Spacelab 3 Mission Science Review

Papers and abstracts of the presentations made at the symposium are given as the scientific report for the Spacelab 3 mission. Spacelab 3, the second flight of the National Aeronautics and Space Administration's (NASA) orbital laboratory, signified a new era of research in space. The primary objective of the mission was to conduct applications, science, and technology experiments requiring the low-gravity environment of Earth orbit and stable vehicle attitude over an extended period (e.g., 6 days) with emphasis on materials processing. The mission was launched on April 29, 1985, aboard the Space Shuttle Challenger which landed a week later on May 6. The multidisciplinary payload included 15 investigations in five scientific fields: material science, fluid dynamics, life sciences, astrophysics, and atmospheric science

Willingness to Pay: Referendum Contingent Valuation and Uncertain Project Benefits

This study uses contingent valuation (CV) methods to estimate the benefit of an environmental water quality project of the Tietê River and its tributaries that flow through the São Paulo, Brazil, Metropolitan Area (SPMA). This paper demonstrates the range alternative central tendency measures for WTP produced under alternative parametric and nonparametric approaches using data gathered from a recent referendum CV survey that was conducted in Brazil to analyze a large, multi-phase water quality improvement project. It explains why one of the most commonly used measures, the unrestricted mean of the conditional inverse distribution function of WTP, may be less desirable and more computationally intensive than simpler alternatives like the nonparametric mean of the marginal inverse distribution function.Water management, Economics, contingent valuation, econometric models, environmental impact analysis, economic development projects

Spacelab 3: Research in microgravity

The Spacelab 3 mission, which focused on research in microgravity, took place during the period April 29 through May 6, 1985. Spacelab 3 was the second flight of the National Aeronautics and Space Administration's modular Shuttle-borne research facility. An overview of the mission is presented. Preliminary scientific results from the mission were presented by investigators at a symposium held at Marshall Space Flight Center on December 4, 1985. This special issue is based on reports presented at that symposium

A Quantitative Sensory Testing Approach to Pain in Autism Spectrum Disorders.

Sensory abnormalities in autism has been noted clinically, with pain insensitivity as a specified diagnostic criterion. However, there is limited research using psychophysically robust techniques. Thirteen adults with ASD and 13 matched controls completed an established quantitative sensory testing (QST) battery, supplemented with measures of pain tolerance and central modulation. The ASD group showed higher thresholds for light touch detection and mechanical pain. Notably, the ASD group had a greater range of extreme scores (the number of z-scores outside of the 95% CI > 2), dynamic mechanical allodynia and paradoxical heat sensation; phenomena not typically seen in neurotypical individuals. These data support the need for research examining central mechanisms for pain in ASD and greater consideration of individual difference

Computed Normal Range of Iowa Statewide July Precipitation

Iowa summer rainfall distributions are examined to identify small-scale anomalies. Examination of extremely wet and dry summer months shows that large rain amounts fall mainly in small, cellular areas for both extremely wet and dry months. These configurations result from individual rainfall events. Analysis of the distribution of mean July rainfall across the state reveals significant anomalous wet and dry regions that contrast with the background, east-west rainfall gradient. Because of the skewed nature of summer rainfall distributions, the median value is used to represent a more realistic expected rainfall amount for any given year. Some parts of the stare have a more variable distribution and are more sensitive to the expected annual swing of one standard deviation. On the basis of statistical probabilities, these areas can expect summers of more severe moisture deficiencies to occur more often than in the rest of the stare

Population characteristics of gulf menhaden, Brevoortia patronus

The status of the Gulf menhaden, Brevoortia patronus, fishery was assessed with purse-seine landings data from 1946 to 1997 and port sampling data from 1964 to 1997. These data were analyzed to determine growth rates, biological reference points for fi shing mortality from yield per recruit and maximum spawning potential analyses, spawner-recruit relationships, and maximum sustainable yield (MSY). The separable virtual population approach was used for the period 1976–97 (augmented by earlier analyses for 1964–75) to obtain point estimates of stock size, recruits to age 1, spawning stock size, and fishing mortality rates. Exploitation rates for age-1 fi sh ranged between 11% and 45%, for age-2 fi sh between 32% and 72%, and for age-3 fi sh between 32% and 76%. Biological reference points from yield per recruit (F0.1: 1.5–2.5/yr) and spawning potential ratio (F20: 1.3–1.9/yr and F30: 0.8–1.2/yr) were obtained for comparison with recent estimates of F (0.6–0.8/yr). Recent spawning stock estimates (as biomass or eggs) are above the long-term average, while recent recruits to age 1 are comparable to the long-term average. Parameters from Ricker-type spawner-recruit relations were estimated, although considerable unexplained variability remained. Recent survival to age-1 recruitment has generally been below that expected based on the Ricker spawner-recruit relation. Estimates of long-term MSY from PRODFIT and ASPIC estimation of production model ranged between 717,000 t and 753,000 t, respectively. Declines in landings between 1988 and 1992 raised concerns about the status of the Gulf menhaden stock. Landings have fl uctuated without trend since 1992, averaging about 571,000 t. However, Gulf menhaden are short lived and highly fecund. Thus, variation in recruitment to age 1, largely mediated by environmental conditions, infl uences fi shing success over the next two years (as age-1 and age-2 fi sh). Comparisons of recent estimates of fi shing mortality to biological reference points do not suggest overfishing. (PDF file contains 22 pages.

Paramagnetic Resonance Absorption in Some Organic Biradicals

Four compounds of the form 4,4′‐polymethylenebistriphenylmethyl, one compound of the form (1,4‐phenylene)bisdiarylmethyl, three compounds of the form (4,4′‐biphenylene)bisdiarylmethyl, and one compound, 4,4′‐oxybistriphenylmethyl have been shown to possess unpaired electrons by paramagnetic resonance absorption. The resonance spectra of 0.01 M solutions of these compounds in benzene exhibit a hyperfine structure arising from a spherically symmetrical contribution of the magnetic dipole interaction between the unpaired electron and the nuclear magnetic moments of the hydrogen atoms. The g‐factors for the compounds investigated in the first three classes were found to be 2.0025±0.0004 and 2.0031±0.0004 for the last compound. Such a close approach of the g‐factor to the free electron value plus the sharpness of the hyperfine structure lines indicates that the anisotropic contributions of the spin‐orbit interaction, which would normally lift the degeneracy of the triplet state, are averaged out by the tumbling of the molecules.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70965/2/JCPSA6-25-4-697-1.pd

The spatial ordering of knowledge economies: The growth of furniture industry in nineteenth-century London

Small businesses in the same sector tend to be geographically concentrated. Understanding why businesses in some industries cluster is a key issue in urban economic theory, particularly in the Marshallian and Jacobsian traditions. These emphasize the logistical and informational synergies (advantages) that accrue to firms in agglomeration economies, allowing firms located near one another to accelerate their rate of innovation. However, little is known about how spatial forms foster the clustering of firms or the mechanisms through which this process might facilitate knowledge spillover over between different businesses. In this paper we present an historical case study in which space syntax methods, archival research and urban economic theory were used to enhance understanding of the spatial ordering of London's nineteenth-and early twentieth-century furniture industry, a sector characterised by a proliferation of small, local firms. The spatial morphologies of the furniture industry in the Shoreditch and Fitzrovia areas of London are profiled by linking business directories, historical Ordnance Survey maps and Goad fire insurance plans to space syntax measures describing the spatial configuration of London's street network, on a GIS platform. Historically, the two casestudy areas have hosted a wide range of furniture-manufacturing businesses. We hypothesise that the contrast between the spatial structures of the two districts contributed to the divergent paths development of the furniture industry in these places. Our results suggest the two areas developed as different knowledge economies, in part as a consequence of their contrasting spatial configurations and their influence on industrial organization. Shoreditch became a 'specialization' economy (i.e. Marshallian). Here the organic pattern of streets allowed specialized businesses to be located in close proximity to key streets, benefiting from more local footfall, and in close localization of firms belonging to the same industry. Fitzrovia, however, showed a more 'diversified' economy (i.e. Jacobsian), accommodating most of its retailers on streets highly integrated across scales and more commercially-driven. In the context of constraints of land use and rising land values, manufacturing operations moved to other places whilst retaining large-size firms that created a retail destination in a high footfall location good for attracting passing trade. We anticipate that this research will contribute to understanding the distinctive spatial cultures of urban manufacturing and to the development of a methodological approach that opens up new prospects for inter-disciplinary research

Quantum limits to center-of-mass measurements

We discuss the issue of measuring the mean position (center-of-mass) of a group of bosonic or fermionic quantum particles, including particle number fluctuations. We introduce a standard quantum limit for these measurements at ultra-low temperatures, and discuss this limit in the context of both photons and ultra-cold atoms. In the case of fermions, we present evidence that the Pauli exclusion principle has a strongly beneficial effect, giving rise to a 1/N scaling in the position standard-deviation -- as opposed to a $1/\sqrt{N}$ scaling for bosons. The difference between the actual mean-position fluctuation and this limit is evidence for quantum wave-packet spreading in the center-of-mass. This macroscopic quantum effect cannot be readily observed for non-interacting particles, due to classical pulse broadening. For this reason, we also study the evolution of photonic and matter-wave solitons, where classical dispersion is suppressed. In the photonic case, we show that the intrinsic quantum diffusion of the mean position can contribute significantly to uncertainties in soliton pulse arrival times. We also discuss ways in which the relatively long lifetimes of attractive bosons in matter-wave solitons may be used to demonstrate quantum interference between massive objects composed of thousands of particles.Comment: 12 pages, 6 figures. Submitted to PRA. Revised to include more references as well as a discussion of fermionic center-of-mas