Investigation of seismicity and related effects at NASA Ames-Dryden Flight Research Facility, Computer Center, Edwards, California

This report discusses a geological and seismological investigation of the NASA Ames-Dryden Flight Research Facility site at Edwards, California. Results are presented as seismic design criteria, with design values of the pertinent ground motion parameters, probability of recurrence, and recommended analogous time-history accelerograms with their corresponding spectra. The recommendations apply specifically to the Dryden site and should not be extrapolated to other sites with varying foundation and geologic conditions or different seismic environments

Advocacy coalitions involved in California's menu labeling policy debate: Exploring coalition structure, policy beliefs, resources, and strategies.

Advocacy coalitions often play an important role in the state health policymaking process, yet little is known about their structure, composition, and behavior. In 2008, California became the first state to enact a menu labeling law. Using the advocacy coalition framework, we examine different facets of the coalitions involved in California's menu labeling policy debate. We use a qualitative research approach to identify coalition members and explore their expressed beliefs and policy arguments, resources, and strategies by analyzing legislative documents (n = 87) and newspaper articles (n = 78) produced between 1999 and 2009. Between 2003 and 2008, six menu labeling bills were introduced in the state's legislature. We found the issue received increasing media attention during this period. We identified two advocacy coalitions involved in the debate-a public health (PH) coalition and an industry coalition. State organizations acted as coalition leaders and participated for a longer duration than elected officials. The structure and composition of each coalition varied. PH coalition leadership and membership notably increased compared to the industry coalition. The PH coalition, led by nonprofit PH and health organizations, promoted a clear and consistent message around informed decision making. The industry coalition, led by a state restaurant association, responded with cost and implementation arguments. Each coalition used various resources and strategies to advance desired outcomes. PH coalition leaders were particularly effective at using resources and employing advocacy strategies, which included engaging state legislators as coalition members, using public opinion polls and information, and leveraging media resources to garner support. Policy precedence and a local policy push emerged as important policymaking strategies. Areas for future research on the state health policymaking process are discussed

Compilation of extended recursion in call-by-value functional languages

This paper formalizes and proves correct a compilation scheme for mutually-recursive definitions in call-by-value functional languages. This scheme supports a wider range of recursive definitions than previous methods. We formalize our technique as a translation scheme to a lambda-calculus featuring in-place update of memory blocks, and prove the translation to be correct.Comment: 62 pages, uses pi

Vlasov moments, integrable systems and singular solutions

The Vlasov equation for the collisionless evolution of the single-particle probability distribution function (PDF) is a well-known Lie-Poisson Hamiltonian system. Remarkably, the operation of taking the moments of the Vlasov PDF preserves the Lie-Poisson structure. The individual particle motions correspond to singular solutions of the Vlasov equation. The paper focuses on singular solutions of the problem of geodesic motion of the Vlasov moments. These singular solutions recover geodesic motion of the individual particles.Comment: 16 pages, no figures. Submitted to Phys. Lett.

Modelling the impacts of ammonia emissions reductions on North American air quality

A unified regional air-quality modelling system (AURAMS) was used to investigate the effects of reductions in ammonia emissions on regional air quality, with a focus on particulate-matter formation. Three simulations of one-year duration were performed for a North American domain: (1) a base-case simulation using 2002 Canadian and US national emissions inventories augmented by a more detailed Canadian emissions inventory for agricultural ammonia; (2) a 30% North-American-wide reduction in agricultural ammonia emissions; and (3) a 50% reduction in Canadian beef-cattle ammonia emissions. The simulations show that a 30% continent-wide reduction in agricultural ammonia emissions lead to reductions in median hourly PM<sub>2.5</sub> mass of <1 μg m<sup>−3</sup> on an annual basis. The atmospheric response to these emission reductions displays marked seasonal variations, and on even shorter time scales, the impacts of the emissions reductions are highly episodic: 95th-percentile hourly PM<sub>2.5</sub> mass decreases can be up to a factor of six larger than the median values. <br><br> A key finding of the modelling work is the linkage between gas and aqueous chemistry and transport; reductions in ammonia emissions affect gaseous ammonia concentrations close to the emissions site, but substantial impacts on particulate matter and atmospheric deposition often occur at considerable distances downwind, with particle nitrate being the main vector of ammonia/um transport. Ammonia emissions reductions therefore have trans-boundary consequences downwind. Calculations of critical-load exceedances for sensitive ecosystems in Canada suggest that ammonia emission reductions will have a minimal impact on current ecosystem acidification within Canada, but may have a substantial impact on future ecosystem acidification. The 50% Canadian beef-cattle ammonia emissions reduction scenario was used to examine model sensitivity to uncertainties in the new Canadian agricultural ammonia emissions inventory, and the simulation results suggest that further work is needed to improve the emissions inventory for this particular sector. It should be noted that the model in its current form neglects coarse mode base cation chemistry, so the predicted effects of ammonia emissions reductions shown here should be considered upper limits

Voluntary DNA-based information exchange and contact services following donor conception: an analysis of service users’ needs

Medical science has enabled the creation of families through the use of donor conception but some lifelong policy and practice implications are only recently being recognized. Research and practice have shown that donor conception can, for some, carry substantial long-term consequences. In this paper we present findings from a questionnaire-based study that sought to shed light on donor-conceived adults’ and gamete donors’ views on service and support needs when searching for genetic relatives with the aid of DNA testing. The findings demonstrate the complexity and sensitivity of providing services in this newly emerging area of need. Such provision requires collaboration between very different disciplines and agencies (scientific and psychosocial), introduces the potential for blurring of lines of accountability and responsibility, and highlights the challenges of identifying appropriate funding streams. In addition, the findings demonstrate the opportunities and limitations afforded by the use of DNA in identifying unknown genetic relatives

Proving Determinacy of the PharOS Real-Time Operating System

International audienceExecutions in the PharOS real-time system are deterministic in the sense that the sequence of local states for every process is independent of the order in which processes are scheduled. The essential ingredient for achieving this property is that a temporal window of execution is associated with every instruction. Messages become visible to receiving processes only after the time window of the sending message has elapsed. We present a high-level model of PharOS in TLA+ and formally state and prove determinacy using the TLA+ Proof System

Alpha-band rhythms in visual task performance: phase-locking by rhythmic sensory stimulation

Oscillations are an important aspect of neuronal activity. Interestingly, oscillatory patterns are also observed in behaviour, such as in visual performance measures after the presentation of a brief sensory event in the visual or another modality. These oscillations in visual performance cycle at the typical frequencies of brain rhythms, suggesting that perception may be closely linked to brain oscillations. We here investigated this link for a prominent rhythm of the visual system (the alpha-rhythm, 8-12 Hz) by applying rhythmic visual stimulation at alpha-frequency (10.6 Hz), known to lead to a resonance response in visual areas, and testing its effects on subsequent visual target discrimination. Our data show that rhythmic visual stimulation at 10.6 Hz: 1) has specific behavioral consequences, relative to stimulation at control frequencies (3.9 Hz, 7.1 Hz, 14.2 Hz), and 2) leads to alpha-band oscillations in visual performance measures, that 3) correlate in precise frequency across individuals with resting alpha-rhythms recorded over parieto-occipital areas. The most parsimonious explanation for these three findings is entrainment (phase-locking) of ongoing perceptually relevant alpha-band brain oscillations by rhythmic sensory events. These findings are in line with occipital alpha-oscillations underlying periodicity in visual performance, and suggest that rhythmic stimulation at frequencies of intrinsic brain-rhythms can be used to reveal influences of these rhythms on task performance to study their functional roles

Increased chromosomal radiosensitivity in asymptomatic carriers of a heterozygous BRCA1 mutation

Background: Breast cancer risk increases drastically in individuals carrying a germline BRCA1 mutation. The exposure to ionizing radiation for diagnostic or therapeutic purposes of BRCA1 mutation carriers is counterintuitive, since BRCA1 is active in the DNA damage response pathway. The aim of this study was to investigate whether healthy BRCA1 mutations carriers demonstrate an increased radiosensitivity compared with healthy individuals. Methods: We defined a novel radiosensitivity indicator (RIND) based on two endpoints measured by the G2 micronucleus assay, reflecting defects in DNA repair and G2 arrest capacity after exposure to doses of 2 or 4 Gy. We investigated if a correlation between the RIND score and nonsense-mediated decay (NMD) could be established. Results: We found significantly increased radiosensitivity in the cohort of healthy BRCA1 mutation carriers compared with healthy controls. In addition, our analysis showed a significantly different distribution over the RIND scores (p = 0.034, Fisher’s exact test) for healthy BRCA1 mutation carriers compared with non-carriers: 72 % of mutation carriers showed a radiosensitive phenotype (RIND score 1–4), whereas 72 % of the healthy volunteers showed no radiosensitivity (RIND score 0). Furthermore, 28 % of BRCA1 mutation carriers had a RIND score of 3 or 4 (not observed in control subjects). The radiosensitive phenotype was similar for relatives within several families, but not for unrelated individuals carrying the same mutation. The median RIND score was higher in patients with a mutation leading to a premature termination codon (PTC) located in the central part of the gene than in patients with a germline mutation in the 5′ end of the gene. Conclusions: We show that BRCA1 mutations are associated with a radiosensitive phenotype related to a compromised DNA repair and G2 arrest capacity after exposure to either 2 or 4 Gy. Our study confirms that haploinsufficiency is the mechanism involved in radiosensitivity in patients with a PTC allele, but it suggests that further research is needed to evaluate alternative mechanisms for mutations not subjected to NMD