On modeling pollution-generating technologies

Distinguishing between intended ("good") production and unintended or residual ("bad") generation, we introduce the concept of by-production. In by-production technologies, pollution is an output that satises a "costly disposability" assumption and violates standard free disposability with respect to pollution-causing inputs. Our approach therefore differs substantially from standard approaches to modeling pollution-generating technologies. We show how by-production can be modeled using data envelopment analysis (DEA) methods. With an electric power plant database, we illustrate shortcomings under by-production of two popular eciency indexes: the hyperbolic index and the directional distance function. We propose and implement an alternative eciency index with superior properties.pollution-generating technologies, free disposability, weak disposability, data envelopment analysis, environmental and technical eciency measurement

The Identification of Male-Specific Transcripts From D. melanogaster

A primary Lambda genomic library was screened with cDNA probes derived from male and female 3rd instar larval mRNA. Twenty clones which show male-specific or male-elevated expression were identified. Ten of these clones have been characterised in some detail. Two of the clones, gK14 and gK21, appear to be re-isolates of the previously identified male-specific genes mst349 and mst336 (DiBenedetto et al., 1987). These, along with five new isolates (gS4, gS8, gS9, gS10, gK33) show expression patterns on northern blots consistent with germline-specific expression. The transcripts are expressed in male larvae, pupae and adults but not in agametic males or XX individuals transformed to somatic males by the tra2 mutation (pseudomales). Two of these clones, gS8 and gS9, are non-overlapping but cross hybridise at high stringency indicating that they contain the same or very similar sequences. Partial cDNA clones identify a single band in female DNA but multiple bands in male DNA, suggesting the transcribed sequence is Y associated. Many of these male-specific bands are conserved in at least 3 different laboratory strains. Northern blots using RNA from XO and XY males show similar levels of the transcript suggesting that the non sex-specific locus can be transcribed, at least in the absence of a Y chromosome. In-situ hybridisation to polytene chromosomes with either of the genomic clones give no signal suggesting that the non sex-specific genomic location is under replicated or heterochromatic. Another of these germline-specific clones, gS4, appears to be heterochromatic. Southern blots of genomic DNA indicate the presence of several different repeats. In addition in-situ hybridisation to polytene chromosomes indicate that these repeats reside at a single genomic location: at the base of the left arm of chromosome 2. Of the three remaining clones, gS1 identifies a weakly expressed 3.0kb male-specific transcript. Although this transcript is not detected in agametic males low levels of expression during the pupal stage suggests that it may not be germline specific. The other two clones gS2 and gK15, are overlapping and map uniquely to region 61F on the polytene chromosome map. These clones identify at least 3 male-specific transcripts on northern blots as well as a non sex-specific transcript which is elevated during the embryonic and pupal stages. The pattern of expression appears to be complex, all of the transcripts are developmentally regulated. One of the male-specific transcripts is expressed in agametic males and possibly in pseudomales. This transcript is also present in the embryo although it is not known at present if it is sex-specific at this stage

Science requirements and feasibility/design studies of a very-high-altitude aircraft for atmospheric research

The advantages and shortcomings of currently available aircraft for use in very high altitude missions to study such problems as polar ozone or stratosphere-troposphere exchange pose the question of whether to develop advanced aircraft for atmospheric research. To answer this question, NASA conducted a workshop to determine science needs and feasibility/design studies to assess whether and how those needs could be met. It was determined that there was a need for an aircraft that could cruise at an altitude of 30 km with a range of 6,000 miles with vertical profiling down to 10 km and back at remote points and carry a payload of 3,000 lbs

The contribution of dance to daily physical activity among adolescent girls

<p>Abstract</p> <p>Background</p> <p>Structured physical activity (PA) programs are well positioned to promote PA among youth, however, little is known about these programs, particularly dance classes. The aims of this study were to: 1) describe PA levels of girls enrolled in dance classes, 2) determine the contribution of dance classes to total moderate-to-vigorous physical activity (MVPA), and 3) compare PA between days with a dance class (program days) and days without a dance class (non-program days).</p> <p>Methods</p> <p>Participants were 149 girls (11-18 years) enrolled in dance classes in 11 dance studios. Overall PA was assessed with accelerometry for 8 consecutive days, and girls reported when they attended dance classes during those days. The percent contribution of dance classes to total MVPA was calculated, and data were reduced to compare PA on program days to non-program days. Data were analyzed using mixed models, adjusting for total monitoring time.</p> <p>Results</p> <p>Girls engaged in 25.0 ± 0.9 minutes/day of MVPA. Dance classes contributed 28.7% (95% CI: 25.9%-31.6%) to girls' total MVPA. Girls accumulated more MVPA on program (28.7 ± 1.4 minutes/day) than non-program days (16.4 ± 1.5 minutes/day) (p < 0.001). Girls had less sedentary behavior on program (554.0 ± 8.1 minutes/day) than non-program days (600.2 ± 8.7 minutes/day) (p < 0.001).</p> <p>Conclusions</p> <p>Dance classes contributed a substantial proportion (29%) to girls' total MVPA, and girls accumulated 70% more MVPA and 8% less sedentary behavior on program days than on non-program days. Dance classes can make an important contribution to girls' total physical activity.</p

The Relationship of Stomatal Conductnace to Mechanical Strength in Leaves of Santa Monica Plants

The Santa Monica Mountains ecosystem has a high diversity of plants with different lifestyles that produce different physiological characteristics individual to all plants. Studies in Australia, another Mediterranean ecosystem, have shown that mechanical strength of leaves is relatable to soil stress. This experiment seeks to determine whether mechanical strengths of leaves correlate to stomatal conductance of leaves across different species in the Santa Monica Mountains. Four species of plants are tested for their stomatal conductance in the field, and the leaves are tested for tensile strength using Young’s Modulus for comparison across leaves. These data show that there was no comparable linear relationship across species, but also found that there were statistical differences in tensile strength and stomatal conductance for all species

Objectively Measured Sedentary Behavior in Preschool Children: Comparison Between Montessori and Traditional Preschools

Background: This study aimed to compare the levels of objectively-measured sedentary behavior in children attending Montessori preschools with those attending traditional preschools. Methods: The participants in this study were preschool children aged 4 years old who were enrolled in Montessori and traditional preschools. The preschool children wore ActiGraph accelerometers. Accelerometers were initialized using 15-second intervals and sedentary behavior was defined as/15-second. The accelerometry data were summarized into the average minutes per hour spent in sedentary behavior during the in-school, the afterschool, and the total-day period. Mixed linear regression models were used to determine differences in the average time spent in sedentary behavior between children attending traditional and Montessori preschools, after adjusting for selected potential correlates of preschoolers’ sedentary behavior. Results: Children attending Montessori preschools spent less time in sedentary behavior than those attending traditional preschools during the in-school (44.4. min/hr vs. 47.1 min/hr, P=0.03), after-school (42.8. min/hr vs. 44.7 min/hr, P=0.04), and total-day (43.7 min/hr vs. 45.5 min/hr, P = 0. 009) periods. School type (Montessori or traditional), preschool setting (private or public), socio-demographic factors (age, gender, and socioeconomic status) were found to be significant predictors of preschoolers’ sedentary behavior. Conclusions: Levels of objectively-measured sedentary behavior were significantly lower among children attending Montessori preschools compared to children attending traditional preschools. Future research should examine the specific characteristics of Montessori preschools that predict the lower levels of sedentary behavior among children attending these preschools compared to children attending traditional preschools

Aerobrake assembly with minimum Space Station accommodation

The minimum Space Station Freedom accommodations required for initial assembly, repair, and refurbishment of the Lunar aerobrake were investigated. Baseline Space Station Freedom support services were assumed, as well as reasonable earth-to-orbit possibilities. A set of three aerobrake configurations representative of the major themes in aerobraking were developed. Structural assembly concepts, along with on-orbit assembly and refurbishment scenarios were created. The scenarios were exercised to identify required Space Station Freedom accommodations. Finally, important areas for follow-on study were also identified

Measurements and computational analysis of heat transfer and flow in a simulated turbine blade internal cooling passage

Visual and quantitative information was obtained on heat transfer and flow in a branched-duct test section that had several significant features of an internal cooling passage of a turbine blade. The objective of this study was to generate a set of experimental data that could be used to validate computer codes for internal cooling systems. Surface heat transfer coefficients and entrance flow conditions were measured at entrance Reynolds numbers of 45,000, 335,000, and 726,000. The heat transfer data were obtained using an Inconel heater sheet attached to the surface and coated with liquid crystals. Visual and quantitative flow field results using particle image velocimetry were also obtained for a plane at mid channel height for a Reynolds number of 45,000. The flow was seeded with polystyrene particles and illuminated by a laser light sheet. Computational results were determined for the same configurations and at matching Reynolds numbers; these surface heat transfer coefficients and flow velocities were computed with a commercially available code. The experimental and computational results were compared. Although some general trends did agree, there were inconsistencies in the temperature patterns as well as in the numerical results. These inconsistencies strongly suggest the need for further computational studies on complicated geometries such as the one studied

Adipokines and the Right Ventricle: The MESA-RV Study.

ObjectiveObesity is associated with changes in both right (RV) and left (LV) ventricular morphology, but the biological basis of this finding is not well established. We examined whether adipokine levels were associated with RV morphology and function in a population-based multiethnic sample free of clinical cardiovascular disease.MethodsWe examined relationships of leptin, resistin, TNF-α, and adiponectin with RV morphology and function (from cardiac MRI) in participants (n = 1,267) free of clinical cardiovascular disease from the Multi-Ethnic Study of Atherosclerosis (MESA)-RV study. Multivariable regressions (linear, quantile [25th and 75th] and generalized additive models [GAM]) were used to examine the independent association of each adipokine with RV mass, RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV), RV stroke volume (RVSV) and RV ejection fraction (RVEF).ResultsHigher leptin levels were associated with significantly lower levels of RV mass, RVEDV, RVESV and stroke volume, but not RVEF, after adjustment for age, gender, race, height and weight. These associations were somewhat attenuated but still significant after adjustment for traditional risk factors and covariates, and were completely attenuated when correcting for the respective LV measures. There were no significant interactions of age, gender, or race/ethnicity on the relationship between the four adipokines and RV structure or function.ConclusionsLeptin levels are associated with favorable RV morphology in a multi-ethnic population free of cardiovascular disease, however these associations may be explained by a yet to be understood bi-ventricular process as this association was no longer present after adjustment for LV values. These findings complement the associations previously shown between adipokines and LV structure and function in both healthy and diseased patients. The mechanisms linking adipokines to healthy cardiovascular function require further investigation

SimArray: a user-friendly and user-configurable microarray design tool.

BACKGROUND: Microarrays were first developed to assess gene expression but are now also used to map protein-binding sites and to assess allelic variation between individuals. Regardless of the intended application, efficient production and appropriate array design are key determinants of experimental success. Inefficient production can make larger-scale studies prohibitively expensive, whereas poor array design makes normalisation and data analysis problematic. RESULTS: We have developed a user-friendly tool, SimArray, which generates a randomised spot layout, computes a maximum meta-grid area, and estimates the print time, in response to user-specified design decisions. Selected parameters include: the number of probes to be printed; the microtitre plate format; the printing pin configuration, and the achievable spot density. SimArray is compatible with all current robotic spotters that employ 96-, 384- or 1536-well microtitre plates, and can be configured to reflect most production environments. Print time and maximum meta-grid area estimates facilitate evaluation of each array design for its suitability. Randomisation of the spot layout facilitates correction of systematic biases by normalisation. CONCLUSION: SimArray is intended to help both established researchers and those new to the microarray field to develop microarray designs with randomised spot layouts that are compatible with their specific production environment. SimArray is an open-source program and is available from http://www.flychip.org.uk/SimArray/.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are