Internal spin structure of the proton from high energy polarized e-p scattering

A review is given of experimental knowledge of the spin dependent structure functions of the proton, which is based on inclusive high energy scattering of longitudinal polarized electrons by longitudinally polarized protons in both the deep inelastic and resonance regions, and includes preliminary results from our most recent SLAC experiment. Implications for scaling, sum rules, models of proton structure, and the hyperfine structure interval in hydrogen are given. Possible future directions of research are indicated

Weak Lensing from Space I: Instrumentation and Survey Strategy

A wide field space-based imaging telescope is necessary to fully exploit the technique of observing dark matter via weak gravitational lensing. This first paper in a three part series outlines the survey strategies and relevant instrumental parameters for such a mission. As a concrete example of hardware design, we consider the proposed Supernova/Acceleration Probe (SNAP). Using SNAP engineering models, we quantify the major contributions to this telescope's Point Spread Function (PSF). These PSF contributions are relevant to any similar wide field space telescope. We further show that the PSF of SNAP or a similar telescope will be smaller than current ground-based PSFs, and more isotropic and stable over time than the PSF of the Hubble Space Telescope. We outline survey strategies for two different regimes - a ``wide'' 300 square degree survey and a ``deep'' 15 square degree survey that will accomplish various weak lensing goals including statistical studies and dark matter mapping.Comment: 25 pages, 8 figures, 1 table, replaced with Published Versio

Comparison of telemetry and pellet-group counts for determining habitat selectivity by roe deer (Capreolus capreolus) in winter

In two forest of Sweden, has been compared winter habitat use by roe deer with habitat availability from two kinds of data (telemetry and pellet group counts). No correlation was found between comparison from two techniques except for the strongly avoided habitat types. Improvement of the methods are discusssed / Dans deux habitats forestiers de Suède, a été comparée l'utilisation hivernale de l'habitat par le chevreuil à partir de 2 méthodes : le radiopistage et le comptage des fumées. Les résultats obtenus à partir de ces approches ne montrent aucune corrélation, à l'exception des habitats profondement évités. Une discussion est amorcée sur l'absence de convergence de résultats des 2 méthodes, une amélioration des méthodes utilisées est proposée

Structure and stability of small titanium/oxygen clusters studied by ab initio quantum chemical calculations

Ab initio calcns. have been performed on TinO2n-δ clusters, with n = 1-3 and δ = 0, 1, as well as on some of their ionized species. The geometries of the different clusters were optimized and vibrational analyses were performed at the ground-state equil. geometries. The Ti-O bond lengths are essentially detd. by the coordination nos. of the resp. atoms, independent of n. The clusters are characterized by having any low pendant oxygen vibrational frequencies. The ionization energies for the (TiO2)n clusters were significantly higher than those of oxygen-deficient, TinO2n-1, clusters. Some anomalous features of the n = 1 cluster, TiO2, as compared to clusters with n > 1, are discussed. Recent exptl. mass spectrometric observations on titanium oxide clusters are discussed in the light of the present findings

Agonist-like activity of antibodies to angiotensin II receptor subtype 1 (AT1) from rats immunized with AT1 receptor peptide

In the present study, rats were immunized with angiotensin II receptor subtype 1 (AT1) receptor peptides for 3 months to see if the immunization produced specific anti-AT1 receptor antibodies and if continuous stimulation for 3 months affected blood pressure or induced morphological changes in the organs containing AT1 receptors. Our results showed that there were constant high levels of circulating antibodies throughout the study period in all rats of the immunized group, but not in the control rats, and that there were almost no significant cross-reactions of antisera with AT2 receptor peptide and alpha1 adrenoceptor peptide, except in four rats, which showed low cross-reactions with alpha1 adrenoceptor and AT2 receptor peptides. When an affinity-purified anti-AT1 receptor antibody was used, it specifically displayed the AT1-stimulatory positive chronotropic effect and also localized AT1 receptors. However, in the immunized group, saturation binding of AT1 in homogenates from kidneys showed no difference either in maximal binding sites (Bmax) or in antagonist affinity (Kd). No difference in mRNA of AT1a was found in either kidney or heart, and no morphological changes in the organs were observed, as compared with the control group. Furthermore, immunization did not cause hypertension. In conclusion, the synthetic peptide corresponding to the second extra-cellular loop of the human AT1 receptor was able to produce highly specific and functionally active anti-AT1 receptor antibodies, but unable to induce pathological structural changes or hypertension