Hands-On Universe: A Global Program for Education and Public Outreach in Astronomy

Hands-On Universe (HOU) is an educational program that enables students to investigate the Universe while applying tools and concepts from science, math, and technology. Using the Internet, HOU participants around the world request observations from an automated telescope, download images from a large image archive, and analyze them with the aid of user-friendly image processing software. This program is developing now in many countries, including the USA, France, Germany, Sweden, Japan, Australia, and others. A network of telescopes has been established among these countries, many of them remotely operated, as shown in the accompanying demo. Using this feature, students in the classroom are able to make night observations during the day, using a telescope placed in another country. An archive of images taken on large telescopes is also accessible, as well as resources for teachers. Students are also dealing with real research projects, e.g. the search for asteroids, which resulted in the discovery of a Kuiper Belt object by high-school students. Not only Hands-On Universe gives the general public an access to professional astronomy, but it is also a more general tool to demonstrate the use of a complex automated system, the techniques of data processing and automation. Last but not least, through the use of telescopes located in many countries over the globe, a form of powerful and genuine cooperation between teachers and children from various countries is promoted, with a clear educational goal.Comment: 4 pages, 1 figure, to appear in the proceedings of the ADASS X conference, Boston, October 2000, ASP conf. pro

Line Arrester Application on a 110 kV High Alpine Overhead Line to reduce Lightning-Caused Outages

This contribution discusses a project, which aims to increase the reliability in an existing 110 kV overhead transmission network by taking measures addressing lightning and grounding issues. Due to the fault statistic in the past, a single overhead line was identified as a main reason for the lightning-caused outages in the area. In this work a number of possibilities for the reduction of lightning-caused outages are discussed and the measures taken in the network are described. All considerations took the special geographical situation of 2300 meter above sea level, the grounding resistance of up to 1200 Ohm and the local lightning activity of more than 6 lightning strikes per km² and year into account (4 to 5 times higher than in other Austrian regions). An analytical process was carried out to evaluate relevant parameters and to develop a concept of practical measures. Within these evaluations, the footing resistance, the effectiveness of the shielding angle of the shielding wires and the line arrester locations were analyzed. A multiplicity of numerical calculations were performed to assess the application of surge arresters regarding the insulation coordination for the system. To improve the line performance and to decrease the line outage rate, a number of practical measures were applied to the 110 kV line. In the past, the double three phase systems of the 110 kV overhead line was constructional converted into one active single three phase system with two additional earth wires. According to the numerical results, 18 surge arresters have been installed in a line section of 9 towers, located in a high alpine part and in an area of high lightning activity. Three years of field experiences have shown that the theoretical investigations and the practical measures led to a significant decrease of lightning caused outages. In the year 2007 a new project was started to evaluate a reconstruction of the line into the original double three phase system. New numerical calculation routines were made to apply line arresters at this important 110 kV system in an Austrian extreme mountain region. Based on this results, a new application of line arresters and the constructional change of the system is planned

Petrogenesis of rift-related tephrites, phonolites and trachytes (Central European Volcanic Province, Rhön, FRG): Constraints from Sr, Nd, Pb and O isotopes

Highlights: • Some differentiated alkaline rocks may evolve by FC or AFC but not both • Analyses of acid-leached samples necessary to detect unsupported 87Sr • Crustal contamination hardly detectable in high-Sr lavas but obvious in low-Sr lavas • Deep crustal contamination confirmed by high-precision Pb double-spike data • Positively correlated 87Sr/86Sr ratios - δ18O values also indicate crustal contamination The volcanic rocks of the Rhön area (Central European Volcanic Province, Germany) belong to a moderately alkali basaltic suite that is associated with minor tephriphonolites, phonotephrites, tephrites, phonolites and trachytes. Based on isotope sytematics (87Sr/86Sr: 0.7033-0.7042; 143Nd/144Nd: 0.51279-0.51287; 206Pb/204Pb: 19.1-19.5), the inferred parental magmas formed by variable degrees of partial melting of a common asthenospheric mantle source (EAR: European Asthenospheric Reservoir of Cebria and Wilson, 1995). Tephrites, tephriphonolites, phonotephrites, phonolites and trachytes show depletions and enrichments in some trace elements (Sr, Ba, Nb, Zr, Y) indicating that they were generated by broadly similar differentiation processes that were dominated by fractionation of olivine, clinopyroxene, amphibole, apatite and titaniferous magnetite ± plagioclase ± alkalifeldspar. The fractionated samples seem to have evolved by two distinct processes. One is characterized by pure fractional crystallization indicated by increasing Nb (and other incompatible trace element) concentrations at virtually constant 143Nd/144Nd ~ 0.51280 and 87Sr/86Sr ~ 0.7035. The other process involved an assimilation-fractional crystallization process (AFC) where moderate assimilation to crystallization rates produced evolved magmas characterized by higher Nb concentrations at slightly lower 143Nd/144Nd down to 0.51275. Literature data for some of the evolved rocks show more variable 87Sr/86Sr ranging from 0.7037-0.7089 at constant 143Nd/144Nd ~ 0.51280. These features may result from assimilation of upper crustal rocks by highly differentiated low-Sr (< 100 ppm Sr) lavas. However, based on the displacement of the differentiated rocks from this study towards lower 143Nd/144Nd ratios and modeled AFC processes in 143Nd/144Nd vs. 87Sr/86Sr and 207Pb/204Pb vs. 143Nd/144Nd space assimilation of lower crustal rocks seems more likely. The view that assimilation of lower crustal rocks played a role is confirmed by high-precision double-spike Pb isotope data that reveal higher 207Pb/204Pb ratios (15.62-15.63) in the differentiated rocks than in the primitive basanites (15.58-15.61). This is compatible with incorporation of radiogenic Pb from lower crustal xenoliths (207Pb/204Pb: 15.63-15.69) into the melt. However, 206Pb/204Pb ratios are similar for the differentiated rocks (19.13-19.35) and the primitive basanites (19.12-19.55) implying that assimilation involved an ancient crustal end member with a higher U/Pb ratio than the mantle source of the basanites. In addition, alteration-corrected δ18O values of the differentiated rocks range from c. 5 to 7 ‰ which is the same range as observed in the primitive alkaline rocks. This study confirms previous interpretations that highlighted the role of AFC processes in the evolution of alkaline volcanic rocks in the Rhön area of the Central European Volcanic Province

The role of executive function in bridging the intention-behaviour gap for binge-drinking in university students

Background: Alcohol consumption contributes to a significant proportion of disease and the high prevalence amongst young adults is a worldwide health concern. Purpose: To determine which aspects of executive function (EF) distinguish binge-drinkers from non binge-drinkers and to establish the role of EF in predicting behaviour. Methods: Self-report questionnaires, four tests of self-regulation and a behaviour measure were administered to 153 students. Results: The Theory of Planned Behaviour model was significant in predicting both intentions and behaviour. Although binge-drinkers and non binge-drinkers were found to differ on three of the four measures of EF,none predicted additional variance in behaviour. Planning ability and inhibition control moderated the relationship between intention and behaviour such that for individuals who intended to binge-drink, those with high planning ability or high inhibitory control were more likely to avoid doing so.Conclusions: Interventions targeting binge-drinking behaviour should aim to develop planning skills and inhibitory control

When the Diagnosis is a Victim of the Circumstances

Introduction: Haemoptysis is a common symptom which can sometimes mimic gastrointestinal bleeding. Case description: We describe the case of a 31-year-old man who presented to the emergency department after an episode of sudden nausea and presumed massive haematemesis. The situation was interpreted as gastrointestinal bleeding but clinical evolution and greater attention to the anamnesis resulted in a diagnosis of pulmonary tuberculosis and the provision of appropriate care. Discussion: This report emphasizes the difficulty of differentiating between haemoptysis and haematemesis and the importance of a careful anamnesis and attention to all clinical circumstances for an accurate diagnosis. Learning points: Haematemesis and haemoptysis are not always distinguished from each other when a patient's history is being collected.Despite being a rare manifestation of tuberculosis, in the correct epidemiological context, haemoptysis should raise the suspicion of pulmonary tuberculosis.The clinical setting and the need for immediate care should not limit clinical investigation or the differential diagnosis.info:eu-repo/semantics/publishedVersio

Aging is associated with an earlier arrival of reflected waves without a distal shift in reflection sites

Background-Despite pronounced increases in central pulse wave velocity (PWV) with aging, reflected wave transit time (RWTT), traditionally defined as the timing of the inflection point (T-INF) in the central pressure waveform, does not appreciably decrease, leading to the controversial proposition of a "distal-shift" of reflection sites. T-INF, however, is exceptionally prone to measurement error and is also affected by ejection pattern and not only by wave reflection. We assessed whether RWTT, assessed by advanced pressure-flow analysis, demonstrates the expected decline with aging. Methods and Results-We studied a sample of unselected adults without cardiovascular disease (n=48; median age 48 years) and a clinical population of older adults with suspected/established cardiovascular disease (n=164; 61 years). We measured central pressure and flow with carotid tonometry and phase-contrast MRI, respectively. We assessed RWTT using wave-separation analysis (RWTTWSA) and partially distributed tube-load (TL) modeling (RWTTTL). Consistent with previous reports, T-INF did not appreciably decrease with age despite pronounced increases in PWV in both populations. However, aging was associated with pronounced decreases in RWTTWSA (general population -15.0 ms/decade, P<0.001; clinical population -9.07 ms/decade, P=0.003) and RWTTTL (general -15.8 ms/decade, P<0.001; clinical -11.8 ms/decade, P<0.001). There was no evidence of an increased effective reflecting distance by either method. TINF was shown to reliably represent RWTT only under highly unrealistic assumptions about input impedance. Conclusions-RWTT declines with age in parallel with increased PWV, with earlier effects of wave reflections and without a distal shift in reflecting sites. These findings have important implications for our understanding of the role of wave reflections with aging

Learning probabilistic relational planning rules

To learn to behave in highly complex domains, agents must represent and learn compact models of the world dynamics. In this paper, we present an algorithm for learning probabilistic STRIPS-like planning operators from examples. We demonstrate the effective learning of rule-based operators for a wide range of traditional planning domains