The generalized F-statistic: multiple detectors and multiple GW pulsars

The F-statistic, derived by Jaranowski, Krolak & Schutz (1998), is the optimal (frequentist) statistic for the detection of nearly periodic gravitational waves from known neutron stars, in the presence of stationary, Gaussian detector noise. The F-statistic was originally derived for the case of a single detector, whose noise spectral density was assumed constant in time, and for a single known neutron star. Here we show how the F-statistic can be straightforwardly generalized to the cases of 1) a network of detectors with time-varying noise curves, and 2) a population of known sources. Fortunately, all the important ingredients that go into our generalized F-statistics are already calculated in the single-source/single-detector searches that are currently implemented, e.g., in the LIGO Software Library, so implementation of optimal multi-detector, multi-source searches should require negligible additional cost in computational power or software development.Comment: 6 pages, 0 figures, submitted to PRD; section IV substantially enlarged and revised, and a few typos correcte

Cold‐Adapted Reassortants of Influenza A Virus in MDCK Cells

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/101846/1/mim03574.pd

Differential activity of Drosophila Hox genes induces myosin expression and can maintain compartment boundaries

Compartments are units of cell lineage that subdivide territories with different developmental potential. In Drosophila, the wing and haltere discs are subdivided into anterior and posterior (A/P) compartments, which require the activity of Hedgehog, and into dorsal and ventral (D/V) compartments, needing Notch signaling. There is enrichment in actomyosin proteins at the compartment boundaries, suggesting a role for these proteins in their maintenance. Compartments also develop in the mouse hindbrain rhombomeres, which are characterized by the expression of different Hox genes, a group of genes specifying different structures along their main axis of bilaterians. We show here that the Drosophila Hox gene Ultrabithorax can maintain the A/P and D/V compartment boundaries when Hedgehog or Notch signaling is compromised, and that the interaction of cells with and without Ultrabithorax expression induces high levels of non-muscle myosin II. In the absence of Ultrabithorax there is occasional mixing of cells from different segments. We also show a similar role in cell segregation for the Abdominal-B Hox gene. Our results suggest that the juxtaposition of cells with different Hox gene expression leads to their sorting out, probably through the accumulation of non-muscle myosin II at the boundary of the different cell territories. The increase in myosin expression seems to be a general mechanism used by Hox genes or signaling pathways to maintain the segregation of different groups of cells.Peer Reviewe

Will Einstein Have the Last Word on Gravity?

This is a whitepaper submitted to the 2010 Astronomy Decadal Review process, addressing the potential tests of gravity theory that could be made by observations of gravitational waves in the milliHertz frequency band by the proposed ESA-NASA gravitational wave observatory LISA. A key issue is that observations in this band of binary systems consisting of black holes offer very clean tests with high signal-to-noise ratios. Gravitational waves would probe nonlinear gravity and could reveal small corrections, such as extra long-range fields that arise in unified theories, deviations of the metric around massive black holes from the Kerr solution, massive gravitons, chiral effects, and effects of extra dimensions. The availability of strong signals from massive black hole binaries as well as complex signals from extreme mass-ratio binaries is unique to the milliHertz waveband and makes LISA a particularly sensitive probe of the validity of general relativity.Comment: Science White Paper submitted to the Astro2010 Decadal Surve

Method and system for enabling real-time speckle processing using hardware platforms

An accelerator for the speckle atmospheric compensation algorithm may enable real-time speckle processing of video feeds that may enable the speckle algorithm to be applied in numerous real-time applications. The accelerator may be implemented in various forms, including hardware, software, and/or machine-readable media

Global warming reshapes European pyroregions

Wildland fire is expected to increase in response to global warming, yet little is known about future changes to fire regimes in Europe. Here, we developed a pyrogeography based on statistical fire models to better understand how global warming reshapes fire regimes across the continent. We identified five large-scale pyroregions with different levels of area burned, fire frequency, intensity, length of fire period, size distribution, and seasonality. All other things being equal, global warming was found to alter the distribution of these pyroregions, with an expansion of the most fire prone pyroregions ranging respectively from 50% to 130% under 2° and 4°C global warming scenarios. Our estimates indicate a strong amplification of fire across parts of southern Europe and a subsequent shift toward new fire regimes, implying substantial socio-ecological impacts in the absence of mitigation or adaptation measures

Growing Our Own: A Longitudinal Evaluation of a Professional Development Program for Early-Career 4-H Professionals

We present the results of a longitudinal evaluation of the Western Region 4-H Institute, a 5-day training program designed to enhance the skill sets of early-career Extension professionals organized around the 4-H professional research, knowledge, and competencies model. Programs such as this often are assessed for their short-term relevance and effectiveness; we expanded the scope of our evaluation by following up with program participants 12 months after the program. Both short- and medium-term results indicated that networking and developing effective programs for youth were paramount for participants, suggesting the importance of providing professional development opportunities for early-career professionals

Slavic Dialectology: A Survey of Research since 1989

The last 25 years in Slavic dialectology mark the period not only of JSL’s founding but also of major and multiple political, social, and economic reorganizations in predominantly Slavic-speaking states. During this period research institutions and their priorities and projects have both continued and changed; technological innovation has meant moving towards electronic dissemination, “digital humanities,” and innovative modes of presenting research data and findings. In some cases major works (e.g., dialect atlases) have advanced during this period. Moreover, a new generation of scholars has had greater opportunities for mobility and therefore exposure to a variety of linguistic frameworks and approaches, which has fostered cross-border collaboration in the field. The present essay gives an overview of progress made on dialect projects both created institutionally and individually and including both traditional (book, article) and new digital means of dissemination