1,720,986 research outputs found
Valutazione dei modelli di gestione del rischio grandine nella produzione delle mele
No full textAlpine fruit farms usually insure their production (passive defense) against hail damage and rarely use anti-hail nets (active defense).
To explain the choice between two alternatives for hail risk management in the case of the production of apples, we developed a model that simulates the effects of changes in the costs per hectare with and without public aids.
The cost per hectare of insurance (passive defense) increases linearly with the rate of risk hail, ceteris paribus. The cost per hectare of anti hail nets (active defense) is always independent of the rate of risk. We can therefore determine the level of risk hail that leads to the break even point (BEP). To the left of the BEP is the preferred passive defense, active defense on the right.
The model was then validated in three areas with different levels of risk hail.
Results obtained allow evaluating how the level of hail risk influences the choice between insurance and anti-hail nets in the case of apple production. In alpine areas analyzed, the public aid moves the BEP to the right and then change the choice in favor of passive defense, perhaps because of the negative externalities (effects on the rural landscape) generated by the anti-hail nets.
Since the public aid per hectare increases linearly with the rate of hail risk, farmers choose the passive defense even when the environmental matrix is almost adverse.
There is, therefore, a lot of scope for improving the efficiency of choice, both in public and private sectors
Sequencing the movements of honey bee colonies between the forage sites with the microeconomic model of the migratory beekeeper
Full text linkA beekeeper who moves his honeybee colonies from one forage site to another during the productive season does not passively follow a prefixed sequence, but must create one by comparing a wide range of forage sites. How can migratory beekeeper sequence the movements of his honeybee colonies from one forage site to another? The microeconomic model formalized in Section 3 offers a solution to this question. The model assumes that the migratory beekeeper is following, in conditions of certainty, a profitability target under the constraint that the time taken up by each sequence of sites is less than or equal to the duration of the honeybee colonies’ annual biological cycle. Each forage site that the honeybee colonies visit contributes not just to the profitability but also to the sustainability of the sequence to which it belongs. Replacing one or more forage sites within a sequence therefore simultaneously affects the levels of profitability and sustainability. In Section 4, the sustainability of the sequence will be explained in terms of the characteristics of the sites, their agro-environmental context, the honey bee well-being and the timing and duration of the placement period of the honeybee colonies on the site
Commercial pollination of apple orchards: Val di Non case study
Full text linkThis chapter presents the results of a survey conducted in spring 2019 within the beekeepers who rent their colonies for the pollination of apple orchards in Val di Non, an alpine area in North Italy. The commercial pollination of apple orchards in this area is managed in an associated form by their cooperatives. The survey, carried out in collaboration with the local farmer cooperatives, submitted to the beekeepers a questionnaire containing questions on the economic and apidological aspects of their migratory beekeeping. The answers, referring to 43 questionnaires, show that beekeepers mostly: plan the migration itinerary at the beginning of the year; proceed to balance the colonies of honey bees before the pollination of the apple orchards; believe that the strength of the colonies must affect the pollination fee paid by the farmers and that the concentration of the colonies for the pollination of crops is not a relevant factor in the spread of bee diseases. The winter losses of honey bee colonies suffered by the responding beekeepers are on average 11.9%. The average cost of feeding the honey bee colony amounts to 19.1 €/colony. Finally, there is a wide interest in beekeepers to ensure the honey bee colonie
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
COMPATIBILITA' ECONOMICA PER LO SVILUPPO DELL'AGRICOLTURA SOSTENIBILE NEL BACINO DEL MEOLO
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Ecosystem services for farms: a methodological evaluation proposal of the pollination ecosystem service
Full text link
- …
