The Role of Pitch Memory in Pitch Discrimination and Pitch Matching

Accurate control of vocal pitch (fundamental frequency) requires coordination of sensory and motor systems. Previous research has supported the relationship between perceptual accuracy and vocal pitch matching accuracy. The purpose of this study was to investigate the role of memory for pitch in pitch matching and pitch discrimination ability. Three experimental tasks were used. First, a pitch matching task was completed, in which the participants listened to target tones and vocally matched the pitch of the tones. The second task was a pitch discrimination task that required the participants to judge the pitch (same or different) of complex tone pairs. The third task was pitch discrimination with memory interference task that was similar to the pitch discrimination task except interference tones were added. Results of the pitch matching and pitch discrimination tasks yielded a significant correlation between these values. When there was memory interference, pitch discrimination ability was poorer, and there was no significant correlation between pitch discrimination and pitch matching. These results support earlier findings of a relationship between pitch discrimination and pitch matching abilities. The results also suggest a possible role of pitch memory in both tasks. These findings may have implications for abilities related to accurate pitch control.     

High speed analysis of underivatized drugs by gas chromatography–mass spectrometry

The technique of choice for many types of forensic drug confirmations is gas chromatography/mass spectrometry (GC/MS). Significant amounts of analytical time can be involved in a GC/MS run. The use of a 0.1 mm i.d. fused silica capillary column with hydrogen carrier gas can significantly increase the speed of an analysis without sacrificing resolution. Nanogram levels of underivatized drugs, from amphetamine to strychnine, can be eluted in less than twelve minutes. The multitasking system permits data acquisition, while performing data reduction on the previous run.     

The self-diffusion coefficient of liquid methane

Self-diffusion coefficients of methane have been calculated over a wide density range using the method of molecular dynamics. Methane intermolecular interactions were modelled using an m-6–8 potential with coefficients determined from viscosity data for the dilute gas. After adding a contribution to the diffusion coefficient due to the long-time behaviour of the velocity autocorrelation function, agreement with experimental data is within the estimated errors given for both the calculated values and the experimental data.     

Ueber die Atomgewichte von Gold, Platina, Iridium, Osmium, Rhodium und Palladium

Ohne Zusammenfassung     

Modulation of amyloid-β aggregation by metal complexes with a dual binding mode and their delivery across the blood–brain barrier using focused ultrasound

One of the key hallmarks of Alzheimer''s disease is the aggregation of the amyloid-β peptide to form fibrils. Consequently, there has been great interest in studying molecules that can disrupt amyloid-β aggregation. While a handful of molecules have been shown to inhibit amyloid-β aggregation in vitro, there remains a lack of in vivo data reported due to their inability to cross the blood–brain barrier. Here, we investigate a series of new metal complexes for their ability to inhibit amyloid-β aggregation in vitro. We demonstrate that octahedral cobalt complexes with polyaromatic ligands have high inhibitory activity thanks to their dual binding mode involving π–π stacking and metal coordination to amyloid-β (confirmed via a range of spectroscopic and biophysical techniques). In addition to their high activity, these complexes are not cytotoxic to human neuroblastoma cells. Finally, we report for the first time that these metal complexes can be safely delivered across the blood–brain barrier to specific locations in the brains of mice using focused ultrasound.

We report a series of non-toxic cobalt(iii) complexes which inhibit Aβ peptide aggregation in vitro; these complexes can be safely delivered across the blood–brain barrier in mice using focused ultrasound.     

Fine structure in the cosmic ray electron spectrum measured by the ATIC-2 and ATIC-4 experiments

A strong anomaly in form of a wide peak in the energy range 300–800 GeV was discovered in the first measurements of the electron spectrum in the energy range from 20 GeV to 3 TeV by the balloon-borne experiment ATIC [1]. The experimental data processing and analysis of the electron spectrum with different criteria for selection of electrons completely independent of the results reported in [1] is employed in the present paper. New independent analysis generally confirms the results of [1] but shows that the spectrum in the region of the anomaly is represented by a number of narrow peaks. Measured spectrum is compared to the spectrum of [1] and to the spectrum of the Fermi/LAT experiment.     

Third virial coefficient for hard spheres with embedded dipoles

The doublet stability of the SCF solutions for the allyl radical is re-examined for various ab-initio model hamiltonians, based on the minimum, double-zeta and double-zeta plus polarization atomic orbital basis sets in the LCAO scheme. The calculations are carried out for a wide range of the C-C bond lengths (1.3 Å to 2·0 Å). In all cases the critical bond length, separating regions of stability and instability, is found to be shorter than the corresponding equilibrium C-C bond length (1·36 Å versus 1·44 Å, respectively, for the minimum basis set). In contrast to the results of McKelvey and Berthier we find that the doublet-stability problem yields at most one negative eigenvalue in the whole range of the C-C bond lengths studied, this implying only one possible (other than spin) symmetry breaking, in complete agreement with the semi-empirical PPP model results for this system. The basis dependence of the doublet instability is also re-examined and the generality of this phenomenon is firmly established for the system studied : while the actual values of the energy lowering due to the symmetry breakdown and the critical value of the C-C bond length for the onset of instability will of course depend on the basis and approximations used, there is no doubt about the general occurrence of doublet instability in this system for large enough C-C internuclear separations, and about the implied non-analytic behaviour of the potential energy hypersurface in this region, for any basis. Finally, a simple physically and chemically plausible source of the doublet instability of allyl RHF solutions is pointed out.     

The use of stress for the control of magnetic anisotropy in amorphous FeSiBC thin films: a magneto-optic study

Magnetostrictive FeSiBC amorphous thin films based on the METGLAS^® 2605SC composition have been produced by RF magnetron sputtering. The magnetic properties were investigated using the magneto-optical Kerr effect, with both point hysteresis measurements and domain imaging. Significant in-plane anisotropy is observed in the as-grown samples, which was attributed to the residual field from the magnetron sputter source. The effects of various treatments on the samples were investigated, including the use of forming fields, stress, and thermal processing. The deliberate introduction of stress into these materials is found to allow excellent control of both the direction and magnitude of magnetic anisotropy, and can also be used as a novel method for the absolute measurement of magnetostriction. The treatments are evaluated for their potential to control anisotropy in magnetostrictive device applications.