City dwelling wild bees: how communal gardens promote species richness

Urban areas consist of wide expanses of impervious surfaces which are known to negatively affect insect biodiversity in general, but green spaces within cities have the potential to provide necessary habitat and foraging resources. Although, communal gardens were primarily intended to provide fresh, regional food to denizens, these green islands also host a surprisingly high number of wild bee species.

The gardens were characterized based on structural elements such as flower frequency, the relative percentage of lawn, trees, shrubs, planted crops and infrastructure (e.g. seating possibilities or garden houses). Further, the effects of different landscape structures surrounding the gardens and distance to the city center were analyzed on the total wild bee species richness and functional traits. Focusing on these putative influencing factors, statistical analyses calculating random decision forests along with generalized linear mixed models were applied. With 113 observed wild bee species, communal gardens provide habitat for a quarter of all known species in Vienna. In conclusion, results revealed that only elements within the gardens had an effect on species richness, with flower frequency as the major positive driver. The examined communal gardens promote and conserve wild bees independent from the location within the city or garden size. Furthermore, these green patches are important sanctuaries, hosting rare and threatened species as well as remarkably special wild bee communities.

     

The impact of child and parental age on protective factors against child maltreatment

Although young age for both the parent and child is implicated in incidences of maltreatment, little is known about the association between parent or child age and protective factors related to child maltreatment prevention. With a sample of parents receiving child maltreatment prevention services in Kansas ( N  = 1993), we used regression analyses to examine whether the interaction of child and parent age influences family‐level protective factors over time. We found mixed support for each hypothesis, indicating that the age of parents and children differentially impacts family‐level protective factors. Implications for the Strengthening Families approach and child maltreatment prevention are discussed.     

Simulation of Multivariate Gaussian Time Series

The paper discusses a simulation method for multivariate Gaussian time series by means of the discrete Fourier transform (Borgman, 1982). The procedure is quite general with respect to the correlation and spectral properties of the series and allows In addition simulations conditional on a subset of the time series. Simulations of the output from a set of ocean wave recorders are shown as an illustration of the method.     

Objective and Reputational Rankings of Ph.D.-Granting Departments of Sociology, 1965–1982

Abstract

From its inception in 1965 until 1975 when it stopped publishing such studies, The American Sociologist (TAS) published numerous quality rankings of Ph.D.-granting sociology departments and several articles that compared different rankings. During these years TAS published far more rankings of sociology departments than did any other journal This article reviews these studies as well as the rankings of sociology departments found in three major multi-disciplinary rankings (Cartter, 1966; Roose and Andersen, 1970; Jones, Lindzey, and Coggeshall, 1982). It discusses the major methodological approaches used in these studies and reviews the debate among scholars regarding the most appropriate ways to rank departments. An analysis of the various objective and subjective rankings reveals that there is an elite group of seven departments that consistently rank at the top regardless of the ranking method employed.     

Discusion

Resumen

En esta investigación se estudia la validez de una versión castellana de la escala «Environmental Concern Scale» (ECS) llevada a cabo con 716 estudiantes. Las puntuaciones obtenidas por los sujetos proambientalistas y no proambientalistas resultan significativamente diferentes. Asímismo, se estudian las relaciones entre las actitudes hacia la preocupación por el medio ambiente, la energía nuclear y la ideología política, mostrándose una relación entre ellas de diferente intensidad. Mientras la energía nuclear está fuertemente vinculada a la ideología política, no sucede en tal medida entre ésta y las actitudes conservacionistas, ya que tanto los de derechas como los de izquierdas participan de la preocupación por el medio ambiente, aunque no en la misma medida.     

ETF低成本指数基金受追捧——指数化趋势将会持续

在过去几年，基金投资有两个并行的趋势：资金大量流入ETF（交易型开放式指数基金）以及追踪股票指数的投资组合。 更多的投资者已经意识到，运作和持有这两种基金的低成本能带来其他投资难以超越的长赢优势。     

A comparison of methods for the fitting of generalized additive models

There are several procedures for fitting generalized additive models, i.e. regression models for an exponential family response where the influence of each single covariates is assumed to have unknown, potentially non-linear shape. Simulated data are used to compare a smoothing parameter optimization approach for selection of smoothness and of covariates, a stepwise approach, a mixed model approach, and a procedure based on boosting techniques. In particular it is investigated how the performance of procedures is linked to amount of information, type of response, total number of covariates, number of influential covariates, and extent of non-linearity. Measures for comparison are prediction performance, identification of influential covariates, and smoothness of fitted functions. One result is that the mixed model approach returns sparse fits with frequently over-smoothed functions, while the functions are less smooth for the boosting approach and variable selection is less strict. The other approaches are in between with respect to these measures. The boosting procedure is seen to perform very well when little information is available and/or when a large number of covariates is to be investigated. It is somewhat surprising that in scenarios with low information the fitting of a linear model, even with stepwise variable selection, has not much advantage over the fitting of an additive model when the true underlying structure is linear. In cases with more information the prediction performance of all procedures is very similar. So, in difficult data situations the boosting approach can be recommended, in others the procedures can be chosen conditional on the aim of the analysis.