Pulse propagation in the pulmonary and systemic arteries

The one-dimensional model of Olufsen (2000) [*] for blood flow in the systemic arteries has been extended and built upon in a number of ways. Firstly, it has been applied to hypotheses of diseases of the systemic circulation, and that of the microcirculation. With a view to better understanding the microcirculation (the smallest vessels of the systemic circulation) and its diseases, the model has been extended to provide predictions of the propagating pressure pulse and flow rate in small arteries. Secondly, Olufsen’s model has been used as a base upon which to build a model of the pulmonary circulation, incorporating both the pulmonary arterial and venous circulations, with detailed simulations of pressure and flow predicted in the large pulmonary arteries and large pulmonary veins. To this end, a new model has been eveloped to describe a connected network of small arteries and small veins, replacing the small arterial model used as an outflow condition in the original model. A new outflow condition to describe the return of blood from the pulmonary venous system to the left atrium of the heart has also been implemented. Finally, this new pulmonary model has been applied to various hypotheses as to the causes of diseases and disorders of the pulmonary circulation, providing predictions of pressure and flow in the large pulmonary arteries and veins in both normal and abnormal circumstances, and showing agreement with clinical observations. [*] M.S. Olufsen at al. Numerical simulation and experimental validation of blood flow in arteries with structured-tree outflow conditions. Ann Biomed Eng, 28:1281–1299, 2000

United classification of cosmic gamma-ray bursts and their counterparts

United classification of gamma-ray bursts and their counterparts is established on the basis of measured characteristics: photon energy E and emission duration T. The founded interrelation between the mentioned characteristics of events consists in that, as the energy increases, the duration decreases (and vice versa). The given interrelation reflects the nature of the phenomenon and forms the E-T diagram, which represents a natural classification of all observed events in the energy range from 10E9 to 10E-6 eV and in the corresponding interval of durations from about 10E-2 up to 10E8 s. The proposed classification results in the consequences, which are principal for the theory and practical study of the phenomenon.Comment: Keywords Gamma rays: burst

Cigarette smoking and adenocarcinomas of the esophagus and esophagogastric junction: a pooled analysis from the International BEACON Consortium

BackgroundPrevious studies that showed an association between smoking and adenocarcinomas of the esophagus and esophagogastric junction were limited in their ability to assess differences by tumor site, sex, dose–response, and duration of cigarette smoking cessation.MethodsWe used primary data from 10 population-based case–control studies and two cohort studies from the Barrett’s Esophagus and Esophageal Adenocarcinoma Consortium. Analyses were restricted to white non-Hispanic men and women. Patients were classified as having esophageal adenocarcinoma (n = 1540), esophagogastric junctional adenocarcinoma (n = 1450), or a combination of both (all adenocarcinoma; n = 2990). Control subjects (n = 9453) were population based. Associations between pack-years of cigarette smoking and risks of adenocarcinomas were assessed, as well as their potential modification by sex and duration of smoking cessation. Study-specific odds ratios (ORs) estimated using multivariable logistic regression models, adjusted for age, sex, body mass index, education, and gastroesophageal reflux, were pooled using a meta-analytic methodology to generate summary odds ratios. All statistical tests were two-sided.ResultsThe summary odds ratios demonstrated strong associations between cigarette smoking and esophageal adenocarcinoma (OR = 1.96, 95% confidence interval [CI] = 1.64 to 2.34), esophagogastric junctional adenocarcinoma (OR = 2.18, 95% CI = 1.84 to 2.58), and all adenocarcinoma (OR = 2.08, 95% CI = 1.83 to 2.37). In addition, there was a strong dose–response association between pack-years of cigarette smoking and each outcome ( P &lt; .001). Compared with current smokers, longer smoking cessation was associated with a decreased risk of all adenocarcinoma after adjusting for pack-years (&lt;10 years of smoking cessation: OR = 0.82, 95% CI = 0.60 to 1.13; and ≥10 years of smoking cessation: OR = 0.71, 95% CI = 0.56 to 0.89). Sex-specific summary odds ratios were similar.ConclusionsCigarette smoking is associated with increased risks of adenocarcinomas of the esophagus and esophagogastric junction in white men and women; compared with current smoking, smoking cessation was associated with reduced risks.<br/

BICCO-Net II. Final report to the Biological Impacts of Climate Change Observation Network (BICCO-Net) Steering Group

• BICCO-Net Phase II presents the most comprehensive single assessment of climate change impacts on UK biodiversity to date. • The results provide a valuable resource for the CCRA 2018, future LWEC report cards, the National Adaptation Programme and other policy-relevant initiatives linked to climate change impacts on biodiversity

Situationally edited empathy: an effect of socio-economic structure on individual choice

Criminological theory still operates with deficient models of the offender as agent, and of social influences on the agent’s decision-making process. This paper takes one ‘emotion’, empathy, which is theoretically of considerable importance in influencing the choices made by agents; particularly those involving criminal or otherwise harmful action. Using a framework not of rational action, but of ‘rationalised action’, the paper considers some of the effects on individual psychology of social, economic, political and cultural structure. It is suggested that the climate-setting effects of these structures promote normative definitions of social situations which allow unempathic, harmful action to be rationalised through the situational editing of empathy. The ‘crime is normal’ argument can therefore be extended to include the recognition that the uncompassionate state of mind of the criminal actor is a reflection of the self-interested values which govern non-criminal action in wider society

DETERMINATION OF INTERSTITIAL SOLID-SOLUBILITY LIMIT IN TANTALUM AND IDENTIFICATION OF THE PRECIPITATE PHASES

Solid-solubility limits at 1500, 1000, snd 500/sup o/C for carbon, nitrogen, and oxygen in high-punity tantalum were determined by x-ray lattice- parameter methods. For carbon, the solubility was found to be 0.17 at. % at 1500/sup o/C and less than 0.07 at. % at l00/sup o/C. A nitrogen solubility of 3.70 at. % at l500/sup o/C decreased linearly with temperature to 2.75 at. % at 1000/sup o/C and 1.8 at. % at 500/sup o/C. In the case of oxygen, the solubility was found to be 3.65 at. % at 1500/sup o/C, 1.95 at. % at l0O0/sup o/ C, and 2.5 at. % at 500/sup o/C. The phases Ta/sub 2/, the lowtemperature modificstion of Ta/sub 2/O/sub 5/, and Ta/sub x/N of unknown coznposition hut which has a superlattice structure based upon the oniginsl body-centered-cubic tantalum lattice were identified is the initisl precipitates in the respective systems. (auth

X-ray Periodicity in AGN

Significant (marginal) detections of periodic signals have been recently reported in 3 (4) Active Galactic Nuclei. Three of the detections were obtained from long EUVE light curves of moderate-luminosity Seyfert galaxies; the fourth was discovered in Chandra data from the low-luminosity Seyfert 1 galaxy NGC 4395. When compared with Cyg X-1, I find that the period is related to the luminosity as $P\propto L^{2/3}$ rather than the expected one-to-one relationship. This result might be explained if the QPO is associated with the inner edge of the optically thick accretion disk, and the inner edge radius depends on the source luminosity (or black hole mass). A discussion of uncertainties in the period detection methodology is also discussed.Comment: To appear in From X-ray Binaries to Quasars: Black Hole Accretion on All Mass Scales, eds. T. J. Maccarone, R. P. Fender, and L. C. Ho (Dordrecht: Kluwer

Delivering 21st century Antarctic and Southern Ocean science

The Antarctic Roadmap Challenges (ARC) project identified critical requirements to deliver high priority Antarctic research in the 21st century. The ARC project addressed the challenges of enabling technologies, facilitating access, providing logistics and infrastructure, and capitalizing on international co-operation. Technological requirements include: i) innovative automated in situ observing systems, sensors and interoperable platforms (including power demands), ii) realistic and holistic numerical models, iii) enhanced remote sensing and sensors, iv) expanded sample collection and retrieval technologies, and v) greater cyber-infrastructure to process ‘big data’ collection, transmission and analyses while promoting data accessibility. These technologies must be widely available, performance and reliability must be improved and technologies used elsewhere must be applied to the Antarctic. Considerable Antarctic research is field-based, making access to vital geographical targets essential. Future research will require continent- and ocean-wide environmentally responsible access to coastal and interior Antarctica and the Southern Ocean. Year-round access is indispensable. The cost of future Antarctic science is great but there are opportunities for all to participate commensurate with national resources, expertise and interests. The scope of future Antarctic research will necessitate enhanced and inventive interdisciplinary and international collaborations. The full promise of Antarctic science will only be realized if nations act together

Enhanced delivery and detection of terahertz frequency radiation from a quantum cascade laser within dilution refrigerator

We report on significant enhancements to the integration of terahertz (THz) quantum cascade lasers (QCL) and THz detection with a two-dimensional electron gas (2DEG) within a dilution refrigerator obtained by the inclusion of a multi-mesh 6 THz low-pass filter to block IR radiation, a Winston cone to focus light output, and gating the 2DEG for optimised sensitivity. We show that these improvements allow us to obtain a > 2.5 times reduced sample electron temperature (160 mK compared with 430 mK previously), during cyclotron resonance (CR) measurements of a 2DEG under QCL illumination. This opens up a route to performing sub-100 mK experiments using excitation by THz QCLs

Free-space and polarisation maintaining delivery of terahertz radiation from a quantum cascade laser in a dry dilution refrigerator

We demonstrate a free-space terahertz (THz) optical system inside a dry dilution refrigerator that allows us to direct polarized THz radiation from a quantum cascade laser (QCL) to a sample held at a base temperature of 28 mK. The sample temperature increases to 47 mK for an average applied 2.6 THz QCL power of 27 μW at a 10% duty cycle, as determined by calibrated thermometry. We also demonstrate that polarization is maintained using a polarization-sensitive bowtie-antenna-patterned photo-electric tunable step device and, additionally, that the polarization can be adjusted using a set of quartz waveplates in a filter wheel. With this work we introduce the ability to measure materials under polarized THz radiation at previously unreachable millikelvin temperatures