Analysis Concerning the Disaster of the Forest: A Theoretical and Practical Approach: Working Paper Series--04-09

The explosion of serious forest fires in the Rocky Mountain West in recent years has opened the public eye to the unhealthy condition of forests. The extended drought has combined with dense forest conditions to make many residents of rural Arizona quite fearful of the possibility of additional fires. The public interest has even resulted in federal policy changes known as the Healthy Forests Initiative, which has, of course, stimulated increased public discussion. In order to find solutions to the problem, as based on Norgaard, Smith and Jacobs, society must create new ways of organizing and doing. This article explores possible market-based solutions as the one of the available practical remediation processes. Utilizing the forest restoration and engineering literature, we believe that a new forest-based industry founded on the concepts of science-based forest management and ecological sustainability is the logical solution in a market-based economy

Virtual models in online shopping: do they help or hinder customers?

Virtual experience and other technology-dependent methods of describing products online are frequently touted as the way of the future in e-commerce. However, despite the hyperbole, these claims have actually not been tested rigorously on systems used by major online retailers. This paper reports the results of an experiment that assesses user perceptions of the informativeness and ultimate usefulness of systems that use personalization and rich media to enhance the online product evaluation process. Our results challenge the commonly held view that the “high-tech” approach is, in its own right, beneficial to either the customer or the vendor. Key results are (i) the highest levels of informativeness about anticipated (future) experiences were achieved when no personalization systems were used; and (ii) the system that provided the most personalized support was perceived to be least informative about future experience, and least useful overall. Overall, our results indicate that although these systems can improve awareness of some important product attributes, with this enhanced awareness comes a reduced awareness of other product characteristics. At worst, these systems actually appear to make the customer less informed, and result in negative assessments of the retailer

Rates of Bone Loss in Young Adult Males

Osteoporosis-related fractures occur more frequently in women compared with men, but mortality is greater in men compared with women. Peak bone mass is a significant predictor of osteoporosis and fracture risk; therefore, it is important to optimize peak bone mass during young adulthood. Several recent longitudinal studies, which are summarized in this article, have investigated bone changes among young men. Cortical bone loss does not appear to be significant until individuals reach their mid-30s and is associated with decreased sex hormone concentrations. Significant trabecular bone loss in young men aged in their 20s has been reported and is associated with reduced lean mass and activity levels, especially among former athletes. Whether changes in activity levels among nonathletes lead to bone loss among young men requires further investigation

Modelling Molecular Motors as Folding-Unfolding Cycles

We propose a model for motor proteins based on a hierarchical Hamiltonian that we have previously introduced to describe protein folding. The proposed motor model has high efficiency and is consistent with a linear load-velocity response. The main improvement with respect to previous models is that this description suggests a connection between folding and function of allosteric proteins.Comment: 5 pages RevTeX, 2 Postscript figures, replaced due to LaTeX proble

Constraining ^(26)Al+p resonances using ^(26)Al(^3He,d)^(27)Si

The ^(26)Al(^3He,d)^(27)Si reaction was measured from 0°≤θ_(c.m.)≤35° at E(^3He)=20 MeV using a quadrupole-dipole-dipole-dipole magnetic spectrometer. States in ^(27)Si were observed above the background at 7652 and 7741 keV and upper limits were set for the state at 7592 keV. Implications for the ^(26)Al(p,γ)^(27)Si stellar reaction rate are discussed

The Discovery of Cometary Activity in Near-Earth Asteroid (3552) Don Quixote

The near-Earth object (NEO) population, which mainly consists of fragments from collisions between asteroids in the main asteroid belt, is thought to include contributions from short-period comets as well. One of the most promising NEO candidates for a cometary origin is near-Earth asteroid (3552) Don Quixote, which has never been reported to show activity. Here we present the discovery of cometary activity in Don Quixote based on thermal-infrared observations made with the Spitzer Space Telescope in its 3.6 and 4.5 {\mu}m bands. Our observations clearly show the presence of a coma and a tail in the 4.5 {\mu}m but not in the 3.6 {\mu}m band, which is consistent with molecular band emission from CO2. Thermal modeling of the combined photometric data on Don Quixote reveals a diameter of 18.4 (-0.4/+0.3) km and an albedo of 0.03 (-0.01/+0.02), which confirms Don Quixote to be the third-largest known NEO. We derive an upper limit on the dust production rate of 1.9 kg s^-1 and derive a CO2 gas production rate of (1.1+-0.1)10^26 molecules s^-1. Spitzer IRS spectroscopic observations indicate the presence of fine-grained silicates, perhaps pyroxene rich, on the surface of Don Quixote. Our discovery suggests that CO2 can be present in near-Earth space over a long time. The presence of CO2 might also explain that Don Quixote's cometary nature remained hidden for nearly three decades.Comment: 40 pages, 8 figures, accepted by Ap

FLAVIIR, An innovative university/industry research program for collaborative research and demonstration of UAV technologies

A major research programme into advanced technologies for Uninhabited Airborne Vehicles (UAVs) in June 2004. The £6.5M, five-year project represents a major investment in aerospace technology for BAE SYSTEMS and their partner, the Engineering and Physical Sciences Research Council (EPSRC). The focus of “FLAVIIR” is to develop technologies which support low cost (to acquire and operate) UAVs, together with the broader goal of improving the exploitation and hence impact of the research work completed through closer management of the research team. The project involves ten universities working together at two levels: inter-university collaboration within disciplines and interdisciplinary collaboration both within and across university boundaries. This aspect makes the project particularly challenging for Cranfield, as it is managing the complete project (with BAE Systems) and is to deliver the benefits of these joint activities. This work leads to the integration of the technologies into a sophisticated flying demonstrator UAV which is scheduled to fly in 2009. A particularly challenging requirement is that the vehicle should demonstrate an entire flight cycle, without the use of conventional flap-type control surfaces. The project now has more than 35 researchers working in subject areas ranging from novel aerodynamic techniques to develop control forces, novel flight control systems, to hybrid laser techniques to ‘write’ sensors and actuators directly onto carbon composite structures. The paper gives a description of the new technologies being developed, their integration into a number of demonstrations and the plans for their culmination in the Demon flying demonstrator vehicle, which will be based on the Eclipse Vehicle. The paper will also discuss the equally important issues of integrating, a multi-university/Industry research team

Massive Young Stellar Objects in the Galactic Center. I. Spectroscopic Identification from Spitzer/IRS Observations

We present results from our spectroscopic study, using the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope, designed to identify massive young stellar objects (YSOs) in the Galactic Center (GC). Our sample of 107 YSO candidates was selected based on IRAC colors from the high spatial resolution, high sensitivity Spitzer/IRAC images in the Central Molecular Zone (CMZ), which spans the central ~300 pc region of the Milky Way Galaxy. We obtained IRS spectra over 5um to 35um using both high- and low-resolution IRS modules. We spectroscopically identify massive YSOs by the presence of a 15.4um shoulder on the absorption profile of 15um CO2 ice, suggestive of CO2 ice mixed with CH3OH ice on grains. This 15.4um shoulder is clearly observed in 16 sources and possibly observed in an additional 19 sources. We show that 9 massive YSOs also reveal molecular gas-phase absorption from CO2, C2H2, and/or HCN, which traces warm and dense gas in YSOs. Our results provide the first spectroscopic census of the massive YSO population in the GC. We fit YSO models to the observed spectral energy distributions and find YSO masses of 8 - 23 Msun, which generally agree with the masses derived from observed radio continuum emission. We find that about 50% of photometrically identified YSOs are confirmed with our spectroscopic study. This implies a preliminary star formation rate of ~0.07 Msun/yr at the GC.Comment: Accepted for publication in Ap

Infrared Lightcurves of Near Earth Objects

We present lightcurves and derive periods and amplitudes for a subset of 38 near earth objects (NEOs) observed at 4.5 microns with the IRAC camera on the the Spitzer Space Telescope, many of them having no previously reported rotation periods. This subset was chosen from about 1800 IRAC NEO observations as having obvious periodicity and significant amplitude. For objects where the period observed did not sample the full rotational period, we derived lower limits to these parameters based on sinusoidal fits. Lightcurve durations ranged from 42 to 544 minutes, with derived periods from 16 to 400 minutes. We discuss the effects of lightcurve variations on the thermal modeling used to derive diameters and albedos from Spitzer photometry. We find that both diameters and albedos derived from the lightcurve maxima and minima agree with our previously published results, even for extreme objects, showing the conservative nature of the thermal model uncertainties. We also evaluate the NEO rotation rates, sizes, and their cohesive strengths.Comment: 16 pages, 4 figures, 3 tables, to appear in the Astrophysical Journal Supplement Serie