The degradation of alzak by short wavelength ultraviolet radiation

The changes in reflectance of thermal aluminum coating samples exposed to different irradiating utraviolet wavelengths are discussed. It is shown that the coating is damaged faster and further by 180 to 210 in radiation than by Lyman alpha radiation. On an equivalent incident energy basis, Lyman alpha does less damage than 180 to 210 nm radiation. Above 300 nm no degradation is observed for long exposures and below 300 nm increasing degradation with decreasing wavelength is found. It is concluded that Lyman alpha radiation need not be included in laboratory testing of this thermal coating for spacecraft structures

Patients with Essential thrombocythaemia have an increased prevalence of antiphospholipid antibodies which may be associated with thrombosis

A significant proportion of patients with Essential Thrombocythaemia (ET) have thrombotic complications which have an important impact upon the quality, and duration of their life. We performed a retrospective cross sectional study of the prevalence of antiphospholipid antibodies (APA) in 68 ET patients. Compared to 200 elderly controls (> 50 years) there was a significant increase in anticardiolipin IgM (p < 0.0001) and anti β2 glycoprotein I (anti-β2GPI) IgM (p < 0.0001) antibodies in ET. Thrombosis occurred in 10/20 with APA and 12/48 without, p = 0.04, relative risk 2.0 (95% confidence intervals 1.03-3.86); these patients did not differ in terms of other clinical features. The prevalence of thrombosis in patients with dual APA (6/7) was significant when compared to those with single APA (p = 0.02) and the remaining patients (p < 0.0002). Also anti-β2GPI IgM antibodies either alone, or in combination with another APA, were associated with thrombosis (p = 0.02). These results suggest that the prevalence of APA in ET and their influence upon thrombotic risk merit investigation in a larger study

Controls on the width of tropical precipitation and its contraction under global warming

AD and ARA were funded by the National Science Foundation Paleo Perspective on Climate Change (P2C2) Grant number AGS-1702827.Climate models robustly and unanimously simulate narrowing of the intense tropical precipitation under greenhouse gas forcing. We argue that the meridional width of tropical precipitation is controlled by the seasonal meridional range of the intertropical convergence zone (ITCZ). The contraction of tropical precipitation under greenhouse forcing results from a reduced seasonal range of ITCZ migration. An energetic theory -- similar to the energetic theory for ITCZ shifts based on the hemispheric contrast of energy input to the atmosphere-- is developed. The meridional width of tropical precipitation is proportional to the seasonal range of the inter-hemispheric contrast in atmospheric heating divided by the efficiency of atmospheric cross-equatorial heat transport. Climate models are biased toward overly expansive tropical precipitation resulting from an exaggerated seasonal atmospheric heating. The robust contraction of tropical precipitation under global warming results from increased efficiency of inter-hemispheric energy transport consistent with enhanced gross moist stability of the tropical atmosphere.Publisher PDFPeer reviewe

Context-aware microgrid storage using electric cars

Electric cars could provide a viable power storage option for suburban microgrids. Such stored power could be used by the microgrid or supplied to the main grid at key times as part of the operation and management of a microgrid cluster. Tracking driver behaviour then becomes important in order to estimate and forecast the level of stored power at any given time. Context-aware information gathered from external sources such as an electronic work calendar can provide one means of predicting driver and car movements. We are using simulation studies to quantify the benefit of such context-aware information for calculating and forecasting battery storage capacity in a microgrid cluster. This capacity is then used in a simulation of power trading between the cluster and a main grid

The measurement of lubricant-film thickness using ultrasound

Ultrasound is reflected from a liquid layer between two solid bodies. This reflection depends on the ultrasonic frequency, the acoustic properties of the liquid and solid, and the layer thickness. If the wavelength is much greater than the liquid-layer thickness, then the response is governed by the stiffness of the layer. If the wavelength and layer thickness are similar, then the interaction of ultrasound with the layer is controlled by its resonant behaviour. This stiffness governed response and resonant response can be used to determine the thickness of the liquid layer, if the other parameters are known. In this paper, ultrasound has been developed as a method to determine the thickness of lubricating films in bearing systems. An ultrasonic transducer is positioned on the outside of a bearing shell such that the wave is focused on the lubricant-film layer. The transducer is used to both emit and receive wide-band ultrasonic pulses. For a particular lubricant film, the reflected pulse is processed to give a reflection-coefficient spectrum. The lubricant-film thickness is then obtained from either the layer stiffness or the resonant frequency. The method has been validated using fluid wedges at ambient pressure between flat and curved surfaces. Experiments on the elastohydrodynamic film formed between a sliding ball and a flat surface were performed. Film-thickness values in the range 50-500 nm were recorded, which agreed well with theoretical film-formation predictions. Similar measurements have been made on the oil film between the balls and outer raceway of a deep-groove ball bearing

Cancer Cachexia: Mechanisms and Clinical Implications

Cachexia is a multifactorial process of skeletal muscle and adipose tissue atrophy resulting in progressive weight loss. It is associated with poor quality of life, poor physical function, and poor prognosis in cancer patients. It involves multiple pathways: procachectic and proinflammatory signals from tumour cells, systemic inflammation in the host, and widespread metabolic changes (increased resting energy expenditure and alterations in metabolism of protein, fat, and carbohydrate). Whether it is primarily driven by the tumour or as a result of the host response to the tumour has yet to be fully elucidated. Cachexia is compounded by anorexia and the relationship between these two entities has not been clarified fully. Inconsistencies in the definition of cachexia have limited the epidemiological characterisation of the condition and there has been slow progress in identifying therapeutic agents and trialling them in the clinical setting. Understanding the complex interplay of tumour and host factors will uncover new therapeutic targets

Pressure Tuning of the Charge Density Wave in the Halogen-Bridged Transition-Metal (MX) Solid Pt2Br6(NH3)4Pt_2Br_6(NH_3)_4

We report the pressure dependence up to 95 kbar of Raman active stretching modes in the quasi-one-dimensional MX chain solid $Pt_2Br_6(NH_3)_4$. The data indicate that a predicted pressure-induced insulator-to-metal transition does not occur, but are consistent with the solid undergoing either a three-dimensional structural distortion, or a transition from a charge-density wave to another broken-symmetry ground state. We show that such a transition cacan be well-modeled within a Peierls-Hubbard Hamiltonian. 1993 PACS: 71.30.+h, 71.45.Lr, 75.30.Fv, 78.30.-j, 81.40.VwComment: 4 pages, ReVTeX 3.0, figures available from the authors on request (Gary Kanner, [email protected]), to be published in Phys Rev B Rapid Commun, REVISION: minor typos corrected, LA-UR-94-246

Mechanics and dynamics of X-chromosome pairing at X inactivation

At the onset of X-chromosome inactivation, the vital process whereby female mammalian cells equalize X products with respect to males, the X chromosomes are colocalized along their Xic (X-inactivation center) regions. The mechanism inducing recognition and pairing of the X’s remains, though, elusive. Starting from recent discoveries on the molecular factors and on the DNA sequences (the so-called "pairing sites") involved, we dissect the mechanical basis of Xic colocalization by using a statistical physics model. We show that soluble DNA-specific binding molecules, such as those experimentally identified, can be indeed sufficient to induce the spontaneous colocalization of the homologous chromosomes but only when their concentration, or chemical affinity, rises above a threshold value as a consequence of a thermodynamic phase transition. We derive the likelihood of pairing and its probability distribution. Chromosome dynamics has two stages: an initial independent Brownian diffusion followed, after a characteristic time scale, by recognition and pairing. Finally, we investigate the effects of DNA deletion/insertions in the region of pairing sites and compare model predictions to available experimental data

The impact of a gender-specific physical activity intervention on the fitness and fatness profile of men in Ireland

Background: Amid increasing concerns about rising obesity rates and unhealthy lifestyle behaviours, physical activity (PA) is seen as a prophylactic to many chronic conditions affecting men. Men respond best to community-based PA programmes, using gender-specific promotional and delivery strategies. ‘Men on the Move’ (MOM) was developed on this basis and targeted inactive adult men in Ireland. Methods: Sedentary men (n=927; age=50.7±10.9yr; Weight=92.7±16.0kg; METS=6.06±2.13) were recruited across 8 counties; 4 ‘intervention group’ (IG; n=501), and 4 ‘comparison-in-waiting group’ (CG; n=426). The MOM programme involved structured group exercise twice weekly for 12 weeks, along with health-related workshops with the groups maintained up to 52W. Primary outcome measures (aerobic fitness, bodyweight and waist circumference (WC)) together with self-administered questionnaires were used to gather participant data at baseline, 12, 26 and 52 weeks (W). Results: Results show a net positive effect on aerobic fitness, bodyweight and WC, with significant (p<0.05) net change scores observed in the IG compared to the CG (METS: 12W=+2.20, 26W=+1.89, 52W=+0.92; Weight: 12W=-1.72kg, 26W=-1.95kg, 52W=-1.89kg; WC: 12W=-4.54cm, 26W=-2.69cm, 52W=-3.16cm). The corresponding reduction in cardiovascular disease risk is particularly significant in the context of a previously inactive and overweight cohort. The high ‘dropout’ (42.7% presenting at 52W) however, is of particular concern, with ‘dropouts’ having lower levels of aerobic fitness and higher bodyweight/WC at baseline. Conclusions: Notwithstanding dropout issues, findings address an important gap in public health practice by informing the translational scale-up of a small controllable gender-specific PA intervention, MOM, to a national population based PA intervention targeting inactive men