A Risk Assessment Method for Biological Introductions

This article describes an application of a method for assessing risks associated with the introduction of an organism into a new environment. The test organism was a binucleate Rhizoctonia fungal isolate that has potential for commercial development as a biological control agent for damping-off diseases in bedding plants. A test sample of host plant species was selected using the centrifugal phylogenetic host range principles, but with an emphasis on economic species. The effect of the fungus on the plant was measured for each species and expressed on a logarithmic scale. The effects on weights of shoots and roots per container were not normally distributed, nor were the effects on the number of plants standing (those which survived). Statements about the effect on the number standing and the shoot weight per container involved using the observed (empirical) distribution. This is illustrated with an example. Problems were encountered in defining the population of species at risk, and in deciding how this population should be formally sampled. The limitations of the method are discussed.     

Estimating the Concentration of Propagules of a Plant Pathogen from Soil Dilution Plate Counts when the Response is Non-linear

The estimation of micro-organism concentrations from dilution plate data is discussed for situations where expected counts are not proportional to the amount of sample per plate. Aspects of design and analysis are investigated in relation to an alternative non-linear model in which the concentration is given by the slope at the origin. This exponential model generally provides a good fit to available experimental data. Simulations show that estimators based on the model perform well when the response is non-linear and remain reasonably efficient when the response is linear.     

Notes on likelihood intervals and profiling

In many applications, decisions are made on the basis of function of parameters g(θ). When the value of g(theta;) is calculated using estimated values for te parameters, its is important to have a measure of the uncertainty associated with that value of g(theta;). Likelihood ratio approaches to finding likelihood intervals for functions of parameters have been shown to be more reliable, in terms of coverage probability, than the linearization approach. Two approaches to the generalization of the profiling algorithm have been proposed in the literature to enable construction of likelihood intervals for a function of parameters (Chen and Jennrich, 1996; Bates and Watts, 1988). In this paper we show the equivalence of these two methods. We also provide and analysis of cases in which neither profiling algorithm is appropriate. For one of these cases an alternate approach is suggested Whereas generalized profiling is based on maximizing the likelihood function given a constraint on the value of g(θ), the alternative algorithm is based on optimizing g(θ) given a constraint on the value of the likelihood function.     

Multimodal representational gestures in the transition to multi-word productions

The aim of this study was to analyze the use of representational gestures from a multimodal point of view in the transition from one-word to multi-word constructions. Twenty-one Spanish-speaking children were observed longitudinally at 18, 21, 24, and 30 months of age. We analyzed the production of deictic, symbolic, and conventional gestures and their coordination with different verbal elements. Moreover, we explored the relationship between gestural multimodal and unimodal productions and independent measures of language development. Results showed that gesture production remains stable in the period studied. Whereas deictic gestures are frequent and mostly multimodal from the beginning, conventional gestures are rare and mainly unimodal. Symbolic gestures are initially unimodal, but between 24 and 30 months of age, this pattern reverses, with more multimodal symbolic gestures than unimodal. In addition, the frequency of multimodal representational gestures at specific ages seems to be positively related to independent measures of vocabulary and morphosyntax development. By contrast, the production of unimodal representational gestures appears negatively related to these measures. Our results suggest that multimodal representational gestures could have a facilitating role in the process of learning to combine meanings for communicative goals.     

Examining the Global North Migration Policies: A “Push Out – Push Back” Approach to Forced Migration

In this paper we focus on adapting the concept of push – pull factors to forced migration by proposing a “push out – push back” approach that underlines two most crucial elements of forced migrants’ experience. On the one hand, it stresses the reasons for leaving countries of origin or of temporary refuge that are not dependant on the will of people who flew those places, thus the “push out” factors. On the other hand, it represents the refusal of the countries of the Global North to accept forced migrants and their use of various practices, amounting to “push back” factors, to prevent them from entering or leaving their territory if they manage to reach it. These factors can be divided into three groups: passive, active, and symbolic.     

Constructing Clean Dreams: Accounts,Future Selves,and Social and Structural Support as Desistance Work

This article investigates the discourse individuals use when talking about desisting from criminal offending. I analyze the links between offenders’ accounts of past negative behavior, their construction of their possible “clean” future selves, and the social and structural conditions in which they were raised and continue to be embedded. Applying Scott and Lyman's (1968) framework on accounts and Markus and Nurius's (1986) framework of possible selves to interview data with twenty‐eight criminal offenders, I illustrate how excuses for past behavior provide a way for people to distance themselves from their past selves in attempts to preserve or re‐create a possible self that is still worthy to be redeemed in the future. This discourse becomes one mechanism that motivates individuals to change their lives—but it can be short‐lived. The analysis highlights how limited structural opportunities influence individuals’ lifestyles and behaviors, how individuals approach the desistance process even in the face of structural deprivation, and how they attempt to sustain this desistance process.     

When the Learning Disabled Go to College

Abstract

During the last decade, federal laws have provided for remedial education in elementary and secondary schools for students with learning disabilities, preparing large numbers of them for college. Federal law also mandates helping learning-disabled students with their needs once they matriculate. Declining numbers of high school graduates in the aftermath of the baby boom have made more colleges open their doors to these students. The disabilities, and the accommodations they require, arrive in college with the rest of a student's baggage, demanding attention. Colleges and universities have chosen a variety of approaches, from specific remedial programs and individual accomodations according to need to more general programs. Some colleges pretend these disabilities do not exist and seem oblivious to their presence on campus. Learning disabilities can have an impact in every class and lecture hall and can contribute to unhappiness and the college's attrition rate. On the other hand, responsive and responsible programs provide students with the resources for the same education, honors, and opportunities as their nondisabled peers.     

Evidence of bias in the Eurovision song contest: modelling the votes using Bayesian hierarchical models

The Eurovision Song Contest is an annual musical competition held among active members of the European Broadcasting Union since 1956. The event is televised live across Europe. Each participating country presents a song and receive a vote based on a combination of tele-voting and jury. Over the years, this has led to speculations of tactical voting, discriminating against some participants and thus inducing bias in the final results. In this paper we investigate the presence of positive or negative bias (which may roughly indicate favouritisms or discrimination) in the votes based on geographical proximity, migration and cultural characteristics of the participating countries through a Bayesian hierarchical model. Our analysis found no evidence of negative bias, although mild positive bias does seem to emerge systematically, linking voters to performers.