Spatial variation in adult sex ratio across multiple scales in the invasive golden apple snail, Pomacea canaliculata

Adult sex ratio (ASR) has critical effects on behavior and life history and has implications for population demography, including the invasiveness of introduced species. ASR exhibits immense variation in nature, yet the scale dependence of this variation is rarely analyzed. In this study, using the generalized multilevel models, we investigated the variation in ASR across multiple nested spatial scales and analyzed the underlying causes for an invasive species, the golden apple snail Pomacea canaliculata. We partitioned the variance in ASR to describe the variations at different scales and then included the explanatory variables at the individual and group levels to analyze the potential causes driving the variation in ASR. We firstly determined there is a significant female-biased ASR for this species when accounting for the spatial and temporal autocorrelations of sampling. We found that, counter to nearly equal distributed variation at plot, habitat and region levels, ASR showed little variation at the town level. Temperature and precipitation at the region level were significantly positively associated with ASR, whereas the individual weight, the density characteristic, and sampling time were not significant factors influencing ASR. Our study suggests that offspring sex ratio of this species may shape the general pattern of ASR in the population level while the environmental variables at the region level translate the unbiased offspring sex ratio to the female-biased ASR. Future research should consider the implications of climate warming on the female-biased ASR of this invasive species and thus on invasion pattern.

Do Gifts Increase Consent to Home-based HIV Testing? A Difference-in-differences Study in Rural KwaZulu-Natal, South Africa

Background Despite the importance of HIV testing for controlling the HIV epidemic, testing rates remain low. Efforts to scale-up testing coverage and frequency in hard-to-reach and at-risk populations commonly focus on home-based HIV testing. This study evaluates the effect of a gift (a food voucher for families, worth US$ 5) on consent rates for home-based HIV testing.
Methods We use data on 18,478 men and women who participated in the 2009 and 2010 population-based HIV surveillance carried out by the Wellcome Trust Africa Centre for Health and Population Studies in rural KwaZulu-Natal, South Africa. Our quasi-experimental difference-in-differences approach controls for unobserved confounding in estimating the causal effect of the intervention on HIV testing consent rates.
Results Allocation of the gift to a family in 2010 increased the probability of family members consenting to test in 2010 by 25 percentage points (95% CI 21-30; p<0.001). The intervention effect persisted, slightly attenuated, in the year following the intervention (2011), further increasing intervention value for money.
Conclusions In HIV hyperendemic settings a gift can be highly effective at increasing consent rates for home-based HIV testing. Given the importance of HIV testing for treatment uptake and individual health, as well as for HIV treatment-and-prevention strategies and for monitoring the population impact of the HIV response, gifts should be considered as a supportive intervention for HIV testing initiatives where consent rates have been low.

Counter-Mappings: Cartography and Difference

Introduction to the co-edited book 'Cartographies of Differences: Interdisciplinary Perspectives

Visible Difference, Stigmatising Language(s) and the Distinctive Construction of Prejudices against Others in Leeds and Warsaw

The chapter argues that language and cultural communication matter in a transnational world and that the transmission of prejudices against minorities has to be closely analysed while contextualising national histories with minorities. Looking at two spatial sites (Leeds and Warsaw) and analysing interview material that was drawn from a larger study, the authors discuss the way local people address difference particularly through the axes of gendered ethnicity (Muslim men) and gendered class (male underclass). It explores how the same categories of difference are discursively produced in Poland and the UK/ England; to what degree they differ or overlap.

Computerized key to the genus Bursaphelenchus Fuchs, analysis of species clusters based on morphology, using information of insect vectors and associated plants, with a revision of the genus.

The genus Bursaphelenchus includes B. xylophilus (Steiner et Buhrer, 1934) Nickle, 1981, which is of world economic and quarantine importance. Distinction among several species of the pinewood nematodes species complex (PWNSC) is often difficult. Besides standard morphology, morphometrics and molecular biology, new tools are welcome to better understand this group. The computerized (or e-) key of this genus, presented in this communication, includes 74 species (complete list of valid species of the world fauna) and 35 characters, that were used by the taxonomic experts of this group, in the original descriptions. Morphology of sex organs (male spicules and female vulval region) was digitized and classified to distinguish alternative types. Several qualitative characters with overlapping character states (expressions) were transformed into the morphometric indices with the discontinuous ranges (characters of ratios of the spicule dimensions). Characters and their states (expressions) were illustrated in detail and supplied by brief user-friendly comments. E-key was created in the BIKEY identification system (Dianov & Lobanov, 1996-2004). The system has built-algorithm ranging characters depending on their diagnostic values at each step of identification. Matrix of species and the character states (structural part of the e-key database) may be easily transformed using statistical packages into the dendrograms of general phenetic similarities (UPGMA, standard distance: mean character difference). It may be useful in the detailed analysis of taxonomy and evolution of the genus and in its splitting to the species groups based on morphology. The verification of the dendrogram using the information on the species links with insect vectors and their associated plants, provided an opportunity to recognize the five clusters (xylophilus, hunti, eremus sensu stricto, tusciae and piniperdae sensu stricto), which seem to be the natural species groups. The hypothesis about the origin and the first stages of the genus evolution is proposed. A general review of the genus Bursaphelenchus is presented.

Sex-related invariance across cultures in an online role-playing game

This study examines the Social Dominance Orientation of players of the online roleplaying game World of Warcraft. The World of Warcraft offers an opportunity to investigate social dominance and biological sex differences in an environment where there is no cultural dominance of one sex over another. Social Dominance Orientation has been found to be different between males and females, with males scoring higher. However, this might be the consequence of social context. To this end sex differences between male and female players were investigated in the World of Warcraft environment, as well as the effects of chosen character sex. Player sex and character sex were found to have effects on Social Dominance Orientation. These results add further support to claims that Social Dominance Orientation has the characteristics of a sexually selected disposition to acquire resources and out-compete rival groups.

Spiking neural network model of sound localisation using the interaural intensity difference

In this paper, a spiking neural network (SNN) architecture to simulate the sound localization ability of the mammalian auditory pathways using the interaural intensity difference cue is presented. The lateral superior olive was the inspiration for the architecture, which required the integration of an auditory periphery (cochlea) model and a model of the medial nucleus of the trapezoid body. The SNN uses leaky integrateand-fire excitatory and inhibitory spiking neurons, facilitating synapses and receptive fields. Experimentally derived headrelated transfer function (HRTF) acoustical data from adult domestic cats were employed to train and validate the localization ability of the architecture, training used the supervised learning algorithm called the remote supervision method to determine the azimuthal angles. The experimental results demonstrate that the architecture performs best when it is localizing high-frequency sound data in agreement with the biology, and also shows a high degree of robustness when the HRTF acoustical data is corrupted by noise.

Youth attitudes toward difference and diversity: a cross-national analysis

This paper analyses youth attitudes toward difference and cultural diversity. Firstly, we analyse data from 65 countries showing that youths are more tolerant than older people toward both stigmatised groups and groups perceived as racially or ethnically different. Findings also show that political conservatism is a very stable predictor of intolerance to difference. Secondly, we study the appraisals of cultural diversity in 21 European countries, showing that youths express greater openness to cultural diversity than older people. In this new study, while values of conservation correlate negatively with openness to cultural diversity, values of self-transcendence correlate positively.

Children’s Friendships and Learning in School: Cognitive Enhancement Through Social Interaction?

Background. Recent literature has identified that children's performance on cognitive (or problem-solving) tasks can be enhanced when undertaken as a joint activity among pairs of pupils. Performance on this ‘social’ activity will require quality relationships between pupils, leading some researchers to argue that friendships are characterized by these quality relationships and, therefore, that friendship grouping should be used more frequently within classrooms. Aims. Children's friendship grouping may appear to be a reasonable basis for cognitive development in classrooms, although there is only inconsistent evidence to support this argument. The inconsistency may be explained by the various bases for friendship, and how friendship is affected by cultural contexts of gender and schooling. This study questions whether classroom-based friendship pairings will perform consistently better on a cognitive task than acquaintance pairings, taking into account gender, age, and ability level of children. The study also explores the nature of school-based friendship described by young children. Sample. 72 children were paired to undertake science reasoning tasks (SRTs). Pairings represented friendship (versus acquaintance), sex (male and female pairings), ability (teacher-assessed high, medium, and low), and age (children in Years 1, 3, and 5 in a primary school). Method. A small-scale quasi-experimental design was used to assess (friendship- or acquaintance-based) paired performance on SRTs. Friendship pairs were later interviewed about qualities and activities that characterized their friendships. Results. Girls' friendship pairings were found to perform at the highest SRT levels and boys' friendship pairing performed at the lowest levels. Both boy and girl acquaintance pairings performed at mid-SRT levels. These findings were consistent across Year (in school) levels and ability levels. Interviews revealed that male and female friendship pairs were likely to participate in different types of activity, with girls being school-inclusive and boys being school-exclusive. Conclusion. Recommendations to use friendship as a basis for classroom grouping for cognitive tasks may facilitate performance of some pairings, but may also inhibit the performance of others. This is shown very clearly with regard to gender. Some of the difference in cognitive task performance may be explained by distinct, cultural (and social capital) orientations to friendship activities, with girls integrating school and educational considerations into friendship, and boys excluding school and educational considerations.