Selected aspects of lunar mare geology from Apollo orbital photography

Crater size-frequency distributions were studied (100-500 m) and are shown to provide significant integrated information concerning mare surface ages, subsurface stratigraphy, and surficial geology. Equilibrium cratering is discussed gradually reducing the relative numbers of craters smaller than 300-400 m in diameter as surfaces age and regolith thickens. Results for surface ages are in good agreement with other published crater ages. The existing correlations of large ring structures among various circular mare basins are shown to be based on criteria that are inconsistent and nonstandardized. A means of comparing equivalent ring structures in the different maria is proposed which takes into account the important characteristics of young unflooded basins (Orientale) as well as the progressive development of tectonic and volcanic features within the older flooded maria. Specific geologic aspects of several of the lunar maria are discussed and especially Mare Smythii, because of its great age and significantly different surface morphology. Lunar photographs and maps are shown

Calculating partial expected value of perfect information via Monte Carlo sampling algorithms

Partial expected value of perfect information (EVPI) calculations can quantify the value of learning about particular subsets of uncertain parameters in decision models. Published case studies have used different computational approaches. This article examines the computation of partial EVPI estimates via Monte Carlo sampling algorithms. The mathematical definition shows 2 nested expectations, which must be evaluated separately because of the need to compute a maximum between them. A generalized Monte Carlo sampling algorithm uses nested simulation with an outer loop to sample parameters of interest and, conditional upon these, an inner loop to sample remaining uncertain parameters. Alternative computation methods and shortcut algorithms are discussed and mathematical conditions for their use considered. Maxima of Monte Carlo estimates of expectations are biased upward, and the authors show that the use of small samples results in biased EVPI estimates. Three case studies illustrate 1) the bias due to maximization and also the inaccuracy of shortcut algorithms 2) when correlated variables are present and 3) when there is nonlinearity in net benefit functions. If relatively small correlation or nonlinearity is present, then the shortcut algorithm can be substantially inaccurate. Empirical investigation of the numbers of Monte Carlo samples suggests that fewer samples on the outer level and more on the inner level could be efficient and that relatively small numbers of samples can sometimes be used. Several remaining areas for methodological development are set out. A wider application of partial EVPI is recommended both for greater understanding of decision uncertainty and for analyzing research priorities

Cooldown time for simple cryogenic pipelines

Cooldown time for simple cryogenic pipeline

The Role Body-Esteem Plays in Impairment Associated with Hair-Pulling and Skin Picking in Adolescents

Trichotillomania (hair pulling disorder, HPD) and pathological skin picking (PSP) are associated with significant rates of psychosocial impairment and distress. Little research has addressed the physical consequences and associated impairment in youth (e.g., poor body-esteem). The present study explores the relationship between body-esteem, skin picking (SP), and pulling-related impairment in a sample of adolescents with primary HPD. Ninety four adolescents who pull their hair, 40 of whom also pick their skin, were recruited via internet-sampling as part of the Child and Adolescent Trichotillomania Impact Study (CA-TIP). All youth and a parent completed anonymous questionnaires online assessing psychiatric symptoms, repetitive behaviors, and psychosocial impairment, among other variables. Appearance-based body-esteem was not found to be predictive of more severe psychosocial impairment in these youth. However, SP, in combination with HPD, contributed to worse appearance-based body-esteem above and beyond symptoms of HPD alone. The current study suggests that psychosocial functioning in youth with HPD is less impacted by body-esteem or pulling than other factors (e.g., depression and anxiety), and that SP contributes to lowered body-esteem. These findings suggest the importance of addressing body-esteem in case conceptualization for youth with both HPD and SP. Further research is required to confirm these suggestions

Effect of row spacing, nitrogen and weed control on crop and weed in low rainfall zones of western Australia

Wide rows essentially ensure some temporal and spatial water availability in water-limiting crop environments, thus minimising the risk of water deficits at critical crop growth stages to ensure profitable yields (Whish et al., 2005). Presence of weeds will have a major impact on water availability to crops irrespective of planting geometries. Decreasing crop plant population and increasing row spacing decreases crop competitive ability against weeds, and generally wider row spacing will reduce crop competition for homogeneously distributed production factors, as postulated mathematically by Fischer and Miles, (1973). Hence good weed management becomes critical to the success of wide row systems, as failure to control water-using weeds defeats the purpose of wide row cropping where water conservation is the focus. With a perceived decline in rainfall in central and eastern wheat belt of Western Australia (WA), wide row cropping practices may prove more productive if weeds can be managed by appropriate herbicides and depriving weeds from applied nitrogen (N). We examined the effect of nitrogen and herbicide on the crop performance and weed control under normal and wide row spacing in a wheat – lupin– canola rotation at Cunderdin and wheat – chickpea rotation at Merredin, WA

Bobwhite Brood Ecology in Relation to Fallow Field Management Techniques and Prescribed Fire Regime

We used compositional analysis to rank habitats used by nesting and brood-rearing northern bobwhites (Colinus virginianus) in northern Florida. We used a residence index based on brood movement rates and turning angles to predict distribution of organisms among habitat types within brood ranges. We examined relationships among residence indices and vegetation and invertebrate characteristics of the habitat to draw inferences as to brood habitat quality. We related brood survival to vegetation, landscape structure and composition, and invertebrate characteristics within brood ranges. Finally, we reported effects of season of disking (fall vs spring) on vegetative (composition, canopy cover, density, ground cover) and invertebrate (richness and biomass) communities in fallow agricultural fields

Evaluation of Two Marking Methods for 1-day-old Northern Bobwhite Chicks

We compared survival, weight gain, and mark retention of wing bands (n = 50), passive integrated transponders (PITs)(n = 50), and leg bands proportional to the chicks size (control) (n = 50) on 1-day-old northern bobwhite (Colinus virginianus) chicks. A repeated measures, generalized complete randomized block ANOV A of the weekly gain in weight showed no difference in the chicks growth (p \u3e) 0.05). Survival was similar between marking methods (wing band, PITs, leg band, and control). Retention of bands during the twelve-week pen study were equal but 4% of PITs were destroyed when adult birds were recovered after harvest. We concluded that wing bands may be the most practical method of marking 1-day-old bobwhite chicks

Effects of Radio-Transmitters on Body Condition, Harvest Rate, and Survival of Bobwhites

Numerous studies of northern bobwhite (Colinus virginianus) population and habitat ecology employ use of radio-telemetry techniques to relocate and monitor individuals. Radio-telemetry enables estimation of reproductive success, survival, movements, and home range at levels of resolution not otherwise possible. Unbiased estimation of these parameters via radio-telemetry assumes that survival, reproduction, and behavior of radio-marked individuals are not affected by carrying the radio-transmitter. These assumptions have not been rigorously tested for bobwhites. In 1993, we initiated a study at Divide Section Wildlife Management Area in Mississippi and at Tall Timbers Research Station to test the effects of radio-transmitters on survival, harvest rate, and body condition of bobwhites. From 1993 to 1996 we banded 221 and radio-marked 259 bobwhites on Tall Timbers Research Station. Harvest rate for radio-marked bobwhites was 18.5% and banded birds 12.7%. In 2 of 3 years, radio-marked birds experienced greater mean weight loss between capture and harvest than banded birds. From 1994 to 1995 we radio marked 188 and banded 210 birds on Divide Section Wildlife Management Area. Harvest rate for radio-marked birds was 40% and banded birds 30%. In the 1995-1996 hunting season radiomarked birds had lower mean weight gain from capture to harvest than banded birds. Based on our sample of marked birds, 34% of the fall population on this area was harvested. We have established a captive breeding colony of wild bobwhites at the Blackjack Captive Animal Research Facility at Mississippi State University. During the summer of 1996, genetically wild progeny are being produced to be used in a pen study to evaluate the effects of radio-transmitters on bobwhite body weight and lipid levels under abundant and scarce food resources. This study will provide the first harvest rate estimates for bobwhites on a public hunting area in Mississippi. Additionally, this study will evaluate the effects of radio-transmitters on bobwhite body condition, survival, and harvest rate. It will either validate the assumption of no radio effects and aid interpretation of previous and future radio studies or elucidate critical violations of fundamental assumptions of this methodology. If radio effects are detected, this study will identify the specific mechanisms creating bias in estimation of population parameters. This information will enable researchers to target radio design problems and develop new radio technology with reduced effects. Preliminary results suggest that radio-marking may marginally increase bobwhite vulnerability to harvest and potentially predation

Can the United States Afford a “No-Fault” System of Compensation for Medical Injury?

One of the key issues separating US critics of a no-fault alternative to the tort system for compensating victims of medical injury from supporters is its anticipated cost. Results from a study are presented that estimate the costs of a no-fault system, one that is similar to the system now in operation in Sweden, within the context of the US health care system