Long range inhabited surface transportation system power source for the exploration of Mars (manned Mars mission)

A hydrogen-oxygen fuel cell system is identified as a viable power source for a long range inhabited surface transportation system for the exploration of Mars. Power system weights and power requirements are determined as a function of vehicle weight. For vehicles weighing from 2700 to 7300 kg in LEO, the total power system weight ranges from 1140 to 1860 kg, with the reactants and energy conversion hardware (fuel cells, reactant storage, and radiator) weighing 430 to 555 kg and 610 to 1110 kg, respectively. Vehicle power requirements range from 45 kW for a 2700 kg vehicle to 110 kW for a 7300 kg vehicle. Power system specific weights and power profiles for housekeeping and the operation of scientific equipment such as coring drills and power tools are also specified

Brownfields Redevelopment in Wisconsin: A Survey of the Field

As the third paper in our three-part series on Wisconsin brownfields, this paper reports the results of a survey on the objectives of brownfields redevelopment, constraints to the redevelopment, the role of the state’s Department of Natural Resources (DNR), and institutional controls. The 260 survey respondents include elected officials, staff from economic development and planning agencies, attorneys, private sector representatives, and professionals at nonprofit organizations. We find that: 1) respondents value both economic and environmental gains associated with brownfields redevelopment; 2) the high costs of cleanup are the principal barrier to brownfields redevelopment; 3) no single factor stands out as constraining DNR’s ability to oversee cleanups; 4) owners are more likely to be aware of institutional controls implemented through deed restrictions than through an electronic registry; and 5) attitudes regarding changes in DNR behavior along dimensions of flexibility, fairness, knowledge, and willingness to negotiate are more rather than less positive.Brownfields, contamination, hazardous waste, regulatory reform

Medicaid Managed Care and Infant Health: A National Evaluation

In this study, we examine the effects of Medicaid managed care (MMC) on prenatal care utilization and infant health. We obtain separate estimates of the effect of primary care case management (PCCM) managed care programs and HMO managed care plans on prenatal care utilization, birth weight, and cesarean section. The results suggest the following: MMC was associated with a small, clinically unimportant decrease in the number of prenatal care visits; MMC had no statistically significant relationship to the APNCU index of the adequacy of prenatal care; MMC was associated with a significant increase in the incidence of low-birth weight and pre-term birth; and MMC had no association with the incidence of cesarean section. We argue that a causal interpretation of the first and third findings is unsupported by a careful reading of the evidence, and we conclude that Medicaid managed care had virtually no causal effect on, prenatal care use, birth outcomes, and cesarean section.

The Computational Structure of Spike Trains

Neurons perform computations, and convey the results of those computations through the statistical structure of their output spike trains. Here we present a practical method, grounded in the information-theoretic analysis of prediction, for inferring a minimal representation of that structure and for characterizing its complexity. Starting from spike trains, our approach finds their causal state models (CSMs), the minimal hidden Markov models or stochastic automata capable of generating statistically identical time series. We then use these CSMs to objectively quantify both the generalizable structure and the idiosyncratic randomness of the spike train. Specifically, we show that the expected algorithmic information content (the information needed to describe the spike train exactly) can be split into three parts describing (1) the time-invariant structure (complexity) of the minimal spike-generating process, which describes the spike train statistically; (2) the randomness (internal entropy rate) of the minimal spike-generating process; and (3) a residual pure noise term not described by the minimal spike-generating process. We use CSMs to approximate each of these quantities. The CSMs are inferred nonparametrically from the data, making only mild regularity assumptions, via the causal state splitting reconstruction algorithm. The methods presented here complement more traditional spike train analyses by describing not only spiking probability and spike train entropy, but also the complexity of a spike train's structure. We demonstrate our approach using both simulated spike trains and experimental data recorded in rat barrel cortex during vibrissa stimulation.Comment: Somewhat different format from journal version but same conten

Planned, motivated and habitual hygiene behaviour: an eleven country review.

Handwashing with soap (HWWS) may be one of the most cost-effective means of preventing infection in developing countries. However, HWWS is rare in these settings. We reviewed the results of formative research studies from 11 countries so as to understand the planned, motivated and habitual factors involved in HWWS. On average, only 17% of child caretakers HWWS after the toilet. Handwash 'habits' were generally not inculcated at an early age. Key 'motivations' for handwashing were disgust, nurture, comfort and affiliation. Fear of disease generally did not motivate handwashing, except transiently in the case of epidemics such as cholera. 'Plans' involving handwashing included to improve family health and to teach children good manners. Environmental barriers were few as soap was available in almost every household, as was water. Because much handwashing is habitual, self-report of the factors determining it is unreliable. Candidate strategies for promoting HWWS include creating social norms, highlighting disgust of dirty hands and teaching children HWWS as good manners. Dividing the factors that determine health-related behaviour into planned, motivated and habitual categories provides a simple, but comprehensive conceptual model. The habitual aspects of many health-relevant behaviours require further study

EVALUATING FACTORS INFLUENCING GROCERY STORE CHOICE

This paper analyzes consumer preferences toward grocery store choices given a set of attributes of stores. This information will then be used to make inferences on how the opening of a Wal-Mart supercenter would affect the other grocery stores in a small city.Consumer/Household Economics, Institutional and Behavioral Economics,

THE BIG PICTURE: PRODUCTION AND ENVIRONMENTAL IMPACTS OF REDUCED US OBESITY

This paper assesses how successfully reducing the incidence of overweight and obesity in the US to meet public health objectives might influence agricultural production. We also examine the consequent agri-environmental effects of the production changes. Our estimates show that a reduction in aggregate consumption by between 2 and 6 percent, associated with public health goals being met, would lead to reduced production of primary agricultural commodities, increased exports, and reduced discharge of agricultural pollutants. In both cases, neither the estimated changes in commodity production nor the subsequent environmental impacts would be uniform across the landscape. Results indicate that in value terms, the largest changes (either positive or negative) in agricultural producer net returns would occur in the Corn Belt and the Lake States; conversely, the largest impacts on consumer surplus would occur in the Northeast and Pacific regions.Health Economics and Policy,

Spectroscopic and Computational Studies of Matrix-Isolated iso-CXBr3 (X=F,Cl,Br): Structure, Properties, and Photochemistry of Substituted Iso-Tribromomethanes

Iso-polyhalomethanes are important reactive intermediates in the condensed and gas-phase chemistry of halomethanes. Building upon our recent study of iso-bromoform, in this work the substituted iso-tribromomethanes (iso-CXBr3; X = F, Cl, Br) were characterized by matrix isolation infrared and UV/Vis spectroscopy, supported by ab initio calculations, to further probe the structure, spectroscopy, properties, and photochemistry of these important intermediates. Selected wavelength laser irradiation of CXBr3 samples in an inert rare gas (typically Ar; mixing ratio 1:500) held at ∼5 K yielded iso-CXBr3 (XBrC–Br–Br or Br2C–Br–X). The observed infrared and UV/Vis absorptions are in excellent agreement with computational predictions, and the energies of various stationary points on the CXBr3 Potential Energy Surfaces (PESs) were characterized computationally using DFT, MP2, and CCSD (T) methods in combination with triple-zeta quality basis sets. These calculations show that the isomers are minima on the PESs that lie ∼200 kJ/mol above the global CXBr3 minimum, yet are bound by some 50–70 kJ/mol in the gas-phase with respect to the CXBr2 + Br asymptote. Laser irradiation of the isomers resulted in back photoisomerization to CXBr3, and intrinsic reaction coordinate (IRC) calculations confirmed the existence of a first order saddle point connecting the two isomers. Calculations of important stationary points on the CXBr3 PESs show that in the gas-phase the isomerization barrier lies energetically near the threshold for simple bond fission. The iso-CXBr3 species are significantly stabilized in the condensed phase, due to the high degree of ion-pair character, as revealed by Natural Resonance Theory analysis