Association Patterns (association + pattern)

Distribution by Scientific Domains

Selected Abstracts

Word association patterns: unpacking the assumptions

Tess Fitzpatrick
First page of article [source]

Quantifying the influence of sociality on population structure in bottlenose dolphins

Summary 1The social structure of a population plays a key role in many aspects of its ecology and biology. It influences its genetic make-up, the way diseases spread through it and the way animals exploit their environment. However, the description of social structure in nonprimate animals is receiving little attention because of the difficulty in abstracting social structure from the description of association patterns between individuals. 2Here we focus on recently developed analytical techniques that facilitate inference about social structure from association patterns. We apply them to the population of bottlenose dolphins residing along the Scottish east coast, to detect the presence of communities within this population and infer its social structure from the temporal variation in association patterns between individuals. 3Using network analytical techniques, we show that the population is composed of two social units with restricted interactions. These two units seem to be related to known differences in the ranging pattern of individuals. By examining social structuring at different spatial scales, we confirm that the identification of these two units is the result of genuine social affiliation and is not an artefact of their spatial distribution. 4We also show that the structure of this fission-fusion society relies principally on short-term casual acquaintances lasting a few days with a smaller proportion of associations lasting several years. These findings highlight how network analyses can be used to detect and understand the forces driving social organization of bottlenose dolphins and other social species. [source]

Can isotropy vs. anisotropy in the spatial association of plant species reveal physical vs. biotic facilitation?

Peter Haase
In dryland ecosystems and other harsh environments, a large part of the vegetation is often clustered, appearing as ,islands'. If ,independent' species, usually colonizers, can be distinguished from species which are ,dependent' on the presence of the colonizing species for successful establishment and/or persistence, the type of spatial pattern of the association - isotropic (spatially symmetric) or anisotropic (spatially asymmetric) - can give information on the underlying environmental factors driving the process of association. Modified spatial pattern analysis based on Ripley's K -function can be applied to bivariate clustered patterns by cardinal direction in order to detect possible anisotropy in the pattern of association. The method was applied to mapped distribution patterns of two types of semi-arid shrubland in southeastern Spain. In shrubland of Retama sphaerocarpa, low shrubs of Artemisia barrelieri were significantly clustered under the canopy of the Retama shrubs in all four cardinal directions, suggesting an isotropic facilitation effect. In low shrubland dominated by Anthyllis cytisoides and Artemisia barrelieri, Anthyllis shrubs occurred more frequently than expected on the eastern side (and downslope) of an Artemisia shrub. The possible environmental factors driving the two association patterns are discussed and recommendations for further applications of the analytical method are given. [source]

Medication usage among young adult women: A comparison between Sweden, the USA, and Greece

Evy Lidell rn
Abstract This study evaluated whether or not medication usage among young adult women differed across three countries. An additional aim was to evaluate the association between medication use and sociodemographic factors and exercise habits. A sample of 1098 young adult women were selected in Sweden, the USA, and Greece. Consistent medication usage by young adult women in the three countries related to oral contraceptives and vitamins; nevertheless, there were differences. The main differences were found in the use of laxatives, iron supplements, analgesics, antidepressants, and antacid medication. The most outstanding differences were the frequent use of laxatives in Sweden and vitamins in the USA. Different association patterns were found between medication use and culture, sociodemographic factors, and exercise. The assessment of medication use among young adult women can be performed very easily and provides an immediate indication of their well-being and needs for preventative care. [source]

Measuring Synchronization and Convergence of Business Cycles for the Euro area, UK and US,

Siem Jan Koopman
Abstract This paper investigates business cycle relations among different economies in the Euro area. Cyclical dynamics are explicitly modelled as part of a time series model. We introduce mechanisms that allow for increasing or diminishing phase shifts and for time-varying association patterns in different cycles. Standard Kalman filter techniques are used to estimate the parameters simultaneously by maximum likelihood. The empirical illustrations are based on gross domestic product (GDP) series of seven European countries that are compared with the GDP series of the Euro area and that of the US. The original integrated time series are band-pass filtered. We find that there is an increasing resemblance between the business cycle fluctuations of the European countries analysed and those of the Euro area, although with varying patterns. [source]

MAPRes: Mining association patterns among preferred amino acid residues in the vicinity of amino acids targeted for post-translational modifications

Ishtiaq Ahmad
Abstract Post-translational modification (PTM) of a protein is an important event in regulating cellular functions. An algorithm, MAPRes, has been developed for mining associations among PTM sites and the preferred amino acids in their vicinity. The algorithm has been implemented to O -glycosylation and O -phosphorylation data (phosphorylated/glycosylated Ser/Thr/Tyr). The association patterns mined by MAPRes demonstrate significant correlations and the results are in conformity with the existing methods. These association rules/patterns will be helpful in predicting the sequences/motifs involved for specific PTMs in proteins. [source]

Scramble or contest competition over food in solitarily foraging mouse lemurs (Microcebus spp.): New insights from stable isotopes

Melanie Dammhahn
Abstract The relationships between resource distribution, type of competition, and consequences for social organization have been formalized in the socioecological model (SEM) which predicts that ecological factors are the main determinants of female distribution. We tested this basic prediction in two solitary primates (Microcebus berthae and M. murinus) which differ in female association patterns. Using stable nitrogen and carbon isotope data of hair samples and food sources we quantified inter-specific differences in diet. ,13C in M. berthae reflected a diet composed mainly of insect secretions. Higher within-species as well as seasonal variation in ,13C of M. murinus indicated a wider trophic niche including plant and animal source food. Constantly elevated ,15N in M. murinus most likely reflected extended torpor during the lean season. This energy-saving strategy together with a wider, more opportunistic feeding niche might reduce female competition in this species, facilitating smaller female ranges, and a higher association potential. In contrast, ,15N fluctuated seasonally in M. berthae, most likely indicating varying amounts of arthropod food in the diet. Intense scramble competition over small and seasonally limited resources might lead to female spatial avoidance and a reduced association potential in M. berthae. Thus, differences in female association patterns between these two solitary foragers are due to different types of competition and overall intensities of intra-specific competition. Am J Phys Anthropol, 2010. 2009 Wiley-Liss, Inc. [source]

Kinship and social bonds in female chimpanzees (Pan troglodytes)

Kevin Langergraber
A large body of theoretical and empirical research suggests that kinship influences the development and maintenance of social bonds among group-living female mammals, and that human females may be unusual in the extent to which individuals form differentiated social relationships with nonrelatives. Here we combine behavioral observations of party association, spatial proximity, grooming, and space use with extensive molecular genetic analyses to determine whether female chimpanzees form strong social bonds with unrelated individuals of the same sex. We compare our results with those obtained from male chimpanzees who live in the same community and have been shown to form strong social bonds with each other. We demonstrate that party association is as good a predictor of spatial proximity and grooming in females as it is in males, that the highest party association indices are consistently found between female dyads, that the sexes do not differ in the long-term stability of their party association patterns, and that these results cannot be explained as a by-product of the tendency of females to selectively range in particular areas of the territory. We also show that close kin (i.e. mother,daughter and sibling dyads) are very rare, indicating that the vast majority of female dyads that form strong social bonds are not closely related. Additional analyses reveal that "subgroups" of females, consisting of individuals who frequently associate with one another in similar areas of the territory, do not consist of relatives. This suggests that a passive form of kin-biased dispersal, involving the differential migration of females from neighboring communities into subgroups, was also unlikely to be occurring. These results show that, as in males, kinship plays a limited role in structuring the intrasexual social relationships of female chimpanzees. Am. J. Primatol. 71:840,851, 2009. 2009 Wiley-Liss, Inc. [source]

Social organization of the Milne-Edward's potto

Elizabeth R. Pimley
Abstract Nocturnal prosimian primates are often seen alone during their nocturnal activities, and are therefore categorized as "solitary". Recent research has shown that these animals actually possess social networks that differ among species. Here we present new information on one of the lesser studied prosimian primates, the potto, derived from fieldwork in Cameroon that employed radiotelemetry and behavioral observations. An analysis of association patterns and home-range overlaps between animals revealed that pottos associated more frequently with conspecifics than expected for a supposedly solitary primate. Certain males and females that were seen together regularly throughout the study, but were not observed to have contact with other pottos of the opposite sex, were labeled as "pairs". These pairs were found to have higher levels of association with each other than with other conspecifics. The only affiliative and sexual behaviors observed between members of the opposite sex occurred within the pairs of pottos. Although given the secretive nature of these primates, the possibility of extrapair copulations cannot be ruled out, their relatively small testis size indicates that sperm competition is not so important for this species. Am. J. Primatol. 66:317,330, 2005. 2005 Wiley-Liss, Inc. [source]