Keck Spectroscopy of Two Young Globular Clusters in the Merger Remnant NGC 3921

Low-resolution UV-to-visual spectra of two candidate globular clusters in the merger remnant NGC 3921 are presented. These two clusters of apparent magnitude V = 22.2 (Mv = -12.5) lie at projected distances of ~5 kpc from the center and move with halo-type radial velocities relative to the local galaxy background. Their spectra show strong Balmer absorption lines indicative of main-sequence turnoffs dominated by A-type stars. Comparisons with model-cluster spectra computed by Bruzual & Charlot and others yield cluster ages in the range of 200-530 Myr, and metallicities about solar to within a factor of three. Given their small half-light radii (Reff < 5 pc) and ages corresponding to ~100 core- crossing times, these clusters are gravitationally bound and, hence, indeed young globulars. Assuming that they had Chabrier-type initial mass functions, their estimated current masses are 2.3(+-0.1)x10^6 Msun and 1.5(+-0.1)x10^6 Msun, respectively, or roughly half the mass of omegaCen. Since NGC 3921 itself shows many signs of being a 0.7(+-0.3) Gyr old protoelliptical, these two young globulars of roughly solar metallicity and their many counterparts observed with the Hubble Space Telescope provide supporting evidence that, in the process of forming elliptical-like remnants, major mergers of gas-rich disks can also increase the number of metal-rich globular clusters. (Abridged)Comment: 22 pages, 6 figures, accepted for publication in AJ, July 200

A high-throughput screening system for barley/powdery mildew interactions based on automated analysis of light micrographs

<p>Abstract</p> <p>Background</p> <p>To find candidate genes that potentially influence the susceptibility or resistance of crop plants to powdery mildew fungi, an assay system based on transient-induced gene silencing (TIGS) as well as transient over-expression in single epidermal cells of barley has been developed. However, this system relies on quantitative microscopic analysis of the barley/powdery mildew interaction and will only become a high-throughput tool of phenomics upon automation of the most time-consuming steps.</p> <p>Results</p> <p>We have developed a high-throughput screening system based on a motorized microscope which evaluates the specimens fully automatically. A large-scale double-blind verification of the system showed an excellent agreement of manual and automated analysis and proved the system to work dependably. Furthermore, in a series of bombardment experiments an RNAi construct targeting the <it>Mlo </it>gene was included, which is expected to phenocopy resistance mediated by recessive loss-of-function alleles such as <it>mlo5</it>. In most cases, the automated analysis system recorded a shift towards resistance upon RNAi of <it>Mlo</it>, thus providing proof of concept for its usefulness in detecting gene-target effects.</p> <p>Conclusion</p> <p>Besides saving labor and enabling a screening of thousands of candidate genes, this system offers continuous operation of expensive laboratory equipment and provides a less subjective analysis as well as a complete and enduring documentation of the experimental raw data in terms of digital images. In general, it proves the concept of enabling available microscope hardware to handle challenging screening tasks fully automatically.</p

The accumulation of plutonium isotopes (239+240) in the components of the natural environment in the territory of the Karaganda region adjacent to the Semipalatinsk test site

Presents the results of a radiological survey of the territory of the Karaganda region. The data obtained on contamination of isotopes of plutonium (239+240), assessed the impact of nuclear testing on Semipalatinsk testing nuclear polygon. Currently, the pollution of the examined areas of technogenic radionuclides in most places, does not exceed the background level of global fallout, and only at some points noted in the reading background of global fallout. However, there are local areas of contamination, which could be formed as a result of testing of BRV, or other atmospheric fallout from nuclear testing

A high-throughput screening system for barley/powdery mildew interactions based on automated analysis of light micrographs

Background To find candidate genes that potentially influence the susceptibility or resistance of crop plants to powdery mildew fungi, an assay system based on transient-induced gene silencing (TIGS) as well as transient over-expression in single epidermal cells of barley has been developed. However, this system relies on quantitative microscopic analysis of the barley/powdery mildew interaction and will only become a high-throughput tool of phenomics upon automation of the most time-consuming steps. Results We have developed a high-throughput screening system based on a motorized microscope which evaluates the specimens fully automatically. A large-scale double-blind verification of the system showed an excellent agreement of manual and automated analysis and proved the system to work dependably. Furthermore, in a series of bombardment experiments an RNAi construct targeting the Mlo gene was included, which is expected to phenocopy resistance mediated by recessive loss-of-function alleles such as mlo5. In most cases, the automated analysis system recorded a shift towards resistance upon RNAi of Mlo, thus providing proof of concept for its usefulness in detecting gene-target effects. Conclusion Besides saving labor and enabling a screening of thousands of candidate genes, this system offers continuous operation of expensive laboratory equipment and provides a less subjective analysis as well as a complete and enduring documentation of the experimental raw data in terms of digital images. In general, it proves the concept of enabling available microscope hardware to handle challenging screening tasks fully automatically

Ages and Metallicities of Young Globular Clusters in the Merger Remnant NGC 7252

UV-to-visual spectra of eight young star clusters in the merger remnant and protoelliptical galaxy NGC 7252, obtained with the Blanco 4-m telescope on Cerro Tololo, are presented. These clusters lie at projected distances of 3-15 kpc from the center and move with a velocity dispersion of 140+/-35 km/s in the line of sight. Seven of the clusters show strong Balmer absorption lines in their spectra [EW(H-beta)= 6-13 Angstrom], while the eighth lies in a giant HII region and shows no detectable absorption features. Based on comparisons with model-cluster spectra by Bruzual & Charlot (1996) and Bressan, Chiosi, & Tantalo (1996), six of the absorption-line clusters have ages in the range of 400-600 Myr, indicating that they formed early on during the recent merger. These clusters are globular clusters as judged by their small effective radii and ages corresponding to ~100 core crossing times. The one emission-line object is <10 Myr old and may be a nascent globular cluster or an OB association. The mean metallicities measured for three clusters are solar to within +/-0.15 dex, suggesting that the merger of two likely Sc galaxies in NGC 7252 formed a globular-cluster system with a bimodal metallicity distribution. Since NGC 7252 itself shows the characteristics of a 0.5-1 Gyr old protoelliptical, its second-generation solar-metallicity globulars provide direct evidence that giant ellipticals with bimodal globular-cluster systems can form through major mergers of gas-rich disk galaxies.Comment: 34 pages, incl. 6 figures in EPS format, AAS LaTeX, to be published in AJ, Vol. 116, Nov. 199

National physical activity recommendations: systematic overview and analysis of the situation in European countries

BACKGROUND Developing national physical activity (PA) recommendations is an essential element of an effective national approach to promote PA. METHODS Systematic overview and analysis of national PA recommendations across the European Region of the World Health Organization (WHO). The WHO European national information focal points provided information which was complemented through online searches and input from other experts. RESULTS Information received until summer 2012 from 37 countries was analyzed. Sixteen countries did not have national recommendations while 21 countries did. For 17 countries, the source document was accessible. Seventeen recommendations referred to adults, 14 to young people and 6 to older adults. Most national recommendations for children and young people are quite similar: 12 countries recommend at least 60 minutes of moderate- to vigorous-intensity PA each day, in line with the WHO global recommendation. Three countries recommend longer durations and one a lower one. In some countries, slight variations were found regarding the recommended intensity and minimum bouts. Only one country was fully in line with the WHO recommendations. Two countries have issued separate recommendations for pre-school children. For adults, most countries still follow the 1995 United States recommendations of "at least 30 minutes on 5 days a week". Three countries were fully in line with the WHO recommendations. Four countries give specific recommendations on reducing weight, avoiding weight gain or continuing weight maintenance. The six identified national PA recommendations for older adults are mainly similar to those for adults but underline that particularly for this age group also less activity has important health benefits; four countries also recommend balance training. CONCLUSIONS About half of the countries for which information was available and likely less than 40% of all 53 countries in the WHO European Region have developed national PA recommendations. Further investment is needed to address this important step towards a comprehensive PA promotion approach. Much remains to be done for the 2010 WHO recommendations to be fully reflected in national documents across all parts of the Region and all age groups. In addition, avoiding extended periods of inactivity and overweight are only addressed by a minority of countries yet