Search

In his 1874 classic Far From the Madding Crowd, Thomas Hardy gives us a memorable account of celestial motion. 'To persons standing alone on a hill during a clear midnight [...]

Shame on you, LtGen Dennis McCarthy, for your negative comments regarding our Reserve Component forces during most of the Cold War ("Risking All We Have Gained" The Officer, June 2006). […]

The Society for Research in Rapport and Telekinesis (SORRAT) claims to be in contact with spirit 'entities' that can divine the order of sealed decks of cards. A test was [...]

While paintings are typically subject to the artist's interpretation, we collaborated to create a realistic view of the eclipse and Concorde as if photographed by a 35-mm camera with a [...]

With the unprecedented photometric precision of the Kepler spacecraft, significant systematic and stochastic errors on transit signal levels are observable in the Kepler photometric data. These errors, which include discontinuities, outliers, systematic trends, and other instrumental signatures, obscure astrophysical signals. The presearch data conditioning (PDC) module of the Kepler data analysis pipeline tries to remove these errors while preserving planet transits and other astrophysically interesting signals. The completely new noise and stellar variability regime observed in Kepler data poses a significant problem to standard cotrending methods. Variable stars are often of particular astrophysical interest, so the preservation of their signals is of significant importance to the astrophysical community. We present a Bayesian maximum a posteriori (MAP) approach, where a subset of highly correlated and quiet stars is used to generate a cotrending basis vector set, which is in turn used to establish a range of "reasonable" robust fit parameters. These robust fit parameters are then used to generate a Bayesian prior and a Bayesian posterior probability distribution function (PDF) which, when maximized, finds the best fit that simultaneously removes systematic effects while reducing the signal distortion and noise injection that commonly afflicts simple least-squares (LS) fitting. A numerical and empirical approach is taken where the Bayesian prior PDFs are generated from fits to the light-curve distributions themselves.

With the unprecedented photometric precision of the Keplerspacecraft, significant systematic and stochastic errors on transit signal levels are observable in the Keplerphotometric data. These errors, which include discontinuities, outliers, systematic trends, and other instrumental signatures, obscure astrophysical signals. The presearch data conditioning (PDC) module of the Keplerdata analysis pipeline tries to remove these errors while preserving planet transits and other astrophysically interesting signals. The completely new noise and stellar variability regime observed in Keplerdata poses a significant problem to standard cotrending methods. Variable stars are often of particular astrophysical interest, so the preservation of their signals is of significant importance to the astrophysical community. We present a Bayesian maximum a posteriori (MAP) approach, where a subset of highly correlated and quiet stars is used to generate a cotrending basis vector set, which is in turn used to establish a range of "reasonable" robust fit parameters. These robust fit parameters are then used to generate a Bayesian prior and a Bayesian posterior probability distribution function (PDF) which, when maximized, finds the best fit that simultaneously removes systematic effects while reducing the signal distortion and noise injection that commonly afflicts simple least-squares (LS) fitting. A numerical and empirical approach is taken where the Bayesian prior PDFs are generated from fits to the light-curve distributions themselves.

Keplerprovides light curves of 156,000 stars with unprecedented precision. However, the raw data as they come from the spacecraft contain significant systematic and stochastic errors. These errors, which include discontinuities, systematic trends, and outliers, obscure the astrophysical signals in the light curves. To correct these errors is the task of the Presearch Data Conditioning (PDC) module of the Keplerdata analysis pipeline. The original version of PDC in Keplerdid not meet the extremely high performance requirements for the detection of miniscule planet transits or highly accurate analysis of stellar activity and rotation. One particular deficiency was that astrophysical features were often removed as a side effect of the removal of errors. In this article we introduce the completely new and significantly improved version of PDC which was implemented in KeplerSOC version 8.0. This new PDC version, which utilizes a Bayesian approach for removal of systematics, reliably corrects errors in the light curves while at the same time preserving planet transits and other astrophysically interesting signals. We describe the architecture and the algorithms of this new PDC module, show typical errors encountered in Keplerdata, and illustrate the corrections using real light curve examples.

A survey of Nevada residents in the Las Vegas Valley was conducted to determine perceptions and attitudes as they may contribute to the marketing potential of composted biosolids for residential use. Currently only 5 percent of Nevada's sludge is being composted, 15 percent is land applied while 80 percent is being sent to landfills. Sludge generated in the Las Vegas Valley is extremely low in heavy metals due to the low presence of industries that are characterized with the release of heavy metals. A residential survey was developed and mailed to over one percent of the valley's households resulting in a 21.5 percent return. Seventy-six percent of the respondents rated recycling as important or very important and 74 percent indicated that it is important or very important to find uses specifically for sewage sludge. A large percentage of residents were not aware of how sewage sludge is disposed (73.7%), but felt the community should be examining sewage sludge recycling options (75.1%). After a descriptive paragraph defining and describing composted sludge, there was a high level of support for the use of composted sludge on golf courses and public landscapes but a much smaller level of support for its use on vegetable gardens and houseplants. Respondents were more concerned about safety and health than they were about the cost of the product. Respondents looked to public health officials and University scientists for information concerning its safety. Backward multiple regression analysis indicated that males, individuals with higher incomes and higher education were more supportive of the use of composted sludge. Comparing responses from two different cities within the Las Vegas Valley, it was found that differences in demographics between communities led to differences in response. In particular, differences in the level of education, income, sex and ethnicity influenced responses from the two communities. Evaluation of the data suggests that based on a community's demographics, different educational and marketing approaches may need to be considered.

The use of poor quality water for irrigation purposes in the urban landscape has the potential to save significant quantities of good quality water for higher priority uses. Research was conducted to determine the impact leaching fractions (LF = drainage volume/irrigation volume) and irrigation‐uniformity distributions have on the spatial distribution of water and salts and plant response when irrigating with saline water. Tall fescue (Festuca arundinaceaSchreb. ‘Monarch’) was grown in 18 plots, each with a centrally located lysimeter that enabled estimates of evapotranspiration and irrigation requirements. Imposed treatments included setting LF at 0.05, 0.15, or 0.25 and manipulating plot irrigation systems such that the Christiansen uniformity coefficient (CUC) was set at 0.65, 0.75, or 0.85. Saline irrigation water (2.5 dS m−1) was applied for an 18‐mo period. Significant LF × CUC interactions were observed for depth‐weighted soil salinity, yield, evapotranspiration (ET), tissue moisture content, and canopy temperatures. Although the coefficient of variation increased with each measured parameter as the CUC decreased, only the depth‐weighted electrical conductivity (ECc) showed a coefficient of variation > 20%. A 14% savings in irrigation water was obtained when the high CUC, low LF treatment was compared with the high LF, low CUC treatment. Ninety‐one percent of the variability in the average plot ECccould be accounted for if the actual LF, lysimeter ET, and average plot canopy temperatures at the end of the experiment were taken into consideration. Under the conditions of this experiment, irrigating tall fescue with 2.5 dS m−1water would be an acceptable practice even at LFs as low as 0.05 if the CUC is optimized.

Limited water resources in the arid southwestern USA have created greater interest on the part of municipalities to utilize nonpotable waters in urban areas. Research was conducted to assess the feasibility of using a perched saline aquifer as an alternative irrigation source for turfgrass. Two line‐source irrigation gradients, one using municipal water with an EC of ≈ 1.1 dS m−1and the other using saline aquifer water blended with municipal water to an EC of 6.0 dS m−1, were established to impose a salinity and/or water deficit gradient on tall fescue (Festuca arundinaceaSchreb. ‘Monarch’) and an improved common bermudagrass (Cynodon dactylonL. ‘Numex Sahara’). Yield was found to be highly correlated with actual evapotranspiration (ETa) (r= 0.92, P< 0.001 for bermudagrass; r= 0.83, P< 0.001 for tall fescue), regardless of how the stress was imposed. Relative ETa(ratio of ETato maximum ETaunder municipal irrigation) values as a function of the summation of the leaf‐to‐air temperature differences also indicated no distinguishable change in stress response based on water quality (r= 0.94, P< 0.001 for tall fescue; r= 0.86, P<0.001 for bermudagrass). Relative turf color and percent cover remained unchanged if the ratio of irrigation volume to potential evapotranspiration (I/ETo) remained above species‐specific threshold values of 0.80 for tall fescue and 0.65 for bermudagrass. Below these thresholds, cover and color declined linearly, with differences due to water quality treatment in tall fescue but with no differences due to water quality treatment in bermudagrass.

This article discusses an episode of mustiness that was extremely resistant to treatment processes, which occurred on the Cedar River in Iowa during June through July, 1961. A study was done on the chemical characteristics of the metabolic products of actinomycetes isolated and cultured from the Cedar River during the 1961 period of musty taste. The difficulty of analysis, effect of cultural conditions, isolation procedures and actinomycete‐produced substances are all discussed, along with neutral‐fraction characteristics, further purification, constituents of eluate, and infrared analysis. An illustration of the similarity between organic materials of river water and extracted actinomycete metabolites is provided in a comparison of the infrared spectra of an extract of musty Cedar River water, and an extract of the laboratory‐cultured actinomycetes.

Data on various raw‐water sources in Iowa are analyzed in relation to the finished waters produced from them; periods of high agricultural runoff are distinctly associated with peaks in halomethanes. Turbidity removal prior to chlorination is shown to be critical to minimize chloroform production during disinfection. Municipalities may be interested by the inexpensive new methodology developed to test for these substances, a current concern in the water‐supply field.

With the loss of two spacecraft reaction wheels precluding further data collection for the Keplerprimary mission, even greater pressure is placed on the processing pipeline to eke out every last transit signal in the data. To that end, we have developed a new method to optimize the KeplerSimple Aperture Photometry (SAP) photometric apertures for both planet detection and minimization of systematic effects. The approach uses a per cadence modeling of the raw pixel data and then performs an aperture optimization based on signal-to-noise ratio and the KeplerCombined Differential Photometric Precision (CDPP), which is a measure of the noise over the duration of a reference transit signal. We have found the new apertures to be superior to the previous Keplerapertures. We can now also find a per cadence flux fraction in aperture and crowding metric. The new approach has also been proven to be robust at finding apertures in K2data that help mitigate the larger motion-induced systematics in the photometry. The method further allows us to identify errors in the Keplerand K2input catalogs.

A compound produced by certain actinomycete cultures is responsible for a persistent musty odor. It has been isolated in high purity and identified by chemical and spectroscopic properties. Possible structures are discussed.

A letter to the editor is presented in response to an article about the new format for the monthly ecumenical journal "First Things," by Joseph Botum.

Field testing nationwide is now under way to test the feasibility of delivering combined health and social services to an elderly population. The social/health maintenance organization (S/HMO), incorporating features of health maintenance organizations with the home care approach of community social services, will be financed on a prepaid, capitated basis through premium contributions from Medicare, Medicaid, and enrollees. It will test whether social services can reduce medical costs and whether institutional days can be reduced, family care maintained, and health and quality of life enhanced.