On a Centrality Maximization Game

The Bonacich centrality is a well-known measure of the relative importance of nodes in a network. This notion is, for example, at the core of Google's PageRank algorithm. In this paper we study a network formation game where each player corresponds to a node in the network to be formed and can decide how to rewire his m out-links aiming at maximizing his own Bonacich centrality, which is his utility function. We study the Nash equilibria (NE) and the best response dynamics of this game and we provide a complete classification of the set of NE when m=1 and a fairly complete classification of the NE when m=2. Our analysis shows that the centrality maximization performed by each node tends to create undirected and disconnected or loosely connected networks, namely 2-cliques for m=1 and rings or a special "Butterfly"-shaped graph when m=2. Our results build on locality property of the best response function in such game that we formalize and prove in the paper.Comment: 10 pages, 11 figure

Power, Structure, Gender Relations and Community-Based Conservation: The Cawswe Study of the Sariska Region, Rajasthan, India

Most current community development projects have a built in gender component. Despite the WID, WED and GAD schools of thought there is still however a long way to go in order to effectively implement these principles in conservation projects. Merely getting women a place on the policy-making agenda is not enough, especially if it comes at the cost of promoting a simplistic and often wildly inaccurate picture of gender-environment relations. This article analyses the repercussions of community-based conservation on women in terms of use, access, and control of natural resources. The area chosen is the Sariska region of Rajasthan, India. The article analyses also the role of women inside the Gram Sabbha, which is the village institution used at community level for the management of natural resources. A distinction is made between the different groups of women. The issue of women’s empowerment and its importance in community-based conservation will also be discussed

The JAMU System in Indonesia: Linking Small-Scale Enterprises, Traditional Knowledge and Social Empowerment Among Women in Indonesia

Medicinal plants have been used extensively in numerous countries, Indonesia included, in the domain of traditional medicine and of natural product industry. Few studies have focused on the commercial aspects of medicinal plants in local communities and on its potential impact on gender development in urban and peri-urban areas. This article aims to analyze the impact of women enterprises active in the traditional herbal sector (jamu) in Indonesia in terms of household revenues and social status. The paper emphasizes how, despite the important socio-economic results of small-scale enterprises in the jamu sector in the city of Jogjakarta, some challenges of the potential of this commercial activity on local women still remain

Abuse of Lower Castes in South India: The Institution of Devadasi

The ‘devadasi’ system has been the object of several studies and is quite controversial. Some authors, particularly in the past associated the ‘devadasi’ with power and prestige, other, more lately, with degradation and prostitution. This article firstly explores the origin of ‘devadasi’ practice and its evolution over time as well as its religious and ritual meaning, while attempting to identify the main factors explaining the signification of the ‘devadasi’ system in the past. Secondly it analyses the social status and economic condition of ‘devadasis’ and draws a global view of the reasons why young girls are still today consecrated in rural areas. Our argument is that the sanctions provided by social custom and apparently by religion are strictly combined with economic and social pressures. The social control and hegemonic masculinity of upper caste men is asserted and maintained through defilement and appropriation of lower caste and ‘dalit’ women’s sexuality. The symbolic meaning of the devadasis relies upon the gendering and sexualising of caste relations of domination and subordination. In this logic, this article examines the intersections between gender, caste and violence

Neuronal nicotinic receptors modulate glutamatergic transmission on neonatal rat hypoglossal motoneurons

In the neonate the muscles of the tongue, which are exclusively innervated by the XII cranial nerves originating from the brainstem nucleus hypoglossus, must contract rhythmically in coincidence with breathing, suckling and swallowing. These motor commands are generated by hypoglossal motoneurons excited by glutamatergic inputs. Since in forebrain areas the efficiency of glutamatergic transmission is modulated by neuronal nicotinic receptors (nAChRs), the role and identity of nAChRs within the nucleus hypoglossus of the neonatal rat were explored using an in vitro brainstem slice preparation. This area expressed immunoreactivity for a4, a7 and b2 subunits. Whole cell patch clamp recording from hypoglossal motoneurons showed lack of spontaneous cholinergic events mediated by nAChRs even in the presence of a cholinesterase inhibitor. However, pharmacological antagonism of a7 or b2 containing receptors depressed glutamatergic currents arising either spontaneously or by electrical stimulation of the reticular formation. Hypoglossal motoneurons expressed functional nAChRs with characteristics of a4b2 and a7 receptor subunits, and displaying fast desensitization (time constant of 200 ms) from which full recovery developed within one min. Low (0.5 \ub5M) concentration of nicotine first facilitated glutamatergic transmission on motoneurons and later depressed it through receptor desensitization. When 0.1 \ub5M nicotine was used, only depression of synaptic transmission occurred, in keeping with the suggestion that nAChRs can be desensitized without prior activation. These results highlight the role of tonic nAChR activity in shaping excitatory inputs to hypoglossal motoneurons and suggest that their desensitization by ambient nicotine could contribute to disorders of tongue muscle movements

Comparison of Multispectral and Hyperspectral UAV Imagery for Late Blight (Phytophtora infestans) detection in a potato (Solanum tuberosum) field

Mestrado em Engenharia Agronómica. Universidade de Lisboa, Instituto Superior de AgronomiaLate Blight (LB) is of high concern in the potato crop production. The disease, caused by the oomycete Phytophtora infestans, is responsible for causing huge impacts on the global production. A prompt and specific control, besides being most likely to succeed, enables strategies of small-scale site-specific management which, when combined with a correct detection and good decision model, are expected to reduce the pesticide use. The detection of diseased plants with multispectral and hyperspectral UAV imagery has a great potential in improving LB management and control. In this context, the Portuguese company HPDRONES, within the PG-PSA project, wants to investigate the use of hyperspectral solutions for LB early detection. A drone embedded with a hyperspectral camera has been flighted across an experimental plot in the Ribatejo region. The present work provide an exemplification of a model for the detection of LB using UAV imagery in an open field of potato, involving the use of drones for the image collection and of machine learning algorithms to implement the data analysis. A supervised classification method is proposed. The result is a hyperspectral classifier able to perform an accurate LB detection. On the basis of the limitation of the hyperspectral technologies, a sensitivity approach is proposed, in which spatial and spectral degraded data are used to evaluate the classification’s success under different conditions. The results suggest that the use of drones with multispectral sensors or using different operational parameters (i.e. flight altitude) do not affect the efficiency of the LB detection.O míldio é uma das principais doenças que afeta a produção de batata. A doença, causada pelo oomiceta Phytophtora infestans, é responsável por ter grandes impactos na produção mundial desta cultura. Um controle rápido e específico, para além de ter maior probabilidade de sucesso, permite estratégias de controle smallscale e site-specific que, quando combinadas com uma detecção correta e um modelo de decisão adequado, conseguem reduzir sensivelmente o uso de pesticidas. A detecção de plantas doentes através de imagens multiespectrais e hiperespectrais de drone tem um grande potencial para o controle de míldio. Neste contexto, a empresa portuguesa HPDRONES, no âmbito do projeto PG-PSA, pretende investigar a utilização de soluções hiperespectrais para a deteção precoce de míldio. Para o efeito, foi usado um drone com uma câmara hiperespectral para a captura das imagens aéreas de uma parcela experimental localizada na região do Ribatejo. O presente trabalho oferece uma exemplificação de um modelo de detecção de míldio usando imagens coletadas em um campo aberto de batata, envolvendo o uso de drones para a coleta de imagens e de algoritmos de aprendizagem para implementar a análise de dados. Propõe-se um método de classificação supervisionado. O resultado é um classificador hiperespectral capaz de detectar a presença de míldio em campo. Com base nas limitações das tecnologias hiperespectrais, propõe-se uma análise de sensibilidade, através da qual os dados espaciais e espectrais degradados são usados para avaliar o sucesso da classificação sob diferentes condições. Os resultados sugerem que o uso de drones com sensores multiespectrais ou usar diferentes parâmetros operacionais (ou seja, altitude de voo) não afeta a eficiência da detecção de míldio.N/