Accurate test of chiral dynamics in the γp→π0p reaction.

A precision measurement of the differential cross sections dσ/dΩ and the linearly polarized photon asymmetry Σ≡(dσ⊥-dσ∥)/(dσ⊥+dσ∥) for the γp→π0p reaction in the near-threshold region has been performed with a tagged photon beam and almost 4π detector at the Mainz Microtron. The Glasgow-Mainz photon tagging facility along with the Crystal Ball/TAPS multiphoton detector system and a cryogenic liquid hydrogen target were used. These data allowed for a precise determination of the energy dependence of the real parts of the S- and all three P-wave amplitudes for the first time and provide the most stringent test to date of the predictions of chiral perturbation theory and its energy region of agreement with experiment.

Convection in colloidal suspensions with particle-concentration-dependent viscosity.

The onset of thermal convection in a horizontal layer of a colloidal suspension is investigated in terms of a continuum model for binary-fluid mixtures where the viscosity depends on the local concentration of colloidal particles. With an increasing difference between the viscosity at the warmer and the colder boundary the threshold of convection is reduced in the range of positive values of the separation ratio psi with the onset of stationary convection as well as in the range of negative values of psi with an oscillatory Hopf bifurcation. Additionally the convection rolls are shifted downwards with respect to the center of the horizontal layer for stationary convection psi>0 and upwards for the Hopf bifurcation (psi<0.

Stripe-hexagon competition in forced pattern-forming systems with broken up-down symmetry.

We investigate the response of two-dimensional pattern-forming systems with a broken up-down symmetry, such as chemical reactions, to spatially resonant forcing and propose related experiments. The nonlinear behavior immediately above threshold is analyzed in terms of amplitude equations suggested for a 1:2 and 1:1 ratio between the wavelength of the spatial periodic forcing and the wavelength of the pattern of the respective system. Both sets of coupled amplitude equations are derived by a perturbative method from the Lengyel-Epstein model describing a chemical reaction showing Turing patterns, which gives us the opportunity to relate the generic response scenarios to a specific pattern-forming system. The nonlinear competition between stripe patterns and distorted hexagons is explored and their range of existence, stability, and coexistence is determined. Whereas without modulations hexagonal patterns are always preferred near onset of pattern formation, single-mode solutions (stripes) are favored close to threshold for modulation amplitudes beyond some critical value. Hence distorted hexagons only occur in a finite range of the control parameter and their interval of existence shrinks to zero with increasing values of the modulation amplitude. Furthermore, depending on the modulation amplitude, the transition between stripes and distorted hexagons is either subcritical or supercritical.

Differences in immediacy between traditional and nontraditional students.

Reported differences between 83 traditional and 44 nontraditional college students on immediacy were nonsignificant.

A methodological note on mail survey response rates.

Five mail surveys of broadcast managers during the 1990s yielded consistently low response rates. Implications for research are discussed.

The new topical steroid ciclesonide is effective in the treatment of allergic rhinitis.

A randomized, placebo-controlled, double-blind crossover study was performed to investigate the efficacy of ciclesonide nasal spray in allergic rhinitis at the dose level of 200 micrograms per nostril. Twenty-four subjects (13 males, 11 females; median age: 28 years) with a history of allergic rhinitis but free of symptoms at screening entered the study. Ciclesonide and placebo were given for 7 days each with a washout period of at least 14 days in between. In both treatment periods, controlled intranasal allergen provocation with pollen extracts was performed on the 2 days before start of treatment (days -2 and -1) and on all treatment days (days 1 to 7) about 2 hours after administration of the study medication. At 5 and 30 minutes after each allergen provocation, rhinal airflow was measured by anterior rhinomanometry, and the subjective symptoms of obstruction, itching, and rhinorrhea were assessed by means of a standardized visual analog scale. Rhinal airflow improved significantly from day 5, while the subjective symptom of obstruction improved from day 2. Itching and rhinorrhea also improved significantly. The local and systemic tolerability of ciclesonide nasal spray was excellent. The results of this study clearly indicate that the new topical steroid ciclesonide is effective in the treatment of allergic rhinitis without producing local or systemic side effects.

The Kogan Attitudes Toward Old People scale: is it time for a revision?

The Kogan Attitudes Toward Old People scale scale has been used in gerontological research for more than 35 years. Criticisms of the scale, including dated wording and response bias, have increased in the 1990s. Researchers must examine the scale and decide whether a revision is now necessary.

Epidemiology of gambling and depression in an adult sample.

As a relationship has been reported between pathological gambling and depression, the objective of this study was to explore whether there was a relationship between gambling and depression in a sample of 400 adults. No relationship was found.

Television news and elderly persons.

Previous studies concerning elderly people have examined either use of all media by older adults or their depiction in television entertainment programs. What has been overlooked has been television news and its effects on elderly people. Careful research is needed to gauge this.

Scanning molecular sieve chromatography of interacting protein systems: nonlinear least-squares analysis of small zone experiments.

A simple routine for nonlinear least-squares analysis is applied to small zone scanning data, where calibration of the gel column requires the use of fully characterized markers of known molecular size. Application of nonlinear least-squares analysis eliminates the difficulty encountered because of scarcity of calibrating markers for gels whose porosities span certain size ranges by providing a sensitive measure of changes in molecular size of the interacting protein system, in order to determine the interaction parameters, size heterogeneity, and the centroid position for time difference chromatographic experiments.