1,721,272 research outputs found
Irrigation water resource in a rice-growing area : economic evaluation under different pricing conditions
Full text linkWater Framework Directive (60/20000/EC), in order to assign an appropriate cost to irrigation water resource, urges member states to introduce the concept of full cost and to adopt economic instruments to improve the efficiency of its allocation. The option to apply a volumetric supply fee promoting the rationalization of the resource, could thus play a role in addressing emerging and future problems of water scarcity.
The study aims to evaluate economic performances of farms and estimate water irrigation costs in a typical Lombard rice-cultivated area through a simple non-linear programming model. It returns the current structural features of farms, their productive inputs and performances. Secondly, different scenarios are considered, related both to a different water government, in terms of price, quantity and distribution method, and crop water requirements; in this way it is possible to analyze the observable consequences on supply and compare the output data of different scenarios.
Obtained results allow to identify critical points in water management and incentivize interventions for a better resource allocation, and their evaluation represents a useful instrument for supporting future policies on water resource
Cyclic AMP and thyroglobulin biosynthesis in the experimental rat thyroid tumor.
No full textThe cyclic AMP content and its relationship with thyroglobulin biosynthesis is determined in the experimental transplantable tumor (Wollman Line 1-1C2) in which it was previously shown a lack of sialic acid incorporation into thyroglobulin. The tumor has lower cyclic AMP content than the thyroid. The impaired thyroglobulin biosynthesis and the defective incorporation of N-acetylmannosamine into thyroglobulin is restored towards normal by the cyclic AMP analogous dibutyryl cyclic AMP. The in vitro addition to tumor slices of dibutryl cyclic AMP enhances leucine and restores to normal level sialic acid incorporation into thyroglobulin. These results indicate that the defective thyroglobulin biosynthesis is related to the low cyclic AMP content of the thyroid tumor tissue
Nessi causali tra liberalizzazione dei mercati e risicoltura europea. Una lettura attraverso l'analisi delle serie storiche
Full text linkLe principali preoccupazioni che emergono dalla completa liberalizzazione del mercato nel settore risicolo riguardano le ripercussioni sulla competitività della coltivazione del riso in Europa. La recente richiesta alla Commissione europea presentata dagli Stati Membri produttori sottolinea l'urgenza di intervenire per mitigare le ripercussioni negative sulle superfici coltivate, che si ritiene derivino dalle massicce importazioni di riso a dazio zero in provenienza dai paesi meno sviluppati (PMA). Le attuali conoscenze circa queste preoccupazioni rimangono ancora vaghe, poiché non si rifanno a strumenti analitici che possano indagare sulla reale minaccia dei mercati emergenti al settore risicolo dell'Unione. Per cercare di colmare queste lacune viene proposto l’utilizzo di un modello autoregressivo a ritardi distribuiti (ARDL) per verificare l’esistenza di una relazione causale tra la variazione delle superfici risicole in Europa e la dimensione delle importazioni di riso dai PMA. Serie storiche (1999-2017) riguardanti il commercio internazionale, l'estensione delle superfici, il sostegno interno riservato al settore vengono utilizzate a tal proposito. I risultati indicano come tutte le variabili siano associate in sia nel breve che nel lungo periodo. Tuttavia, la liberalizzazione del mercato si relaziona differentemente con le aree coltivate a riso. I risultati suggeriscono una relazione più stretta nel breve periodo, che si inverte però in un lasso di tempo più lungo. La variazione delle estensioni delle aree risicole è riconducibile principalmente all'effetto congiunto di tutti i regressori, piuttosto che a singoli elementi: solo le importazioni di riso dai PMA africani hanno stabilito un nesso causale con l’entità delle superfici coltivate, dimostrando come le importazioni dall'Asia non siano state l'unico motore di questo cambiamento
A "positive" and integrated approach to assess climate change adaptations : A case study in agriculture
Full text linkClimate change is expected to severely affect freshwater availability across much of Europe by the end of the century, with greater repercussions on the most vulnerable areas of Southern Europe and the Mediterranean basin. Agriculture is here particularly sensitive to such conditions, which may affect both irrigation water supply and crop response. In the last decade Po valley experienced a few extremely dry years, with sever water crises in most of river basins and agriculture suffering from intense water deficits and massive decrease in production. Since resource abundance rather than scarcity was often the primary concern in the region, local water institutions remain scarcely inclined to change their consolidated practices. This policy inertia represents a major barrier for novel policies, particularly under the non-stationary conditions predicted for the near future. On the other hand, the close frequency of droughts, the growing water demands, the uncertainty about future hydrological regimes urge for more sustainable solutions and force regional authorities to undertake initiatives aimed at rationalizing and containing water consumption.
Accordingly, an economic-territorial analysis based on Positive Mathematical Programming (PMP) is here proposed to depict the relevant adaptations of agriculture in a large portion of the Po Valley (i.e. Adda River Basin). The model assumes that interventions to increase water use efficiency can mitigate climate change effects, and relevant results can be explicitly derived by seeking for production patterns that (i) either properly manage or contrast resource shortages compared to the current situation and (ii) maximize farmers’ margins. The study at hand benefits from an integrated approach, based on prior climate and hydrological modelling to predict water availability and crop requirements in the near and far future. The present model combines such outputs with farm-level economic and structural data, as well as stakeholders’ perceptions on plausible scenarios; this way it is adopted for the simulation of farmers’ behaviour in response to each modified condition, and to assess the implications of adaptation strategies on farm incomes and economic viability of the territory.
Ultimately, though the use of PMP is not new for the Po Valley area, the integrated approach is particularly suited to support water administrations in facing challenges related to climate change and normative prescriptions (e.g. Water Framework Directive, Rural Development Policy). The focus on the choice of the selected area is once more important for the assessment of water scarcity problems, as the Basin also represents the reference unit identified by water regulations and policies for the analysis of their implications
La risorsa idrica ad uso irriguo in un distretto risicolo : valutazione economica in differenti condizioni di pricing
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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
Exploring the role of structural and financial factors to implement Natural Small Water Retention Measures in agriculture: insights from a survey to practitioners
Full text linkDiffuse pollution from agriculture remains a major threat to the quality of surface and
groundwater across Europe, continuing to significantly pressure water usability. Alongside soil erosion, nutrient run-off and leaching, this condition deteriorates the production capacity of agricultural areas and diminishes the potential income for farmers. In response, farmers must adapt their practices to mitigate these impacts, while addressing environmental challenges and complying with a sustainable resource management. Natural Small Water Retention Measures (NSWRMs), which leverage natural processes for pollution mitigation, offer valid alternatives in this direction. Promoted and supported by decision- and policymakers at various levels, NSWRMs represent an opportunity for farmers to wider take-up or adopt new practices to improve water quality and availability. Exploring whether and how structural conditions, financial and technical support may influence NSWRM implementation at farms is crucial for identifying current weaknesses and opportunities, and refining policies to better support farmers. This presentation stems from the activities carried out within the H2020 EU project OPTAIN (“OPtimal strategies to retAIN and re-use water and nutrients in small agricultural catchments across different soil-climatic regions in Europe”). As such, it aims to explore the current adoption status of different agricultural NSWRMs that have already demonstrated or are expected to ameliorate either water availability or quality at farm level. Through a targeted survey conducted in project case study areas, the esearch collected qualitative and quantitative data and information on farmers’ knowledge, attitudes and practices related to relevant NSWRMs. The results provide a snapshot of farmers’ perspectives on NSWRMs attractiveness and reveal insights into successful practices. In addition, the findings highlight potential bottlenecks, constraints and limitations to wider implementation, offering valuable insights and inputs for policymaker and strategic planners to direct future investments in NSWRMs effectively
Variations 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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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