1,720,961 research outputs found
Precision water stress measurements to screen berry cultivars and pre-breeding material water stress tolerance for reducing water use and increasing fruit sensorial and nutritional quality
No full textAlla luce del cambiamento climatico, la siccità è emersa come un problema significativo per l'agricoltura, in particolare nelle regioni aride e semi-aride del pianeta. Questo studio affronta l'urgente necessità di identificare e selezionare piante resistenti alla siccità, sviluppando metodi applicabili dai breeders per svolgere tale compito. La seguente tesi si compone di quattro capitoli. Il primo capito è un'introduzione sul panorama dei 'berries' attuale e sulle difficoltà nella coltivazione, comportate dalla siccità. Il secondo capitolo affronta i cambiamenti dello stato fisiologico di piante di fragola, tra cultivars moderne, cultivars antiche (Fragaria x ananassa) e nuove selezioni (F. ananassa x F. chiloensis) del programma di miglioramento genetico dell'IFAPA (Malaga, Spagna) , in condizioni sia di corretta irrigazione e sia di siccità. I risultati confermano l'efficienza della carbossilazione istantanea (AN/Ci) come misura affidabile della tolleranza di una pianta alla siccità. Inoltre, le nuove selezioni basate sul germoplasma di Fragaria chiloensis hanno mostrato carenze nella resilienza al deficit idrico, al contrario di 'Rociera' che ha dimostrato una resistenza significativa alla carenza di acqua. Il terzo capitolo pone a confronto due cultivars ed una selezione del programma di miglioramento genetico fragola condotto presso l'università Politecnica delle Marche (Ancona, Italia), coltivate in un sistema a tre differenti livelli di irrigazione. Sono state valutate, oltre alla performance produttiva, anche le qualità sia organolettiche sia nutrizionali dei frutti ottenuti. 'Lauretta' si rivelata la varietà più resistente alle condizioni di siccità, preservando le molecole bio-funzionali all'interno dei frutti anche nelle condizioni di coltivazione più siccitose. L'analisi del substrato ha evidenziato un potenziale risparmio idrico del 25% ottimizzando le strategie di irrigazione. Infine, le molecole di polifenoli si sono dimostrate le più reattive in risposta alle condizioni di stress (con una tendenza ad aumentare in risposta allo stress), rendendo l'analisi dei polifenoli la procedura analitica più promettente per fare uno screening sulle piante più resistenti a carenza idrica. Il quarto capitolo, svolto in azienda (Sant'Orsola S.C.A., Pergine Valsugana, Italia), ha rivelato la performance del 'sap flow sensor' su coltivazioni di lamponi, come tecnologia per calcolare in tempo reale l'assorbimento dell'acqua di irrigazione da parte delle piante. Ciò ha evidenziato i benefici di un sistema di irrigazione a goccia, rispetto ad un sistema a sprinkler aereo. Infine tutto ciò ha permesso di testare e di confermare la necessità di integrare sistemi di questo tipo all'interno di programmi di miglioramento genetico di Rubus idaeus, per valutare le selezioni migliori nel consumo di acqua. In light of climate change, drought has emerged as a significant problem for agriculture, particularly in arid and semi-arid regions of the world. This study addresses the urgent need to identify and select drought-tolerant berry plants, and to develop methods applicable by breeders to accomplish this task. The following thesis consists of four chapters. The first chapter is an introduction to the current ‘berries’ landscape and the difficulties in cultivation caused by dryness. The second chapter deals with the changes in the physiological state of strawberry plants, between modern cultivars, old cultivars (Fragaria x ananassa) and new selections (F. ananassa x F. chiloensis) from the IFAPA genetic improvement programme (Malaga, Spain), under both correct irrigation and drought conditions. The results confirm the efficiency of instantaneous carboxylation (AN/Ci) as a reliable measure of a plant's drought tolerance. Furthermore, the new selections based on Fragaria chiloensis germplasm showed deficiencies in resilience to water deficit, in contrast to ‘Rociera’ which showed significant resistance to water scarcity. The third chapter compares two cultivars and one selection from the strawberry breeding programme conducted at the Università Politencica delle Marche (Ancona, Italy), grown in a system with three different irrigation levels. In addition to the production performance, the qualities of the fruits obtained were also evaluated. ‘Lauretta’ proved to be the most drought-resistant cultivar, preserving the bio-functional molecules within the fruit even in the driest growing conditions. The substrate analysis showed a potential water saving of 25% by optimising irrigation strategies. Finally, polyphenol molecules proved to be the most reactive in response to stress conditions, making polyphenol analysis (TPH) the most promising analytical procedure for screening the most water-deficient plants. The fourth chapter, carried out on-farm (Sant'Orsola S.C.A., Pergine Valsuga, Italy), revealed the performance of the ‘sap flow sensor’ on raspberry crops, as a reliable technology to calculate, in real time, the uptake of irrigation water by the plants. This highlighted the benefits of a drip irrigation system, compared to a sprinkler system. Finally, all this made it possible to test and confirm the necessity of integrating systems of this type into Rubus idaeus genetic improvement programmes, to evaluate the best selections in water consumption.
A study on selective laser melting (SLM) to produce a compact motorcycle heat exchanger
No full textHeat exchangers are important devices used in many
fields of industry. They play a fundamental role in determining
thermal and energetic efficiency of industrial processes and
products. Conventional heat exchangers, especially radiators are
designed to respect the conventional manufacturing methods and
have witnessed very little change in design in the last couple of
decades. The basic functioning principle of these devices can be
exploited in many different ways if the manufacturability of the
designed form is possible. Additive manufacturing technologies, in
particular selective laser melting (SLM) can open new possibility
for this kind of components, giving more freedom to their design
The present work investigates the use of SLM technology to
produce an innovative and compact motorcycle heat exchanger.
The investigation explores the potential of this technology to
develop new forms to fulfil the desired function. This preliminary
study is conducted on 18Ni300 maraging steel, a material with
known feasibility for the process, allowing to study the feasibility
of achieving thin walls within the process. The work follows a
process-based approach in designing and producing the heat
exchangers with three steps: 1- fluid flow optimization exploiting
Additive Manufacturing ability to realize complex shapes; 2-
technological feasibility of a heat exchanger’s key features: thin
walls (200 – 500 μm), 3- final testing of a compact heat exchanger
prototype through a “transient test”
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Yield and Sensorial and Nutritional Quality of Strawberry (<i>Fragaria</i> × <i>ananassa</i> Duch.) Fruits from Plants Grown Under Different Amounts of Irrigation in Soilless Cultivation
Get PDFWater scarcity is an ecological issue affecting over 10% of Europe. It is intensified by rising temperatures, leading to greater evaporation and reduced precipitation. Agriculture has been confirmed as the sector accounting for the highest water consumption globally, and it faces significant challenges relating to drought, impacting crop yields and food security. Sustainable practices, precision irrigation, and the development of drought-resistant crops are essential for the mitigation of this threat. Effective, innovative solutions are crucial for optimizing water use for intensive crops such as cultivated strawberries (Fragaria × ananassa). This study emphasizes the importance of identifying the genotypes most resilient to low water availability. Experimental trials involving reduced irrigation levels were set up to identify genotypes with a greater capacity to increase fruit quality and maintain fruit yield. Reduced water conditions positively influenced strawberry fruit quality, exhibiting improved citric acid, soluble solids, and color brightness linked to decreased water use, while firmness remained stable. Notably, the total phenolic content was most affected by stress, indicating strong antioxidant responses. With these interesting variations in fruit quality came a different response in plant yield. Plants belonging to the Lauretta and AN15,07,53 cultivars maintained a 98% fruit yield when grown under WS1 conditions. While the yield for the Francesca cultivar increased by 10% under the stressed WS1 conditions in comparison to the control conditions, water stress in the WS2 treatment caused a strong reduction in yield in all three genotypes. Overall, the findings emphasize the importance of identifying for each new cultivar the most appropriate water regime in order to amplify the quality of the fruit, thus maintaining high production standards and saving water
Variations on the Author
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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