Preliminary study of kaonic deuterium X-rays by the SIDDHARTA experiment at DAFNE

The study of the KbarN system at very low energies plays a key role for the understanding of the strong interaction between hadrons in the strangeness sector. At the DAFNE electron-positron collider of Laboratori Nazionali di Frascati we studied kaonic atoms with Z=1 and Z=2, taking advantage of the low-energy charged kaons from Phi-mesons decaying nearly at rest. The SIDDHARTA experiment used X-ray spectroscopy of the kaonic atoms to determine the transition yields and the strong interaction induced shift and width of the lowest experimentally accessible level (1s for H and D and 2p for He). Shift and width are connected to the real and imaginary part of the scattering length. To disentangle the isospin dependent scattering lengths of the antikaon-nucleon interaction, measurements of Kp and of Kd are needed. We report here on an exploratory deuterium measurement, from which a limit for the yield of the K-series transitions was derived: Y(K_tot)<0.0143 and Y(K_alpha)<0.0039 (CL 90%). Also, the upcoming SIDDHARTA-2 kaonic deuterium experiment is introduced.Comment: Accepted by Nuclear Physics

Impacts of blockchain technology in agrifood: exploring the interplay between transactions and firms’ strategic resources

Purpose: Despite the growing interest in blockchain technology (BCT) applications in the agri-food industry, evidence of their economic and strategic implications remains scarce. This study aims to contribute to filling this gap by jointly investigating how BCT adoption affects transactional relationships, and how it contributes to the firm’s strategic resources. Design/methodology/approach: An explanatory case study is conducted based on a theoretical framework grounded on transaction cost economics and the resource-based-dynamic capabilities view. Six BCT implementations by agri-food firms are studied. Data were collected through semi-structured interviews and analysed using thematic analysis. Findings: Findings reveal that BCT benefits depend on how companies integrate technology across their supply chains. In fact, the results suggest that overall transaction efficiency within the supply chain is enhanced only for those firms prioritising stakeholder engagement during technology implementation and leveraging existing trust relationships with economic agents. Moreover, the results suggest that BCT is not yet perceived as a strategic resource, but rather that it has the potential to enhance firms’ operational-adaptive, absorptive and innovative capabilities. When all supply chain actors clearly understand blockchain’s functionality and value, the development of these capabilities becomes more pronounced. Practical implications: The study identifies two BCT adoption configurations. One primarily focuses on enhancing supply chain efficiency and transparency (dynamic BCT), while the other uses BCT mainly for marketing purposes (static BCT). These configurations lead to varied possibilities for leveraging BCT’s potential advantages. Furthermore, they show how a mismatch between a strategic approach and its chosen configuration could work against any positive impact and lead to disillusionment with the BCT. Thus, managers should assess carefully the impact of such different configuration choices on performance. Originality/value: To the best of the authors’ knowledge, this is the first study to attempt to analyse the economic implications of adopting BCT in the food sector from both a firm and supply chain perspective. Additionally, it shows how interpreting these impacts is contingent on the diverse modalities for embedding BCT into existing supply chains

Day-night and inter-habitat variations in ant assemblages in a mosaic agroforestry landscape

Throughout the Mediterranean basin, the long-term interaction between human activities and natural processes has led to the formation of unique ecosystems whose biodiversity may be higher than that of the “original” systems. This is particularly true in the case of transformations of continuous stretches of closed forest into a complex mosaic of open and closed habitat over the course of centuries. In this study, we assessed the variation in diversity of ant assemblages in a typical patchy landscape, sampling ants in the three most important constituting habitats: olive plantation, harvested forest, and mature forest. In the study we used two different sampling methods—pitfall traps and observation at baits—which provided information on species presence at different temporal scales. The three habitats displayed different species assemblages, and considerable variation in species composition was observed at different times of the day, particularly in the harvested forest. Functional group analysis showed that the olive plantation, although the most artificial habitat, displayed the highest number of functional groups, suggesting a wider spectrum of available ecological niches for ant species within this habitat type. Overall, it was concluded that each of the three habitats contributes to enhance diversity at the landscape scale, which is greater than that expected from a more homogeneous habitat composition

Ants modulate stridulatory signals depending on the behavioural context

Insect societies require an effective communication system to coordinate members’ activities. Although eusocial species primarily use chemical communication to convey information to conspecifics, there is increasing evidence suggesting that vibroacoustic communication plays a significant role in the behavioural contexts of colony life. In this study, we sought to determine whether stridulation can convey information in ant societies. We tested three main hypotheses using the Mediterranean ant Crematogaster scutellaris: (i) stridulation informs about the emitter’caste; (ii) workers can modulate stridulation based on specific needs, such as communicating the profitability of a food resource, or (iii) behavioural contexts. We recorded the stridulations of individuals from the three castes, restrained on a substrate, and the signals emitted by foragers workers feeding on honey drops of various sizes. Signals emitted by workers and sexuates were quantitatively and qualitatively distinct as was stridulation emitted by workers on different honey drops. Comparing across the experimental setups, we demonstrated that signals emitted in different contexts (restraining vs feeding) differed in emission patterns as well as certain parameters (dominant frequency, amplitude, duration of chirp). Our findings suggest that vibrational signaling represents a flexible communication channel paralleling the well-known chemical communication system