Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
164 result(s) for "Valentini, Gabriele"
Sort by:
A Design Pattern for Decentralised Decision Making
The engineering of large-scale decentralised systems requires sound methodologies to guarantee the attainment of the desired macroscopic system-level behaviour given the microscopic individual-level implementation. While a general-purpose methodology is currently out of reach, specific solutions can be given to broad classes of problems by means of well-conceived design patterns. We propose a design pattern for collective decision making grounded on experimental/theoretical studies of the nest-site selection behaviour observed in honeybee swarms (Apis mellifera). The way in which honeybee swarms arrive at consensus is fairly well-understood at the macroscopic level. We provide formal guidelines for the microscopic implementation of collective decisions to quantitatively match the macroscopic predictions. We discuss implementation strategies based on both homogeneous and heterogeneous multiagent systems, and we provide means to deal with spatial and topological factors that have a bearing on the micro-macro link. Finally, we exploit the design pattern in two case studies that showcase the viability of the approach. Besides engineering, such a design pattern can prove useful for a deeper understanding of decision making in natural systems thanks to the inclusion of individual heterogeneities and spatial factors, which are often disregarded in theoretical modelling.
The non-additive effects of body size on nest architecture in a polymorphic ant
Like traditional organisms, eusocial insect societies express traits that are the target of natural selection. Variation at the colony level emerges from the combined attributes of thousands of workers and may yield characteristics not predicted from individual phenotypes. By manipulating the ratios of worker types, the basis of complex, colony-level traits can be reduced to the additive and non-additive interactions of their component parts. In this study, we investigated the independent and synergistic effects of body size on nest architecture in a seasonally polymorphic harvester ant, Veromessor pergandei. Using network analysis, we compared wax casts of nests, and found that mixed-size groups built longer nests, excavated more sand and produced greater architectural complexity than single-sized worker groups. The nests built by polymorphic groups were not only larger in absolute terms, but larger than expected based on the combined contributions of both size classes in isolation. In effect, the interactions of different worker types yielded a colony-level trait that was not predicted from the sum of its parts. In nature, V. pergandei colonies with fewer fathers produce smaller workers each summer, and produce more workers annually. Because body size is linked to multiple colony-level traits, our findings demonstrate how selection acting on one characteristic, like mating frequency, could also shape unrelated characteristics, like nest architecture. This article is part of the theme issue ‘Interdisciplinary approaches for uncovering the impacts of architecture on collective behaviour'.
The Evolution of Phenolic Compounds in Vitis vinifera L. Red Berries during Ripening: Analysis and Role on Wine Sensory—A Review
The study of phenolic maturity in Vitis vinifera L. requires a multidisciplinary approach to understand how the evolution of berry flavonoids and cell wall material influence the colour and the textures of red wine. This is a challenging issue which involves researchers of viticulture and enology, and the results of their work are of particular interest for the producers of high-quality red wines. This review reports the current knowledge regarding phenolic maturity, describing the sensorial traits of the different compounds, the evolution of berry flavonoids and the methodologies used to evaluate their characteristics. Finally, the role of cell wall material in influencing the extractability of anthocyanins and proanthocyanidins was shown. By means of a critical review of the results, it can be hypothesised that prolonged ripening improved colour characteristics and mouthfeel properties, thanks to the higher amounts of extractable skin flavonoids associated with lower amounts of seed proanthocyanidins, and to the increased affinity of the cell wall material for the proanthocyanidins most involved in the perception of unpleasant astringency.
Whole Plant Temperature Manipulation Affects Flavonoid Metabolism and the Transcriptome of Grapevine Berries
Among environmental factors, temperature is the one that poses serious threats to viticulture in the present and future scenarios of global climate change. In this work, we evaluated the effects on berry ripening of two thermal regimes, imposed from veraison to harvest. Potted vines were grown in two air-conditioned greenhouses with High Temperature (HT) and Low Temperature (LT) regimes characterized by 26 and 21°C as average and 42 and 35°C as maximum air daily temperature, respectively. We conducted analyses of the main berry compositional parameters, berry skin flavonoids and berry skin transcriptome on HT and LT berries sampled during ripening. The two thermal conditions strongly differentiated the berries. HT regime increased sugar accumulation at the beginning of ripening, but not at harvest, when HT treatment contributed to a slight total acidity reduction and pH increase. Conversely, growing temperatures greatly impacted on anthocyanin and flavonol concentrations, which resulted as strongly reduced, while no effects were found on skin tannins accumulation. Berry transcriptome was analyzed with several approaches in order to identify genes with different expression profile in berries ripened under HT or LT conditions. The analysis of whole transcriptome showed that the main differences emerging from this approach appeared to be more due to a shift in the ripening process, rather than to a strong rearrangement at transcriptional level, revealing that the LT temperature regime could delay berry ripening, at least in the early stages. Moreover, the results of the in-depth screening of genes differentially expressed in HT and LT did not highlight differences in the expression of transcripts involved in the biosynthesis of flavonoids (with the exception of PAL and STS) despite the enzymatic activities of PALs and UFGT being significantly higher in LT than HT. This suggests only a partial correlation between molecular and biochemical data in our conditions and the putative existence of post-transcriptional and post-translational mechanisms playing significant roles in the regulation of flavonoid metabolic pathways and in particular of anthocyanins.
Optimizing Viticulture Sustainability Through Foliar Zeolite Treatments: An In‐Depth Analysis of Their Impact on Gas Exchange, Yield, and the Composition of Sangiovese Grapes and Wine
In response to increasingly hot and dry summers driven by climate change, grapevines ( Vitis vinifera L.) can utilize adaptive mechanisms that often prioritize survival over yield and grape quality. The efficiency of the vine canopy, particularly in terms of gas exchange and net assimilation, declines with water scarcity, underscoring the importance of mitigating strategies such as emergency irrigation. However, in Mediterranean vineyards, water shortages often render irrigation impractical. An alternative approach is the application of minerals, such as zeolites, to mitigate the negative effects of summer stress. This study aimed to evaluate the physiological, vegetative–productive, and qualitative effects of chabazite‐rich zeolite treatments on potted grapevines subjected to both water and heat stress, and on field‐grown vines exposed only to heat stress. The research was conducted over a 3‐year period (2021–2023) on Sangiovese grapevines, divided into two distinct trials: the first on potted vines (2021) and the second on field‐grown vines (2022–2023). The potted trial involved 12 plants placed on lysimeters, subjected to water restriction (50% restitution of water lost through transpiration), and divided into two treatments: water stress vines (WS) and WS vines treated with natural zeolite (WS + ZEO). The field trial involved 24 nonirrigated plants with two treatments: untreated control (WS) and zeolite treatment (WS + ZEO). Microclimatic conditions were monitored during ripening, and the effects of zeolite were assessed in terms of canopy physiology, yield, sunburn damage, and grape composition. Grapes from the field trial vines were microvinified, and the resulting wine color was analyzed twice, after 3 months and 1 year. The results showed that zeolite treatments effectively reduced canopy temperature by two degrees Celsius, enhancing gas exchange efficiency and photosynthetic activity in potted vines. In field‐grown vines, these treatments significantly improved grape composition, particularly boosting total anthocyanin levels by 19% in the berries and 10% in the resulting wine, compared to the untreated control. In conclusion, zeolite‐based treatments appear to be a valuable tool for improving the productive performance of Sangiovese in environments characterized by multiple summer stresses.
Adult-onset Still’s disease: evaluation of prognostic tools and validation of the systemic score by analysis of 100 cases from three centers
Background Adult-onset Still’s disease (AOSD) is rare inflammatory disease of unknown etiology that usually affects young adults. The more common clinical manifestations are spiking fevers, arthritis, evanescent rash, elevated liver enzymes, lymphadenopathy, hepatosplenomegaly, and serositis. The multi-visceral involvement of the disease and the different complications, such as macrophage activation syndrome, may strongly decrease the life expectancy of AOSD patients. Methods This study aimed to identify the positive and negative features correlated with the outcome of patients. A retrospective analysis of AOSD patients prospectively admitted to three rheumatologic centers was performed to identify the clinical features present at the time of diagnosis and to predict the possible outcome. Furthermore, we investigated the as yet to be validated prognostic value of the systemic score previously proposed. Results One hundred consecutive AOSD patients were enrolled. The mean systemic score showed that the majority of patients had a multi-organ involvement. Sixteen patients showed different complications, mainly the macrophage activation syndrome. A strong increase of inflammatory markers was observed. All patients received steroids at different dosages, 55 patients in association with immunosuppressive drugs and 32 in association with biologic agents. Sixteen patients died during the follow-up. Regression analysis showed that the higher values of the systemic score and the presence of AOSD-related complications, assessed at the time of diagnosis, were significantly correlated with patient mortality. A prognostic impact of the systemic score of ≥ 7.0 was reported. Conclusions Our study showed that a higher systemic score and the presence of AOSD-related complications at the time of diagnosis were significantly associated with mortality. Of note, a cut-off at 7.0 of the systemic score showed a strong prognostic impact in identifying patients at risk of AOSD-related death.
Naïve individuals promote collective exploration in homing pigeons
Group-living animals that rely on stable foraging or migratory routes can develop behavioural traditions to pass route information down to inexperienced individuals. Striking a balance between exploitation of social information and exploration for better alternatives is essential to prevent the spread of maladaptive traditions. We investigated this balance during cumulative route development in the homing pigeon Columba livia . We quantified information transfer within pairs of birds in a transmission-chain experiment and determined how birds with different levels of experience contributed to the exploration–exploitation trade-off. Newly introduced naïve individuals were initially more likely to initiate exploration than experienced birds, but the pair soon settled into a pattern of alternating leadership with both birds contributing equally. Experimental pairs showed an oscillating pattern of exploration over generations that might facilitate the discovery of more efficient routes. Our results introduce a new perspective on the roles of leadership and information pooling in the context of collective learning.
Zeolite application and irrigation during ripening reduced berry sunburn damage and yield loss in cv. Sangiovese (Vitis vinifera L.)
Climate change poses significant challenges to the grapevine cultivation for wine production. In the last years, the occurrence of extreme weather events such as intense heat waves and prolonged period of drought increased sunburn damage with negative consequences to yield and berry composition. Short-term adaptation strategies are urgently needed to mitigate these effects. In this light, our study aimed to evaluate the efficacy of zeolite application on the canopy and irrigation during ripening on sunburn damage, yield, and berry composition in cv. Sangiovese ( Vitis vinifera L.). Over 3 years (2021–2023), canopy management and irrigation treatments were arranged in a strip-plot design. Canopy management treatments included leaf removal on the cluster zone, with and without zeolite application, and no defoliated control; irrigation treatments comprised irrigation from berry softening and no irrigation. Both zeolite application and irrigation reduced sunburn damage, thus mitigating yield loss. Regarding berry composition, zeolite application did not alter the main parameters whereas irrigation led to reductions in sugar and anthocyanin concentrations. These findings suggest that zeolite application and irrigation during ripening represent promising and cost-effective solutions for grape growers facing climate change-induced challenges. However, further studies are necessary to optimize timing of irrigation to avoid detrimental effects on anthocyanin accumulation.
Coordination of movement via complementary interactions of leaders and followers in termite mating pairs
In collective animal motion, coordination is often achieved by feedback between leaders and followers. For stable coordination, a leader's signals and a follower's responses are hypothesized to be attuned to each other. However, their roles are difficult to disentangle in species with highly coordinated movements, hiding potential diversity of behavioural mechanisms for collective behaviour. Here, we show that two Coptotermes termite species achieve a similar level of coordination via distinct sets of complementary leader–follower interactions. Even though C. gestroi females produce less pheromone than C. formosanus , tandem runs of both species were stable. Heterospecific pairs with C. gestroi males were also stable, but not those with C. formosanus males. We attributed this to the males' adaptation to the conspecific females; C. gestroi males have a unique capacity to follow females with small amounts of pheromone, while C. formosanus males reject C. gestroi females as unsuitable but are competitive over females with large amounts of pheromone. An information-theoretic analysis supported this conclusion by detecting information flow from female to male only in stable tandems. Our study highlights cryptic interspecific variation in movement coordination, a source of novelty for the evolution of social interactions.
The European Scleroderma Trials and Research group (EUSTAR) task force for the development of revised activity criteria for systemic sclerosis: derivation and validation of a preliminarily revised EUSTAR activity index
BackgroundValidity of European Scleroderma Study Group (EScSG) activity indexes currently used to assess disease activity in systemic sclerosis (SSc) has been criticised.MethodsThree investigators assigned an activity score on a 0–10 scale for 97 clinical charts. The median score served as gold standard. Two other investigators labelled the disease as inactive/moderately active or active/very active. Univariate–multivariate linear regression analyses were used to define variables predicting the ‘gold standard’, their weight and derive an activity index. The cut-off point of the index best separating active/very active from inactive/moderately active disease was identified by a receiver-operating curve analysis. The index was validated on a second set of 60 charts assessed by three different investigators on a 0–10 scale and defined as inactive/moderately active or active/very active by other two investigators. One hundred and twenty-three were investigated for changes over time in the index and their relationships with those in the summed Medsger severity score (MSS).ResultsA weighted 10-point activity index was identified and validated: Δ-skin=1.5 (Δ=patient assessed worsening during the previous month), modified Rodnan skin score (mRss) >18=1.5, digital ulcers=1.5, tendon friction rubs=2.25, C-reactive protein >1 mg/dL=2.25 and diffusing capacity of the lung for CO (DLCO) % predicted <70%=1.0. A cut-off ≥2.5 was found to identify patients with active disease. Changes in the index paralleled those of MSS (p=0.0001).ConclusionsA preliminarily revised SSc activity index has been developed and validated, providing a valuable tool for clinical practice and observational studies.