A Study of Human Adaptability in Antarctica

The metabolic and nutritional conditions in Antarctica were studied in 29 members of the 10th Japanese wintering party (1968-1970), 25-47 years of age. 1. Change in basal metabolism : It has long been known that there is an apparent seasonal variation in basal metabolism of Japanese people ; higher rate in the winter and lower late in the summer. There has hitherto been much argument, and many possible factors such as natural environment, composition of food, mode of living, racial disposition, have come up for discussion. However, little is known about the real mechanism causing this peculiar phenomenon. This report is the experiments carried out by author in hope that a comparative study in a special environmental condition might throw light on this problem. Generally, in Antarctica, the basal metabolism showed the highest value, 40-43 kcal/m^2/h in January-February, then it gradually decreased to 35-38 kcal in the Antarctic fall. Then it tended to rise again to 39.42 kcal in August and September. In the Antarctic winter, June and July, there is little daylight and little chance to go out, and basal metabolism drops to the lowest level of the year. As described above, the characteristic feature of basal metabolism in Japanese, the apparent seasonal variation, was not affected by the Antarctic environmental and living conditions. However, the values for basal metabolism in Antarctica are higher in every age than the standard values in Japan, as recorded by the Ministry of Health and Welfare. 2. As to the behavioral pattern and activity level of wintering members in Antarctica, several studies have been reported. The author tried to show physical activity level of the subjects by counting daily step using a stepmeter (pedometer). On the average, in the Antarctic summer, December and January, the step count is 15,000, the largest count of the year. It drops to the lowest level, 6,000 steps, in the antarctic midwinter, June and July. These changes seem to have a close relation to the changes in length of daylight. The correlation coefficient between step count and ambient temperature was 0.53, and that between step count and daylight length was 0.64. 3. Food intake: In general, the metabolic balance was always positive throughout the year in Antarctica, resulting in the weight-increase of most wintering members during their stay in Antarctica. Skinfold thickness in the upper arm and around the navel increased in parallel with body weight. 4. Comparing the sleeping pattern of the summer with that of the winter, there was no conspicuous feature in the former, but a symptom of intermittent sleep and a tendency of nocturnal habits were observed. 5. Considering monthly the change of physical rhythm per day, there was only narrow margin of variation and the night-and-day rhythm was absent in midwinter period

Discovery of the first methanol (CH3OH) maser in the Andromeda galaxy (M31)

We present the first detection of a 6.7 GHz Class II methanol (CH3OH) maser in the Andromeda galaxy (M31). The CH3OH maser was found in a Very Large Array (VLA) survey during the fall of 2009. We have confirmed the methanol maser with the new Expanded VLA (EVLA), in operation since March 2010, but were unsuccessful in detecting a water maser at this location. A direct application for this methanol maser is the determination of the proper motion of M31, such as was obtained with water masers in M33 and IC10 previously. Unraveling the three-dimensional velocity of M31 would solve for the biggest unknown in the modeling of the dynamics and evolution of the Local Group of galaxies.Comment: Letter, accepted by ApJ

The distance to a star forming region in the Outer arm of the Galaxy

We performed astrometric observations with the VLBA of WB89-437, an H2O maser source in the Outer spiral arm of the Galaxy. We measure an annual parallax of 0.167 +/- 0.006 mas, corresponding to a heliocentric distance of 6.0 +/- 0.2 kpc or a Galactocentric distance of 13.4 +/- 0.2 kpc. This value for the heliocentric distance is considerably smaller than the kinematic distance of 8.6 kpc. This confirms the presence of a faint Outer arm toward l = 135 degrees. We also measured the full space motion of the object and find a large peculiar motion of ~20 km/s toward the Galactic center. This peculiar motion explains the large error in the kinematic distance estimate. We also find that WB89-437 has the same rotation speed as the LSR, providing more evidence for a flat rotation curve and thus the presence of dark matter in the outer Galaxy.Comment: The Astrophysical Journal, accepted, 16 pages, 4 Figure

Distance of W3(OH) by VLBI annual parallax measurement

The most powerful tool for measuring distances within our Galaxy is the annual parallax. We carried out phase-referencing VLBI observations of H$_{2}$O masers in the star forming region W3(OH) with respect to the extragalactic continuum source ICRF 0244+624 to measure their absolute proper motions. The measured annual parallax is 0.484 $\pm$ 0.004 milli-arcseconds which corresponds to a distance of 2.07^{+0.01}_{-0.02}$ kpc from the sun. This distance is consistent with photometric and kinematic distances from previous observations.Comment: Proceedings of the 7th European VLBI Network Symposium (October 12-15 2004, Toledo, Spain), eds. Bachiller, R., Colomer, F., Desmurs, J. F., & de Vicente, P., 4 pages, 4 figures, needs evn2004.cl

Directional Dipole Model for Subsurface Scattering

Rendering translucent materials using Monte Carlo ray tracing is computationally expensive due to a large number of subsurface scattering events. Faster approaches are based on analytical models derived from diffusion theory. While such analytical models are efficient, they miss out on some translucency effects in the rendered result. We present an improved analytical model for subsurface scattering that captures translucency effects present in the reference solutions but remaining absent with existing models. The key difference is that our model is based on ray source diffusion, rather than point source diffusion. A ray source corresponds better to the light that refracts through the surface of a translucent material. Using this ray source, we are able to take the direction of the incident light ray and the direction toward the point of emergence into account. We use a dipole construction similar to that of the standard dipole model, but we now have positive and negative ray sources with a mirrored pair of directions. Our model is as computationally efficient as existing models while it includes single scattering without relying on a separate Monte Carlo simulation, and the rendered images are significantly closer to the references. Unlike some previous work, our model is fully analytic and requires no precomputation.</jats:p

Structure and Composition of Molecular Clouds with CN Zeeman Detections I: W3OH

We have carried out a multi-species study of a region which has had previous measurements of strong magnetic fields through the CN Zeeman effect in order to to explore the relationship between CN and N$_2$H$^+$, both of which have evidence that they remain in the gas phase at densities of 10$^5$ - 10$^6$ cm$^{-3}$. To achieve this we map the 1 arcmin$^2$ region around the UCHII region of W3(OH) using the Combined Array for Millimeter-wave Astronomy (CARMA). Approximately 105 hours of data were collected in multiple array configurations to produce maps with an effective resolution of $\sim$ 2.5\arcsec at high signal-to-noise in CN, C$^{18}$O, HCN, HCO$^+$, N$_2$H$^+$, and two continuum bands (91.2 GHz and 112 GHz). These data allow us to compare tracer molecules associated with both low and high density regions to infer gas properties. We determine that CARMA resolves out approximately 35% of the CN emission around W3(OH) when compared with spectra obtained from the IRAM-30 meter telescope. The presence of strong absorption lines towards the continuum source in three of the molecular transitions infers the presence of a cold, dark, optically thick region in front of the continuum source. In addition, the presence of high-velocity emission lines near the continuum source shows the presence of hot clumpy emission behind the continuum source. These data determine that future high-resolution interferometric CN Zeeman measurements which cannot currently be performed (due to technical limitations of current telescopes) are feasible. We confirm that CN is indeed a good tracer for high density regions; with certain objects such as W3(OH) it appears to be a more accurate tracer than N$_2$H$^+$.Comment: 33 pages, 16 figures. Accepted by Ap