Photocatalytic production of organic compounds from CO and H2O in a simulated Martian atmosphere

[14C]CO2 and [14C]organic compounds are formed when a mixture of [14C]CO and water vapor diluted in [12C]CO2 or N2 is irradiated with ultraviolet light in the presence of soil or pulverized vycor substratum. The [14C]CO2 is recoverable from the gas phase, the [14C]organic products from the substratum. Three organic products have been tentatively identified as formaldehyde, acetaldehyde, and glycolic acid. The relative yields of [14C]CO2 and [14C]organics are wavelength- and surface-dependent. Conversion of CO to CO2 occurs primarily at wavelengths shorter than 2000 angstrom, apparently involves the photolysis of water, and is inhibited by increasing amounts of vycor substratum. Organic formation occurs over a broad spectral range below 3000 angstrom and increases with increasing amounts of substratum. It is suggested that organic synthesis results from adsorption of CO and H2O on surfaces, with excitation of one or both molecules occurring at wavelengths longer than those absorbed by the free gases. This process may occur on Mars and may have been important on the primitive earth

Earnings Volatility in America: Evidence from Matched CPS

We offer new evidence on earnings volatility of men and women in the United States over the past four decades by using matched data from the March Current Population Survey. We construct a measure of total volatility that encompasses both permanent and transitory instability, and that admits employment transitions and losses from self employment. We also present a detailed decomposition of earnings volatility to account for changing shares in employment probabilities, conditional variances of continuous workers, and conditional mean variances from labor-force entry and exit. Our results show that earnings volatility among men increased by 15 percent from the early 1970s to mid 1980s, while women’s volatility fell, and each stabilized thereafter. However, this pooled series masks important heterogeneity in volatility levels and trends across education groups and marital status. We find that men’s earnings volatility is increasingly accounted for by employment transitions, especially exits, while the share of women’s volatility accounted for by continuous workers rose, each of which highlights the importance of allowing for periods of non-work in volatility studies

Ten Years of Affordable Housing Policy: Is Maine Making Progress-- A Symposium

In December 1987 Governor McKernan appointed a 30-member, statewide task force to address the issue of affordable housing in Maine. The task force was charged with investigating the quality and cost of affordable housing for lower- and middle-income families, and recommending a set of actions to improve the quality of existing housing as well as to increase the supply of housing. In September 1998 the Task Force issued a report that prescribed a number of local and regional—as well as private and public—solutions to the problem of affordable housing. More than ten years later Maine housing advocates note that the state’s “crisis” in affordable housing has returned. Housing markets are tight and, particularly in southern Maine, there is a shortage of affordable housing options for middle- and low-income families. In dealing with the current dearth of affordable housing, policymakers may find it useful to reflect back on the recommendations put forward little more than a decade ago. In this symposium, MPR asked four individuals with long-standing commitments to the issue of housing to comment on the recommendations put forth by the 1988 Task Force: Did Maine accomplish what it said was important ten years ago? Do the Task Force’s recommendations offer sound advice now

The Potential of Differential Astrometric Interferometry from the High Antarctic Plateau

The low infrared background and high atmospheric transparency are the principal advantages of Antarctic Plateau sites for astronomy. However, the poor seeing (between one and three arcseconds) negates much of the sensitivity improvements that the Antarctic atmosphere offers, compared to mid-latitude sites such as Mauna Kea or Cerro Paranal. The seeing at mid-latitude sites, though smaller in amplitude, is dominated by turbulence at altitudes of 10 to 20 km. Over the Antarctic plateau, virtually no high altitude turbulence is present in the winter. The mean square error for an astrometric measurement with a dual-beam, differential astrometric interferometer in the very narrow angle regime is proportional to the integral of $h^2 C_N^2(h)$. Therefore, sites at which the turbulence occurs only at low altitudes offer large gains in astrometric precision. We show that a modest interferometer at the South Pole can achieve 10 $\mu$as differential astrometry 300 times faster than a comparable interferometer at a good mid-latitude site, in median conditions. Science programs that would benefit from such an instrument include planet detection and orbit determination and astrometric observation of stars microlensed by dark matter candidates.Comment: Accepted for publication in Publications of the Astronomical Society of Australi

Principal forms X^2 + nY^2 representing many integers

In 1966, Shanks and Schmid investigated the asymptotic behavior of the number of positive integers less than or equal to x which are represented by the quadratic form X^2+nY^2. Based on some numerical computations, they observed that the constant occurring in the main term appears to be the largest for n=2. In this paper, we prove that in fact this constant is unbounded as n runs through positive integers with a fixed number of prime divisors.Comment: 10 pages, title has been changed, Sections 2 and 3 are new, to appear in Abh. Math. Sem. Univ. Hambur

The role of discharge variability in determining alluvial stratigraphy

We illustrate the potential for using physics-based modeling to link alluvial stratigraphy to large river morphology and dynamics. Model simulations, validated using ground penetrating radar data from the Río Paraná, Argentina, demonstrate a strong relationship between bar-scale set thickness and channel depth, which applies across a wide range of river patterns and bar types. We show that hydrologic regime, indexed by discharge variability and flood duration, exerts a first-order influence on morphodynamics and hence bar set thickness, and that planform morphology alone may be a misleading variable for interpreting deposits. Indeed, our results illustrate that rivers evolving under contrasting hydrologic regimes may have very similar morphology, yet be characterized by marked differences in stratigraphy. This realization represents an important limitation on the application of established theory that links river topography to alluvial deposits, and highlights the need to obtain field evidence of discharge variability when developing paleoenvironmental reconstructions. Model simulations demonstrate the potential for deriving such evidence using metrics of paleocurrent variance

(G)hosting television: Ghostwatch and its medium

This article’s subject is Ghostwatch (BBC, 1992), a drama broadcast on Halloween night of 1992 which adopted the rhetoric of live non-fiction programming, and attracted controversy and ultimately censure from the Broadcasting Standards Council. In what follows, we argue that Ghostwatch must be understood as a televisually-specific artwork and artefact. We discuss the programme’s ludic relationship with some key features of television during what Ellis (2000) has termed its era of ‘availability’, principally liveness, mass simultaneous viewing, and the flow of the television super-text. We trace the programme’s television-specific historicity whilst acknowledging its allusions and debts to other media (most notably film and radio). We explore the sophisticated ways in which Ghostwatch’s visual grammar and vocabulary and deployment of ‘broadcast talk’ (Scannell 1991) variously ape, comment upon and subvert the rhetoric of factual programming, and the ends to which these strategies are put. We hope that these arguments collectively demonstrate the aesthetic and historical significance of Ghostwatch and identify its relationship to its medium and that medium’s history. We offer the programme as an historically-reflexive artefact, and as an exemplary instance of the work of art in television’s age of broadcasting, liveness and co-presence

Geometry of Discrete Quantum Computing

Conventional quantum computing entails a geometry based on the description of an n-qubit state using 2^{n} infinite precision complex numbers denoting a vector in a Hilbert space. Such numbers are in general uncomputable using any real-world resources, and, if we have the idea of physical law as some kind of computational algorithm of the universe, we would be compelled to alter our descriptions of physics to be consistent with computable numbers. Our purpose here is to examine the geometric implications of using finite fields Fp and finite complexified fields Fp^2 (based on primes p congruent to 3 mod{4}) as the basis for computations in a theory of discrete quantum computing, which would therefore become a computable theory. Because the states of a discrete n-qubit system are in principle enumerable, we are able to determine the proportions of entangled and unentangled states. In particular, we extend the Hopf fibration that defines the irreducible state space of conventional continuous n-qubit theories (which is the complex projective space CP{2^{n}-1}) to an analogous discrete geometry in which the Hopf circle for any n is found to be a discrete set of p+1 points. The tally of unit-length n-qubit states is given, and reduced via the generalized Hopf fibration to DCP{2^{n}-1}, the discrete analog of the complex projective space, which has p^{2^{n}-1} (p-1)\prod_{k=1}^{n-1} (p^{2^{k}}+1) irreducible states. Using a measure of entanglement, the purity, we explore the entanglement features of discrete quantum states and find that the n-qubit states based on the complexified field Fp^2 have p^{n} (p-1)^{n} unentangled states (the product of the tally for a single qubit) with purity 1, and they have p^{n+1}(p-1)(p+1)^{n-1} maximally entangled states with purity zero.Comment: 24 page

National priority setting partnership using a Delphi consensus process to develop neonatal research questions suitable for practice-changing randomised trials in the UK

BACKGROUND: The provision of neonatal care is variable and commonly lacks adequate evidence base; strategic development of methodologically robust clinical trials is needed to improve outcomes and maximise research resources. Historically, neonatal research topics have been selected by researchers; prioritisation processes involving wider stakeholder groups have generally identified research themes rather than specific questions amenable to interventional trials. OBJECTIVE: To involve stakeholders including parents, healthcare professionals and researchers to identify and prioritise research questions suitable for answering in neonatal interventional trials in the UK. DESIGN: Research questions were submitted by stakeholders in population, intervention, comparison, outcome format through an online platform. Questions were reviewed by a representative steering group; duplicates and previously answered questions were removed. Eligible questions were entered into a three-round online Delphi survey for prioritisation by all stakeholder groups. PARTICIPANTS: One hundred and eight respondents submitted research questions for consideration; 144 participants completed round one of the Delphi survey, 106 completed all three rounds. RESULTS: Two hundred and sixty-five research questions were submitted and after steering group review, 186 entered into the Delphi survey. The top five ranked research questions related to breast milk fortification, intact cord resuscitation, timing of surgical intervention in necrotising enterocolitis, therapeutic hypothermia for mild hypoxic ischaemic encephalopathy and non-invasive respiratory support. CONCLUSIONS: We have identified and prioritised research questions suitable for practice-changing interventional trials in neonatal medicine in the UK at the present time. Trials targeting these uncertainties have potential to reduce research waste and improve neonatal care

Effect of local medicinal herbs as feed additives on production performance and faecal parameters in laying hens

Medicinal herbs are gaining importance in both human and animal nutrition due to their bioactive components that possess a wide range of beneficial effects on body health enhancement. To concord with the banning of antibiotic growth promoters in animal nutrition, research was carried out to utilize phytogenic feed additives in poultry nutrition as the alternative to improve their overall performance. Therefore, the objective of this study was to evaluate the effects of dietary supplementation of the three selected herbs at the level of 1% on production performance and faecal parameters in laying hens. In this study, a total of 96 Bovans Brown layers of 32 wk old were subjected to four dietary treatments in the form of CRD, namely (T1) control, (T2) basal diet + 1% of turmeric rhizome powder, (T3) basal diet + 1% of Vietnamese coriander leaf powder, and (T4) basal diet + 1% of Dayak onion powder. The layers were given 7-d adaption period before the feeding trial started which lasted for 12 wk. The results showed that there was no significant difference (P>0.05) in the means of overall feed intake, egg mass, feed conversion efficiency as well as body weight gain among the treatment groups. The hen-day egg production and egg weight of birds in treatments T2 and T4 showed significant differences (P<0.05) compared to control group. Besides, the birds in the treatment groups supplemented with medicinal herbs (T2, T3 and T4) also showed significant reduction in faecal pH and faecal Entero bacteriaceae counts (P<0.05) compared to the control, while significantly improved (p<0.05) the faecal lactic acid bacteria counts as compared to those in the control group. Thus, the present study suggests that dietary supplementation of 1% of turmeric rhizome powder, Vietnamese coriander leaf powder and Dayak onion powder in layer diet can achieve better performance in terms of hen-day egg production and egg weight associated with favourable intestinal environment without any adverse effect