Improving the Angular Resolution of EGRET and New Limits on Supersymmetric Dark Matter Near the Galactic Center

Using the EGRET data and an improved point source analysis, including an energy dependent point spread function and an unbinned maximum likelihood technique, we have been able to place considerably lower limits on the gamma ray flux from the galactic center region. We also test this method on known sources, the Crab and Vela pulsars. In both cases, we find that our method improves the angular precision of EGRET data over the 3EG catalog. This new limit on gamma rays from the galactic center can be used to test models of annihilating supersymmetric dark matter and galactic halo profiles. We find that the present EGRET data can limit many supersymmetric models if the density of the galactic dark matter halo is cuspy or spiked toward the galactic center. We also discuss the ability of GLAST to test these models.Comment: 6 pages, 4 figure

Defining, Valuing, and Providing Ecosystem Goods and Services

Ecosystem services are the specific results of ecosystem processes that either directly sustain or enhance human life (as does natural protection from the sun's harmful ultraviolet rays) or maintain the quality of ecosystem goods (as water purification maintains the quality of streamflow). "Ecosystem service" has come to represent several related topics ranging from the measurement to the marketing of ecosystem service flows. In this article we examine several of these topics by first clarifying the meaning of "ecosystem service" and then (1) placing ecosystem goods and services within an economic framework, emphasizing the role and limitations of substitutes; (2) summarizing the methods for valuation of ecosystem goods and services; and (3) reviewing the various approaches for their provision and financing.Many ecosystem services and some ecosystem goods are received without monetary payment. The "marketing" of ecosystem goods and services is basically an effort to turn such recipients - those who benefit without ownership- into buyers, thereby providing market signals that serve to help protect valuable goods and services. We review various formal arrangements for making this happen

Pathogen burden and cortisol profiles over the day

Hypothalamic-pituitary-adrenocortical (HPA) regulation in adults is influenced by early psychosocial adversity, but the role of infectious disease history is poorly understood. We studied the association between cumulative pathogen burden and cortisol profile over the day in a sample of 317 healthy men and women aged 51-72 years. Cumulative pathogen burden was defined as positive serostatus for Chlamydia pneumoniae, cytomegalovirus (CMV) and herpes simplex virus 1 (HSV-1). Salivary cortisol was sampled repeatedly over the day. The cortisol slope was defined as the decrease across the day and evening. Age, gender, grade of employment, body mass index, smoking status, self-rated health, cardiovascular medication, depressed mood and time of waking were included as covariates. The pathogen burden averaged 1.76 (S.D. = 0.92). The cortisol slope was inversely associated with pathogen burden after controlling for covariates. When individual pathogens were studied, only CMV was associated with flatter cortisol rhythms in isolation. We conclude that pathogen burden is independently associated with flatter cortisol slopes over the day, and may contribute to disturbed neuroendocrine regulation

The Rare Decays \piee, \etaee and \etamumu$ in Chiral Perturbation Theory

We calculate the decay rates for \piee, \etaee and \etamumu in chiral perturbation theory. The linear combination of counterterms necessary to render these amplitudes finite is fixed by the recently measured branching fraction for \etamumu. We find \Br(\piee ) = 7\pm 1\times 10^{-8} and \Br(\etaee )=5\pm 1\times 10^{-9}.Comment: (6 pages, 1 figure available on request, uses harvmac.tex), UCSD/PTH 92-23, CALT-68-180

Microscopic calculation of 6Li elastic and transition form factors

Variational Monte Carlo wave functions, obtained from a realistic Hamiltonian consisting of the Argonne v18 two-nucleon and Urbana-IX three-nucleon interactions, are used to calculate the 6Li ground-state longitudinal and transverse form factors as well as transition form factors to the first four excited states. The charge and current operators include one- and two-body components, leading terms of which are constructed consistently with the two-nucleon interaction. The calculated form factors and radiative widths are in good agreement with available experimental data.Comment: 9 pages, 2 figures, REVTeX, submitted to Physical Review Letters, with updated introduction and reference

A proposed new policy for planetary protection

A critical review of the present policy was conducted with emphasis on its application to future planetary exploration. The probable impact of recent data on the implementation of the present policy was also assessed. The existing policy and its implementation were found to: be excessive for certain missions (e.g., Voyager), neglect the contamination hazard posed by the bulk constituent organics of spacecraft, be ambiguous for certain missions (e.g., Pioneer Venus), and treat all extraterrestrial sample return missions alike. The major features of the proposed policy are planet/mission combinations, a qualitative top level statement, and implementation by exception rather than rule. The concept of planet/mission categories permits the imposition of requirements according to both biological interest in the target planet and the relative contamination hazard of the mission type

Soft Tissue to Hard Tissue Advancement Ratios for Mandibular Elongation Using Distraction Osteogenesis in Children

Distraction osteogenesis is extensively used for the elongation of hypoplastic mandibles in children, yet the soft tissue profile response to this is not well understood. The pre- and posttreatment lateral cephalometric radiographs of 27 pediatric patients who underwent bilateral mandibular elongation using distraction osteogenesis were analyzed retrospectively to correlate horizontal soft tissue advancement with horizontal underlying bone advancement at B point and pogonion. Horizontal advancement (in millimeters) of bone and overlying soft tissue at these points was collected from the radiographs of each patient, and linear regression analysis was performed to determine the relationship of hard to soft tissue horizontal advancement at these points. A 1:0.90 mean ratio of bone to soft tissue advancement was observed at B point/labiomental sulcus and at pogonion/soft tissue pogonion (linear regression analysis demonstrated slopes [β1 values] of 0.94 and 0.92, respectively). These ratios were consistent throughout the sample population and are highly predictive of the soft tissue response that can be anticipated. Magnitude of advancement, age, and sex of the patient had no effect on these ratios in our population. This study assists with our understanding of the soft tissue response that accompanies bony elongation during distraction osteogenesis which will allow us to more effectively treatment plan the orthodontic and surgical intervention that will optimize the patients\u27 functional and esthetic outcome

USE OF CHAMBERLAIN FIXED EFFECTS APPROACH TO ESTIMATE WILLINGNESS-TO-PAY FOR LITTLE TENNESSEE RIVER BASIN MANAGEMENT ALTERNATIVES

The paper discusses an application of Chamberlain's fixed effects model to contingent valuation method survey data obtained for eight management alternatives for the Little Tennessee River basin. The advantages of using this approach versus cross-sectional logit, pooled logit, and cross-sectional logit with lags are discussed and a technique to obtain willingness-to-pay estimates from estimated coefficients is offered. Drawbacks of using Chamberlain's fixed effects model, difficulties encountered, and directions for further research are presented.Environmental Economics and Policy,

Kinetic decoupling of neutralino dark matter

After neutralinos cease annihilating in the early Universe, they may still scatter elastically from other particles in the primordial plasma. At some point in time, however, they will eventually stop scattering. We calculate the cross sections for neutralino elastic scattering from standard-model particles to determine the time at which this kinetic decoupling occurs. We show that kinetic decoupling occurs above a temperature $T\sim$ MeV. Thereafter, neutralinos act as collisionless cold dark matter.Comment: Replaced with revised version, new references adde

Distance-Redshift in Inhomogeneous Omega0=1Omega_0=1 Friedmann-Lemaitre-Robertson-Walker Cosmology

Distance--redshift relations are given in terms of associated Legendre functions for partially filled beam observations inspatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmologies. These models are dynamically pressure-free, flat FLRW on large scales but, due to mass inhomogeneities, differ in their optical properties. The partially filled beam area-redshift equation is a Lame$^{\prime}$ equation for arbitrary FLRW and is shown to simplify to the associated Legendre equation for the spatially flat, i.e. $\Omega_0=1$ case. We fit these new analytic Hubble curves to recent supernovae (SNe) data in an attempt to determine both the mass parameter $\Omega_m$ and the beam filling parameter $\nu$. We find that current data are inadequate to limit $\nu$. However, we are able to estimate what limits are possible when the number of observed SNe is increased by factor of 10 or 100, sample sizes achievable in the near future with the proposed SuperNova Acceleration Probe satellite.Comment: 9 pages, 3 figure