A Simulation of the LISA Data Stream from Galactic White Dwarf Binaries

Gravitational radiation from the galactic population of white dwarf binaries is expected to produce a background signal in the LISA frequency band. At frequencies below 1 mHz, this signal is expected to be confusion-limited and has been approximated as gaussian noise. At frequencies above about 5 mHz, the signal will consist of separable individual sources. We have produced a simulation of the LISA data stream from a population of 90k galactic binaries in the frequency range between 1 - 5 mHz. This signal is compared with the simulated signal from globular cluster populations of binaries. Notable features of the simulation as well as potential data analysis schemes for extracting information are presented.Comment: Submitted to QC

Legal Authorities Governing Federal Contracting and Subcontracting with Small Businesses

Congress has generally broad authority to impose requirements upon the federal procurement process, or the process whereby agencies obtain goods and services from the private sector. One of the many ways in which Congress has exercised this authority is by enacting measures intended to promote contracting and subcontracting with "small businesses" by federal agencies

Legal Authorities Governing Federal Contracting and Subcontracting with Small Businesses

This report provides an overview of the various legal authorities governing small business contracting and subcontracting, as well as the relationship between them. It also explains the roles of the Small Business Administration (SBA), procuring activities, Office of Hearings and Appeals (OHA), Government Accountability Office (GAO), and other tribunals in implementing and construing the law governing federal contracting and subcontracting with small businesses

Contracting with Inverted Domestic Corporations: Answers to Frequently Asked Questions

This report provides the answers to 14 frequently asked questions regarding the current restrictions on contracting with inverted domestic corporations; certain amendments thereto proposed, but not enacted, in the 113th Congress; and the relationship between the prohibitions upon contracting with inverted domestic corporations and other provisions of law that restrict dealings with "foreign" contractors

Terminating Contracts for the Government's Convenience: Answers to Frequently Asked Questions

This report provides answers to 12 questions regarding termination for convenience -- the exercise of the government's right to bring to an end the performance of all or part of the work provided for under a contract prior to the expiration of the contract "when it is in the Government's interest" to do so -- frequently asked by congressional committees and staff. These questions and their answers address everything from the contractual and other bases for the government's right to terminate to posttermination settlements between the government and the contractor. They also address differences between termination for convenience and termination for default, cancellation, and certain other actions that the government may take (e.g., "de-scoping" pursuant to a Changes clause)

A new estimation of the recent tropospheric molecular hydrogen budget using atmospheric observations and variational inversion

This paper presents an analysis of the recent tropospheric molecular hydrogen (H2) budget with a particular focus on soil uptake and European surface emissions. A variational inversion scheme is combined with observations from the RAMCES and EUROHYDROS atmospheric networks, which include continuous measurements performed between mid-2006 and mid-2009. Net H2 surface flux, then deposition velocity and surface emissions and finally, deposition velocity, biomass burning, anthropogenic and N2 fixation-related emissions were simultaneously inverted in several scenarios. These scenarios have focused on the sensibility of the soil uptake value to different spatio-temporal distributions. The range of variations of these diverse inversion sets generate an estimate of the uncertainty for each term of the H2 budget. The net H2 flux per region (High Northern Hemisphere, Tropics and High Southern Hemisphere) varies between −8 and +8 Tg yr−1. The best inversion in terms of fit to the observations combines updated prior surface emissions and a soil deposition velocity map that is based on bottom-up and top-down estimations. Our estimate of global H2 soil uptake is −59±9 Tg yr−1. Forty per cent of this uptake is located in the High Northern Hemisphere and 55% is located in the Tropics. In terms of surface emissions, seasonality is mainly driven by biomass burning emissions. The inferred European anthropogenic emissions are consistent with independent H2 emissions estimated using a H2/CO mass ratio of 0.034 and CO emissions within the range of their respective uncertainties. Additional constraints, such as isotopic measurements would be needed to infer a more robust partition of H2 sources and sinks

Missing not at random in end of life care studies : multiple imputation and sensitivity analysis on data from the ACTION study

Background: Missing data are common in end-of-life care studies, but there is still relatively little exploration of which is the best method to deal with them, and, in particular, if the missing at random (MAR) assumption is valid or missing not at random (MNAR) mechanisms should be assumed. In this paper we investigated this issue through a sensitivity analysis within the ACTION study, a multicenter cluster randomized controlled trial testing advance care planning in patients with advanced lung or colorectal cancer. Methods: Multiple imputation procedures under MAR and MNAR assumptions were implemented. Possible violation of the MAR assumption was addressed with reference to variables measuring quality of life and symptoms. The MNAR model assumed that patients with worse health were more likely to have missing questionnaires, making a distinction between single missing items, which were assumed to satisfy the MAR assumption, and missing values due to completely missing questionnaire for which a MNAR mechanism was hypothesized. We explored the sensitivity to possible departures from MAR on gender differences between key indicators and on simple correlations. Results: Up to 39% of follow-up data were missing. Results under MAR reflected that missingness was related to poorer health status. Correlations between variables, although very small, changed according to the imputation method, as well as the differences in scores by gender, indicating a certain sensitivity of the results to the violation of the MAR assumption. Conclusions: The findings confirmed the importance of undertaking this kind of analysis in end-of-life care studies

Perceived Causes and Solutions to Soil Degradation in the UK and Norway

Soil quality is declining in many parts of the world, with implications for the productivity, resilience and sustainability of agri-food systems. Research suggests multiple causes of soil degradation with no single solution and a divided stakeholder opinion on how to manage this problem. However, creating socially acceptable and effective policies to halt soil degradation requires engagement with a diverse range of stakeholders who possess different and complementary knowledge, experiences and perspectives. To understand how British and Norwegian agricultural stakeholders perceived the causes of and solutions to soil degradation, we used Q-methodology with 114 respondents, including farmers, scientists and agricultural advisers. For the UK, respondents thought the causes were due to loss of soil structure, soil erosion, compaction and loss of organic matter; the perceived solutions were to develop more collaborative research between researchers and farmers, invest in training, improve trust between farmers and regulatory agencies, and reduce soil compaction. In Norway, respondents thought soils were degrading due to soil erosion, monocultures and loss of soil structure; they believed the solutions were to reduce compaction, increase rotation and invest in agricultural training. There was an overarching theme related to industrialised agriculture being responsible for declining soil quality in both countries. We highlight potential areas for land use policy development in Norway and the UK, including multi-actor approaches that may improve the social acceptance of these policies. This study also illustrates how Q-methodology may be used to co-produce stakeholder-driven policy options to address land degradation

Legislative Options After Citizens United v. FEC: Constitutional and Legal Issues

In Citizens United v. FEC, the Supreme Court invalidated two provisions of the Federal Election Campaign Act (FECA), finding that they were unconstitutional under the First Amendment. In response to the Supreme Court's ruling, various proposals have been discussed and legislation has been introduced in the 111th Congress. This report provides an analysis of the constitutional and legal issues raised by several proposals, organized by regulatory topic: increasing disclaimer requirements, increasing disclosure for tax-exempt organizations, requiring shareholder notification and approval, restricting U.S. subsidiaries of foreign corporations, restricting political expenditures by government contractors and grantees, taxing corporate independent expenditures, and providing public financing for congressional campaigns. The report also addresses amending the Constitution