Inherent variation of functional traits in winter and summer leaves of Mediterranean seasonal dimorphic species. Evidence of a 'within leaf cohort' spectrum

The covariation pattern among leaf functional traits involved in resource acquisition has been successfully provided by the leaf economic spectrum (LES). Nevertheless, some aspects such as how the leaf trait variation sources affect LES predictions are still little investigated. Accordingly, the aim of this paper was to test whether leaf trait variations within different leaf cohorts could alter LES. Improving this knowledge can extend the potential of trait-based approaches in simulating future climate effects on ecosystems. A database on leaf morphological and physiological traits from different leaf cohorts of Cistus spp. was built by collecting data from literature. These species are seasonal dimorphic shrubs with two well-defined leaf cohorts during a year: summer leaves (SL) and winter leaves (WL). Traits included: leaf mass area (LMA), leaf thickness (LT), leaf tissue density (LTD), net photosynthetic rate on area (Aa) and mass (Am) base, nitrogen content on area (Na) and mass (Nm) base. The obtained patterns were analysed by standardized major axis regression and then compared with the global spectrum of evergreens and deciduous species. Climatic variable effect on leaf traits was also tested. Winter leaves and SL showed a great inherent variability for all the considered traits. Nevertheless, some relationships differed in terms of slopes or intercepts between SL and WL and between leaf cohorts and the global spectrum of evergreens and deciduous. Moreover, climatic variables differently affected leaf traits in SL and WL. The results show the existence of a 'within leaf cohort' spectrum, providing the first evidence on the role of leaf cohorts as LES source of variation. In fact, WL showed a high return strategy as they tended to maximize, in a short time, resource acquisition with a lower dry mass investment, while SL were characterized by a low return strategy

Short-term physiological plasticity.Trade-off between drought and recovery responses in three Mediterranean cistus species

Short-term physiological plasticity allows plants to thrive in highly variable environments such as the Mediterranean ecosystems. In such context, plants that maximize physiological performance under favorable conditions, such as Cistus spp., are generally reported to have a great cost in terms of plasticity (i.e., a high short-term physiological plasticity) due to the severe reduction of physiological performance when stress factors occur. However, Cistus spp. also show a noticeable resilience ability in response to stress factors. We hypothesized that in Cistus species the short-term physiological response to stress and that to subsequent recovery can show a positive trade-off to offset the costs of the photosynthetic decline under drought. Gas exchange, chlorophyll fluorescence, and water relations were measured in C. salvifolius, C. monspeliensis, and C. creticus subsp. eriocephalus during an imposed experimental drought and subsequent recovery. Plants were grown outdoor in common garden conditions from seeds of different provenances. The short-term physiological response to stress and that to recovery were quantified via phenotypic plasticity index (PIstress and PIrecovery, respectively). A linear regression analysis was used to identify the hypothesized trade-off PIstress-PIrecovery. Accordingly, we found a positive trade-off between PIstress and PIrecovery, which was consistent across species and provenances. This result contributes in explaining the profit, more than the cost, of a higher physiological plasticity in response to short-term stress imposition for Cistus spp because the costs of a higher PIstress are payed back by an as much higher PIrecovery. The absence of leaf shedding during short-term drought supports this view. The trade-off well described the relative variations of gas exchange and water relation parameters. Moreover, the results were in accordance with the ecology of this species and provide the first evidence of a consistent trade-off between the short-term physiological responses to drought and recovery phases in Mediterranean species

Design by copying: a methodology for product design - case study of coupled by PumPum®

LAUREA MAGISTRALEQuesta tesi esplora l'applicazione della metodologia pragmatica "Design by Copying" nel redesign di Coupled by PumPum®, un'applicazione per le relazioni. In un'era in cui le interfacce digitali dominano le interazioni personali, garantire un'ottima usabilità e coinvolgimento è fondamentale per il successo di un'app. Questa ricerca documenta il percorso dall'analisi iniziale a un redesign completo, con un focus sulla retention (utilizzo prolungato nel tempo). Il progetto è iniziato con un esame approfondito delle caratteristiche esistenti di Coupled e dei feedback degli utenti, identificando aree significative di miglioramento. Copiando elementi di design efficaci dai leader del settore, la riprogettazione ha incorporato strategie comprovate da app come Duolingo, BeReal e Nike Run Club. I miglioramenti chiave includono la semplificazione dell'architettura dei contenuti, l'implementazione di funzionalità di coinvolgimento quotidiano e la creazione di un'interfaccia utente più intuitiva. Un aspetto centrale di questo progetto è stata l'integrazione di principi di scienza comportamentale per promuovere la formazione di abitudini e migliorare la comunicazione nelle relazioni. Il redesign ha enfatizzato semplicità e usabilità, introducendo un processo di onboarding dinamico, incentivi basati su streak (serie di utilizzi consecutivi) ed esperienze personalizzate. La tesi descrive anche la metodologia "Design by Copying", un approccio pragmatico al design digitale e interattivo, sostenendo la sua più ampia accettazione nell'educazione e nella pratica del design. Si sostiene che la copia intenzionale e strategica possa accelerare significativamente i processi di design e migliorare i risultati dei progetti. I risultati di questo studio suggeriscono che la copia metodica, combinata con principi di design centrati sull'utente, può creare esperienze digitali più coinvolgenti ed efficaci. Il redesign proposto per Coupled by PumPum® offre preziose strategie per designer e sviluppatori che mirano a creare app capaci di influenzare i comportamenti degli utenti.This thesis explores applying the pragmatic “Design by Copying” methodology in the redesign of Coupled by PumPum®, a relationship app. In an era when anyone can make apps, excellent design is not just an added detail. It’s an essential determinating factor for an app’s survival. Design by Copying embraces intentional copying to improve, accelerate, and guide the design process. This research documents what such a process may look like, from the initial analysis to a comprehensive redesign. The project began with an in-depth examination of Coupled’s existing features and user feedback, revealing significant areas for improvement. By leveraging successful design elements from industry leaders, the redesign process incorporated proven strategies from apps like Duolingo, BeReal, and Nike Run Club. Key enhancements included streamlining content architecture, implementing daily engagement features, and making the user interface more actionable. A central aspect of this redesign was the integration of behavioral science principles to foster habit formation and improve relationship communication. The redesign emphasized simplicity and usability, introducing a dynamic onboarding process, streak-based engagement incentives, and personalized interactions. The thesis also introduces the “Design by Copying” methodology, a fresh take on a pragmatic digital and interaction design approach. It advocates for its broader acceptance in design education and practice. It argues that intentional and strategic copying can significantly speed up design processes and improve the final results. This study’s findings suggest that systematic copying, combined with user-centric design principles, can create more engaging and effective digital experiences. The proposed redesign for Coupled by PumPum® offers valuable insights for designers and developers who aim to build apps that impact users’ behaviors

Can we leverage botanical gardens to study global plant functional diversity?

Biodiversity is a multidimensional concept spanning the diversity of organismal form and function (functional diversity) together with taxonomic and genetic diversity. In the case of plants, botanical gardens have historically strived to preserve taxonomic diversity with a global scope. However, their success in preserving global functional diversity lacks testing. Given that living collections in botanical gardens span major global vegetation types and evolutionary histories, it is reasonable to expect that a species assemblage in a botanical garden is a representative random sample of global vegetation. In such a case, botanical gardens should contain global functional diversity. Testing for this could elect botanical gardens as laboratories for studying global plant functional diversity, providing a much-needed alternative in the way we study global patterns of this diversity facet

The cholesterol ester cycle regulates signalling complexes and synapse damage caused by amyloid-ß

Cholesterol is required for the formation and function of some signalling platforms. In synaptosomes, amyloid-β (Aβ) oligomers, the causative agent in Alzheimer's disease, bind to cellular prion proteins (PrPC) resulting in increased cholesterol concentrations, translocation of cytoplasmic phospholipase A2 (cPLA2, also known as PLA2G4A) to lipid rafts, and activation of cPLA2. The formation of Aβ-PrPC complexes is controlled by the cholesterol ester cycle. In this study, Aβ activated cholesterol ester hydrolases, which released cholesterol from stores of cholesterol esters and stabilised Aβ-PrPC complexes, resulting in activated cPLA2. Conversely, cholesterol esterification reduced cholesterol concentrations causing the dispersal of Aβ-PrPC complexes. In cultured neurons, the cholesterol ester cycle regulated Aβ-induced synapse damage; cholesterol ester hydrolase inhibitors protected neurons, while inhibition of cholesterol esterification significantly increased Aβ-induced synapse damage. An understanding of the molecular mechanisms involved in the dispersal of signalling complexes is important as failure to deactivate signalling pathways can lead to pathology. This study demonstrates that esterification of cholesterol is a key factor in the dispersal of Aβ-induced signalling platforms involved in the activation of cPLA2 and synapse degeneration

Critical structure factor in Ising systems

We perform a large-scale Monte Carlo simulation of the three-dimensional Ising model on simple cubic lattices of size L^3 with L=128 and 256. We determine the corresponding structure factor (Fourier transform of the two-point function) and compare it with several approximations and with experimental results. We also compute the turbidity as a function of the momentum of the incoming radiation, focusing in particular on the deviations from the Ornstein-Zernicke expression of Puglielli and Ford.Comment: 16 page

Leaf rolling as indicator of water stress in Cistus incanus from different provenances

Leaf movements such as leaf rolling affect plant physiological performance by reducing light capture. The relationship between leaf rolling and physiological traits under imposed water stress conditions was analyzed in two population of Cistus incanus. We tested the hypothesis that leaf rolling reflected physiological changes occurring during water stress irrespective of the different acclimation in order to cope with water stress. On the whole, our results confirmed our hypothesis since leaf rolling significantly reflected physiological activity changes. Moreover, leaf rolling might be involved in protecting the PSII complex under water stress during the progressive inhibition of photosynthetic metabolism. Thus, leaf rolling could be part of C. incanus adaptive strategy to cope with water stress by sustaining leaf turgor. As such, leaf rolling may be used as a morphological index to evaluate the progressive inhibition of photosynthesis irrespective of the different acclimation to cope with water stress