On Estimating the QSO Transmission Power Spectrum

We present new methods to minimize the systematic and random errors for measuring the transmission power spectrum from the Lyman-alpha forest. Sources of systematic errors explored include metal line contamination and continuum-fitting. We advocate the technique of trend-removal in place of traditional continuum-fitting -- here, a spectrum is normalized by its (smoothly varying) mean rather than its continuum -- this method is easily automated and removes biases introduced by continuum-fitting. Trend- removal can be easily applied to spectra where continuum-fitting is difficult, such as when the resolution or signal-to-noise is low, or for spectra at high redshifts. Furthermore, a measurement of the continuum power spectrum using trend-removal, from either low redshift quasar spectra or the red-side of Lyman-alpha, allows in principle the removal of spurious power introduced by the continuum and thereby expanding scales probed to larger ones. We also derive expressions for the shot-noise bias and variance of the power spectrum estimate, taking into account the non-Poissonian nature of the shot-noise and the non-Gaussianity of the cosmic fluctuations. An appropriate minimum variance weighting of the data is given. Finally, we give practical suggestions on observing strategy: the desired resolution and S/N for different purposes, and how to distribute one's finite observing time among quasar targets. Also discussed is the quasar spectroscopic study of the Sloan Digital Sky Survey, which has the potential to measure the power spectrum at z ~ 2-4 accurate to better than 1 % per mode -- the techniques presented here will be useful for tackling the anticipated issues of shot-noise and continuum contamination.Comment: 35 pages, 14 figures, submitted to Ap

Disposal of Household Wastewater in Soils of High Stone Content (1981-1983)

Four experimental filter fields were constructed with built-in monitoring equipment in Nixa soils. These soils contain many chert fragments and a fragipan about 60 cm below the soil surface. The fragipan restricts downward movement of water and is the designlimitingfeature. The four filter fields were: 1. A standard filter field, 76 cm deep. The bottom of the trench was in the fragipan. 2. A modified standard filter field, 30 cm deep. The bottom of the trench was above the fragipan. 3. A modified pressure filter field, 40 cm deep. The bottom of the trench was above the fragipan. In addition, a pressure-distribution system was used to insure uniform distribution of effluent in the trench. Inadvertently, this field was installed in a different soil, and the results cannot be compared directly with the other three. 4. Another modified pressure filter field with the bottom of the trench only 6 cm below the soil surface. Observation of these systems confirms that placing filter fields higher in the soil above the hydraulically limiting horizon results in improved hydraulic performance. The presence of the fragipan amplified the adverse effects attributable to climatic stress. The seepage beds which are higher in the soil profile are able to handle the effluent load and climate load with less danger of surfacing

Disposal of Household Wastewater in Soils of High Stone Content (1977-1980)

Two experimental septic tank filter fields were constructed with built-in monitoring equipment in Nixa soils. These soils contain many chert fragments and a fragipan about 60 cm deep which restricts downward water movement and is the design-limiting feature. The standard filter field (76 cm deep) was built into the fragipan and the modified standard filter field (30 cm deep) was placed above it. During 30 months\u27 observation, the modified standard performed better than the standard filter field. Maximum rise of effluent in the standard and modified standard came within 11 and 19 cm of the soil surface, respectively. Performance of these systems indicates filter fields should be designed to function during climatic stresses, i.e. when the soil has a maximum hydraulic load and surfacing may occur. Filter fields should be designed to withstand a stress period of specified intensity. The filter fields in this study were observed under less than normal stress. Therefore, their long range performance is less clear. Our observations indicate that filter field performance is related more to rates of water movement than to stone content. Major influences on filter field performance are rates and directions of water movement, stress period intensity, designs, and construction techniques

On the Efficacy and Mediation of a One-on-One HIV Risk-Reduction Intervention for African American Men Who Have Sex With Men: A Randomized Controlled Trial

We examined the efficacy and mediation of Being Responsible for Ourselves (BRO), an HIV/STI risk reduction intervention for African American men who have sex with men (MSM), the population with the highest HIV diagnosis rate in the US. We randomized African American MSM to one of two interventions: BRO HIV/STI risk reduction, targeting condom use; or attention-matched control, targeting physical activity and healthy diet. The interventions were based on social cognitive theory, the reasoned-action approach, and qualitative research. Men reporting anal intercourse with other men in the past 90 days were eligible and completed pre-intervention

Chandra X-Ray Observatory Observations of the Globular Cluster M71

We observed the nearby, low-density globular cluster M71 (NGC 6838) with the Chandra X-ray Observatory to study its faint X-ray populations. Five X-ray sources were found inside the cluster core radius, including the known eclipsing binary millisecond pulsar (MSP) PSR J1953+1846A. The X-ray light curve of the source coincident with this MSP shows marginal evidence for periodicity at the binary period of 4.2 h. Its hard X-ray spectrum and luminosity resemble those of other eclipsing binary MSPs in 47 Tuc, suggesting a similar shock origin of the X-ray emission. A further 24 X-ray sources were found within the half-mass radius, reaching to a limiting luminosity of 1.5 10^30 erg/s (0.3-8 keV). From a radial distribution analysis, we find that 18+/-6 of these 29 sources are associated with M71, somewhat more than predicted, and that 11+/-6 are background sources, both galactic and extragalactic. M71 appears to have more X-ray sources between L_X=10^30--10^31 erg/s than expected by extrapolating from other studied clusters using either mass or collision frequency. We explore the spectra and variability of these sources, and describe the results of ground-based optical counterpart searches.Comment: 36 pages including 7 figures and 8 tables, accepted by The Astrophysical Journa

Spectroscopic Discovery of the Broad-Lined Type Ic Supernova 2010bh Associated with the Low-Redshift GRB 100316D

We present the spectroscopic discovery of a broad-lined Type Ic supernova (SN 2010bh) associated with the nearby long-duration gamma-ray burst (GRB) 100316D. At z = 0.0593, this is the third-nearest GRB-SN. Nightly optical spectra obtained with the Magellan telescopes during the first week after explosion reveal the gradual emergence of very broad spectral features superposed on a blue continuum. The supernova features are typical of broad-lined SNe Ic and are generally consistent with previous supernovae associated with low-redshift GRBs. However, the inferred velocities of SN 2010bh at 21 days after explosion are a factor of ~2 times larger than those of the prototypical SN 1998bw at similar epochs, with v ~ 26,000 km/s, indicating a larger explosion energy or a different ejecta structure. A near-infrared spectrum taken 13.8 days after explosion shows no strong evidence for He I at 1.083 microns, implying that the progenitor was largely stripped of its helium envelope. The host galaxy is of low luminosity (M_R ~ -18.5 mag) and low metallicity (Z < 0.4 Z_solar), similar to the hosts of other low-redshift GRB-SNe.Comment: 6 pages, 4 figures, 1 table, submitted to ApJ Letter

Syndemic factors associated with adult sexual HIV risk behaviors in a sample of Latino men who have sex with men in New York City

Objective: Syndemic theory has been proposed as a framework for understanding the role of multiple riskfactors driving the HIV epidemic among sexual and gender minority individuals. As yet, the frameworkhas been relatively absent in research on Latinos/as.Methods: We used logistic regression to assess relationships among cumulative syndemic conditions –including clinically significant depression, high-risk alcohol consumption, discrimination, and childhoodsexual abuse – engagement with multiple partners and condomless anal intercourse (CAI) in a sample of176 Latino men who have sex with men (MSM) in New York City.Results: In bivariate analyses, an increase in the number of syndemic factors experienced was associatedwith an increased likelihood of reporting multiple partners and CAI. In multivariable analyses, participantswith 2, 3, and 4 factors were significantly more likely to report multiple partners than those with 0(aOR = 4.66, 95% CI [1.29, 16.85); aOR = 7.28, 95% CI [1.94, 27.28] and aOR = 8.25, 95% CI [1.74, 39.24]respectively; p \u3c 0.05. Regarding CAI, only participants with 3 and 4 factors differed from those with 0aOR = 7.35, 95% CI [1.64, 32.83] and OR = 8.06, 95% CI [1.39, 46.73] respectively.Conclusions: Comprehensive approaches that address syndemic factors, and capitalize on resiliency, areneeded to address the sexual health needs of Latino MSM

Syndemic factors associated with adult sexual HIV risk behaviors in a sample of Latino men who have sex with men in New York City

Objective: Syndemic theory has been proposed as a framework for understanding the role of multiple riskfactors driving the HIV epidemic among sexual and gender minority individuals. As yet, the frameworkhas been relatively absent in research on Latinos/as.Methods: We used logistic regression to assess relationships among cumulative syndemic conditions –including clinically significant depression, high-risk alcohol consumption, discrimination, and childhoodsexual abuse – engagement with multiple partners and condomless anal intercourse (CAI) in a sample of176 Latino men who have sex with men (MSM) in New York City.Results: In bivariate analyses, an increase in the number of syndemic factors experienced was associatedwith an increased likelihood of reporting multiple partners and CAI. In multivariable analyses, participantswith 2, 3, and 4 factors were significantly more likely to report multiple partners than those with 0(aOR = 4.66, 95% CI [1.29, 16.85); aOR = 7.28, 95% CI [1.94, 27.28] and aOR = 8.25, 95% CI [1.74, 39.24]respectively; p \u3c 0.05. Regarding CAI, only participants with 3 and 4 factors differed from those with 0aOR = 7.35, 95% CI [1.64, 32.83] and OR = 8.06, 95% CI [1.39, 46.73] respectively.Conclusions: Comprehensive approaches that address syndemic factors, and capitalize on resiliency, areneeded to address the sexual health needs of Latino MSM

Chandra X-ray Observations of 12 Millisecond Pulsars in the Globular Cluster M28

We present a Chandra X-ray Observatory investigation of the millisecond pulsars (MSPs) in the globular cluster M28 (NGC 6626). In what is one of the deepest X-ray observations of a globular cluster, we firmly detect seven and possibly detect two of the twelve known M28 pulsars. With the exception of PSRs B1821-24 and J1824-2452H, the detected pulsars have relatively soft spectra, with X-ray luminosities 10^30-31 ergs s^-1 (0.3-8 keV),similar to most "recycled" pulsars in 47 Tucanae and the field of the Galaxy, implying thermal emission from the pulsar magnetic polar caps. We present the most detailed X-ray spectrum to date of the energetic PSR B1821-24. It is well described by a purely non-thermal spectrum with spectral photon index 1.23 and luminosity 1.4x10^33Theta(D/5.5 kpc)^2 ergs s^-1 (0.3-8 keV), where Theta is the fraction of the sky covered by the X-ray emission beam(s). We find no evidence for the previously reported line emission feature around 3.3 keV, most likely as a consequence of improvements in instrument calibration. The X-ray spectrum and pulse profile of PSR B1821--24 suggest that the bulk of unpulsed emission from this pulsar is not of thermal origin, and is likely due to low-level non-thermal magnetospheric radiation, an unresolved pulsar wind nebula, and/or small-angle scattering of the pulsed X-rays by interstellar dust grains. The peculiar binary PSR J1824-2452H shows a relatively hard X-ray spectrum and possible variability at the binary period, indicative of an intrabinary shock formed by interaction between the relativistic pulsar wind and matter from its non-degenerate companion star.Comment: 9 pages, 6 figures. Accepted for publication in the Astophysical Journa

Limited Liability Companies in Kentucky: Applications & New Topics for the LLC

Materials from the Limited Liability Companies in Kentucky conference held by UK/CLE in October 1999