University of Winnipeg

About: University of Winnipeg is a education organization based out in Winnipeg, Manitoba, Canada. It is known for research contribution in the topics: Population & Context (language use). The organization has 3235 authors who have published 6413 publications receiving 150564 citations. The organization is also known as: U of W.

Asymmetric sibling rivalry and nestling growth in red-winged blackbirds (Agelaius phoeniceus)

Abstract: Many birds hatch their offspring asynchronously, and the adaptive significance of this trait, if any, is controversial. David Lack suggested long ago that by facilitating brood reduction when resources are scarce, hatching asynchrony provides relief from the effects of overcrowding. Some field workers interpret this to mean that the growth and survival of survivors should rise following partial brood loss. Here we show in a 6-year study of red-winged blackbirds (Agelaius phoeniceus) that the presence or absence of marginal offspring in experimentally manipulated broods had virtually no effect upon the growth of core offspring, whereas alterations of the size of core brood had strong and significant effects. Nestling growth was, not surprisingly, slower in broods with partial brood loss. Intriguingly, marginal offspring showed significantly greater variation in mass. Core offspring are less sensitive to, but not exempt from, the inimical effects of resource shortfall than are marginal offspring. The phenotypic handicap appears to marginal offspring a caste of high-variance progeny whose fitness prospects rest upon levels of parental input (stochastic resources) and the size of the core brood (stochastic development).

The social phobia and social interaction anxiety scales: An exploration of the dimensions of social anxiety and sex differences in structure and relations with pathology

Abstract: This study sought to provide information on the Social Phobia Scale (SPS) and Social Interaction Anxiety Scale (SIAS) of Mattick and Clarke (1989) with respect to factor structure, relations with psychopathology, and sex differences. A sample of 200 university students completed the SPS and SIAS and various measures of anxiety symptoms and depression. The results from the factor analyses for the sample as a whole suggest the presence of three factors corresponding to scrutiny fears, social interaction anxiety, and a general level of discomfort in social interactions. The results for men replicated this structure. For women, the three-factor solution demonstrated a blurring between the types of anxiety-provoking situations, and a general discomfort in situations involving differences in social power. In general, the discomfort factor was not correlated with measures of pathology, raising the possibility that uneasiness in these situations represents a process that is not part of social anxiety. The distinction between scrutiny fears and social interaction anxiety was also supported by the pattern of partial correlations that suggests that the presence of scrutiny fears is a stronger predictor of psychopathology than is social interaction anxiety, especially for men.

Connection admission control algorithms for OFDM wireless networks

Abstract: We present queueing analysis for two connection admission control (CAC) schemes for OFDM wireless networks. The first one is a threshold-based CAC scheme in which admissibility for a new connection is determined based on a certain threshold and the number of ongoing connections. The second scheme uses the information on queue status to determine the probability to accept an incoming call. The connection-level and the packet-level performance measures for both CAC schemes are obtained from the queueing analytical models. Typical numerical results based on the proposed model are presented which provide interesting insights on the behavior of these two different CAC schemes. Also, simulation results are presented to validate the analytical results