The role of dispersal and local environment in urban land snail assemblages: an example of three cities in Central Italy

Ecologists increasingly appreciate the central role that urban biodiversity plays in ecosystems, however much urban biodiversity is neglected, especially some very diverse groups of invertebrates. For the first time in southern Europe, land snail communities are analysed in four urban habitats along a geographical gradient of three cities, using quantitative methods and assessing the relative roles of local environmental conditions (“distance from sea”, “distance from city centre”, “vegetation cover”) and spatial effects by principal coordinate analysis of neighbour matrices, redundancy analysis and variation partitioning. A total of 53 species was recorded, a richness similar to that of natural areas. At habitat level, species richness did not show a clear increasing trend from more to less urbanized habitats, but rather a homogeneous pattern. At city level, study areas hosted rather heterogeneous species assemblages and biotic homogenization did not seem to have any impact; indeed, only three species could be considered alien. Variation partitioning showed that land snail communities were mostly structured by environmental factors, even when spatial structures independent of measured environmental variables were included: “vegetation cover” and “distance from city centre” were the environmental variables that explained most of the variation in species composition. The lack of strong spatial structure also unexpectedly suggested that transport by humans aids dispersal of organisms with low mobility, which are usually limited by spatial constraints in natural environments. These results provide ecological and conservation implications for other invertebrate groups, suggesting to set priorities in management strategies that include habitat conservation at local scale.     

Atypical feeding of woodpeckers,crows and redstarts on mass-swarming <Emphasis Type="Italic">Hydropsyche pellucidula</Emphasis> caddisflies attracted to glass panes

Artificial shiny dark objects reflecting horizontally polarized light (e.g. asphalt roads, black cars, solar panels) can attract polarotactic aquatic insects in mass. Glass buildings on the riverside also lure swarming caddisflies emerging from the river. These caddisfly swarms are a temporary rich food source for certain bird species, such as white wagtails (Motacilla alba), house sparrows (Passer domesticus), magpies (Pica pica) and great tits (Parus major). We report here about our observation of great spotted woodpeckers (Dendrocopos major), hooded crows (Corvus cornix) and black redstarts (Phoenicurus ochruros) feeding atypically on Hydropsyche pellucidula caddisflies swarming at glass buildings placed on the shore of the river Danube in Budapest (Hungary).     

Transition from playing with simulated gambling games to gambling with real money: a longitudinal study in adolescence

Digital technology advances have supported an expansion of gambling activities, which is notable via the advent of simulated gambling games. Simulated gambling reproduces ‘real’ gambling activities, which enables the users to gamble without investing money. According to research evidence, a certain number of adolescents are playing with these games, but until now little has been known about how they could facilitate the migration to gambling with real money. Using a longitudinal design with a one-year interval period, the goal of this study was to assess the potential transition between playing with simulated gambling and the initiation to gambling with real money. The final sample was constituted of 1220 adolescents (age range = 14 to 18 y.o.) who had never played with real money at the first measurement time. At the second measurement time, 28.8% of the participants had gambled for the first time with real money. Logistic regressions revealed that the predictive association between simulated gambling and gambling with real money only holds for adolescents who transitioned from simulated poker to poker with real money. These findings highlight the need for regulation and monitoring on Internet gambling poker sites, as well as further research to assess the mechanisms at work.     

Contrast Estimation for Parametric Stationary Determinantal Point Processes

We study minimum contrast estimation for parametric stationary determinantal point processes. These processes form a useful class of models for repulsive (or regular, or inhibitive) point patterns and are already applied in numerous statistical applications. Our main focus is on minimum contrast methods based on the Ripley's K‐function or on the pair correlation function. Strong consistency and asymptotic normality of theses procedures are proved under general conditions that only concern the existence of the process and its regularity with respect to the parameters. A key ingredient of the proofs is the recently established Brillinger mixing property of stationary determinantal point processes. This work may be viewed as a complement to the study of Y. Guan and M. Sherman who establish the same kind of asymptotic properties for a large class of Cox processes, which in turn are models for clustering (or aggregation).     

Remittances and inequality: a dynamic migration model

We develop a model to study the effects of migration and remittances on inequality in the origin communities. While wealth inequality is shown to be monotonically reduced along the time-span, the short- and the long-run impacts on income inequality may be of opposite signs, suggesting that the dynamic relationship between migration/remittances and inequality may well be characterized by an inverse U-shaped pattern. This is consistent with the findings of the empirical literature, yet offers a different interpretation from the usually assumed migration network effects. With no need to endogenize migration costs through the role of migration networks, we generate the same results via intergenerational wealth accumulation.     

Towards a critical realist epistemology?

When critical realists consider epistemology they typically start from “epistemological relativism.” We find this position necessary, but we also find it insufficient because it lacks a critique of the highly unequal social relations among observers themselves—relations that shape the very production of knowledge. While it is indeed the case that all knowledge is fallible, it is also the case that all knowledge is positioned, with a particular standpoint. What is more, the social power relations between standpoints organize the production of truth in ways that produce systematic distortions. In this paper, we propose a critical realist social epistemology. We introduce feminist standpoint theory and postcolonial theory as our suggested interventions into critical realism and we use two case studies of existing work to highlight i) the social production of truth and the real, and ii) what is at stake for radicalizing epistemology in critical realism. In so doing, our paper emphasizes the epistemic complexities that continuously shape ontology, a commitment to subaltern voices or experiences, and a thorough interrogation of the relations between positions of knowledge production.     

Labeling albinism: language and discourse surrounding people with albinism in Tanzania

This article is based on a qualitative study that set out to analyze the labels and terms attached to 28 people affected by albinism in villages in Kilolo district, Tanzania. Even though national and international attention to killings of people with albinism has attempted to improve general knowledge of albinism and reduce discrimination, most of the community members within the study had little knowledge of the (bio)medical explanations for albinism and tended to marginalize people with albinism. Framed within a wider moral discourse on illness, disability and socially appropriate behavior, albinism is mostly considered to be God’s will or the consequence of past misdeeds within the family, and many of the existing labels for people with albinism express such ideas.     

民族主义视野下的阿富汗重建

2001年以来的阿富汗重建可以分为国际社会主导和阿富汗政府主导两个阶段。在国际社会的协助下,阿富汗政府在政治、安全、经济等领域取得了一定的成绩,但问题依然严峻。民族主义对阿富汗重建具有重要的影响,它不仅是阿富汗政治合法性的重要来源,也是阿富汗社会动员的主要方式,还直接影响着阿富汗国际形象的重塑。阿富汗重建的进程也是阿富汗民族主义重构的过程。     

Reports of Wins and Risk Taking: An Investigation of the Mediating Effect of the Illusion of Control

Two experiments examined the relationships between the knowledge that another person has won in a gamble, the illusion of control and risk taking. Participants played a computer-simulated French roulette game individually. Before playing, some participants learnt that another person won a large amount of money. Results from a first experiment (n = 24) validated a causal model where the knowledge of another person’s win increased the illusion of control, measured with betting times, expectancy and self-reports on scales, which in turn encourages risk taking. In the second experiment (n = 36), some participants were told the previous player acknowledged the win to be fortuitous. The suppression of the belief that the previous winner had himself exerted control over the outcome resulted in lower rates of risk-taking behaviors. This suggests that it was not the knowledge of another person’s win in itself that increased risk taking, but rather, the belief that the other person had some control over the gamble’s outcome. Theoretical implications for the study of social mechanisms involved in gambling behavior are discussed.