Cancellation of Glauber gluon exchange in the double Drell-Yan process

An essential part of any factorisation proof is the demonstration that the exchange of Glauber gluons cancels for the considered observable. We show this cancellation at all orders for double Drell-Yan production (the double parton scattering process in which a pair of electroweak gauge bosons is produced) both for the integrated cross section and for the cross section differential in the transverse boson momenta. In the process of constructing this proof, we also revisit and clarify some issues regarding the Glauber cancellation argument and its relation to the rest of the factorisation proof for the single Drell-Yan process.Comment: 65 pages, 23 figure

Prototype selection for parameter estimation in complex models

Parameter estimation in astrophysics often requires the use of complex physical models. In this paper we study the problem of estimating the parameters that describe star formation history (SFH) in galaxies. Here, high-dimensional spectral data from galaxies are appropriately modeled as linear combinations of physical components, called simple stellar populations (SSPs), plus some nonlinear distortions. Theoretical data for each SSP is produced for a fixed parameter vector via computer modeling. Though the parameters that define each SSP are continuous, optimizing the signal model over a large set of SSPs on a fine parameter grid is computationally infeasible and inefficient. The goal of this study is to estimate the set of parameters that describes the SFH of each galaxy. These target parameters, such as the average ages and chemical compositions of the galaxy's stellar populations, are derived from the SSP parameters and the component weights in the signal model. Here, we introduce a principled approach of choosing a small basis of SSP prototypes for SFH parameter estimation. The basic idea is to quantize the vector space and effective support of the model components. In addition to greater computational efficiency, we achieve better estimates of the SFH target parameters. In simulations, our proposed quantization method obtains a substantial improvement in estimating the target parameters over the common method of employing a parameter grid. Sparse coding techniques are not appropriate for this problem without proper constraints, while constrained sparse coding methods perform poorly for parameter estimation because their objective is signal reconstruction, not estimation of the target parameters.Comment: Published in at http://dx.doi.org/10.1214/11-AOAS500 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

2+1 flavor QCD with the fixed point action in the ϵ\epsilon-regime

We generated configurations with the approximate fixed-point Dirac operator $D_\mathrm{FP}$ on a $12^4$ lattice with $a \approx 0.13$fm where the scale was set by $r_0$. The distributions of the low lying eigenvalues in different topological sectors were compared with those of the Random Matrix Theory which leads to a prediction of the chiral condensate.Comment: 6 pages, 5 figures, presented at the XXV International Symposium on Lattice Field Theory, July 30 - August 4 2007, Regensburg, German

Alaska's Participation in the Interstate Compact for Probation and Parole

The Interstate Compact for the Supervision of Parolees and Probationers is an agreement whereby one state agrees to provide supervision for offenders on community release from other states. Participants in the interstate compact agree that any state will accept supervision of a parolee or probationer providing the offender has proper residence either as a resident of that state or with family, and that he/she is able to find employment. Major increases in Alaska's prison population over the past decade have been accompanied by corresponding increases in the number of persons under probation/parole supervision and in the caseloads of individual probation officers. Using a master listing of all persons under the jurisdiction of the Alaska Department of Corrections from 1976 to 1983, the Justice Center at University of Alaska Anchorage made a preliminary assessment of the impact on Alaska of participation in the Interstate Compact. From 1976 to 1983, Alaska processed 1,551 offenders through the Interstate Compact, of whom 999 were received for supervision from other states (64.4% of the total) and 552 (35.6%) were sent to other states. Based on this data, the interstate compact has not yet been an equitable arrangement for any city in Alaska: each city has seen a greater number of incoming than of outgoing transfers.Alaska Division of Probation and ParoleIntroduction / Research Results / Demographics / Discussion / Note / Tables & Figures / Bibliograph

Resilient Communities: Empowering Older Adults in Disasters and Daily Life

New York City's 1.4 million people age 60 and over consti-tute 17 percent of the city's total population. This number is projected to increase by 50 percent over the next 20 years. The vast majority of older adults live independently, requiring little to no assistance under routine conditions.Yet over the last 12 years, New York City has experienced multiple catastrophic events. The 2001 attack on the World Trade Center, the blackout of 2003, Hurricane Irene, and, most recently, Hurricane Sandy, posed significant chal-lenges to older adults. A common denominator of these incidents was the loss of power and the disruption of sys-tems and services upon which older adults rely, including but not limited to transportation, communication, health care, elevators, and social supports. As a result, tens of thousands of older adults were isolated in high-rise build-ings and private homes, in need of food, water, warming or cooling, medical attention, and medication.Efforts to increase individual preparedness among older people through the creation of "go-bags" and the stock-piling of supplies have been repeatedly undertaken but have not improved overall outcomes for older people following subsequent disasters in New York City. With extreme weather projected to increase, a new strategy is required to keep older adults, who are often among the city's most long-term, civically engaged residents, safe

Evaluation of the Community Child Health Research Network (CCHN) Community-Academic Partnership

Background: The Community Child Health Network (CCHN) is a research collaborative network of five communities in the U.S. formed to study maternal and child health disparities, via a community-based participatory research study design. CCHN studies how community, family, and individual level influences interact with biological processes to affect maternal stress, resilience, and allostatic load; ultimately, the study evaluates whether such factors result in health disparities in pregnancy outcomes and infant and early childhood mortality and morbidity. The purpose of this paper is to assess the community-based participatory research (CBPR) process that governs the CCHN and offer lessons from our experiences. Methods: This study employs a qualitative approach to evaluate the CBPR process among CCHN community and academic partners. Qualitative interviews (n=17) were completed by both community and academic CCHN partners. Results: Content analysis of qualitative data revealed six major themes (1) lack of necessary resources; (2) collaborative learning; (3) perceived benefits; (4) communication and education; (5) trust and expectations; and (6) sustainability. Discussion: The benefits and challenges of implementing productive, community-academic partnerships were present both at the local site-level and the network-level. Ultimately, the inclusion of community-based participatory research principles and methods enhanced the study development, implementation, analysis, and dissemination of findings. Conclusion: Lessons learned from a multi-site CBPR project, including strategies for managing learning and communication across different geographic sites, may be useful to other CBPR and multi-site community-based research endeavors