Search results for "Frontier"

Cost-effective forest conservation and criteria for potential conservation targets: a Finnish case study

2008

International audience; Selecting reserves for forest biodiversity maintenance is often done by setting criteria for components of structural elements of biodiversity, such as a volume of decaying wood. We tested how the different threshold values for the components of structural elements affect the cost-effective site selection. Using Finnish National Forest Inventory information and remote sensing data, we determined a habitat quality index and economic value for each site in Satakunta region in Finland. Moreover, we defined several sets of potential conservation targets using alternative criteria for the habitat quality index developed for the Finnish case study. These figures were used …

2019

Conflicts between biodiversity conservation and resource production can be mitigated by multi-objective management planning. Optimizing management for multiple objectives over larger land areas likely entails trading off the practicability of the process against the goodness of the solution. It is therefore worthwhile to resolve how large areas are required as management planning regions to reconcile conflicting objectives as effectively as possible. We aimed to reveal how the extent of forestry planning regions impacts the potential to mitigate a forestry-conservation conflict in Finland, represented as a trade-off between harvest income and deadwood availability. We used forecasted data f…

To B or Not to B: Comparative Genomics Suggests Arsenophonus as a Source of B Vitamins in Whiteflies

2018

Insect lineages feeding on nutritionally restricted diets such as phloem sap, xylem sap, or blood, were able to diversify by acquiring bacterial species that complement lacking nutrients. These bacteria, considered obligate/primary endosymbionts, share a long evolutionary history with their hosts. In some cases, however, these endosymbionts are not able to fulfill all of their host's nutritional requirements, driving the acquisition of additional symbiotic species. Phloem-feeding members of the insect family Aleyrodidae (whiteflies) established an obligate relationship with Candidatus Portiera aleyrodidarum, which provides its hots with essential amino acids and carotenoids. In addition, ma…

La fortificación del Reino de Valencia en la década de1640 a la luz de la revolución militar

2019

This article proposes a study of the traditions in defensive architecture that concurred in the projects designed by Spanish military engineers for the fortification of the Valencian frontier in 1648 and 1649, in the context of the War of Catalonia (1640-1652). For this it is essential to follow the route of the Valencian adaptations to the military revolution in the matter of fortifications throughout the sixteenth century and compare them with those brought to Valencia in 1641 by the Marquis of Leganes and his engineers from the school of Milan.

A fuzzy ranking strategy for portfolio selection applied to the Spanish stock market

2007

In this paper we present a fuzzy ranking procedure for the portfolio selection problem. The uncertainty on the returns of each portfolio is approximated by means of a trapezoidal fuzzy number. The expected return and risk of the portfolio are then characteristics of that fuzzy number. A rank index that accounts for both expected return and risk is defined, allowing the decision-maker to compare different portfolios. The paper ends with an application of that fuzzy ranking strategy to the Spanish stock market.

Fuzzy Portfolio Selection Models: A Numerical Study

2012

In this chapter we analyze the numerical performance of some possibilistic models for selecting portfolios in the framework of risk-return trade-off. Portfolio optimization deals with the problem of how to allocate wealth among several assets, taking into account the uncertainty involved in the behavior of the financial markets. Different approaches for quantifying the uncertainty of the future return on the investment are considered: either assuming that the return on every individual asset is modeled as a fuzzy number or directly measuring the uncertainty associated with the return on a given portfolio. Conflicting goals representing the uncertain return on and risk of a fuzzy portfolio a…

Recensione di African Migrants and Europe. Managing the Ultimate Frontier di Lorenzo Rinelli

2016

Climate variability and agriculture in Italy: a stochastic frontier analysis at the regional level

2020

In the next future, climate change effects will represent a challenge for Europe and the Mediterranean area. These will have to cope with a rapid increase in climate variability. Although many economic sectors may be affected, agriculture is the most susceptible as climate heavily affects crop production trends, yield variability and the availability of areas suitable for cultivation. Using the stochastic frontier approach, the aim of this work is to analyse the impacts of climate variability on Italian regional technical efficiency in the agricultural sector for a period spanning from 2000 to 2009. Considering that technical inefficiency could be influenced by two main annual meteorologica…

Gender and potential wage in Europe: a stochastic frontier approach

2011

PurposeThe purpose of this paper is to provide evidence concerning wage differentials and the existence of gender pay discrimination in France, Germany, Italy, Spain and the United Kingdom.Design/methodology/approachThe authors used the stochastic frontier approach as an alternative method to measure the relevance of gender discrimination. This methodology allows them to explain the differences between the potential and the observed wage that an individual could obtain, given his or her human capital endowment.FindingsThe authors found support for wage discrimination against women. The results show that a significant part of the gender wage gap in all the countries analysed is not attributa…

Determinants and efficiency of Pakistan's chemical products' exports: An application of stochastic frontier gravity model.

2019

The estimation of efficiency of industry-specific exports is very important to find exports' gap and to frame exports promotion policy for targeted industry. This study attempts to investigate the main determinants of chemical products' exports of Pakistan with 62 trading partners by applying Stochastic Frontier Analysis (SFA) on an augmented gravity model for a period 1995-2015. The results corroborate that chemical products' exports follow gravity patterns. This study finds a negative and significant impact of import tariff on exports of chemical products while the positive impact of devaluation has been observed. Further, the estimations also take into account the impact of Preferential …