Fire and restoration of the largest urban forest of the world in Rio de Janeiro City,Brazil

National Park of Tijuca in Rio de Janeiro (Brazil) is about 3,300 ha and considered the largest urban forest in the world. Its floristic composition is typical of Atlantic Rain Forest. The reserve is being altered because of fire occurrences and urban expansion. This study identified locations and causes of forest fires, and makes management recommendations to restore damaged areas. From 1991 to 2000, forest firefighters recorded an average of 75-fire occurrences/year. Identified causes included hot air balloons (24%), intentional (24%), rubbish burning (21%) and religious practices (17%). Primary fuels included invasive grasses and ferns. Although hot air balloons destroyed larger areas of forest in each occurrence, a greater number of fires started in the invasive vegetation along roads that bisect the forest. In response to recurrent forests, invasive vegetation has spread gradually into the forest increasing forest degradation. To decrease fire damage, sites with high fire frequencies and density of invasive vegetation were planted with less flammable species. Results indicate that fire frequency decreased and density of invasive vegetation declined. This approach appears to prevent fire incidence, reduce the need for fire fighting, and preserve existing biodiversity.     

Overeducation and the skills of UK graduates

Summary.  During the early 1990s the proportion of a cohort entering higher education in the UK doubled over a short period of time. The paper investigates the effect of the expansion on graduates' early labour market attainment, focusing on overeducation. We define overeducation by combining occupation codes and a self-reported measure for the appropriateness of the match between qualification and the job. We therefore define three groups of graduates: matched, apparently overeducated and genuinely overeducated. This measure is well correlated with alternative definitions of overeducation. Comparing pre- and post-expansion cohorts of graduates, we find with this measure that the proportion of overeducated graduates has doubled, even though overeducation wage penalties have remained stable. We do not find that type of institution affects the probability of genuine overeducation. Apparently overeducated graduates are mostly indistinguishable from matched graduates, whereas genuinely overeducated graduates principally lack non-academic skills and suffer a large wage penalty. Individual unobserved heterogeneity differs between the three groups of graduates but controlling for it does not alter these conclusions.     

Human mobility and environmental change: a survey of perceptions and policy direction

Population and Environment - Research concerning human mobility in the context of environmental change is primarily focused on analyses of the nexus itself. We have taken a less-travelled route,...     

Political trust,young people and institutions in Europe. A multilevel analysis

The constant decline of political trust has been shown in political sociology. Young people in particular seem to display lower levels of political trust, which is a challenge for the sustainability of democracy. Still, these levels of political trust among youth differ greatly from one country to another. This article therefore seeks to answer the following question: How can we account for cross‐national diversity with regard to young people’s political trust? To answer this question, I performed multilevel analyses based on data from the European Social Survey. I show in the article that cross‐national diversity stems from the institutional arrangements that structure entry into adulthood, i.e., what I call ‘youth welfare citizenship regimes’: The more inclusive is the youth economic citizenship and the more individualised is their social citizenship, the higher is young people’s political trust – which could buffer the decline in political trust.     

The long-run labour market consequences of teenage motherhood in Britain

Common wisdom states that teenage childbearing reduces schooling, labour market experience and adult wages. However, the decisions to be a teenage mother, to quit school, and be less attached to the labour market might all stem from some personal or family characteristics.  Using the National Child Development Study (NCDS), we find that in Britain teenage childbearing decreases the probability of post-16 schooling by 12–24%. Employment experience is reduced by up to three years, and the adult pay differential ranges from 5% to 22%. The negative impact of teen motherhood on various adult outcomes is not only due to some pre-motherhood characteristics; hence policies aiming to encourage return to school and participation in the labour market may be an efficient way to reduce the long-term consequences of teenage pregnancy. Received: 10 October 2000/Accepted: 3 April 2002 All correspondence to Arnaud Chevalier. We are indebted to Martyn Andrews, Colm Harmon, Gauthier Lanot, Ian Walker and to the participants at the EEEG annual meeting (Southampton, 2000) and seminars at Keele University, LSE and Warwick University for their comments that greatly improved earlier versions of this paper. We also thank two anonymous referees and Christoph Schmidt for their insightful comments. All remaining errors are ours. The data was supplied by the Economic and Research Council's Data Archive at the University of Essex and are used with permission of the Controller of Her Majesty's Stationery Office. Responsible editor: Christoph M. Schmidt.     

Peakedness‐Based Staffing for Call Center Outsourcing

This study considers the staffing problem of a vendor call center in a co‐sourcing setting. The aim is to take short‐term variability and correlations in time for call arrivals at such a vendor call center into account. To do so, peakedness is proposed as a useful measure of the burstiness in the arrival stream. The study empirically demonstrates the presence of bursty arrivals at a call center and proposes an approach to the measurement of the peakedness of the arrival stream making use of standard call center data. The problematic nature of bursty arrivals in the context of call center co‐sourcing is demonstrated along with an asymptotic result establishing that the problem persists in large call centers. The study then analyzes two peakedness‐based staffing methods: one which is a well known extension of the square root staffing rule and another which makes use of the Hayward approximation principles. Both approaches are simple and enable the vendor to improve its staffing procedure with good accuracy.     

Nested Kriging predictions for datasets with a large number of observations

This work falls within the context of predicting the value of a real function at some input locations given a limited number of observations of this function. The Kriging interpolation technique (or Gaussian process regression) is often considered to tackle such a problem, but the method suffers from its computational burden when the number of observation points is large. We introduce in this article nested Kriging predictors which are constructed by aggregating sub-models based on subsets of observation points. This approach is proven to have better theoretical properties than other aggregation methods that can be found in the literature. Contrarily to some other methods it can be shown that the proposed aggregation method is consistent. Finally, the practical interest of the proposed method is illustrated on simulated datasets and on an industrial test case with \(10^4\) observations in a 6-dimensional space.     

A review of Rankian will therapy and its relevance for social casework

Conclusion In this study I have postulated on teh basis of Rankian philosophy and my own personal and professional experience that 1) self-knowledge in and of itself rarely heals; 2) a client who is accepted by another, in his totality, is able to change; and 3) persons have an inherent need to become fate-determining beings.Engaging the other in a process of willing his own growth is the central aim and way of helping. Thus, the caseworker is not a foe, educator, or passive on-looker; rather, he lendshimself, to be used or not as the client chooses. There is in the caseworker a willingness to let the client fumble, flounder, and waver until his rigid Will can soften enough to encompass and use another. A caseworker who can permit this freedom offers his steadiness as a springboard against and with whom the patient finds his own strength. This process is characterized by a slow coming together, a period of union, and a separation when the newly-won self fears, yet seeks autonomy. Having discovered that he can unite with another without being destroyed, the client leaves, not cured, yet less restricted, more open to the promises of life.     

Optimizing the Staffing and Routing of Small‐Size Hierarchical Call Centers

Multiple‐skill call centers propagate rapidly with the development of telecommunications. An abundance of literature has already been published on call centers. Here, we want to focus on centers that would typically occur in business‐to‐business environments; these are call centers that handle many types of calls but where the arrival rate for each type is low. To find an optimal configuration, the integrality of the decision variables is a much more important issue than for larger call centers. The present paper proposes an approach that uses elements of combinatorial optimization to find optimal configurations. We develop an approximation method for the evaluation of the service performance. Next, we search for the minimum‐cost configuration subject to service‐level constraints using a branch‐and‐bound algorithm. What is at stake is to find the right balance between gains resulting from the economies of scale of pooling and the higher cost or cross‐trained agents. The article shows that in most cases this method significantly decreases the staffing cost compared with configurations with only cross‐trained or dedicated operators.