Extraction of black hole coalescence waveforms from noisy data

We describe an independent analysis of LIGO data for black hole coalescence events. Gravitational wave strain waveforms are extracted directly from the data using a filtering method that exploits the observed or expected time-dependent frequency content. Statistical analysis of residual noise, after filtering out spectral peaks (and considering finite bandwidth), shows no evidence of non-Gaussian behaviour. There is also no evidence of anomalous causal correlation between noise signals at the Hanford and Livingston sites. The extracted waveforms are consistent with black hole coalescence template waveforms provided by LIGO. Simulated events, with known signals injected into real noise, are used to determine uncertainties due to residual noise and demonstrate that our results are unbiased. Conceptual and numerical differences between our RMS signal-to-noise ratios (SNRs) and the published matched-filter detection SNRs are discussed.Comment: 15 pages, 11 figures. Version accepted for publicatio

Cow, farm, and herd management factors in the dry period associated with raised somatic cell counts in early lactation

This study investigated cow characteristics, farm facilities, and herd management strategies during the dry period to examine their joint influence on somatic cell counts (SCC) in early lactation. Data from 52 commercial dairy farms throughout England and Wales were collected over a 2-yr period. For the purpose of analysis, cows were separated into those housed for the dry period (6,419 cow-dry periods) and those at pasture (7,425 cow-dry periods). Bayesian multilevel models were specified with 2 response variables: ln SCC (continuous) and SCC >199,000 cells/mL (binary), both within 30 d of calving. Cow factors associated with an increased SCC after calving were parity, an SCC >199,000 cells/mL in the 60 d before drying off, increasing milk yield 0 to 30 d before drying off, and reduced DIM after calving at the time of SCC estimation. Herd management factors associated with an increased SCC after calving included procedures at drying off, aspects of bedding management, stocking density, and method of pasture grazing. Posterior predictions were used for model assessment, and these indicated that model fit was generally good. The research demonstrated that specific dry-period management strategies have an important influence on SCC in early lactation

Quantum Gravity and Higher Curvature Actions

Effective equations are often useful to extract physical information from quantum theories without having to face all technical and conceptual difficulties. One can then describe aspects of the quantum system by equations of classical type, which correct the classical equations by modified coefficients and higher derivative terms. In gravity, for instance, one expects terms with higher powers of curvature. Such higher derivative formulations are discussed here with an emphasis on the role of degrees of freedom and on differences between Lagrangian and Hamiltonian treatments. A general scheme is then provided which allows one to compute effective equations perturbatively in a Hamiltonian formalism. Here, one can expand effective equations around any quantum state and not just a perturbative vacuum. This is particularly useful in situations of quantum gravity or cosmology where perturbations only around vacuum states would be too restrictive. The discussion also demonstrates the number of free parameters expected in effective equations, used to determine the physical situation being approximated, as well as the role of classical symmetries such as Lorentz transformation properties in effective equations. An appendix collects information on effective correction terms expected from loop quantum gravity and string theory.Comment: 28 pages, based on a lecture course at the 42nd Karpacz Winter School of Theoretical Physics ``Current Mathematical Topics in Gravitation and Cosmology,'' Ladek, Poland, February 6-11, 200

Engineering study for a mass memory system for advanced spacecrafts Final report, 1 Dec. 1969 - 1 Jul. 1970

Mass memory system for advanced spacecraf

Welfare Reform in Agricultural California

When welfare reforms were enacted in 1996, a higher than average percentage of residents in the agricultural heartland of California, the San Joaquin Valley, received cash assistance. Average annual unemployment rates during the 1990s ranged from 12% to 20%, and 15% to 20% of residents in major farming counties received cash benefits. This analysis develops and estimates a two-equation cross-sectionally correlated and timewise autoregressive model to test the hypothesis that in agricultural areas, seasonal work, low earnings, and high unemployment, as well as few entry-level jobs that offer wages and benefits equivalent to welfare benefits, promote welfare use and limit the potential of local labor markets to absorb ex-welfare recipients.cross-sectionally correlated and timewise autoregressive model, farm workers, immigration, welfare reform, Public Economics,

Ultra- and Hyper-compact HII regions at 20 GHz

We present radio and infrared observations of 4 hyper-compact HII regions and 4 ultra-compact HII regions in the southern Galactic plane. These objects were selected from a blind survey for UCHII regions using data from two new radio surveys of the southern sky; the Australia Telescope 20 GHz survey (AT20G) and the 2nd epoch Molonglo Galactic Plane Survey (MGPS-2) at 843 MHz. To our knowledge, this is the first blind radio survey for hyper- and ultra-compact HII regions. We have followed up these sources with the Australia Telescope Compact Array to obtain H70-alpha recombination line measurements, higher resolution images at 20 GHz and flux density measurements at 30, 40 and 95 GHz. From this we have determined sizes and recombination line temperatures as well as modeling the spectral energy distributions to determine emission measures. We have classified the sources as hyper-compact or ultra-compact on the basis of their physical parameters, in comparison with benchmark parameters from the literature. Several of these bright, compact sources are potential calibrators for the Low Frequency Instrument (30-70 GHz) and the 100-GHz channel of the High Frequency Instrument of the Planck satellite mission. They may also be useful as calibrators for the Australia Telescope Compact Array, which lacks good non-variable primary flux calibrators at higher frequencies and in the Galactic plane region. Our spectral energy distributions allow the flux densities within the Planck bands to be determined, although our high frequency observations show that several sources have excess emission at 95 GHz (3 mm) that can not be explained by current models.Comment: 13 pages, 7 figures, accepted for publication in MNRA

The provision of education and training for healthcare professionals through the medium of the internet

This paper describes a new initiative to provide Internet based courses to student and professional occupational therapists in four centres in the UK, Belgium the Netherlands and Sweden. The basis of this collaborative Occupational Therapy Internet School (OTIS) is the concept of the “Virtual College”. This comprises the design and implementation of a sophisticated Internet-based system through which courses can be managed, prepared and delivered online in an effective fashion, and where students can communicate both with the staff and their peers. The aim is to support and facilitate the whole range of educational activities within a remote electronic environment. A major feature of the course organisation is the adoption of a problem-based approach in which students will collaborate internationally to propose effective intervention in given case study scenarios. The paper outlines the rationale for OTIS, the content and structure of the courseware, the technical specification of the system and evaluation criteria. In addition to the more conventional web-based learning facilities generally offered, a number of agent-based approaches are being adopted to assist in the management of the course by ensuring the proper delivery of course materials and to assist the functioning of project groups. </p

Gravitational effects in ultrahigh-energy string scattering

Ultrahigh-energy string scattering is investigated to clarify the relative role of string and gravitational effects, and their possible contributions to nonlocal behavior. Different regimes can be characterized by varying the impact parameter at fixed energy. In the regime where momentum transfers reach the string scale, string effects appear subdominant to higher-loop gravitational processes, approximated via the eikonal. At smaller impact parameters, "diffractive" or "tidal" string excitation leads to processes dominated by highly excited strings. However, new evidence is presented that these excitation effects do not play a direct role in black hole formation, which corresponds to breakdown of gravitational perturbation theory and appears to dominate at sufficiently small impact parameters. The estimated amplitudes violate expected bounds on high-energy behavior for local theories.Comment: 19 pages, harvmac. v2: fixed typos, added refs and discussion of longitudinal spread. v3: minor changes to agree with published versio

THE IMPACT OF MUTUAL FUND FAMILY MEMBERSHIP ON INVESTOR RISK

Many investors confine their mutual fund holdings to a single fund family, either for simplicity or through restrictions placed by their retirement savings plan. We find evidence that mutual fund returns are more closely correlated within than between fund families. As a result, restricting investment to one fund family leads to a greater total portfolio risk than diversifying across fund families. The increased correlation is due primarily to common stock holdings, but is also more generally related to families having similar exposures to economic sectors or industries. Fund families also show a propensity to focus on high risk or low risk strategies, which leads to a greater dispersion of risk across restricted investors. An investor considering adding an additional fund either inside or outside the family would need to believe the inside fund offered an additional 50 to 70 basis points in return to achieve the same Sharpe ratio

The Impact of Mutual Fund Family Membership on Investor Risk

Many investors confine their mutual fund holdings to a single fund family, either for simplicity or through restrictions placed by their retirement savings plan. We find evidence that mutual fund returns are more closely correlated within fund families, which reduces the benefits of investor diversification. The increased correlation is due primarily to common stock holdings, but is also more generally related to families having similar exposures to economic sectors or industries. Fund families also show a propensity to focus on high risk or low risk strategies, which leads to a greater dispersion of risk across restricted investors