The Effect of Micro-Gravity on in vitro Calcification

The experiment focuses on mineral deposition or calcification of cartilage. The experiments were used to compare the mineral formed in the microgravity of space with that formed on earth. Results of these experiments were anticipated to provide direct insight into how calcification in cartridge and bone may be controlled in space. In the C-2 experiment (STS 66), we found that mineralization started later in the cartridges (both on the ground and in hypo-gravity) than in plastic, and that mineralization appeared to be retarded in hypo-gravity. The flight experiments also showed that the cells differentiated normally, but more slowly than the ground controls, and that the matrix produced was not different from that made on the ground. The purpose of the C-5 experiment was to confirm these findings. The C-5 experiment was flown on STS-72. Because of a computer problem, cells received no gases and no nutrition. The C-7 was flown on STS-77. Ground controls were repeated a week later, however, because there was a problem with the temperature control during the flight, the concurrent ground controls were performed at a different temperature. Despite these problems, the results of the C-2 experiment were confirmed. The cells in the flight cultures did not mature, formed few cartilage nodules, and showed no evidence of mineral deposition up to a culture age of 28 days. Ground controls showed the presence of mineral (based on chemical, spectroscopic, and histochemical analyses) by 21 days. The mineral in these cultures was analogous to that found in calcifying cartilage of young chicks

Characterization of Bovine Osteoclasts on an Ionomeric Cement In Vitro

Primary bovine osteoclasts were obtained by an outgrowth method from bovine periosteum and cultured for 7 days on an ionomeric cement for biomaterial testing. Osteoclasts cultured on slices of bovine bone and on glass microscope cover-slides served as a control. The cells were characterised as osteoclasts by a number of tests. Osteoclasts showed positive staining for tartrate resistant acid phosphatase and reactivity with the antibodies 13C2 and 23C6, which react with the alphachain of the vitronectin receptor. Addition of salmon calcitonin to the culture medium led to sudden cessation of lamellipodial activity. The cells resorbed bone by making pits. In mixed cultures with osteoblasts, the morphology of the osteoclasts on the smooth ionomeric cement surface was comparable to the one on glass cover-slides, revealing broad cytoplasmatic extensions on the material. Acridine orange staining demonstrated viability of cells until the end of the culture period and increased acidification after parathyroid hormone (PTH) stimulation. Scanning electron microscopy did not reveal erosion of the material by osteoclasts. No signs of aluminium toxicity on osteoclasts could be detected during the 7 day culture period, although an increased uptake of aluminium into the cell was demonstrated

OH far-infrared emission from low- and intermediate-mass protostars surveyed with Herschel-PACS

OH is a key species in the water chemistry of star-forming regions, because its presence is tightly related to the formation and destruction of water. This paper presents OH observations from 23 low- and intermediate-mass young stellar objects obtained with the PACS integral field spectrometer on-board Herschel in the context of the Water In Star-forming Regions with Herschel (WISH) key program. Most low-mass sources have compact OH emission (< 5000 AU scale), whereas the OH lines in most intermediate-mass sources are extended over the whole PACS detector field-of-view (> 20000 AU). The strength of the OH emission is correlated with various source properties such as the bolometric luminosity and the envelope mass, but also with the OI and H2O emission. Rotational diagrams for sources with many OH lines show that the level populations of OH can be approximated by a Boltzmann distribution with an excitation temperature at around 70 K. Radiative transfer models of spherically symmetric envelopes cannot reproduce the OH emission fluxes nor their broad line widths, strongly suggesting an outflow origin. Slab excitation models indicate that the observed excitation temperature can either be reached if the OH molecules are exposed to a strong far-infrared continuum radiation field or if the gas temperature and density are sufficiently high. Using realistic source parameters and radiation fields, it is shown for the case of Ser SMM1 that radiative pumping plays an important role in transitions arising from upper level energies higher than 300 K. The compact emission in the low-mass sources and the required presence of a strong radiation field and/or a high density to excite the OH molecules points towards an origin in shocks in the inner envelope close to the protostar.Comment: Accepted for publication in Astronomy and Astrophysics. Abstract abridge

The Importance of Mammalogy, Infectious Disease Research, and Biosafety in the Field

Large amounts of data and multitudes of publications have been independently generated by researchers in mammalogy and infectious diseases. The frequent confluence of these fields in epidemiological research as well as the facility of the data generated to be used in applied methods (e.g., conservation, public outreach, public health interventions) suggests that the intersection of these fields is important not only to their committed scientists but also to other areas of investigation, including public health. Given the increased frequency with which researchers in these fields interact with potentially infected humans, animals, and tissues, their occupations present a higher risk of exposure to a variety of pathogens than those in other fields of biology or among most jobs of the general public. However, a variety of methods are available for minimizing this risk, including increasing awareness of potential risks, using medical prophylaxes (when available), properly employing personal protective equipment, and using adequate disinfectants. Although instances of serious illness from zoonotic diseases among field researchers may be uncommon, they do occur; the purpose of this document is to increase awareness of risks that researchers—principal investigators and students alike—face and highlight steps and resources that can mitigate those risks

The Importance of Mammalogy, Infectious Disease Research, and Biosafety in the Field

Large amounts of data and multitudes of publications have been independently generated by researchers in mammalogy and infectious diseases. The frequent confluence of these fields in epidemiological research as well as the facility of the data generated to be used in applied methods (e.g., conservation, public outreach, public health interventions) suggests that the intersection of these fields is important not only to their committed scientists but also to other areas of investigation, including public health. Given the increased frequency with which researchers in these fields interact with potentially infected humans, animals, and tissues, their occupations present a higher risk of exposure to a variety of pathogens than those in other fields of biology or among most jobs of the general public. However, a variety of methods are available for minimizing this risk, including increasing awareness of potential risks, using medical prophylaxes (when available), properly employing personal protective equipment, and using adequate disinfectants. Although instances of serious illness from zoonotic diseases among field researchers may be uncommon, they do occur; the purpose of this document is to increase awareness of risks that researchers—principal investigators and students alike—face and highlight steps and resources that can mitigate those risks

Bounding the dimensions of rational cohomology groups

Let $k$ be an algebraically closed field of characteristic $p > 0$, and let $G$ be a simple simply-connected algebraic group over $k$ that is defined and split over the prime field $\mathbb{F}_p$. In this paper we investigate situations where the dimension of a rational cohomology group for $G$ can be bounded by a constant times the dimension of the coefficient module. We then demonstrate how our results can be applied to obtain effective bounds on the first cohomology of the symmetric group. We also show how, for finite Chevalley groups, our methods permit significant improvements over previous estimates for the dimensions of second cohomology groups.Comment: 13 page

TESS Data Release Notes: Sector 17, DR24

This release note discusses the science data products produced by the Science Processing Operations Center at Ames Research Center from Sector 17 observations made with the TESS spacecraft and cameras as a means to document instrument performance and data characteristics

Ma Lady Lu / music by Edwin S. Brill; words by Chas W. Doty

Cover: photo of Greg Patti; description reads a darky love lament; Publisher: Chas B. Ward Music Publishing Co. (New York)https://egrove.olemiss.edu/sharris_a/1063/thumbnail.jp

TESS Data Release Notes: Sector 18 DR25

This release note discusses the science data products produced by the Science Processing Operations Center at Ames Research Center from Sector 18 observations made with the TESS spacecraft and cameras as a means to document instrument performance and data characteristics

TESS Data Release Notes: Sector 20, DR27

This release note discusses the science data products produced by the Science Processing Operations Center at Ames Research Center from Sector 20 observations made with the TESS spacecraft and cameras as a means to document instrument performance and data characteristics