Adaptive estimating function inference for nonstationary determinantal point processes

Estimating function inference is indispensable for many common point process models where the joint intensities are tractable while the likelihood function is not. In this article, we establish asymptotic normality of estimating function estimators in a very general setting of nonstationary point processes. We then adapt this result to the case of nonstationary determinantal point processes, which are an important class of models for repulsive point patterns. In practice, often first‐ and second‐order estimating functions are used. For the latter, it is a common practice to omit contributions for pairs of points separated by a distance larger than some truncation distance, which is usually specified in an ad hoc manner. We suggest instead a data‐driven approach where the truncation distance is adapted automatically to the point process being fitted and where the approach integrates seamlessly with our asymptotic framework. The good performance of the adaptive approach is illustrated via simulation studies for non‐stationary determinantal point processes and by an application to a real dataset.     

Getting tuned in to those who are different: The role of empathy as mediator between diversity and performance

We present a theoretical model on the processes that mediate and moderate the diversity-performance relationship. Past research on this topic—for example the categorization elaboration model (van Knippenberg et al. 2004)—has often focused on information elaboration as mediator. Complementing this cognitive perspective, we propose that group diversity can also stimulate group members to engage with each other emotionally, resulting in higher levels of empathy—an emotional state which arises from the comprehension and apprehension of fellow group members’ emotional state. Empathy, in turn, is likely to enhance performance through processes within a single group member and through processes between group members. At the core of the model lies the proposition that group- as well as individual-level empathy mediate the relationship between diversity of organizational units and the performance of individual members and groups at large (multilevel mediation). Furthermore, we specify moderating conditions for the relationship between diversity and empathy. Diversity beliefs and diversity climates are introduced as second-order moderators.     

Estimation of the Intensity Parameter of the Germ‐Grain Quermass‐Interaction Model when the Number of Germs is not Observed

The Quermass‐interaction model allows to generalize the classical germ‐grain Boolean model in adding a morphological interaction between the grains. It enables to model random structures with specific morphologies, which are unlikely to be generated from a Boolean model. The Quermass‐interaction model depends in particular on an intensity parameter, which is impossible to estimate from classical likelihood or pseudo‐likelihood approaches because the number of points is not observable from a germ‐grain set. In this paper, we present a procedure based on the Takacs–Fiksel method, which is able to estimate all parameters of the Quermass‐interaction model, including the intensity. An intensive simulation study is conducted to assess the efficiency of the procedure and to provide practical recommendations. It also illustrates that the estimation of the intensity parameter is crucial in order to identify the model. The Quermass‐interaction model is finally fitted by our method to P. Diggle's heather data set.     

Rethinking the nation and international relations: The space of nation states

Efforts to move sociology beyond the nation state and international relations theory have both been plagued by several limitations and dualisms. Recent research has begun to find ways beyond the problems by turning to Pierre Bourdieu's relational conception of social structure and practice. Yet one specific relational structure forming a key part of the puzzle has been neglected or merely implicitly assumed so far: the space of nation states. After clarifying the structural-constructivist nature of this concept, we aim to specify it by constructing an empirical model of the contemporary space of nation states using a specially compiled dataset and tools of geometric data analysis. The analysis reveals the distribution of powers on the world scene, and more specifically, the uneven possession of two varieties of “meta-capital” understood as capacities to regulate the value and exchangeability of certain capitals and to decree what even defines a legitimate “state”. We argue that the nation state, which is accurately understood as a contingent construct and well-founded fiction from a Bourdieusian viewpoint, should not be excluded when analyzing the expression and reproduction of contemporary global power relations.     

Cognitive and organizational ergonomics in the transition of the new integrated center of control of an oil refinery: human reliability and administration of changes

The conception of a product is closely tied to its adaptation level to the users. In this view, designers are increasingly oriented to survey the needs and features of the users. This paper aims at developing a diagnosis of employees working in high-complexity activities in a petrochemical company, in light of the physical and operating changes in the Integrated Center of Control; assessing the reception sensibility to changes; assessing the cognitive pattern of the group; and making suggestions that might eliminate or minimize the difficulties in the transition process of the change, in order to reduce the adaptation period. The field of study comprised 111 production, transfer and storage operators, forming 5 groups of desktop activities. The stages of the study followed the following flow: survey of the prescribed tasks and organizational structure; Concentrated Attention test; application of the Work and Disease Risks Inventory (ITRA, Portuguese acronym); and structured psychological interview. The ITRA results pointed to a serious cognitive cost (3.83) for all five groups, this being the largest intervention focus. The items: division of task contents (3.52), social professional relationships (2.93), quality of the physical environment (2.91), physical cost (3.24), emotional cost (2.71), freedom of expression (3.77), professional fulfillment (3.41); experience and suffering (2.75), lack of recognition (2.18) and physical injuries (2.07) were considered critical. Meanwhile, social damages (1.64) and psychological injuries (1.35) are bearable. As to the Concentrated Attention test, most workers registered average level. In the individual interviews, workers showed that larger involvement in the process of physical, organizational and operational change in the desktops and on field works was required, as well as the follow up of implementations, so as to reduce the adaptation process and prevent rework (furniture, equipment, noise, form of communication with the area and training for the changes). As a result of the findings handed to the management and returned to the workers, several actions were implemented on ergonomic non-conformities found in the analysis. It is possible to prove the importance of the insertion of cognitive and organizational ergonomics in the building projects of new facilities for high-complexity activities in petrochemical plants.     

The impact of remittances from Canada's seasonal workers programme on Mexican farms

Based on a survey of participants in Canada's Seasonal Agricultural Workers Program, the authors’ three‐stage least squares estimation of a simultaneous equation model finds that migrants’ remittances enhance on‐farm investments in Mexico, which, in turn, increase farm income. Remittances are also found to have a positive influence on non‐farm income in Mexico, by giving respondents the possibility of starting a new business and diversifying their investments. These results support the hypothesis underlying the “new economics of labour migration” that remittances contribute to economic development by relaxing the credit constraint on the investment function of family farms.     

What fuels the fire: Job- or task-specific motivation (or both)? On the hierarchical and multidimensional nature of teacher motivation in relation to job burnout

Drawing on a hierarchical (job and task level) and multidimensional conceptualisation of work motivation (intrinsic, identified, introjected, and external regulations), this study examines relationships between motivational regulations and burnout. Participants were 806 French-Canadian teachers working in public elementary and high schools. Results reveal different associations between burnout and the regulations that drive teachers to engage in their overall job or in specific tasks: autonomous regulations (intrinsic and identified) are negatively associated with burnout but more negatively at the job than task level, whereas controlled regulations (introjected and external) are positively associated with burnout but more positively at the task than job level. This study provides valuable insights into how teachers’ motivations towards both the job and tasks can foster or prevent burnout symptoms. Implications for theory and research on burnout and work motivation are discussed.     

A Bayesian dose‐finding design for drug combination clinical trials based on the logistic model

In early phase dose‐finding cancer studies, the objective is to determine the maximum tolerated dose, defined as the highest dose with an acceptable dose‐limiting toxicity rate. Finding this dose for drug‐combination trials is complicated because of drug–drug interactions, and many trial designs have been proposed to address this issue. These designs rely on complicated statistical models that typically are not familiar to clinicians, and are rarely used in practice. The aim of this paper is to propose a Bayesian dose‐finding design for drug combination trials based on standard logistic regression. Under the proposed design, we continuously update the posterior estimates of the model parameters to make the decisions of dose assignment and early stopping. Simulation studies show that the proposed design is competitive and outperforms some existing designs. We also extend our design to handle delayed toxicities. Copyright © 2014 John Wiley & Sons, Ltd.     

Incremental exercise tests in master athletes and untrained older adults

This study aimed to analyze the impact of step-duration protocols, 1-min vs. 3-min, on cardiorespiratory responses to exercise, whatever the aerobic-fitness level of sedentary (65.5 +/- 2.3 years, n = 8) or highly fit (63.1 +/- 3.2 years, n = 19) participants. Heart rate and VO2 at the first and second ventilatory thresholds (VT1 ,VT2) and maximal exercise were not significantly different between the two protocols. In master athletes, the 3-min protocol elicited significantly lower ventilation at VT2 and maximal exercise (p < .01). In the latter, breathlessness was also lower at maximal exercise (p < .05) than in sedentary participants. In trained or sedentary older adults, VT1, VT2, and were not influenced by stage duration. According to the lower breathlessness and ventilation, however, the 3-min step protocol could be more appropriate in master athletes. In untrained participants, because the cardiorespiratory responses were similar with the two incremental exercise tests, either of them could be used.     

Public Administration and Organizational Theory: Prescribing the Proper Dose

Public Organization Review - Since the founding of the field of public administration, scholars have struggled with questions related to the “publicness” of public organizations...