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Search Results: 1 - 10 of 1718 matches for " Jeff Schieder "
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Longitudinal impact of a youth tobacco education program
Martin C Mahoney, Joseph E Bauer, Laurene Tumiel, Sarah McMullen, Jeff Schieder, Denise Pikuzinski
BMC Family Practice , 2002, DOI: 10.1186/1471-2296-3-3
Abstract: Twenty-eight schools, which were in relatively close geographic proximity, were randomized into three groups; Group 1 was used to assess whether attitudes/knowledge were changed in the hypothesized direction by the intervention, and if those changes were retained four months later. Groups 2 and 3, were used as comparison groups to assess possible test-retest bias and historical effects. Groups 1 and 3 were pooled to assess whether attitudes/knowledge were changed by the intervention as measured by an immediate post-test. The non-parametric analytical techniques of Wilcoxon-Matched Pairs/Sign Ranks and the Mann-Whitney-Wilcoxon Rank Sums Tests were used to compare proportions of correct responses at each of the schools.Pooled analyses showed that short-term retention on most items was achieved. It was also found that retention on two knowledge items 'recognition that smokers have yellow teeth and fingers' and 'smoking one pack of cigarettes a day costs several hundred dollars per year' was maintained for four months.The findings suggest that inexpensive, one-time interventions for tobacco-use prevention can be of value. Changes in attitudes and knowledge conducive to the goal of tobacco-use prevention can be achieved for short-term retention and some relevant knowledge items can be retained for several months.Given the epidemiology of smoking initiation, a great deal of public health policy and programmatic attention has been directed at youth smoking in the United States [1]. Approximately 80% of tobacco users initiate use before 18 years of age, and if this trend in early initiation of cigarette smoking continues, estimates are that 5 million children aged less than 18 years who are alive today will die prematurely as adults [2].In an effort to discourage initiation of tobacco use, several youth tobacco education programs have been created and are currently available for presentation to elementary school students. Many of these approaches are school-based programs,
Geisteswissenschaften - und kein Ende?
Schieder, Wolfgang
Zeitenblicke , 2009,
Abstract:
Perché sono diventato uno storico sociale
Wolfgang Schieder
Scienza & Politica : per una Storia delle Dottrine , 1996, DOI: 10.6092/issn.1825-9618/2926
Abstract: Perché sono diventato uno storico sociale
The Harder-Narasimhan stratification of the moduli stack of G-bundles via Drinfeld's compactifications
Simon Schieder
Mathematics , 2012,
Abstract: We use Drinfeld's relative compactifications and the Tannakian viewpoint on principal bundles to construct the Harder-Narasimhan stratification of the moduli stack Bun_G of G-bundles on an algebraic curve in arbitrary characteristic, generalizing the stratification for G=GL_n due to Harder and Narasimhan to the case of an arbitrary reductive group G. To establish the stratification on the set-theoretic level, we exploit a Tannakian interpretation of the Bruhat decomposition and give a new and purely geometric proof of the existence and uniqueness of the canonical reduction in arbitrary characteristic. We furthermore provide a Tannakian interpretation of the canonical reduction in characteristic 0 which allows to study its behavior in families. The substack structures on the strata are defined directly in terms of Drinfeld's compactifications, which we generalize to the case where the derived group of G is not necessarily simply connected. We furthermore use Drinfeld's compactifications to establish various properties of the stratification, including finer information about the structure of the individual strata and a simple description of the strata closures.
The Drinfeld-Lafforgue-Vinberg degeneration I: Picard-Lefschetz oscillators
Simon Schieder
Mathematics , 2014,
Abstract: We study the singularities of the Drinfeld-Lafforgue-Vinberg compactification of the moduli stack of G-bundles on a smooth projective curve for a reductive group G. The study of these compactifications was initiated by V. Drinfeld (for G=GL_2) and continued by L. Lafforgue (for G=GL_n) in their work on the Langlands correspondence for function fields. A definition of the compactification for a general reductive group G is also due to Drinfeld and relies on the Vinberg semigroup of G; this case will be dealt with in [Sch]. In the present paper we focus on the case G=SL_2. In this case the compactification can alternatively be viewed as a canonical one-parameter degeneration of the moduli space of SL_2-bundles. We study the singularities of this one-parameter degeneration via the weight-monodromy theory of the associated nearby cycles construction: We give an explicit description of the nearby cycles sheaf together with its monodromy action in terms of certain novel perverse sheaves which we call "Picard-Lefschetz oscillators", and then use this description to determine the intersection cohomology sheaf. Our proofs rely on the construction of certain local models for the one-parameter degeneration which themselves form one-parameter families of spaces which are factorizable in the sense of Beilinson and Drinfeld. We also include an application on the level of functions.
Optimization of radio astronomical observations using Allan variance measurements
R. Schieder,C. Kramer
Physics , 2001, DOI: 10.1051/0004-6361:20010611
Abstract: Stability tests based on the Allan variance method have become a standard procedure for the evaluation of the quality of radio-astronomical instrumentation. They are very simple and simulate the situation when detecting weak signals buried in large noise fluctuations. For the special conditions during observations an outline of the basic properties of the Allan variance is given, and some guidelines how to interpret the results of the measurements are presented. Based on a rather simple mathematical treatment clear rules for observations in ``Position-Switch'', ``Beam-'' or ``Frequency-Switch'', ``On-The-Fly-'' and ``Raster-Mapping'' mode are derived. Also, a simple ``rule of the thumb'' for an estimate of the optimum timing for the observations is found. The analysis leads to a conclusive strategy how to plan radio-astronomical observations. Particularly for air- and space-borne observatories it is very important to determine, how the extremely precious observing time can be used with maximum efficiency. The analysis should help to increase the scientific yield in such cases significantly.
Compactification of a Drinfeld Period Domain over a Finite Field
Richard Pink,Simon Schieder
Mathematics , 2010,
Abstract: We study a certain compactification of the Drinfeld period domain over a finite field which arises naturally in the context of Drinfeld moduli spaces. Its boundary is a disjoint union of period domains of smaller rank, but these are glued together in a way that is dual to how they are glued in the compactification by projective space. This compactification is normal and singular along all boundary strata of codimension $\ge2$. We study its geometry from various angles including the projective coordinate ring with its Hilbert function, the cohomology of twisting sheaves, the dualizing sheaf, and give a modular interpretation for it. We construct a natural desingularization which is smooth projective and whose boundary is a divisor with normal crossings. We also study its quotients by certain finite groups.
Embryological studies of reciprocal crosses between Vicia faba and Vicia narbonensis
Maciej Zenkteler,Mechtild Tegeder,Otto Schieder
Acta Societatis Botanicorum Poloniae , 1998, DOI: 10.5586/asbp.1998.004
Abstract: A study was undertaken to asses the reciprocal crossability between Vicia faba and Vicia narbonensis. Flower buds or only ovaries of several varietes and genotypes were cross-pollinated in vivo (green house and field) and in vitro. Only few pollen tubes passed the style and entered into the ovary. On the whole number of 5320 cross pollinated in vivo and in vitro flowers and ovaries of Vicia narbonensis only 78 globular hybrid embryos were observed. After cross pollination in vivo of 3860 flower buds and ovaries of Vicia faba globular embryos developed in 124 ovules. The highest number of globular embryos were obtained when the Vicia faba line 1/33 was pollinated with Vicia narbonensis lines P3, P5, 150, SE.Embryogenesis proceeded till the 6-10 day after pollination, however, karyological disturbances in the cells of embryos and endosperm were often noticed at earlier stages. In vitro pollen grains of Vicia faba germinated on stigmas and ovaries of Vicia narbonensis, a significant increase in the growth of pollen tubes was noticed after ovary pollination. The technique of in vitro pollination was not suitable for Vicia faba as the inoculated explants died shortly after transferring onto the medium. The results indicate that finding a more suitable genotype for crossing may give a chance to obtain higher number of embryos (example line 1/33) - thus sufficient number for culturing them on media.
Australian Consumer Attitudes and Decision Making on Renewable Energy Technology and Its Impact on the Transformation of the Energy Sector  [PDF]
Jeff Sommerfeld, Laurie Buys
Open Journal of Energy Efficiency (OJEE) , 2014, DOI: 10.4236/ojee.2014.33009
Abstract: This paper critically examines research on consumer attitudes and behavior towards solar photovoltaic (PV) and renewable energy technology in Australia. The uptake of renewable energy technology by residential consumers in Australia in the past decade has transformed the electricity supply and demand paradigm. Thus, this paper reviews Australian research on consumer behavior, understanding and choices in order to identify gaps in knowledge. As the role of the consumer transforms, there is a critical need to understand the ways that consumers may respond to future energy policies to mitigate unforeseen negative social and economic consequence of programs designed to achieve positive environmental outcomes.
Laser-Assisted Generation and Detection of Non-Nuclear Low-Energy Neutrino-Antineutrino Beams  [PDF]
Jeff W. Eerkens
Journal of Modern Physics (JMP) , 2018, DOI: 10.4236/jmp.2018.96077
Abstract: It is argued that conservation of energy, momentum, and spin, and QM transition probabilities, allow the generation and detection of low-energy (eV) neutrinos and antineutrinos in intra-atomic (non-nuclear) laser transitions. Two-quantum transitions between an upper and lower excited state in a lasing medium can support paired emissions of a neutrino and a recoiling counter-propagating anti-neutrino, each carrying half of the lasing transition energy. Their propagations are in opposite directions along the same axis as that of the intracavity laser beam in the lasing medium. Estimates show that the probability of this two-quantum event is on the order of 10−7 compared to a one-quantum stimulated emission of a laser photon. Absorptions or emissions of single antineutrinos or neutrinos by molecular/atomic matter are impossible because they carry spins s = ±h/2 which violates Δs = ±nh (n = integer) required for such processes. However, inside a laser, emissions of photons from excited states can be stimulated by neutrinos or anti-neutrinos passing through, provided their undulation frequency is resonant with the transition frequency. This is because in stimulated emissions, neutrinos or antineutrinos are not absorbed, and spin conservation violation is not an issue. Thus, detection of the passage of a laser-generated antineutrino or neutrino beam through a second “receiver” laser is possible provided that the transition energy in the second laser equals half the transition energy of the laser that emits the antineutrino-neutrino beam to be detected.
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