Quantum spectrum as a time series : Fluctuation measures

The fluctuations in the quantum spectrum could be treated like a time series. In this framework, we explore the statistical self-similarity in the quantum spectrum using the detrended fluctuation analysis (DFA) and random matrix theory (RMT). We calculate the Hausdorff measure for the spectra of atoms and Gaussian ensembles and study their self-affine properties. We show that DFA is equivalent to $\Delta_3$ statistics of RMT, unifying two different approaches.We exploit this connection to obtain theoretical estimates for the Hausdorff measure.Comment: 4+ pages. 2 figure

Subharmonic Generation in Quantum Systems

We show how the classical-quantum correspondence permits long-lived subharmonic motion in a quantum system driven by a periodic force. Exponentially small deviations from exact subharmonicity are due to coherent tunneling between quantized vortex tubes which surround classical elliptic periodic orbits.Comment: 11 pages + 5 figures (available upon request), Revtex 3.0, NSF-ITP-93-4

Attitudes of couples towards the destination of surplus embryos: results among couples with cryopreserved embryos in Switzerland

BACKGROUND The purpose of this study was to investigate attitudes towards the donation of surplus embryos among couples with cryopreserved embryos/zygotes, and to identify correlates associated with attitudes toward the destinations of surplus embryos/zygotes. METHODS Eleven of 19 Swiss in vitro fertilization (IVF) centers in existence in 2004 participated in the survey. Questionnaires were sent to 888 eligible couples; 458 men (52%) and 468 women (53%) returned them. RESULTS Fifty-two percent of the participants supported the donation of surplus embryos to other couples, but divided opinions on the disclosure of biological parents' identities were identified. About 70% of participants indicated that donations of surplus embryos for medical research or therapy should be allowed, following strict regulations. Multiple logistic regression analyses revealed couples' position on the moral status of an embryo as the strongest predictor of attitudes toward all destinations of surplus embryos. Having children due to IVF/Intra-Cytoplasmic Sperm Injection (ICSI) treatment was negatively associated with attitudes towards donations to other couples. Perceived importance of religion, age >40, being a resident of the French-speaking region and unsuccessful IVF/ICSI treatment experiences were predictive of supporting donations for medical research. CONCLUSIONS Swiss couples with cryopreserved embryos/zygotes are open to different options related to donating, rather than discarding, surplus embryo

Akzeptanz von Futterpflanzen mit Vorkommen von kondensierten Tanninen bei Schafen und ihre Gehalte an nutzbarem Rohprotein

Plants with moderate contents of condensed tannins are assumed to have anthelmintic Plants with moderate contents of condensed tannins are assumed to have anthelmintic properties and to improve protein supply of ruminants by reducing its ruminal degradability. In the present study, birdsfoot trefoil (Lotus corniculatus), chicory (Cychorium intybus) and sainfoin (Onobrychis viciifolia), suitable to be grown in Central Europe, were tested for their suitability as feed for ruminants. Sainfoin proved to be the most promising forage plant since it was very well accepted by the sheep and presented the highest content of utilizable crude protein as determined in vitro. Only few condensed tannins were detected in chicory. Further in vivo studies are required to confirm a better metabolic protein supply of ruminants when fed sainfoin

The Amateur Sky Survey Mark III Project

The Amateur Sky Survey (TASS) is a loose confederation of amateur and professional astronomers. We describe the design and construction of our Mark III system, a set of wide-field drift-scan CCD cameras which monitor the celestial equator down to thirteenth magnitude in several passbands. We explain the methods by which images are gathered, processed, and reduced into lists of stellar positions and magnitudes. Over the period October, 1996, to November, 1998, we compiled a large database of photometric measurements. One of our results is the "tenxcat" catalog, which contains measurements on the standard Johnson-Cousins system for 367,241 stars; it contains links to the light curves of these stars as well.Comment: 20 pages, including 4 figures; additional JPEG files for Figures 1, 2. Submitted to PAS

Seasonal Associations between Weather Conditions and Suicide—Evidence against a Classic Hypothesis

Psychiatrists, epidemiologists, and sociologists have debated the existence of an association between weather conditions and suicide seasonality since the preliminary statistical investigations in the 19th century. Provided that the effect of weather conditions on suicide operates via a dose-response-like mechanism, time-series (Box-Jenkins) analysis permits an indirect test of the hypothesis that temperature or other weather variables promote higher suicide frequencies in late spring and early summer months. The authors modeled monthly data on suicide and climatic conditions (i.e., temperature, sunshine, and precipitation data) in Switzerland. Cross-correlations between the filtered (prewhitened) residual series were calculated for the period 1881-2000, for consecutive 30-year periods, for different suicide methods, and—with regard to the seasonality hypothesis—for series relying on moving 1- and 3-month frames. Positive cross-correlations emerged between suicide and temperature data for the whole time series, as well as in all consecutive 30-year periods. However, cross-correlations of data series based on moving frames showed a minor peak in associations for summer frames and a major peak in associations for winter frames, the latter reflecting suicides performed mainly outdoors (being run over by a train and jumping from high places). The results represent a novel minor effect in seasonality of suicide, which is hardly compatible with the hypothesized role of temperature in suicide seasonalit

Quantization of Hyperbolic N-Sphere Scattering Systems in Three Dimensions

Most discussions of chaotic scattering systems are devoted to two-dimensional systems. It is of considerable interest to extend these studies to the, in general, more realistic case of three dimensions. In this context, it is conceptually important to investigate the quality of semiclassical methods as a function of the dimensionality. As a model system, we choose various three dimensional generalizations of the famous three disk problem which played a central role in the study of chaotic scattering in two dimensions. We present a quantum-mechanical treatment of the hyperbolic scattering of a point particle off a finite number of non-overlapping and non-touching hard spheres in three dimensions. We derive expressions for the scattering matrix S and its determinant. The determinant of S decomposes into two parts, the first one contains the product of the determinants of the individual one-sphere S-matrices and the second one is given by a ratio involving the determinants of a characteristic KKR-type matrix and its conjugate. We justify our approach by showing that all formal manipulations in these derivations are correct and that all the determinants involved which are of infinite dimension exist. Moreover, for all complex wave numbers, we conjecture a direct link between the quantum-mechanical and semiclassical descriptions: The semiclassical limit of the cumulant expansion of the KKR-type matrix is given by the Gutzwiller-Voros zeta function plus diffractional corrections in the curvature expansion. This connection is direct since it is not based on any kind of subtraction scheme involving bounded reference systems. We present numerically computed resonances and compare them with the corresponding data for the similar two-dimensional N-disk systems and with semiclassical calculations.Comment: 35 pages, LaTeX plus 8 Postscript figures, uses epsf.sty, epsfig.sty and epsf.te