Temperature of a gray body most closely fit- ting the solar extraterrestrial spectrum

Temperature measurements of black body most closely fitting solar extraterrestrial spectru

The new tungsten-filament lamp standards of total irradiance

Instrumentation and methods used in establishing tungsten-filament lamp standards of total irradianc

Ambient air pollution and adverse birth outcomes: A review of underlying mechanisms

Epidemiological data provide varying degrees of evidence for associations between prenatal exposure to ambient air pollutants and adverse birth outcomes (suboptimal measures of fetal growth, preterm birth and stillbirth). To assess further certainty of effects, this review examines the experimental literature base to identify mechanisms by which air pollution (particulate matter, nitrogen dioxide and ozone) could cause adverse effects on the developing fetus. It likely that this environmental insult impacts multiple biological pathways important for sustaining a healthy pregnancy, depending upon the composition of the pollutant mixture and the exposure window owing to changes in physiologic maturity of the placenta, its circulations and the fetus as pregnancy ensues. The current body of evidence indicates that the placenta is a target tissue, impacted by a variety of critical processes including nitrosative/oxidative stress, inflammation, endocrine disruption, epigenetic changes, as well as vascular dysregulation of the maternal‐fetal unit. All of the above can disturb placental function and, as a consequence, could contribute to compromised fetal growth as well increasing the risk of stillbirth. Furthermore, given that there is often an increased inflammatory response associated with preterm labour, inflammation is a plausible mechanism mediating the effects of air pollution on premature delivery. In the light of increased urbanisation and an ever‐changing climate, both of which increase ambient air pollution and negatively affect vulnerable populations such as pregnant individuals, it is hoped that the collective evidence may contribute to decisions taken to strengthen air quality policies, reductions in exposure to air pollution and subsequent improvements in the health of those not yet born

Defect modes in otherwise perfect photonic crystal and photonic crystal fibres

Many of the applications of photonic crystals and photonic crystal fibres require the periodic structure tohave some type of defect. In photonic crystal fibers a point defect defines the fiber core, whereas in photonic crystals a line defect acts as a waveguide, and point defects act as cavities. The modeling of these defects usually either makes use of periodic boundary conditions, by which the defect is replicated periodically, or models a photonic cyrstal of finite extent. HOwever, some applications, for example the cut-off behaviour of a defect mode where the field extends very widely, require methods that can model a defect in an otherwise infinite and perfectly periodic structure. Here we present such a method. It combines the method of fictitious sources with averaging over the Brillouin zone, and we apply it to study the long wavelength behavior of the fundamental mode of photonic crystal fibers

The induced turbulence effect on propagation of radio emission in pulsar magnetospheres

The effect of photon-beam-induced turbulence on propagation of radio emission in a pulsar magnetosphere is discussed. Beamed radio emission with a high brightness temperature can generate low-frequency plasma waves in the pulsar magnetosphere and these waves scatter the radio beam. We consider this effect on propagation of radio emission both in the open field line region and in the closed field line region. The former is applicable to most cases of pulsar radio emission where the propagation is confined to the polar region; it is shown that the induced process is not effective for radio emission of moderately high brightness temperature but can have a severe effect on giant pulses. For giant pulses not to be affected by this process, they must be emitted very close to the light cylinder. We show that the induced process is efficient in the closed field line region, inhibiting propagation of the radio emission in this region.Comment: 11 pages, 3 figures, accepted for publication in MNRA

PRISIM: a computer program that makes PRA useful

PRISIM is an IBM personal computer program that translates probabilistic risk assessment (PRA) information and calculates additional PRA type information for use by those who are not PRA experts. Specifically, PRISIM was developed for the US Nuclear Regulatory Commission for use by their resident inspectors at nuclear power plants. Inspector activities are either scheduled or are in response to a particular status of a plant. PRISIM is useful for either activity

Robust plasmon waveguides in strongly-interacting nanowire arrays

Arrays of parallel metallic nanowires are shown to provide a tunable, robust, and versatile platform for plasmon interconnects, including high-curvature turns with minimum signal loss. The proposed guiding mechanism relies on gap plasmons existing in the region between adjacent nanowires of dimers and multi-wire arrays. We focus on square and circular silver nanowires in silica, for which excellent agreement between both boundary element method and multiple multipolar expansion calculations is obtained. Our work provides the tools for designing plasmon-based interconnects and achieving high degree of integration with minimum cross talk between adjacent plasmon guides.Comment: 4 pages, 5 figure

An evidence-based socioecological framework to understand men’s use of anabolic androgenic steroids and inform interventions in this area

Research into men’s use of anabolic androgenic steroids (AAS) over the past three decades has identified many factors that contribute to decision making in this area. However there are limited theoretical frameworks to synthesize this research and guide practice, such as interventions to prevent use or reduce health risks. To address this gap a socioecological framework is presented based upon the international literature examining AAS use. Socioecological models recognize that individuals and behaviors exist within complex physical and social systems and are useful tools for guiding interventions to ensure consideration is given to multiple influential factors. This framework proposes that use of AAS is the result of the interaction of a range of factors at the individual, social network, institutional, community and societal levels that are likely to change over time and with experience. Viewed through this framework it becomes clear that AAS use can be a complex behavior with many influential environments and relationships impacting on a diverse population in different ways and at different times. The implications of findings for engaging with people who use AAS and delivering interventions are discussed, such as the identification of important transition times and influencing norms within social groups and communities

The subpulse modulation properties of pulsars at 92 cm and the frequency dependence of subpulse modulation

A large sample of pulsars has been observed to study their subpulse modulation at an observing wavelength (when achievable) of both 21 and 92 cm using the Westerbork Synthesis Radio Telescope. In this paper we present the 92-cm data and a comparison is made with the already published 21-cm results. We analysed 191 pulsars at 92 cm using fluctuation spectra. The sample of pulsars is as unbiased as possible towards any particular pulsar characteristics. For 15 pulsars drifting subpulses are discovered for the first time and 26 of the new drifters found in the 21-cm data are confirmed. We discovered nulling for 8 sources and 8 pulsars are found to intermittently emit single pulses that have pulse energies similar to giant pulses. It is estimated that at least half of the total population of pulsars have drifting subpulses when observations with a high enough signal-to-noise ratio would be available. It could well be that the drifting subpulse mechanism is an intrinsic property of the emission mechanism itself, although for some pulsars it is difficult or impossible to detect. Drifting subpulses are in general found at both frequencies, although the chance of detecting drifting subpulses is possibly slightly higher at 92 cm. It appears that the youngest pulsars have the most disordered subpulses and the subpulses become more and more organized into drifting subpulses as the pulsar ages. The correlations with the modulation indices are argued to be consistent with the picture in which the radio emission can be divided in a drifting subpulse signal plus a quasi-steady signal which becomes, on average, stronger at high observing frequencies. The measured values of P3 at the two frequencies are highly correlated, but there is no evidence for a correlation with other pulsar parameters.Comment: 30 pages, 10 figures, accepted for publication in A&A, astro-ph version is missing 191 figures due to file size restrictions. Please download the appendix from http://www.astron.nl/~stappers/wiki/doku.php?id=resources:publication

Dominion cartoon satire as trench culture narratives: complaints, endurance and stoicism

Although Dominion soldiers’ Great War field publications are relatively well known, the way troops created cartoon multi-panel formats in some of them has been neglected as a record of satirical social observation. Visual narrative humour provides a ‘bottom-up’ perspective for journalistic observations that in many cases capture the spirit of the army in terms of stoicism, buoyed by a culture of internal complaints. Troop concerns expressed in the early comic strips of Australians, Canadians, New Zealanders and British were similar. They shared a collective editorial purpose of morale boosting among the ranks through the use of everyday narratives that elevated the anti-heroism of the citizen soldier, portrayed as a transnational everyman in the service of empire. The regenerative value of disparagement humour provided a redefinition of courage as the very act of endurance on the Western Front