University of Canterbury

About: University of Canterbury is a education organization based out in Christchurch, New Zealand. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 11100 authors who have published 29846 publications receiving 893232 citations. The organization is also known as: Te Whare Wānanga o Waitaha & Canterbury College.

A generalized conditional intensity measure approach and holistic ground motion selection

Abstract: A generalized conditional intensity measure (GCIM) approach is proposed for use in the holistic selection of ground motions for any form of seismic response analysis. The essence of the method is the construction of the multivariate distribution of any set of ground-motion intensity measures conditioned on the occurrence of a specific ground-motion intensity measure (commonly obtained from probabilistic seismic hazard analysis). The approach therefore allows any number of ground-motion intensity measures identified as important in a particular seismic response problem to be considered. A holistic method of ground-motion selection is also proposed based on the statistical comparison, for each intensity measure, of the empirical distribution of the ground-motion suite with the ‘target’ GCIM distribution. A simple procedure to estimate the magnitude of potential bias in the results of seismic response analyses when the ground-motion suite does not conform to the GCIM distribution is also demonstrated. The combination of these three features of the approach make it entirely holistic in that: any level of complexity in ground-motion selection for any seismic response analysis can be exercised; users explicitly understand the simplifications made in the selected suite of ground motions; and an approximate estimate of any bias associated with such simplifications is obtained. Copyright © 2010 John Wiley & Sons, Ltd.

Validity of the Polar V800 heart rate monitor to measure RR intervals at rest

Abstract: To assess the validity of RR intervals and short-term heart rate variability (HRV) data obtained from the Polar V800 heart rate monitor, in comparison to an electrocardiograph (ECG). Twenty participants completed an active orthostatic test using the V800 and ECG. An improved method for the identification and correction of RR intervals was employed prior to HRV analysis. Agreement of the data was assessed using intra-class correlation coefficients (ICC), Bland–Altman limits of agreement (LoA), and effect size (ES). A small number of errors were detected between ECG and Polar RR signal, with a combined error rate of 0.086 %. The RR intervals from ECG to V800 were significantly different, but with small ES for both supine corrected and standing corrected data (ES 0.999 for both supine and standing corrected intervals. When analysed with the same HRV software no significant differences were observed in any HRV parameters, for either supine or standing; the data displayed small bias and tight LoA, strong ICC (>0.99) and small ES (≤0.029). The V800 improves over previous Polar models, with narrower LoA, stronger ICC and smaller ES for both the RR intervals and HRV parameters. The findings support the validity of the Polar V800 and its ability to produce RR interval recordings consistent with an ECG. In addition, HRV parameters derived from these recordings are also highly comparable.

Intrasexual selection and the segregation of pollen and stigmas in hermaphrodite plants, exemplified by wahlenbergia albomarginata (campanulaceae)

Abstract: The adaptive significance of floral structures lies in general in the means by which they facilitate cross-fertilization, as Darwin (e.g., 1876) first recognized. The selective advantages of adaptations promoting cross-fertilization in angiosperms may stem from one or more of three sources. Some floral characters promote outcrossing only passively by preventing self-fertilization, thereby allowing more opportunities for crossing without directly bringing it about. Self-incompatibility is one such \"anti-selfing\" mechanism which does not itself promote cross-fertilization-and actually restricts it in incompatible crosses. Other outcrossing mechanisms actively promote the removal of pollen from a potential paternal parent or facilitate the deposition of pollen on the stigma of a maternal parent. Although many flower structures serve both activities of cross-pollination equally, this is not necessarily so. Pollen removal and pollen receipt are separate processes, and structures or behaviors that are optimal for one process do not always coincide precisely with those that are optimal for the other (e.g., Heslop-Harrison, 1972; Willson and Rathcke, 1974; Freeman et al., 1976; van der Pijl, 1978). Hence it is sometimes necessary to distinguish adaptations enhancing paternal fitness in cross-fertilization from those promoting maternal fitness. It has often been stated that sex-differential selection may lead to the separation