Search results for "Productivity"
showing 10 items of 618 documents
Evaluating carbon fluxes in orange orchards in relation to planting density
2009
SUMMARYOrange (Citrus sinensis L.) is one of the main fruit crops worldwide and its evergreen orchards may have a great potential for carbon (C) sequestration, but no data are currently available. In order to understand carbon fluxes in orange orchards, an experiment was undertaken on traditional and intensive planting systems.The experiment used C. sinensis scions grafted onto Citrus aurantium (bitter orange) rootstock. One orchard contained 14-year-old trees of the cv. Tarocco Scirè (a blood orange) grown in a traditional system with 494 trees/ha. The second orchard contained 12-year-old trees of the cv. Newhall (a seedless navel orange) grown in an intensive system with 1000 trees/ha. Ne…
Dry matter accumulation and seasonal partitioning in mature Opuntia ficus-indica (L.) Mill. fruiting trees
2014
Aim of this study was to understand the allocation of biomass into different canopy and root components and to measure the stem area index and its partitioning by cladode functionality (age), for fruiting Opuntia ficus-indica (OFI) Gialla trees, spaced 6x5 m apart and trained to a globe. The net primary productivity (NPP), calculated taking into account dry weight gain for above-ground vegetative components of OFI trees was 3.6 t C ha –1 . Including the fruit component and 1 st flush current-year cladodes, NPP of above-ground components becomes 12 t ha –1 , equivalent to 5.4 t C ha –1 . Current-year cladodes were the highest C sink (49% of total annual C fixed in the canopy), secondary grow…
Education, capital humain et dynamique économique : analyse à partir du secteur industriel sénégalais
2005
The objective of this work is to analyze the relations between education, human capital and the industrial performances in Senegal. The approached questions are different and varied, and more particularly, they relate to the investment of industrial concerns in the human resources (levels of qualification of the workforce, training policies), at the various levels of efficiency (internal and external) of the educational system, in the adequacy training / employment, etc. The impact of the human capital investment of the firms on their own performances is finally studied.
Transport infrastructures, spillover effects and regional growth: evidence of the Spanish case
2005
The impact of transport infrastructures on the economic growth of both regions and sectors, distinguishing among modes of transport, is analysed. An attempt is also made to capture the spillover effects associated with transport infrastructures. Two different methodologies are used: the first adopts an accounting approach based on a regression on indices of total factor productivity; the second uses econometric estimates of the production function. Very similar elasticities are obtained with both methodologies for the private sector of the economy, both for the aggregate capital stock of transport infrastructures and for the various types of infrastructure. However, the disaggregated result…
The resilience of Finnish farms: Exploring the interplay between agency and structure
2020
Resilience implies, in its essence, the capacity of a system to tolerate disturbances while retaining its essential functions. In the context of agriculture, resilience thinking calls for considering the ability of farms to thrive in turbulent times along with the ability of the ecological system – in which the agricultural production is embedded – to retain its function and integrity. Resilience is a relevant conceptual tool to analyse the contradictory management demands that farms are facing within the current neoliberal market regime: being economically viable and environmentally sustainable. In this study, the resilience of farms was operationalised through farmers' perceptions concern…
Trophic ecology of the swimming crab Polybius henslowii Leach, 1820 in Galician and Cantabrian Seas: Influences of natural variability and the Presti…
2008
9 pages, 9 figures, 2 tables.-- Printed version published Nov 15, 2008.
Biomasse, productivité et transferts de matière organique dans une séquence altitudinale de peuplements de Castanea sativa Mill de l'Etna
1996
Les differents compartiments et flux caracterisant la repartition de la matiere organique sont etudies dans quatre taillis de Castanea sativa Mill, etages le long d'un gradient altitudinal, dans le massif de l'Etna (Sicile). Les biomasses epigees sont respectivement de 22 et de 24 Mg ha -1 a 7 ans, 83 Mg ha -1 a 12 ans et 100 Mg ha -1 a 22 ans, avec de bonnes correlations : biomasse/âge et biomasse/facteurs climatiques. Le bois represente 95 % et les feuilles 5 % de ces biomasses. Les productions aeriennes perennes s'echelonnent entre 2,4 et 5,4 Mg ha -1 an -1 en relation a la fois avec l'âge des taillis et leur localisation geographique. Les retombees de litiere, observees durant 3 annees …
The impact of the Little ice age on coccolithophores in the central Mediterranea Sea
2010
The Little Ice Age (LIA) is the last episode of a series of Holocene climatic anomalies. There is still little knowledge on the response of the marine environment to the pronounced cooling of the LIA and to the transition towards the 20th century global warming. Here we present decadal-scale coccolithophore data from four short cores recovered from the central Mediterranean Sea (northern Sicily Channel and Tyrrhenian Sea), which on the basis of <sup>210</sup>Pb activity span the last 200–350 years. The lowermost part of the record of one of the cores from the Sicily Channel, Station 407, which extends down to 1650 AD, is characterized by drastic changes in productivity. Specific…
Regulation and efficiency: the case of European railways
2001
Abstract During the long period of regulation of the railway system in Europe (1950s–1990s) the companies notably improved their levels of productivity. However, parallel to this, the state of their financial accounts also significantly worsened. In order to explain this fact we have estimated both cost and revenue frontier functions, calculating the losses associated with both cost and revenue inefficiencies as well as inefficiencies on the cost side. The results obtained show the existence of significant potential losses of revenue, which can be explained above all by the strong policy of regulation and intervention reigning in this period. A better commercial policy and a supply adapted …
The Global Research Collaboration of Network Meta-Analysis: A Social Network Analysis
2016
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