Liquid droplet radiator program at the NASA Lewis Research Center

The NASA Lewis Research Center and the Air Force Rocket Propulsion Laboratory (AFRPL) are jointly engaged in a program for technical assessment of the Liquid Droplet Radiator (LDR) concept as an advanced high performance heat ejection component for future space missions. NASA Lewis has responsibility for the technology needed for the droplet generator, for working fluid qualification, and for investigating the physics of droplets in space; NASA Lewis is also conducting systems/mission analyses for potential LDR applications with candidate space power systems. For the droplet generator technology task, both micro-orifice fabrication techniques and droplet stream formation processes have been experimentally investigated. High quality micro-orifices (to 50 micron diameter) are routinely fabricated with automated equipment. Droplet formation studies have established operating boundaries for the generation of controlled and uniform droplet streams. A test rig is currently being installed for the experimental verification, under simulated space conditions, of droplet radiation heat transfer performance analyses and the determination of the effect radiative emissivity of multiple droplet streams. Initial testing has begun in the NASA Lewis Zero-Gravity Facility for investigating droplet stream behavior in microgravity conditions. This includes the effect of orifice wetting on jet dynamics and droplet formation. Results for both Brayton and Stirling power cycles have identified favorable mass and size comparisons of the LDR with conventional radiator concepts

Effects of alcohol consumption on mortality in patients with Type 2 diabetes mellitus

Aims/hypothesis: Moderate alcohol intake has been associated with increased life expectancy due to reduced mortality from cardiovascular disease. We prospectively examined the effects of alcohol consumption on mortality in Type 2 diabetic patients in Switzerland. Methods: A total of 287 patients with Type 2 diabetes mellitus (125 women, 162 men), recruited in Switzerland for the WHO Multinational Study of Vascular Disease in Diabetes, were included in this study. After a follow-up period of 12.6±0.6 years (means ± SD), mortality from CHD and from all causes was assessed. Results: During the follow-up, 70 deaths occurred (21 from CHD, 49 from other causes). Compared with non-drinkers, alcohol consumers who drank alcohol 1 to 15g, 16 to 30g and 30g or more per day had the following risk rates of death from CHD: 0.87 (95% CI: 0.25 to 2.51, NS), 0.00 (95% CI: 0.00 to 0.92, p less than 0.05) and 0.37 (95% CI, 0.01 to 2.42, NS), respectively. The corresponding risk rates of death from all causes were 1.27 (95% CI: 0.68 to 2.28, NS), 0.36 (95% CI: 0.09 to 0.99, p less than 0.05) and 1.66 (95% CI: 0.76 to 3.33, NS). Conclusions/interpretation: In Swiss Type 2 diabetic patients moderate alcohol consumption of 16 to 30g per day was associated with reduced mortality from CHD and from all causes. Alcohol intake above 30g per day was associated with a tendency towards increased all-cause mortalit

QTc interval and resting heart rate as long-term predictors of mortality in type 1 and type 2 diabetes mellitus: a 23-year follow-up

Aims/hypothesis: We evaluated the association of QT interval corrected for heart rate (QTc) and resting heart rate (rHR) with mortality (all-causes, cardiovascular, cardiac, and ischaemic heart disease) in subjects with type 1 and type 2 diabetes. Methods: We followed 523 diabetic patients (221 with type 1 diabetes, 302 with type 2 diabetes) who were recruited between 1974 and 1977 in Switzerland for the WHO Multinational Study of Vascular Disease in Diabetes. Duration of follow-up was 22.6 ± 0.6years. Causes of death were obtained from death certificates, hospital records, post-mortem reports, and additional information given by treating physicians. Results: In subjects with type 1 diabetes QTc, but not rHR, was associated with an increased risk of: (1) all-cause mortality (hazard ratio [HR] 1.10 per 10ms increase in QTc, 95% CI 1.02-1.20, p = 0.011); (2) mortality due to cardiovascular (HR 1.15, 1.02-1.31, p = 0.024); and (3) mortality due to cardiac disease (HR 1.19, 1.03-1.36, p = 0.016). Findings for subjects with type 2 diabetes were different: rHR, but not QTc was associated with mortality due to: (1) all causes (HR 1.31 per 10 beats per min, 95% CI 1.15-1.50, p < 0.001); (2) cardiovascular disease (HR 1.43, 1.18-1.73, p < 0.001); (3) cardiac disease (HR 1.45, 1.19-1.76, p < 0.001); and (4) ischaemic heart disease (HR 1.52, 1.21-1.90, p < 0.001). Effect modification of QTc by type 1 and rHR by type 2 diabetes was statistically significant (p < 0.05 for all terms of interaction). Conclusions/interpretation: QTc is associated with long-term mortality in subjects with type 1 diabetes, whereas rHR is related to increased mortality risk in subjects with type 2 diabete

Metabolic and hormonal studies of Type 1 (insulin-dependent) diabetic patients after successful pancreas and kidney transplantation

Long-term normalization of glucose metabolism is necessary to prevent or ameliorate diabetic complications. Although pancreatic grafting is able to restore normal blood glucose and glycated haemoglobin, the degree of normalization of the deranged diabetic metabolism after pancreas transplantation is still questionable. Consequently glucose, insulin, C-peptide, glucagon, and pancreatic polypeptide responses to oral glucose and i.v. arginine were measured in 36 Type 1 (insulin-dependent) diabetic recipients of pancreas and kidney allografts and compared to ten healthy control subjects. Despite normal HbA1 (7.2±0.2%; normal <8%) glucose disposal was normal only in 44% and impaired in 56% of the graft recipients. Normalization of glucose tolerance was achieved at the expense of hyperinsulinaemia in 52% of the subjects. C-peptide and glucagon were normal, while pancreatic polypeptide was significantly higher in the graft recipients. Intravenous glucose tolerance (n=21) was normal in 67% and borderline in 23%. Biphasic insulin release was seen in patients with normal glucose tolerance. Glucose tolerance did not deteriorate up to 7 years post-transplant. In addition, stress hormone release (cortisol, growth hormone, prolactin, glucagon, catecholamines) to insulin-induced hypoglycaemia was examined in 20 graft recipients and compared to eight healthy subjects. Reduced blood glucose decline indicates insulin resistance, but glucose recovery was normal, despite markedly reduced catecholamine and glucagon release. These data demonstrate the effectiveness of pancreatic grafting in normalizing glucose metabolism, although hyperinsulinaemia and deranged counterregulatory hormone response are observed frequently

Methane and nitrous oxide fluxes across an elevation gradient in the tropical Peruvian Andes

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Fuel metabolism during exercise in euglycaemia and hyperglycaemia in patients with type 1 diabetes mellitus—a prospective single-blinded randomised crossover trial

Aims/hypothesis: We assessed systemic and local muscle fuel metabolism during aerobic exercise in patients with type 1 diabetes at euglycaemia and hyperglycaemia with identical insulin levels. Methods: This was a single-blinded randomised crossover study at a university diabetes unit in Switzerland. We studied seven physically active men with type 1 diabetes (mean ± SEM age 33.5 ± 2.4years, diabetes duration 20.1 ± 3.6years, HbA1c 6.7 ± 0.2% and peak oxygen uptake [ $$\mathop {\text{V}}\limits^{\text{.}} {\text{O}}_{2{\text{peak}}}$$ ] 50.3 ± 4.5ml min−1 kg−1). Men were studied twice while cycling for 120min at 55 to 60% of $$\mathop {\text{V}}\limits^{\text{.}} {\text{O}}_{{\text{2peak}}}$$ , with a blood glucose level randomly set either at 5 or 11mmol/l and identical insulinaemia. The participants were blinded to the glycaemic level; allocation concealment was by opaque, sealed envelopes. Magnetic resonance spectroscopy was used to quantify intramyocellular glycogen and lipids before and after exercise. Indirect calorimetry and measurement of stable isotopes and counter-regulatory hormones complemented the assessment of local and systemic fuel metabolism. Results: The contribution of lipid oxidation to overall energy metabolism was higher in euglycaemia than in hyperglycaemia (49.4 ± 4.8 vs 30.6 ± 4.2%; p < 0.05). Carbohydrate oxidation accounted for 48.2 ± 4.7 and 66.6 ± 4.2% of total energy expenditure in euglycaemia and hyperglycaemia, respectively (p < 0.05). The level of intramyocellular glycogen before exercise was higher in hyperglycaemia than in euglycaemia (3.4 ± 0.3 vs 2.7 ± 0.2 arbitrary units [AU]; p < 0.05). Absolute glycogen consumption tended to be higher in hyperglycaemia than in euglycaemia (1.3 ± 0.3 vs 0.9 ± 0.1 AU). Cortisol and growth hormone increased more strongly in euglycaemia than in hyperglycaemia (levels at the end of exercise 634 ± 52 vs 501 ± 32nmol/l and 15.5 ± 4.5 vs 7.4 ± 2.0ng/ml, respectively; p < 0.05). Conclusions/interpretation: Substrate oxidation in type 1 diabetic patients performing aerobic exercise in euglycaemia is similar to that in healthy individuals revealing a shift towards lipid oxidation during exercise. In hyperglycaemia fuel metabolism in these patients is dominated by carbohydrate oxidation. Intramyocellular glycogen was not spared in hyperglycaemia. Trial registration: ClinicalTrials.Gov NCT00325559 Funding: This study was supported by unrestricted grants from the Oetliker-Stiftung für Physiologie, from the Swiss Diabetes Foundation, from NovoNordisk, Switzerland, and from the Swiss National Science Foundatio

On rationality of the intersection points of a line with a plane quartic

We study the rationality of the intersection points of certain lines and smooth plane quartics C defined over F_q. For q \geq 127, we prove the existence of a line such that the intersection points with C are all rational. Using another approach, we further prove the existence of a tangent line with the same property as soon as the characteristic of F_q is different from 2 and q \geq 66^2+1. Finally, we study the probability of the existence of a rational flex on C and exhibit a curious behavior when the characteristic of F_q is equal to 3.Comment: 17 pages. Theorem 2 now includes the characteristic 2 case; Conjecture 1 from the previous version is proved wron

Complex controls on nitrous oxide flux across a large elevation gradient in the tropical Peruvian Andes

Acknowledgements The authors would like to acknowledge the agencies that funded this research; the UK Natural Environment Research Council (NERC; joint grant references NE/H006583, NE/H007849 and NE/H006753). Patrick Meir was supported by an Australian Research Council Fellowship (FT110100457). Javie Eduardo Silva Espejo, Walter Huaraca Huasco and the ABIDA NGO provided critical fieldwork and logistical support. Angus Calder (University of St.Andrews) and Vicky Munro (University of Aberdeen) provided invaluable laboratory support. Thanks to Adrian Tejedor from the Amazon Conservation Association, who provided assistance with site access and site selection at Hacienda Villa Carmen. This publication is a contribution from the Scottish Alliance for Geoscience, Environment and Society (http://www.sages.ac.uk).Peer reviewedPublisher PD

Physical education as Olympic education

Introduction In a recent paper (Parry, 1998, p. 64), I argued that the justification of PE activities lies in their capacity to facilitate the development of certain human excellences of a valued kind. Of course, the problem now lies in specifying those ‘human excellences of a valued kind’, and (for anyone) this task leads us into the area of philosophical anthropology. I suggested that the way forward for Physical Education lies in the philosophical anthropology (and the ethical ideals) of Olympism, which provide a specification of a variety of human values and excellences which: •have been attractive to human groups over an impressive span of time and space •have contributed massively to our historically developed conceptions of ourselves •have helped to develop a range of artistic and cultural conceptions that have defined Western culture. •have produced a range of physical activities that have been found universally satisfying and challenging. Although physical activities are widely considered to be pleasurable, their likelihood of gaining wide acceptance lies rather in their intrinsic value, which transcends the simply hedonic or relative good. Their ability to furnish us with pleasurable experiences depends upon our prior recognition in them of opportunities for the development and expression of valued human excellences. They are widely considered to be such opportunities for the expression of valued human excellences because, even when as local instantiations, their object is to challenge our common human propensities and abilities. I claimed that Olympic ideals may be seen not merely as inert ‘ideals’, but living ideas which have the power to remake our notions of sport in education, seeing sport not as mere physical activity but as the cultural and developmental activity of an aspiring, achieving, well-balanced, educated and ethical individual. This paper seeks to make good that claim by trying to develop a case for Physical Education as Olympic Education. I begin by setting out various accounts and conceptions of the Olympic Idea; then I suggest a unifying and organising account of the philosophical anthropology of Olympism; and this is followed by the practical application of that account in two examples of current ethical issues. Finally, I seek to present an account of Physical Education as Olympic Education