Urban river wall habitat and vegetation: observations from the River Thames through central London

Along heavily engineered urban rivers, river walls and embankments represent the most common habitat available to riparian vegetation. This paper presents the first study into river wall vegetation and the influence of wall surface materials on plant diversity. We were concerned with investigating the plant diversity of such wall habitats, assessing relationships between different wall surface materials and plant diversity, and determining whether river wall and embankment habitats along the River Thames through central London could support native riparian species alongside more typical urban wall flora. Fifteen sites along the River Thames through central London were surveyed to describe wall flora and establish relationships between plant diversity and wall materials. Walls were not species rich, but contained a mix of terrestrial and riparian species. Stone walls with surface fractures and heterogeneous wall surfaces were conducive to plant diversity at the local scale, while wall surface heterogeneity was also important at the landscape scale. Some stratification of vegetation was observed based on wall position relative to flow disturbance. The potential exists for walls to act as sites for habitat improvement and reconciliation ecology within urban rivers.     

Modeling and Forecasting Realized Volatility

We provide a framework for integration of high–frequency intraday data into the measurement, modeling, and forecasting of daily and lower frequency return volatilities and return distributions. Building on the theory of continuous–time arbitrage–free price processes and the theory of quadratic variation, we develop formal links between realized volatility and the conditional covariance matrix. Next, using continuously recorded observations for the Deutschemark/Dollar and Yen/Dollar spot exchange rates, we find that forecasts from a simple long–memory Gaussian vector autoregression for the logarithmic daily realized volatilities perform admirably. Moreover, the vector autoregressive volatility forecast, coupled with a parametric lognormal–normal mixture distribution produces well–calibrated density forecasts of future returns, and correspondingly accurate quantile predictions. Our results hold promise for practical modeling and forecasting of the large covariance matrices relevant in asset pricing, asset allocation, and financial risk management applications.     

Macroeconomic Conditions and the Distribution of Income in Spain

Abstract. This paper analyses the impact of changes in macroeconomic con ditions on the income distribution in Spain. Using household data from the Encuesta Continuada de Presupuestos Familiares (ECPF) from 1985 to 1996 we disentangle the effect of aggregate variables on the income distribution by estimating counterfactual densities conditional on different macroeconomic scenarios. In estimation, we use a semi‐parametric least squares procedure that allows a flexible interaction between the level of income and a first index of individual characteristics and a second index that captures the role of macroeconomic variables. We find that although inequality displays a decreasing trend over the earlier part of the period examined, the poor performance of the Spanish economy during the early 1990s appears to have reversed this trend. We also conclude that while inflation appears to have no impact on the distribution of income for the period examined, there were important redistributive roles for unemployment, government expenditure, and the level of GDP.     

Guiding the Next Generation of NIH Investigators in Responsible Conduct of Research: The Role of the Mentor

National Institutes of Health (NIH) K award recipients and their mentors were surveyed to investigate the role of the mentor. We found that a majority of mentors provided guidance in responsible research conduct (RCR), and that most of these relationships were deemed helpful. Mentors also responded that they played a greater importance in RCR training of their mentees than the mentees reported. Our results suggest both mentors and mentees report that mentors ideally should play a more important role in RCR training than was actually the case. For conflicting interests, subjects' protection, and misconduct, approximately 50% of K recipients found the mentor to be not at all important or only somewhat important for these areas of RCR training. We conclude the mentor's role is important but not optimal based on the results of our study cohort.     

A Mixture Model for Longitudinal Partially Ranked Data

This article discusses the use of mixture models in the analysis of longitudinal partially ranked data, where respondents, for example, choose only the preferred and second preferred out of a set of items. To model such data we convert it to a set of paired comparisons. Covariates can be incorporated into the model. We use a nonparametric mixture to account for unmeasured variability in individuals over time. The resulting multi-valued mass points can be interpreted as latent classes of the items. The work is illustrated by two questions on (post)materialism in three sweeps of the British Household Panel Survey.     

Assassination of political leaders: The role of social conflict

Given human aggression and warfare are often described as the most pressing behavioral problems of our time, we focus on a related phenomenon, with large-scale social, political, and economic consequences: assassination of political leaders. We explore the role of social conflict as a predictor of political assassination and use historiometric methods and an extensive archival dataset to identify and code for contextual factors associated with social conflict and political homicide. Our results indicate an increase in social conflict increases the likelihood of assassination; moreover, environmental constraints and traditional culture predict leader assassination through social conflict. We discuss implications of these findings and suggest future research on contextual factors, assassination of political leaders, and their collective-level impact.     

Pathways from origins to destinations: Stability and change in the roles of cognition,private schools and educational attainment

While much attention has been devoted to measuring levels of social mobility over time, less attention has been given to the possibility of changing pathways to social mobility. This paper examines pathways from social origins to socio-economic destinations in midlife for two British cohorts, born in 1958 and 1970 respectively, using Structural Equation Modelling (SEM). We address the roles of cognitive attainment, private schooling and educational attainment in mediating the link between social origins and destinations. Have these mechanisms become more or less important over time, in a context of structural change in the state schooling system and educational expansion? We find that private schools displayed greater academic selectivity and an increased link to high levels of educational attainment for the younger cohort. Essentially, private schools adapted to changing circumstances, becoming more academically selective and less socially selective, and more focused on educational credentials. Childhood social origins were less strongly linked to childhood cognitive scores in the younger cohort, but cognitive scores were also more weakly linked to educational attainment for this cohort. We also find a decreased association between social origins and educational attainment for the younger cohort. While the finding that educational inequalities weakened over this time period is positive, the lack of a corresponding reduction in the overall link between social origins and destinations suggests that reducing educational inequalities was not sufficient to increase social mobility when accompanied by countervailing changes in the role of private schools.     

Internet alternative media,movement experience,and radicalism: the case of post-Umbrella Movement Hong Kong

This article examines the relationship between online alternative media consumption and public support for radical social movement goals and tactics. Theoretically, online alternative media use could relate to the holding of more radical views either because such views are propagated by the alternative media or because of the breeding of extreme views through communications among like-minded people. At the same time, this relationship is expected to be particularly strong when online alternative media use is coupled with specific types of movement experiences. Analysis of a representative survey (N = 1012) in Hong Kong shows that both online alternative media use and participation in the Umbrella Movement in 2014 related positively to the attitude toward violent protests and toward Hong Kong independence, and the relationship between online alternative media use and radical views was particularly strong among the Umbrella Movement participants. The analysis also shows a distinction between the implications of consumption of alternative media belonging to different political factions.     

What have private schools done for (some of) us?

Many parents in Britain make huge financial sacrifices to send their children to private schools. Are those sacrifices worthwhile? What return, if any, do they get? Do their children end up in better careers, earning more, than if they have been educated at the expense of the state? Francis Green, Stephen Machin, Richard Murphy and Yu Zhu examine who exactly benefits from the privileges of the Old School Tie.