1,720,968 research outputs found
Effetto di sostanze biostimolanti sulla proliferazione in vitro di luppolo
No full textNello scenario attuale, fenomeni come i cambiamenti climatici o la perdita di biodiversità e le diverse problematiche ambientali influiscono negativamente sulle produzioni agricole. Una agricoltura che si possa definire moderna dovrebbe proteggersi da tali dinamiche e, a sua volta, adottare nuove strategie per ridurre al minimo il proprio impatto sugli ecosistemi. A questo proposito, l’impiego di sostanze biostimolanti sembrerebbe rappresentare una soluzione praticabile per migliorare la quantità e la qualità delle produzioni delle colture agrarie e l’efficienza d’uso dei fertilizzanti e dell’acqua, incrementando la resistenza delle piante a stress biotici e abiotici. Gli studi su questi temi sono stati avviati da tempo, sia analizzando il comportamento in pieno campo dei vegetali trattati che raccogliendo utili informazioni preliminari anche con procedure di laboratorio, più veloci e meno condizionate dalla possibile interferenza di fattori soggetti a variabilità. Lo scopo di questo lavoro è stato la valutazione degli effetti di alcune sostanze biostimolanti sulla proliferazione in vitro della varietà di luppolo “Cascade”. La scelta di tale specie coltivata non è casuale: considerando, infatti, l’incremento della domanda e del prezzo di mercato dei coni e la possibilità di diversificazione reddituale dovuta alla multifunzionalità del prodotto, il luppolo rappresenta una coltura ad elevato potenziale economico. Per di più, a causa della mancanza di un settore vivaistico specializzato sul territorio nazionale, la domanda di mercato di materiale vegetale per nuovi impianti non è ancora totalmente soddisfatta; un valido supporto al settore vivaistico può essere dato dalle colture in vitro che contribuirebbero ad aumentare il numero di piante prodotte, limitando, questo modo, il commercio di piante non certificate e di basso valore agronomico. A tal fine, anche sulla scorta di esperienze preliminari condotte su altre specie, sono stati impiegate tre differenti sostanze: Sinergon Bio-Cifo (prodotto commerciale a base di idrolizzati proteici), olio di neem (ottenuto dai semi di Azadirachta indica) ed estratto di alga spirulina (Arthrospira platensis). I risultati hanno mostrato che i trattamenti studiati hanno stimolato la crescita delle masse proliferate di luppolo, facendo rilevare, per i parametri osservati, valori superiori al controllo, con particolare riferimento alla sostanza secca delle masse neoformate. I risultati ottenuti in questa sperimentazione sono un’ottima base di partenza per studi futuri, in quanto confermano, anche su luppolo coltivato in vitro, l’efficacia dell’utilizzo dell’olio di neem, di Sinergon Bio e di Spirulina
Effetto della composizione dell’endosperma artificiale sulla conversione di microtalee incapsulate di luppolo, var. Cascade e Columbus
No full textVitro‐derived hop (Humulus lupulus L.) leaves and roots as source of bioactive compounds: antioxidant activity and polyphenolic profile
No full textBioactive compounds extracted from plant are of great value for those enterprises interested in the use of natural products; plant tissue culture techniques guarantee a reliable and constant biomass production. Hop (Humulus lupulus L.), with its wealth in bioactive compounds, may represent an invaluable resource. The present study focused on the characterization of vitro-derived leaves and roots of two hop plant types, Cascade and Gianni. Extracts obtained from the selected hop explants were investigated, determining their polyphenolic content as their antioxidant capacity, applying DPPH, ABTS and FRAP assays; moreover, extract molecular profile was obtained through UHPLC-MS/MS. Results confirm the wealthy in bioactive compounds and the antioxidant properties of the tested vitro-derived hop explants. The qualitative characterization of vitro-derived hop tissue extracts evidenced the presence of twenty one different compounds, already identified in open field grown hop plants, such as polyphenols, alpha- and beta-acids, as well as xanthohumol and isoxanthohumol. The obtained outcomes lay the groundwork to further investigate the potential of vitro-derived hop plantlets as bioactive compounds source
Sprouts of <i>Moringa oleifera</i> Lam.: Germination, Polyphenol Content and Antioxidant Activity
No full text(1) Background: In recent years, the consumption of sprouts, thanks to their high nutritional value, and the presence of bioactive compounds with antioxidant, antiviral and antibacterial properties, is becoming an increasingly widespread habit. Moringa oleifera Lam. (Moringa) seems to be an inexhaustible resource considering that many parts may be used as food or in traditional medicine; on the other hand, Moringa sprouts still lack a proper characterization needing further insights to envisage novel uses and applications. (2) Methods: In this study, a rapid and easy protocol to induce the in vivo and in vitro germination of Moringa seeds has been set up to obtain sprouts and cotyledons to be evaluated for their chemical composition. Moreover, the effects of sprouts developmental stage, type of sowing substrate, and gibberellic acid use on the chemical characteristics of extracts have been evaluated. (3) Results: Moringa seeds have a high germinability, both in in vivo and in vitro conditions. In addition, the extracts obtained have different total phenolic content and antioxidant activity. (4) Conclusions: This research provides a first-line evidence to evaluate Moringa sprouts as future novel functional food or as a valuable source of bioactive compounds
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
Bioactive compounds in hop leaves: from synthesis factors to practical applications
No full textIn recent years, consumer preference for organic and sustainably produced products has changed significantly. Growing demand has prompted both farmers and industry to rethink and adapt their production methods. This change in consumer behavior is having a profound impact on the way the industry approaches production and is driving innovation in the area of sustainability. Another consequence is that research is also focusing on new strategies for obtaining these biomolecules. In this context, recycling and reuse agri-food waste seems to be the best solution from an economic and ecological point of view.
Based on these considerations, the doctoral project focused on the use of hop plants as a source of biomolecules, in line with the 2030 Green Agenda. The hop plant, known for its cones used in beer brewing, has much more to offer and my research aimed to highlight this untapped potential.
In fact, while the cones are the main product harvested for their economic value in beer production, the rest of the plant, including the leaves and stems, is usually discarded as waste and represents a burden for the farmers. Over the last three years, this research has characterized the hop vegetative biomass in terms of bioactive compounds, in order to individuate several potential applications and increase the sustainability of the hop culture.
The research has been carried out in three research lines: i) Open field - Hop leaves: a source of bio-compounds ii) Hop biomass -from waste to resource; iii) Bioactive compounds from vitro- derived hop plantlets: a green opportunity.
On closer inspection, the first research line focused on the biochemical and molecular characterization of leaves collected from plants of ten hop varieties at the time of cone harvesting; moreover, only for the cv. Cascade, one of the most widely grown hop varieties, the development of the biochemical leaf profile during the growing cycle was investigated. In particular, the bioactivity of the leaf extracts against food-borne and additionally the possible interaction with proteins such as human insulin, amyloid beta peptide, mucin and bovine serum albumin (BSA) was evaluated, indicating their potential to counteract inflammatory processes and protect against Alzheimer’s disease.
Thanks to the collaboration with Packtin srl, a company partner of this research program, that uses innovative techniques to process plant and food waste, hop vegetative biomass was dried and pulverized to obtain a powder that was characterized and employed in different application fields. Specifically, after a biochemical characterization, hop biomass powder was used, in collaboration with University of Palermo, as ingredient in bakery product and, in collaboration with University of Ferrara, its extracts were evaluated for crop protection. Hop biomass powder confirmed its high content bioactive compounds; in detail, when added to bread, hop biomass powder improved its organoleptical and nutritional quality, extending, also, its shelf life. Extracts obtained with different solvents were tested in vitro and in vivo against the bacterium Xanthomonas campestris pv. campestris and showed promising antibacterial activity. The results demonstrated the effective antimicrobial activity of these matrices. In addition, the high efficacy, environmental compatibility and associated sustainability as well as the low cost and low toxicity make these extracts an ideal means of controlling black rot in cruciferous crops. The possibility of converting hop waste into valuable by-products opens up new opportunities for the industry and offers environmentally friendly alternatives that can reduce the amount of waste and increase the sustainability of production processes.
To further explore the potential of hop vegetative biomass, in vitro culture techniques have been applied to work independently from the seasonal constraints that normally affect hop production in the field and, moreover, guarantees a continuous and standardized supply of biomass to stakeholders.
Hop plant (cvs. Cascade, Columbus, Gianni and Magnum) in vitro multiplication was carried out at the University of Parma to obtain the vegetative biomass for further characterization. Specifically, biomass obtained in vitro from all four varieties was analysed in terms of biochemical and molecular properties, which also provides information on the potential of in vitro cultivated hop plants as a source of bioactive compounds.
In another study, four different cytokinins added to the culture medium were tested for the cvs. Cascade and Columbus at the Catholic University of Valencia to increase the production of biomolecules. The results of the growth parameters and biochemical tests showed a strong influence of the genotype on the response of the plant. Specifically, in cv. Columbus, the addition of cytokinins reduced plant growth, but triggered the synthesis of (poly)phenols and molecules with antioxidant activity.
In the last two studies, carried out in collaboration with the University of Palermo, the effects on growth parameters and the stimulation of secondary metabolism were investigated by modifying the culture system and the culture medium composition. In particular, the use of the temporary immersion system (TIS), in comparison with culture on solid medium, with or without sucrose, was tested on the cv. Cascade; while on the cv. Columbus only TIS was carried out evaluating different immersion times and the influence of sucrose in the culture medium.
In conclusion, research conducted during this PhD has demonstrated that hop plants are a valuable resource that goes far beyond their traditional use in brewing. The leaves, stems and even the vitro derived materials offer promising applications in a wide range of industrial applications, contributing to sustainability and reducing waste
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
Biochar: A Valid Additive to Enhance Kiwifruit In Vitro Proliferation
No full textBiochar, a by-product of agri-food waste, has shown benefits in plant growth and soil health. However, its use in vitro remains underexplored. This study investigates the impact of biochar supplementation in the culture medium, alone or in combination, with 6-benzylaminopurine (BAP), on kiwifruit (Actinidia chinensis var. deliciosa), cv. Tomuri proliferation. Kiwifruit explants were cultured on media enriched with 0, 4, or 6 g/L biochar, without or with BAP (0.2 mg/L), over two subcultures (SUB1 and SUB2). Parameters such as shoot and root number and length, fresh and dry weight, as well as plantlets’ total phenolic content and antioxidant activity, were measured and analyzed. Biochar enhanced plantlets proliferation, particularly with BAP. In SUB1, at 4 g/L, biochar promoted shoot production (2.00 vs. 1.63) and their length (1.50 cm vs. 0.98), independently of the presence of BAP. The presence of biochar in the BAP-free media, favored rhizogenesis; particularly in SUB2, where on average, 5.58 roots per plantlets were recorded. Biochar increased the plantlets’ total phenolic content and antioxidant activity, especially in BAP-free media. The addition of biochar as an additive to the culture medium during the kiwifruit in vitro proliferation phase could be a breakthrough outcome for the nursery sector
- …
