The influence of riparian corridor width on ant and plant assemblages in northern Sydney,Australia

Protecting riparian corridors is a commonly applied environmental policy in urban landscapes. However, empirical data demonstrating their efficacy for biodiversity conservation outcomes is scarce. In this study we investigated whether riparian corridor width influences the diversity and community structure of ant (Hymenoptera: Formicidae) and vascular plant assemblages therein. Eighteen corridors of differing widths were selected from within the Ku-ring-gai Local Government Area, Sydney Australia. Ants were sampled using pitfall traps positioned within rectangular vegetation transects (30 × 10 m). Both ant and plant species richness, when standardised for sampling effort, were unrelated to riparian corridor width. However, significant compositional differences between sites were evident with increased width up to ~50 m. Narrow corridors contained greater abundances of opportunistic ant species and higher proportions of exotic plants. We interpret this to be the result of the greater disturbance/edge influence derived from adjacent upland urban environments. Site beta diversity did not increase with corridor width, suggesting that the exclusion of novel upslope habitats in narrow riparian corridors is not a significant cause of community assemblage modification at these sites. To minimise the impact of deleterious edge effects on ant fauna, environmental managers should seek to retain riparian corridors wider than ~50 m. However, we observed substantial between-site variability of biotic assemblages, irrespective of corridor width. Therefore we recommend that environmental management practice needs to take a catchment-wide approach and consider other parameters that may contribute to riparian health so as to optimise the protection of riparian biodiversity.     

Zur Wirkung von Neukunden-Promotions auf Bestandskunden

Service providers frequently offer better deals to prospective customers than they offer to customers who prolong their contracts. The present paper examines the effectiveness of incentives on new customers and, perhaps even more significantly, assesses negative effects on existing customers. To test the hypothesized effects, a series of two experiments was conducted. Results indicate that promotions that are offered exclusively to prospective customers have a negative effect on existing customers, and that this negative effect is stronger for customers with a short relationship age and for those at the end of their contract life-cycle. The unfairness and inequity perceived by existing customers can be substantially reduced if these customers are offered the opportunity to receive a part of the promotion value, while the promotion??s effectiveness to attract new customers remains unaffected.     

THE EFFECT OF FEAR OF SEXUAL VICTIMIZATION ON ADOLESCENT FEAR OF CRIME

The author examines the effect of fear of sexual victimization on fear of crime among adolescents. Criminologists have indicated that gender is one of the strongest predictors of fear of crime: Women are more fearful than men. Some authors (Warr 1984, and Ferraro 1995, among others) have suggested that this differential fear among women can mostly be attributed to their inordinate fear of sexual victimization. This relationship, however, has only been examined among adults. Using a sample of 725 adolescents, the effect of fear of sexual victimization and other demographic and contextual variables on fear of criminal victimization is examined. Results indicate that fear of sexual victimization is the best predictor of fear of nonsexual victimization, whereas the effects of other variables are contingent on race and gender. The reasons for this finding, as well as the implications for social policies, are discussed.     

Mental Rotation of Dynamic,Three‐Dimensional Stimuli by 3‐Month‐Old Infants

Mental rotation involves transforming a mental image of an object so as to accurately predict how the object would look if it were rotated in space. This study examined mental rotation in male and female 3‐month‐olds, using the stimuli and paradigm developed by Moore and Johnson (2008) . Infants were habituated to a video of a three‐dimensional object rotating back and forth through a 240° angle around the vertical axis. After habituation, infants were tested both with videos of the same object rotating through the previously unseen 120° angle, and with the mirror image of that display. Unlike females, who fixated the test displays for approximately equal durations, males spent significantly more time fixating the familiar object than the mirror‐image object. Because familiarity preferences like this emerge when infants are relatively slow to process a habituation stimulus, the data support the interpretation that mental rotation of dynamic three‐dimensional stimuli is relatively difficult—but possible—for 3‐month‐old males. Interpretation of the sex differences observed in 3‐ and 5‐month‐olds’ performances is discussed.     

Toward a cultural conception of the self.

The dominant mental health models rely excessively on a modern Western ideal of the self. Health services in a pluralistic society require interventional approaches that recognize the significance of culture in shaping a person's conception of self as well as mental health and illness.     

INFORMATION POOLS AND RACIALIZED NARRATIVE STRUCTURES

The concept of narrative structures is theorized as cultural master frames and is distinguished from the concept of story, which refers to anything reported that contains a plot. Drawing from the literature on African American folklore, the Church's Chicken story was presented to respondents as an instance of conspiracy and contamination narrative structures. Data show that story availability and believability are clearly race-based. The data ground a model of racialized narrative structures in which story content and story believability are conflated. It is argued that believability is not solely a function of storytelling performance and competence insofar as narrative structures prefigure believability. Racialized narrative structures are discussed as one element of the deep racial gulfs in America that co-exist with increases in cross-racial contact and friendship patterns.     

Testing the Effects of Similarity on Risky Choice: Implications for Violations of Expected Utility

Our aim in this paper was to establish an empirical evaluation for similarity effects modeled by Rubinstein; Azipurua et al.; Leland; and Sileo. These tests are conducted through a sensitivity analysis of two well-known examples of expected utility (EU) independence violations. We found that subjective similarity reported by respondents was explained very well by objective measures suggested in the similarity literature. The empirical results of this analysis also show that: (1) the likelihood of selection for the riskier choice increases as the pair becomes more similar, (2) these choice patterns are consistent with well-known independence violations of expected utility, and (3) a significant proportion of individuals exhibit intransitive choice patterns predicted under similarity effects, but not allowed under generalized expected utility models for risky choice.