Comparing two types of navigational interfaces for Virtual Reality

Previous studies suggest significant differences between navigating virtual environments in a life-like walking manner (i.e., using treadmills or walk-in-place techniques) and virtual navigation (i.e., flying while really standing). The latter option, which usually involves hand-centric devices (e.g., joysticks), is the most common in Virtual Reality-based studies, mostly due to low costs, less space and technology demands. However, recently, new interaction devices, originally conceived for videogames have become available offering interesting potentialities for research. This study aimed to explore the potentialities of the Nintendo Wii Balance Board as a navigation interface in a Virtual Environment presented in an immersive Virtual Reality system. Comparing participants' performance while engaged in a simulated emergency egress allows determining the adequacy of such alternative navigation interface on the basis of empirical results. Forty university students participated in this study. Results show that participants were more efficient when performing navigation tasks using the Joystick than with the Balance Board. However there were no significantly differences in the behavioral compliance with exit signs. Therefore, this study suggests that, at least for tasks similar to the studied, the Balance Board have good potentiality to be used as a navigation interface for Virtual Reality systems.     

Fertility patterns in the Roma population of Spain

The Spanish Roma population have co-existed with the broader population of Spain, under the same laws and regulations for more than 500 years, but they exhibit very different fertility patterns. The aim of this paper is to determine whether there are factors other than income or education that can explain the larger number of children in Spanish Roma families. Our analysis reveals that the existence of a family business, which is highly labor-demanding, appears to be associated with parental decisions concerning the number of children. Since parental authority, in Roma families, holds sway over children even after their own marriage, the future labor contributions of children are particularly beneficial to the family business.     

Life pattern of urban trees: A growth-modelling approach

Urban afforestation improves life quality in urban centers providing social and environmental benefits. Understanding growth of urban trees exposed to air pollution will support planning, managing and expanding urban areas. This approach intends to determine growth patterns of urban trees to support future urban planning. Non-destructive samples were collected from trees of Araucaria angustifolia (Bertol.) Kuntze in Araucaria city, Parana State, Brazil. Growth rings were related to pollutant concentrations and meteorological series. Growth reduction was observed except in the border areas of the city. Trees established during or after the period of industrialization incentives were most affected by air pollution, indicating that immature plants are more vulnerable. Sulphur dioxide and nitric oxide significantly affected growth of smaller trees. Those greater than 60 cm dbh did not demonstrate significant correlation with any identified pollutant. As the trees established before accentuated urbanization were less affected by air pollution, it is reinforced the importance of preserving remaining urban trees. We suggest that planning urban afforestation should precede industries placing. When urban planning is impossible, new planted trees should not be expected to grow as in free pollution areas, but they will still present satisfactory diameter increment, contributing to improve local urban environment.     

Duration and Recurrence of Unemployment Benefits

Using administrative data for the period 2005–2010, we test for the existence of segmentation in the pool of the unemployed receiving benefits and investigate the factors associated with the duration and recurrence of the receipt of unemployment benefits in Spain. The results suggest the existence of (at least) three groups of individuals, each with different combinations of covered unemployment duration and recurrence. We also find that the impact of the employment crisis has been an increase in the average length of time spent receiving unemployment benefits and the recurrence. Our findings support the hypothesis that not only the heterogeneity but also the previous experience of receipt increase the expected duration of subsequent benefit periods.     

Dirty money? The politics of representation in Cuban revolutionary banknotes

This article examines the visual politics of Cuban postrevolutionary banknotes, focusing on the series minted in 1961. It is argued that the iconography of this series – which stresses the revolutionary merits of Fidel Castro and his movement, and associates the latter with the independence wars – portrays the Castro-led Cuban Revolution as the fulfilment of the nation’s aspiration to sovereignty. The article maintains that the design of the 1961 banknote series articulates tropes that convey a fidelista imaginary, presenting the visual rhetoric of currencies as a mechanism of propaganda and persuasion.     

A plug-in technique in nonparametric regression with dependence

The problem addressed is that of smoothing parameter selection in kernel nonparametric regression in the fixed design regression model with dependent noise. An asymptotic expression of the optimum bandwidth parameter has been obtained in recent studies, where this takes the form h = C ₀ n ^?1/5. This paper proposes to use a plug-in methodology, in order to obtain an optimum estimation of the bandwidth parameter, through preliminary estimation of the unknown value of C ₀.     

The Effect of Firm and Host Country Characteristics on the Choice of Entry Mode: Empirical Evidence from Spanish Firms

When investing abroad firms must choose betweengoing alone or with a partner – the so-calledownership structure decision. Additionally,firms can enter a new country by acquisitionsor by greenfield investments – the foreignestablishment mode decision. These twodecisions have traditionally been analyzedseparately in the literature on entry mode.What is more, this literature has much lessanalyzed hybrid entry modes, like partialacquisitions. The aim of this paper is toanalyze how the different factors analyzed inprior research influence the choice of entrymode when jointly taking into account fouralternative entry modes: greenfield whollyowned subsidiaries, greenfield joint ventures,full acquisitions and partial acquisitions. Theempirical analysis was carried out byestimating a multinomial logit model over asample of FDIs made by Spanish firms. Ourresults also contribute to the knowledge ofspecific patterns in the choice of entry modeby firms from late investor countries, likeSpain.     

Asymmetries in Information Processing in a Decision Theory Framework

Research in psychology suggests that some individuals are more sensitive to positive than to negative information while others are more sensitive to negative rather than positive information. I take these cognitive positive–negative asymmetries in information processing to a Bayesian decision-theory model and explore its consequences in terms of decisions and payoffs. I show that in monotone decision problems economic agents with more positive-responsive information structures are always better off, ex ante, when they face problems where payoffs are relatively more sensitive to the action chosen when the state of nature is favorable.      

Structure,power, and discourses of development in Spanish NGOs

Because of its recent and rapid growth, the Spanish development apparatus provides an appropriate arena for studying nongovernmental organizations (NGOs). This article uses case studies of three NGOs—Manos Unidas, Intermón Oxfam, and Madre Coraje—to explore the tension between the internal and external dynamics that affect these organizations. Although powerful external forces promote structural isomorphism with its attendant bureaucratization and professionalization, several internal factors—youth, small size, certain ideologies, charismatic leaders, and privileging identification with the organization rather than expertise when recruiting participants—resist these homogenizing processes. DiMaggio and Powell's iron cage hypothesis (1983) therefore can be only partially confirmed. We suggest an intriguing, intimate connection between charisma and democracy.     

An Empirical Analysis of Monitoring Behaviour and Private Benefits of Investors in the Spanish Market

The objective of our study is to look for anequilibrium among three factors: the privatebenefits that main shareholders can obtain fromthe firm, the social benefits derived from acertain ownership structure (such assupervision and alignment of interests) and thecosts derived from ownership concentration(such as loss of liquidity and riskdiversification). Our empirical analysis allowsus to conclude that the supervisory role ofownership is more intense in firms where thepotential conflict of interest betweenshareholders and managers is greater, andtherefore the value of the firm can beincreased through a specific composition of itsshareholders.