Occupational choices and network effects: Evidence from France

International audienc

Retirement decisions in the presence of technological change: a theoretical and an empirical approach

The paper underlines the major role of productivity as a determinant of the worker’sretirement expectations. We propose an overlapping generation model with a continuum of heterogeneous ability workers. The labor market is endogenously segmented between worker’s having the required ability level to occupy jobs where the productivity is indexed to the technological state (complex jobs) and the rest of workers who are employed in positions whose productivity will be relatively deteriorated in case of technological change (simple jobs). We show that, for a given state of technology, workers in complex positions have a latter retirement date than those in simple positions. Furthermore, in case of a positive technological change, workers in complex positions delay retirement whereas those in simple jobs advance retirement. These findings are confirmed by our empirical approach, where we find that, after a technological change, workers who benefit from a skill upgrading training program have a higher expected retirement ag

Efficacy of pre-emergence herbicides in controlling Sumatran fleabane (Conyza sumatrensis) in the off-season

Received: February 1st, 2023 ; Accepted: May 7th, 2023 ; Published: May 19th, 2023 ; Correspondence: [email protected] herbicides can be effective in controlling Sumatran fleabane (Conyza sumatrensis [Retz.] E.Walker) at soybean and other crops. The goal was to evaluate the effectiveness of sulfentrazone/diuron, imazethapyr/flumioxazin, flumioxazin, diclosulam, s-metolachlor, imazethapyr, clomazone and imazapic/imazapyr in controlling Sumatran fleabane for application in the off-season before soybean planting. Three experiments were conducted in the off season, with 9 treatments. The control of Sumatran fleabane was evaluated at 28, 42 and 49 days after application (DAA), at 49 DAA was performed counting of plants per m2 . In experiment 1, the worst performance was found for s-metolachlor (58.3% final control), in a situation of lower emergence flow of Sumatran fleabane, with equivalence for the other herbicides. In experiments 2 and 3, with greater emergence flow of Sumatran fleabane, clomazone efficacy stood out (≥ 86.3% final control). A micro-encapsulated formulation of clomazone was used, which causes greater intoxication to this weed due to its slow release into the soil, and presents less loss to the environment. In conditions of lower emergence of Sumatran fleabane, sulfentrazone/diuron, imazethapyr/flumioxazin, flumioxazin, diclosulam, imazethapyr, clomazone and imazapic/imazapyr were effective in controlling it. Even in this condition, s-metolachlor was not effective in controlling Sumatran fleabane. The application of clomazone was effective in controlling Sumatran fleabane in the three experiments. Clomazone is characterized as an important herbicide for use in the off season in the management of this weed before soybean sowing

Self-Organization and Complex Networks

In this chapter we discuss how the results developed within the theory of fractals and Self-Organized Criticality (SOC) can be fruitfully exploited as ingredients of adaptive network models. In order to maintain the presentation self-contained, we first review the basic ideas behind fractal theory and SOC. We then briefly review some results in the field of complex networks, and some of the models that have been proposed. Finally, we present a self-organized model recently proposed by Garlaschelli et al. [Nat. Phys. 3, 813 (2007)] that couples the fitness network model defined by Caldarelli et al. [Phys. Rev. Lett. 89, 258702 (2002)] with the evolution model proposed by Bak and Sneppen [Phys. Rev. Lett. 71, 4083 (1993)] as a prototype of SOC. Remarkably, we show that the results obtained for the two models separately change dramatically when they are coupled together. This indicates that self-organized networks may represent an entirely novel class of complex systems, whose properties cannot be straightforwardly understood in terms of what we have learnt so far.Comment: Book chapter in "Adaptive Networks: Theory, Models and Applications", Editors: Thilo Gross and Hiroki Sayama (Springer/NECSI Studies on Complexity Series