Pollen specialization by solitary bees in an urban landscape

Many polylectic bee species are known to specialize locally on one or a few pollen types to increase foraging efficiency. What is relatively unknown is how different landscapes influence foraging decisions, and whether habitat alteration, such as that resulting from urbanization, influences broad-scale foraging activities of bees. This study evaluates the type and diversity of pollen collected by two solitary bees that are common in Toronto, Ontario, Canada, the native Osmia pumila and the exotic O. caerulescens, sampled in trap nests set up in urban parks and gardens. We found that the dominant pollen in every successful brood cell was either of one widespread, cosmopolitan lawn-invasive plant species (Trifolium repens) or one of two wind-pollinated tree genera (Quercus spp. and Betula spp.). In combination, these three represented more than 90 % of all pollen collected by each bee species. Despite considerable overlap in the dominant pollen types collected by each bee species, the exotic O. caerulescens was significantly more specialized than the native O. pumila. Brood cells with Betula as the dominant pollen type were more pollen species-rich than those cells having Trifolium or Quercus as dominant, perhaps a result of the comparatively low protein content in Betula pollen.     

Ergonomic intervention methods for inclusion of people with disabilities at work: Brazilian scene

The aim is to identify ergonomic intervention methods used for including people with disabilities (PD) in the Brazilian labor market, with emphasis on discussion of methods to analyze the fit between the worker and the workplace. Methods to evaluate the fit of the worker to the workplace identify the capabilities and limitations of PDs and the demands of work, combining these data, and comparing them, in order to obtain a detailed analysis of the fit were drawn from national and international publications. These show that the use of specific methods for PDs and others focused on the general population. Mutatis mutandis, there is a need for complementary tools to address this segment. Thus, for the Brazilian scenario, it is essential to develop specific methodological tools to assess the capabilities of a PD so that they may better interact with their job.     

Is occupational stress associated with work engagement ?

The occupational stress is associated with dissatisfaction, excessive demand at work and personal factors. Those factors can reduce work performance and can predispose workers to various diseases. Workers' health may be protected if there is encouragement to face challenges, which may lessen the impact on psychological and somatic stress and thus have greater personal and professional satisfaction. The aim of this study was to evaluate the association between occupational stress and work engagement. Participated in this study 457 male and female workers of a metallurgical industry. Subjects answered personal data, and the Job Stress Scale and Utrecht Work Engagement Scale were applied. Results showed an association between occupational stress and work engagement (P=0,001). The way the individual deals with his frustrations, or rather the work engagement, is associated with the occupational stress.     

Ethical challenges in conducting research with hard to reach families

This paper reflects on some of the ethical challenges encountered by the authors whilst undertaking sensitive qualitative research with parents and children who are traditionally hard to reach. The research aimed to provide more holistic and in‐depth accounts of parenting on a low income in diverse social circumstances than already exist. The nature of the sample and the subject matter that was covered inevitably raised many familiar ethical dilemmas and some that are less often encountered in practice, particularly in relation to child protection. In this article we discuss our approach to ethics, some of the ethical challenges we encountered undertaking work with families and discuss the complexity of decision‐making around risk of harm to children. We conclude that a clear framework to avoid harm should be developed at the outset and a transparent approach to child protection issues should be used. Additional time and resources need to be incorporated at the planning stage of similar projects in order to develop appropriate methods, ensure effective decision‐making and support researchers. Copyright © 2008 John Wiley & Sons, Ltd.     

New two-stage sampling designs based on neoteric ranked set sampling

Neoteric ranked set sampling (NRSS) is a recently developed sampling plan, derived from the well-known ranked set sampling (RSS) scheme. It has already been proved that NRSS provides more efficient estimators for population mean and variance compared to RSS and other sampling designs based on ranked sets. In this work, we propose and evaluate the performance of some two-stage sampling designs based on NRSS. Five different sampling schemes are proposed. Through an extensive Monte Carlo simulation study, we verified that all proposed sampling designs outperform RSS, NRSS, and the original double RSS design, producing estimators for the population mean with a lower mean square error. Furthermore, as with NRSS, two-stage NRSS estimators present some bias for asymmetric distributions. We complement the study with a discussion on the relative performance of the proposed estimators. Moreover, an additional simulation based on data of the diameter and height of pine trees is presented.     

Citing history

ABSTRACT

Although rarely considered within the existing scholarship on social movements, even a cursory analysis of protest activity suggests that movements regularly invoke historical citations (whether consciously or not) while working to clarify aims and mobilize constituencies. In order to make sense of this process, and to account for the variations that arise among the different citation modalities favored by movements on opposite ends of the political spectrum, I draw upon the theoretical contributions of Marxist cultural critic Walter Benjamin and, in particular, on his exploration of ‘wish images’ and ‘dialectical images,’ their attributes, and their interrelationship. According to Benjamin, such images summoned the past either to project visions of future happiness (as with the wish image) or to deposit the witness before a moment of decisive, present-tense reckoning. After outlining the role of historical citation in social movements and in the broader cultural field through which these movements find expression, I analyze two recent protest events – the ‘Unite the Right’ rally in Charlottesville, VA, in which wish images were actively deployed, and the 2017 Women’s Strike in New York City, where a dialectical image arose from the constellated nodes of the march’s route – to consider the relationship between citation modality and protest outcome. Following from this analysis, and in keeping with the unapologetically partisan nature of my investigation, I conclude by advancing some strategic recommendations for movements seeking – as Benjamin once enjoined – to ‘improve our position in the struggle against Fascism.’     

Influence diagnostics for Student-t censored linear regression models

In this paper, we extend the censored linear regression model with normal errors to Student-t errors. A simple EM-type algorithm for iteratively computing maximum-likelihood estimates of the parameters is presented. To examine the performance of the proposed model, case-deletion and local influence techniques are developed to show its robust aspect against outlying and influential observations. This is done by the analysis of the sensitivity of the EM estimates under some usual perturbation schemes in the model or data and by inspecting some proposed diagnostic graphics. The efficacy of the method is verified through the analysis of simulated data sets and modelling a real data set first analysed under normal errors. The proposed algorithm and methods are implemented in the R package CensRegMod.     

A non-parametric regression approach to repeated measures analysis in cancer experiments

The validity conditions for univariate or multivariate analyses of repeated measures are highly sensitive to the usual assumptions. In cancer experiments, the data are frequently heteroscedastic and strongly correlated with time, and standard analyses do not perform well. Alternative non-parametric approaches can contribute to an analysis of these longitudinal data. This paper describes a method for such situations, using the results from a comparative experiment in which tumour volume is evaluated over time. First, we apply the non-parametric approach proposed by Raz in constructing a randomization Ftest for comparing treatments. A local polynomial fit is conducted to estimate the growth curves and confidence intervals for each treatment. Finally, this technique is used to estimate the velocity of tumour growth.     

Galvão among the cannibals: The emotional constitution of colonial power

Colonial domination was not a simple act of violence. Rather, it was written into the bodies and the hearts of the people—"white,” “black,” or whatever other combination might be held to exist. Using the example of the Portuguese African colonies in mid‐twentieth century, this paper aims at illuminating the emotional constitution of colonial power by exploring the uses of the trope cannibalism. In order to do that, recourse is taken to a reading of the non‐fictional writings of Henrique Galvão—one of the most active Portuguese intellectuals and Africanist politicians of the period. Subaltern persons were attributed terrible and mysterious tendencies that escaped simple rationality (they were zombified). In this way, a phantasmagoria of subalternity was constituted that, through fear, transformed domination into a structure of emotions. Thus, the repressive attitudes of colonial power were made to appear natural and unavoidable.