Vibrational energy transfer processes in gaseous systems at high temperatures

A study has been made of the rate of vibrational excitation in shock heated CO for the temperature range l300K - 2500K, by observation of the infrared emission behind the incident shock wave. Care was taken to eliminate'impurity effects and the non uniformity of the flow was accounted for in the prescribed manner. The first measurements were made on the fundamental and overtone of CO in the pure gas and CO/Ne mixtures. The experimental data was reduced using kinetically derived equations, which incorporated the Landau-Teller ratios between the rate constants. For TCO-CO the Landau-Teller constants were found to be A = -22.2; B = 160.2 and for TCO-Ne A = -21.66; B = 148.9. The separate observations of the levels indicated that the population of the v = 2 level was by successive single quantum transitions. It was concluded that the Landau-Teller ratio of the rate constants k21 : k10 = 2 : 1, was incorrect, in the case of the anharmonic oscillator. The coefficient was thought to lie between 2.2 and 2.4. It was demonstrated by computer calculations, using selected models, that the equations used in the reduction of experimental data were inadequate for real systems. Thus studies using the equations were thought to be subject to a small systematic error

Using blubber explants to investigate adipose function in grey seals:glycolytic, lipolytic and gene expression responses to glucose and hydrocortisone

Adipose tissue is fundamental to energy balance, which underpins fitness and survival. Knowledge of adipose regulation in animals that undergo rapid fat deposition and mobilisation aids understanding of their energetic responses to rapid environmental change. Tissue explants can be used to investigate adipose regulation in wildlife species with large fat reserves, when opportunities for organismal experimental work are limited. We investigated glucose removal, lactate, glycerol and NEFA accumulation in media, and metabolic gene expression in blubber explants from wild grey seals. Glycolysis was higher in explants incubated in 25 mM glucose (HG) for 24 h compared to controls (C: 5.5 mM glucose). Adipose-derived lactate likely contributes to high endogenous glucose production in seals. Lipolysis was not stimulated by HG or high hydrocortisone (HC: 500 nM hydrocortisone) and was lower in heavier animals. HC caused NEFA accumulation in media to decrease by ~30% relative to C in females, indicative of increased lipogenesis. Lipolysis was higher in males than females in C and HG conditions. Lower relative abundance of 11-β-hydroxysteroid dehydrogenase 1 mRNA in HG explants suggests glucose involvement in blubber cortisol sensitivity. Our findings can help predict energy balance responses to stress and nutritional state in seals, and highlight the use of explants to study fat tissue function in wildlife

Distributing less, redistributing more: Safe and just low-energy futures in the United Kingdom

Low energy demand pathways may be essential for the transition to net zero. However, to date, the distributional impacts of these futures have been neglected, leaving open crucial questions about living standards and inequality. Using the lens of ‘decent living energy’, this article begins to piece together the puzzle by providing a distributional analysis of a recent low-energy-demand, net-zero scenario for the UK. We find that if the UK succeeded in following a low-energy pathway, but income and energy inequality continued increasing at the current rate, 9 million people could lack sufficient energy for meeting decent living standards in 2050. Theoretically, this can be mitigated either by achieving considerable reductions in income inequality, or by ensuring highly energy-efficient technologies are available at all income levels as this reduces the energy required to meet decent living standards. Reviewing various specific policies that could forge a low-energy-demand future, we find some are inherently equitable and others can easily be designed to be so. However, policies could also prove regressive in numerous ways. We thus argue that an equitable, socially-just, low-energy-demand policy pathway would need to be responsive and dynamic, bold and targeted, and joined-up with respect to both policy implementation and assessment

Critical behavior of gravitating sphalerons

We examine the gravitational collapse of sphaleron type configurations in Einstein--Yang--Mills--Higgs theory. Working in spherical symmetry, we investigate the critical behavior in this model. We provide evidence that for various initial configurations, there can be three different critical transitions between possible endstates with different critical solutions sitting on the threshold between these outcomes. In addition, we show that within the dispersive and black hole regimes, there are new possible endstates, namely a stable, regular sphaleron and a stable, hairy black hole.Comment: Latex, 14 pages, 8 figure

Obtaining accurate glucose measurements from wild animals under field conditions:comparing a hand held glucometer with a standard laboratory technique in grey seals

Glucose is an important metabolic fuel and circulating levels are tightly regulated in most mammals, but can drop when body fuel reserves become critically low. Glucose is mobilized rapidly from liver and muscle during stress in response to increased circulating cortisol. Blood glucose levels can thus be of value in conservation as an indicator of nutritional status and may be a useful, rapid assessment marker for acute or chronic stress. However, seals show unusual glucose regulation: circulating levels are high and insulin sensitivity is limited. Accurate blood glucose measurement is therefore vital to enable meaningful health and physiological assessments in captive, wild or rehabilitated seals and to explore its utility as a marker of conservation relevance in these animals. Point-of-care devices are simple, portable, relatively cheap and use less blood compared with traditional sampling approaches, making them useful in conservation-related monitoring. We investigated the accuracy of a hand-held glucometer for ‘instant’ field measurement of blood glucose, compared with blood drawing followed by laboratory testing, in wild grey seals (Halichoerus grypus), a species used as an indicator for Good Environmental Status in European waters. The glucometer showed high precision, but low accuracy, relative to laboratory measurements, and was least accurate at extreme values. It did not provide a reliable alternative to plasma analysis. Poor correlation between methods may be due to suboptimal field conditions, greater and more variable haematocrit, faster erythrocyte settling rate and/or lipaemia in seals. Glucometers must therefore be rigorously tested before use in new species and demographic groups. Sampling, processing and glucose determination methods have major implications for conclusions regarding glucose regulation, and health assessment in seals generally, which is important in species of conservation concern and in development of circulating glucose as a marker of stress or nutritional state for use in management and monitoring

The direct electrochemistry of ferritin compared with the direct electrochemistry of nanoparticulate hydrous ferric oxide

Horse spleen ferritin is a naturally occurring iron storage protein, consisting of a protein shell encapsulating a hydrous ferric oxide core about 8 nm in diameter. It is known from prior work that the protein can be adsorbed onto the surface of tin-doped indium oxide (ITO) electrodes, where it undergoes voltammetric reduction at about –0.6 V vs Ag/AgCl. This is accompanied by dissolution of Fe(II) through channels in the protein shell. In the present work, it is demonstrated that a pre-wave at about –0.4 V vs Ag/AgCl is due to the reduction of FePO4 also present inside the protein shell. In order to prove that the pre-wave was due to the reduction of FePO4, it was first necessary to prepare 8 nm diameter hydrous ferric oxide nanoparticles without protein shells, adsorb them onto ITO electrodes, and then study their electrochemistry. Having achieved that, it was then necessary to establish that their behaviour was analogous to that of ferritin. This was achieved in several ways, but principally by noting that the same electrochemical reduction reactions occurred at negative potentials, accompanied by the dissolution of Fe(II). Finally, by switching to aqueous phosphate buffer, the pre-wave could be unambiguously identified as the reduction of FePO4 present as a thin layer on the hydrous ferric oxide nanoparticle surfaces. Although the bare and protein-coated hydrous ferric oxide nanoparticles were found to behave identically toward electrochemical reduction, they nevertheless reacted very differently towards H2O2. The bare nanoparticles acted as potent electrocatalysts for both the oxidation and the reduction of H2O2, whereas the horse spleen ferritin had a much lesser effect. It seems likely therefore that the protein shell in ferritin blocks the formation of key intermediates in hydrogen peroxide decomposition

The potential impact of poorly controlled Type 1 diabetes mellitus upon women of childbearing age.

Published abstrac

Human meniscus cells express hypoxia inducible factor-1α and increased SOX9 in response to low oxygen tension in cell aggregate culture

In previous work we demonstrated that the matrix-forming phenotype of cultured human cells from whole meniscus was enhanced by hypoxia (5% oxygen). Because the meniscus contains an inner region that is devoid of vasculature and an outer vascular region, here we investigate, by gene expression analysis, the separate responses of cells isolated from the inner and outer meniscus to lowered oxygen, and compared it with the response of articular chondrocytes. In aggregate culture of outer meniscus cells, hypoxia (5% oxygen) increased the expression of type II collagen and SOX9 (Sry-related HMG box-9), and decreased the expression of type I collagen. In contrast, with inner meniscus cells, there was no increase in SOX9, but type II collagen and type I collagen increased. The articular chondrocytes exhibited little response to 5% oxygen in aggregate culture, with no significant differences in the expression of these matrix genes and SOX9. In both aggregate cultures of outer and inner meniscus cells, but not in chondrocytes, there was increased expression of collagen prolyl 4-hydroxylase (P4H)α(I) in response to 5% oxygen, and this hypoxia-induced expression of P4Hα(I) was blocked in monolayer cultures of meniscus cells by the hypoxia-inducible factor (HIF)-1α inhibitor (YC-1). In fresh tissue from the outer and inner meniscus, the levels of expression of the HIF-1α gene and downstream target genes (namely, those encoding P4Hα(I) and HIF prolyl 4-hydroxylase) were significantly higher in the inner meniscus than in the outer meniscus. Thus, this study revealed that inner meniscus cells were less responsive to 5% oxygen tension than were outer meniscus cells, and they were both more sensitive than articular chondrocytes from a similar joint. These results suggest that the vasculature and greater oxygen tension in the outer meniscus may help to suppress cartilage-like matrix formation