Application of LANDSAT data to delimitation of avalanche hazards in Montane, Colorado

The author has identified the following significant results. Photointerpretation of individual avalanche paths on single band black and white LANDSAT images is greatly hindered by terrain shadows and the low spatial resolution of the LANDSAT system. Maps produced in this way are biased towards the larger avalanche paths that are under the most favorable illumination conditions during imaging; other large avalanche paths, under less favorable illumination, are often not detectable and the smaller paths, even those defined by sharp trimlines, are only rarely identifiable

A Catalog of Background Stars Reddened by Dust in the Taurus Dark Clouds

Normal field stars located behind dense clouds are a valuable resource in interstellar astrophysics, as they provide continua in which to study phenomena such as gas-phase and solid-state absorption features, interstellar extinction and polarization. This paper reports the results of a search for highly reddened stars behind the Taurus Dark Cloud complex. We use the Two Micron All Sky Survey (2MASS) Point Source Catalog to survey a 50 sq deg area of the cloud to a limiting magnitude of K = 10.0. Photometry in the 1.2-2.2 micron passbands from 2MASS is combined with photometry at longer infrared wavelengths (3.6-12 micron) from the Spitzer Space Telescope and the Infrared Astronomical Satellite to provide effective discrimination between reddened field stars and young stellar objects (YSOs) embedded in the cloud. Our final catalog contains 248 confirmed or probable background field stars, together with estimates of their total visual extinctions, which span the range 2-29 mag. We also identify the 2MASS source J04292083+2742074 (IRAS 04262+2735) as a previously unrecognized candidate YSO, based on the presence of infrared emission greatly in excess of that predicted for a normal reddened photosphere at wavelengths >5 microns

Intracranial measurement of current densities induced by transcranial magnetic stimulation in the human brain

Transcranial magnetic stimulation (TMS) is a non-invasive technique that uses the principle of electromagnetic induction to generate currents in the brain via pulsed magnetic fields. The magnitude of such induced currents is unknown. In this study we measured the TMS induced current densities in a patient with implanted depth electrodes for epilepsy monitoring. A maximum current density of 12 microA/cm2 was recorded at a depth of 1 cm from scalp surface with the optimum stimulation orientation used in the experiment and an intensity of 7% of the maximal stimulator output. During TMS we recorded relative current variations under different stimulating coil orientations and at different points in the subject's brain. The results were in accordance with current theoretical models. The induced currents decayed with distance form the coil and varied with alterations in coil orientations. These results provide novel insight into the physical and neurophysiological processes of TMS

Recent Experimental Tests of Special Relativity

We review our recent Michelson-Morley (MM) and Kennedy-Thorndike (KT) experiment, which tests Lorentz invariance in the photon sector, and report first results of our ongoing atomic clock test of Lorentz invariance in the matter sector. The MM-KT experiment compares a cryogenic microwave resonator to a hydrogen maser, and has set the most stringent limit on a number of parameters in alternative theories to special relativity. We also report first results of a test of Lorentz invariance in the SME (Standard Model Extension) matter sector, using Zeeman transitions in a laser cooled Cs atomic fountain clock. We describe the experiment together with the theoretical model and analysis. Recent experimental results are presented and we give a first estimate of components of the $\tilde{c}^p$ parameters of the SME matter sector. A full analysis of systematic effects is still in progress, and will be the subject of a future publication together with our final results. If confirmed, the present limits would correspond to first ever measurements of some $\tilde{c}^p$ components, and improvements by 11 and 14 orders of magnitude on others.Comment: 29 pages. Contribution to Springer Lecture Notes, "Special Relativity - Will it survive the next 100 years ?", Proceedings, Potsdam, 200

Conceptualizing the adventure-sports coach

As a comparatively recent development, the adventure-sports coach struggles for a clear and distinct identity. The generic term ‘instructor’ no longer characterizes the role and function of this subgroup of outdoor professionals. Indeed, although the fields of adventure/outdoor education and leadership are comparatively well researched, the arrival of this ‘new kid on the block’ appears to challenge both the adventure-sports old guard and traditional views of sports coaching. In an attempt to offer clarity and stimulate debate, this paper attempts to conceptualize the adventure-sports coach in the context of the existing roles in the field and current motivations for activity in the outdoors. We identify issues that are specific to the adventure-sports coach while also recognizing those skills and competencies shared with other professionals, both in the adventure sports profession and traditional sports coaching fields. Based on this review, we offer a conceptual model which may be used to focus debate, stimulate research and, at a possible later stage, to underpin accreditation, training and professional development

Construction and Calibration of Optically Efficient LCD-based Multi-Layer Light Field Displays

Near-term commercial multi-view displays currently employ ray-based 3D or 4D light field techniques. Conventional approaches to ray-based display typically include lens arrays or heuristic barrier patterns combined with integral interlaced views on a display screen such as an LCD panel. Recent work has placed an emphasis on the co-design of optics and image formation algorithms to achieve increased frame rates, brighter images, and wider fields-of-view using optimization-in-the-loop and novel arrangements of commodity LCD panels. In this paper we examine the construction and calibration methods of computational, multi-layer LCD light field displays. We present several experimental configurations that are simple to build and can be tuned to sufficient precision to achieve a research quality light field display. We also present an analysis of moiré interference in these displays, and guidelines for diffuser placement and display alignment to reduce the effects of moiré. We describe a technique using the moiré magnifier to fine-tune the alignment of the LCD layers

Rotating Resonator-Oscillator Experiments to Test Lorentz Invariance in Electrodynamics

In this work we outline the two most commonly used test theories (RMS and SME) for testing Local Lorentz Invariance (LLI) of the photon. Then we develop the general framework of applying these test theories to resonator experiments with an emphasis on rotating experiments in the laboratory. We compare the inherent sensitivity factors of common experiments and propose some new configurations. Finally we apply the test theories to the rotating cryogenic experiment at the University of Western Australia, which recently set new limits in both the RMS and SME frameworks [hep-ph/0506074].Comment: Submitted to Lecture Notes in Physics, 36 pages, minor modifications, updated list of reference

Human skeletal muscle feed arteries: evidence of regulatory potential

Aim Recently, it has been recognized that human skeletal muscle feed arteries can be harvested during exploratory surgery for melanoma. This approach provides vessels for in vitro study from a wide spectrum of relatively healthy humans. Although, the regulatory role of skeletal muscle feed arteries in rodent models has been documented, whether such vessels in humans possess this functionality is unknown. Methods Therefore, skeletal muscle feed arteries (~950 μm OD) from 10 humans (48 ± 4, 27–64 years) were studied using pressure myography. Vessel function was assessed using potassium chloride (KCl), phenylephrine (PE), acetylcholine (ACh) and sodium nitroprusside (SNP) concentration–response curves (CRCs) to characterize non-receptor and receptor-mediated vasoconstriction as well as endothelium-dependent and independent vasodilation respectively. To understand the physiological relevance of the diameter changes as a result of pharmacological stimulation, the estimated conductance ratio (CR) was calculated. Results Vessel function protocols revealed significant vasoconstriction in response to PE and KCl (35 ± 6; 43 ± 9%vasoconstriction, respectively) and significant vasodilation with ACh and SNP (85 ± 7; 121 ± 17% vasodilation, respectively). Both PE and KCl significantly reduced the CR (0.26 ± 0.05 and 0.23 ± 0.07, respectively), whereas ACh and SNP increased the CR (2.56 ± 0.10 and 5.32 ± 1.3, respectively). Conclusion These novel findings provide evidence that human skeletal muscle feed arteries are capable of generating significant diameter changes that would translate into significant changes in vascular conductance. Thus, human skeletal muscle feed arteries likely play a significant role in regulating vascular conductance and subsequently blood flow in vivo