physical properties controlling lava flow dynamics. Usually, viscosity is measured in the laboratory where key parameters can be controlled but can never reproduce the natural environment and original state of the lava in terms of crystal and bubble contents, dissolved volatiles, and oxygen fugacity. The most promising approach for quantifying the rheology of molten lava in its natural state is therefore to carry out direct field measurements by inserting a viscometer into the lava while it is flowing. Such in-situ syn-eruptive viscosity measurements are notoriously difficult to perform due to the lack of appropriate instrumentation and the difficulty of working on or near an active lava flow. In the field, rotational viscometer measurements are of particular value as they have the potential to measure the properties of the flow interior rather than an integration of the viscosity of the viscoelastic crust + flow interior. To our knowledge only one field rotational viscometer is available, but logistical constraints have meant that it has not been used for 20 years. Here, we describe new viscosity measurements made using the refurbished version of this custom-built rotational viscometer, as performed on active pāhoehoe lobes from the 61G lava flow of Kilauea’s Pu’u ‘Ō‘ō eruption in 2016. We successfully measured a viscosity of ~380 Pa s at strain-rates between 1.6 and 5 s-1 28 and at 1144 °C. Additionally, synchronous lava sampling allowed us to provide detailed textural and chemical characterization of quenched samples. Application of current physico-chemical models based on this characterization (16±4 vol.% crystals; 50±6 vol.% vesicles), gave viscosity estimates that were approximately compatible with the measured values, highlighting the sensitivity of model-based viscosity estimates on the effect of deformable bubbles. Our measurements also agree on the range of viscosities in comparison to previous field experiments on Hawaiian lavas. Conversely, direct comparison with sub-liquidus rheological laboratory measurements on natural lavas was unsuccessful because recreating field conditions (in particular volatile and bubble content) is so far inaccessible in the laboratory. Our work shows the value of field rotational viscometry fully integrated with sample characterization to quantify three-phase lava viscosity. Finally, this work suggests the need for the development of a more versatile instrument capable of recording precise measurements at low torque and low strain rate, and with synchronous temperature measurements
Interlaboratory Evaluation of Rodent Pulmonary Responses to Engineered Nanomaterials: The NIEHS Nano GO Consortium
Background: Engineered nanomaterials (ENMs) have potential benefits, but they also present safety concerns for human health. Interlaboratory studies in rodents using standardized protocols are needed to assess ENM toxicity.
Methods: Four laboratories evaluated lung responses in C57BL/6 mice to ENMs delivered by oropharyngeal aspiration (OPA), and three labs evaluated Sprague-Dawley (SD) or Fisher 344 (F344) rats following intratracheal instillation (IT). ENMs tested included three forms of titanium dioxide (TiO2) [anatase/rutile spheres (TiO2-P25), anatase spheres (TiO2-A), and anatase nanobelts (TiO2-NBs)] and three forms of multiwalled carbon nanotubes (MWCNTs) [original (O), purified (P), and carboxylic acid “functionalized� (F)]. One day after treatment, bronchoalveolar lavage fluid was collected to determine differential cell counts, lactate dehydrogenase (LDH), and protein. Lungs were fixed for histopathology. Responses were also examined at 7 days (TiO2 forms) and 21 days (MWCNTs) after treatment.
Results: TiO2-A, TiO2-P25, and TiO2-NB caused significant neutrophilia in mice at 1 day in three of four labs. TiO2-NB caused neutrophilia in rats at 1 day in two of three labs, and TiO2-P25 and TiO2-A had no significant effect in any of the labs. Inflammation induced by TiO2 in mice and rats resolved by day 7. All MWCNT types caused neutrophilia at 1 day in three of four mouse labs and in all rat labs. Three of four labs observed similar histopathology to O-MWCNTs and TiO2-NBs in mice.
Conclusions: ENMs produced similar patterns of neutrophilia and pathology in rats and mice. Although interlaboratory variability was found in the degree of neutrophilia caused by the three types of TiO2 nanoparticles, similar findings of relative potency for the three types of MWCNTs were found across all laboratories, thus providing greater confidence in these interlaboratory comparisons
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