Observability and Synchronization of Neuron Models

Observability is the property that enables to distinguish two different locations in $n$-dimensional state space from a reduced number of measured variables, usually just one. In high-dimensional systems it is therefore important to make sure that the variable recorded to perform the analysis conveys good observability of the system dynamics. In the case of networks composed of neuron models, the observability of the network depends nontrivially on the observability of the node dynamics and on the topology of the network. The aim of this paper is twofold. First, a study of observability is conducted using four well-known neuron models by computing three different observability coefficients. This not only clarifies observability properties of the models but also shows the limitations of applicability of each type of coefficients in the context of such models. Second, a multivariate singular spectrum analysis (M-SSA) is performed to detect phase synchronization in networks composed by neuron models. This tool, to the best of the authors' knowledge has not been used in the context of networks of neuron models. It is shown that it is possible to detect phase synchronization i)~without having to measure all the state variables, but only one from each node, and ii)~without having to estimate the phase

Five minutes with Jonathan Portes: “Policy-makers need to be much more open about the benefits of immigration”

The right to free movement is one of the founding principles of the European Union, however it has also been a source of controversy, particularly among Eurosceptic parties across Europe. In an interview with EUROPP’s editor Stuart Brown, Jonathan Portes, Director of the National Institute of Economic and Social Research, discusses the economic costs and benefits of free movement and why policy-makers should be more open about the potential gains from immigration

Efeito da rotação de culturas na atividade enzimática total do solo.

O objetivo do trabalho foi avaliar a atividade enzimática do solo, em rotações de culturas envolvendo espécies de feijão, milho, braquiária e milheto

Migration, communities-on-the-move and international innovation networks: An empirical analysis of Spanish regions

This paper investigates the impact of migration on innovation networks between regions and foreign countries. We posit that immigrants (emigrants) act as a transnational knowledge bridge between the host (home) regions and their origin (destination) countries, thus facilitating their co-inventorship networks. We also argue that the social capital of both the hosting and the moving communities reinforces such a bridging role, along with language commonality and migrants’ human capital. Focusing on Spain, as a country that hosted an intense process of migration over the past two decades, we combine patent data with national data on residents and electors abroad and we apply a gravity model to the co-inventorship between Spanish provinces (NUTS3 regions) and a number of foreign countries. Both immigrants and emigrants affect the kind of innovation networking at stake. The social capital of both the moving and the hosting communities actually moderate this impact in a positive way. The effect of migration is stronger for more skilled migrants and with respect to non-Spanish speaking countries, pointing to a language-bridging role of migrants. Policy implications are drawn accordingly

The use of the Alvarado score in the management of right lower quadrant abdominal pain in the adult

AIM OF THE STUDY: The Alvarado score is a validated test in clinical adult surgery practice which can be helpful in the diagnosis of acute appendicitis. This study aimed to assess the reliability and the reproducibility of this score for patients presenting in the emergency room with acute right lower quadrant abdominal pain. MATERIAL AND METHODS: A prospective monocenter study included all adults who presented in the emergency room with right lower quadrant abdominal pain. The score was calculated by assessing six symptoms and two laboratory values weighted by coefficients. The diagnosis of acute appendicitis was confirmed by the histological examination of the resected appendix. Three groups of patients with high, low, and intermediate scores were defined as described in the literature. RESULTS: Of the 233 patients studied, 174 underwent surgery: three had a normal appendix on histological exam. The statistical analysis of the results showed that a score lower than 4 was significantly associated with the absence of acute appendicitis while a score higher than 6 was significantly associated with acute appendicitis which required surgical care. But a score between 4 and 6 was not discriminant. CONCLUSION: The Alvarado score is a reliable, cheap and reproducible tool for the diagnosis of acute appendicitis in the emergency room; if the score is higher than 6 or lower than 4, there is no need for complementary exams. Patients with a score between 4 and 6, require serial reassessment of physical findings and score over 24 hours and/or complementary diagnostic exam such as ultrasound or CT scan

Teores de nitrogênio e de clorofilas em folhas de feijão e de soja inoculados com rizóbios.

Com o objetivo de avaliar os teores de nitrogênio total e de clorofila total em plantas de feijão e de soja conduziu-se um experimento em Goiânia-GO, utilizando delineamento inteiramente casualizado com três repetições

Work relations and the multiple dimensions of the work-life boundary: Hairstyling at home

This article proposes a multidimensional approach to analysis of the work-life boundary and examines the affects of particular social and organizational relations on the preservation or porous-ness of different dimensions. In line with Nippert-Eng (1996), it is suggested that different dimensions of the boundary are reinforced or weakened by different social and organizational pressures. Analysis describes a specific type of multidimensional breaching – instances when work is taken outside of the worksite (spatial breaching) and is carried out outside of work-time (temporal breaching). Empirical research was conducted among hairstylists working in salons and barbershops in a city in the North of England. Because of the nature of the tasks involved in hairstyling – that the skills involved are widely exchangeable and so may be employed in extra-work environments and temporalities – hairstylists provide a nice site for investigating the circumstances when this does (or does not) occur. Data collection involved a comprehensive self-completion survey of salons and barbershops in the city (response rate: 40%; N=132) and semi-structured interviews with 70 stylists working in 52 salons or barbershops. Findings demonstrate that work relations (hairstylists’ structural relations of production – whether a worker is an owner-proprietor, chair-renter, on-commission stylist, basic-only stylist, or trainee) are critical in determining both workers’ ability and desire to resist the seepage of work into their social lives as well as the particular dimensions of the boundary that are breached. This is because work relations affect the relative importance of four identified motivations for taking work out of the salon (income production; training; inter-personal reciprocity rooted in social relations; and inter-personal reciprocity rooted in the workplace)

Short communication: Genetic parameters for post-weaning visual scores and reproductive traits in Suffolk sheep

          The aim of this study was to estimate the coefficients of heritability and genetic correlations among visual scores (conformation, CPW; precocity, PPW; musculature, MPW) and reproductive traits: age at first lambing (AFL) and scrotal circumference (SC) evaluated at 180 days of age in Suffolk lambs. In the statistical model only the additive genetic effect was considered as random effect. The heritability estimates by univariate analyses for CPW, PPW, MPW, AFL and SC were 0.08, 0.12, 0.09, 0.20 and 0.22, respectively. The genetic correlations among AFL and CPW, PPW, MPW were -0.26, 0.19, and 0.08, respectively. The genetic correlation among SC and CPW, PPW, MPW were, respectively, 0.54, 0.88 and 0.86, and between AFL and SC was 0.26. The direct selection for conformation, precocity and musculature at 180 days of age and age at first lambing will provide slow genetic progress due to low heritability estimates. It is possible to obtain genetic gain in sexual precocity through selection on scrotal circumference in Suffolk rams. The favorable genetic correlation among visual scores and SC and between CPW and AFL, indicated the possibility to gain in genetic progress for reproductive traits through indirect selection of the visual scores in Suffolk sheep

Reconceptualizing Context: A Multilevel Model of the Context of Reception and Second-Generation Educational Attainment

This paper seeks to return scholarly attention to a core intellectual divide between segmented and conventional (or neo-)assimilation approaches, doing so through a theoretical and empirical reconsideration of contextual effects on second-generation outcomes. We evaluate multiple approaches to measuring receiving country contextual effects and measuring their impact on the educational attainment of the children of immigrants. We demonstrate that our proposed measures better predict second-generation educational attainment than prevailing approaches, enabling a multilevel modeling strategy that accounts for the structure of immigrant families nested within different receiving contexts