Escape path complexity and its context dependency in Pacific blue-eyes (Pseudomugil signifer)

The escape paths prey animals take following a predatory attack appear to be highly unpredictable - a property that has been described as ‘protean behaviour’. Here we present a method of quantifying the escape paths of individual animals using a path complexity approach. When individual fish (Pseudomugil signifer) were attacked, we found that a fish's movement path rapidly increased in complexity following the attack. This path complexity remained elevated (indicating a more unpredictable path) for a sustained period (at least 10 seconds) after the attack. The complexity of the path was context dependent; paths were more complex when attacks were made closer to the fish, suggesting that these responses are tailored to the perceived level of threat. We separated out the components of speed and turning rate changes to determine which of these components contributed to the overall increase in path complexity following an attack. We found that both speed and turning rate measures contributed similarly to an individual's path complexity in absolute terms. Overall, our work highlights the context dependent escape responses that animals use to avoid predators and also provides a method for quantifying the escape paths of animals

The interplay between aerobic metabolism and antipredator performance: vigilance is related to recovery rate after exercise

When attacked by a predator, fish respond with a sudden fast-start motion away from the threat. Although this anaerobically-powered swimming necessitates a recovery phase which is fueled aerobically, little is known about links between escape performance and aerobic traits such as aerobic scope (AS) or recovery time after exhaustive exercise. Slower recovery ability or a reduced AS could make some individuals less likely to engage in a fast-start response or display reduced performance. Conversely, increased vigilance in some individuals could permit faster responses to an attack but also increase energy demand and prolong recovery after anaerobic exercise. We examined how AS and the ability to recover from anaerobic exercise relates to differences in fast-start escape performance in juvenile golden gray mullet at different acclimation temperatures. Individuals were acclimated to either 18, 22, or 26°C, then measured for standard and maximal metabolic rates and AS using intermittent flow respirometry. Anaerobic capacity and the time taken to recover after exercise were also assessed. Each fish was also filmed during a simulated attack to determine response latency, maximum speed and acceleration, and turning rate displayed during the escape response. Across temperatures, individuals with shorter response latencies during a simulated attack are those with the longest recovery time after exhaustive anaerobic exercise. Because a short response latency implies high preparedness to escape, these results highlight the trade-off between the increased vigilance and metabolic demand, which leads to longer recovery times in fast reactors. These results improve our understanding of the intrinsic physiological traits that generate inter-individual variability in escape ability, and emphasize that a full appreciation of trade-offs associated with predator avoidance and energy balance must include energetic costs associated with vigilance and recovery from anaerobic exercise

The role of physiological traits in assortment among and within fish shoals

Individuals of gregarious species often group with conspecifics to which they are phenotypically similar. This among-group assortment has been studied for body size, sex and relatedness. However, the role of physiological traits has been largely overlooked. Here, we discuss mechanisms by which physiological traits—particularly those related to metabolism and locomotor performance—may result in phenotypic assortment not only among but also within animal groups. At the among-group level, varying combinations of passive assortment, active assortment, phenotypic plasticity and selective mortality may generate phenotypic differences among groups. Even within groups, however, individual variation in energy requirements, aerobic and anaerobic capacity, neurological lateralization and tolerance to environmental stressors are likely to produce differences in the spatial location of individuals or associations between group-mates with specific physiological phenotypes. Owing to the greater availability of empirical research, we focus on groups of fishes (i.e. shoals and schools). Increased knowledge of physiological mechanisms influencing among- and within-group assortment will enhance our understanding of fundamental concepts regarding optimal group size, predator avoidance, group cohesion, information transfer, life-history strategies and the evolutionary effects of group membership. In a broader perspective, predicting animal responses to environmental change will be impossible without a comprehensive understanding of the physiological basis of the formation and functioning of animal social groups. This article is part of the themed issue ‘Physiological determinants of social behaviour in animals’

Distance Education in Chemistry during the Epidemic Covid-19

During the epidemic Covid-19, in most of the countries schools of all grades and univesities had to face a long period of closure without interrupting the educational mission. Distance education, which has been introduced first in UK in the Nineteen century as “correspondence learning” and then in USA and Australia, with the institution of “Open Universities” (i.e. MOOC and e -learning platforms), became the only way to guarantee the continuity in teaching during the pandemic Covid - 19. The present contribution is a short overview of the literature about limits and advantages of distance education of chemistry, in particular at high school and university levels, with a focus on the experiences and peculiarities of the distance education in the period of the Covid-19 emergency

STEAM Project-Based Learning Activities at the Science Museum as an Effective Training for Future Chemistry Teachers

Non-formal learning environments, such as science museums, have a fundamental role in science education and high potentialities as ideal contexts for science teachers’ training. These aspects have been analyzed and reported in several recent works mainly focused on students’ perception of science and increased engagement towards scientific disciplines. In this work, a project-based learning methodology optimized and experimented in the frame of a pre-service chemistry teachers’ course at the University of Pisa (Italy), during the last eight years, involving in total 171 participants, is presented. This educational project has several distinctive features related to the STEAM philosophy, with a high level of multi-disciplinarity and creativity. Most of the laboratories and chemistry-centered activities were conceived, planned and carried out by the future chemistry teachers in non-formal contexts, such as science museums. A case study based on a series of non-formal laboratories designed by a group of students during their training in the academic year 2018–2019 and performed in a science museum is reported and examined in details. In this paper, all steps of the STEAM project-based learning methodology are described underlining the main learning outcomes and cognitive levels involved in each step and the relevant methodologies proposed during the training course and adopted in the project. The effectiveness of this pre-service teachers’ training methodology is finally discussed in terms of participants’ motivation and interest towards the course’s content, students’ final judgment of their training experiences and, in particular, of the STEAM project-based learning activities. From the students’ feedbacks and final assessment, the role of the non-formal context in teaching and learning chemistry and the efficacy of developing educational activities related to current and real-life chemistry-centered topics emerged as very positive aspects of the proposed approach

The wandering « Leg of an Indian King ». The cultural biography of a friction idiophone now in the Pigorini Museum in Rome, Italy

The article presents new data on the history of a Mesoamerican musical instrument, which is a notched human bone used as a friction idiophone, today, held at the Pigorini Museum in Rome, Italy, where it is recorded as MNPE n. 4209. The documentary data allow for the reconstruction of the instrument’s cultural biography along a time span of almost five centuries. Collected in the Mixtec Kingdom of Tututepec (Oaxaca, Mexico) during the 16th century, it passed through different Italian collections before reaching its present location in Rome toward the end of the 19th century. The text also analyzes how in its long historical journey through different contexts and regimes of value, the notched bone generated diverse sets of discourses on cultural otherness. It is argued that this discursive agency of the object is due to its enduring coevalness, a quality that allows ancient objects to be always contemporary and meaningful to different cultural audiences.Cet article présente des données nouvelles sur l’histoire d’un instrument de musique mésoaméricain, un fémur humain à encoches, utilisé comme idiophone à friction, aujourd’hui conservé au musée Pigorini de Rome, sous le numéro d’inventaire MNPE n. 4029. Les données recueillies permettent de reconstituer la biographie culturelle de cet instrument sur près de cinq siècles. Cet objet fut collecté au xvie siècle dans le royaume mixtèque de Tututepec (Oaxaca, Mexico), et il est passé ensuite dans plusieurs collections italiennes avant d’atteindre l’endroit où il se trouve, à Rome, vers la fin du xixe siècle. L’article analyse également comment, au cours de son long voyage à travers différentes situations historiques et avec des régimes de valeur changeants, cet instrument de musique n’a cessé de susciter le développement de discours divers sur l’altérité culturelle. On avance aussi ici que l’agentivité discursive de l’objet est liée à sa « contemporanéité durable » (enduring coevalness), une qualité qui permet à des objets anciens de demeurer significatifs et actuels pour différents publics.Este trabajo presenta nuevos datos sobre la historia de un instrumento musical mesoamericano, un idiófono de fricción, hecho en un fémur humano, hoy conservado en el museo Pigorini de Roma, donde se registra con el número de inventario MNPE n. 4209. Los datos recopilados permiten reconstituir la biografía cultural del instrumento a lo largo de un lapso de casi cinco siglos. Obtenido en el reino mixteco de Tututepec (Oaxaca, México) en el siglo xvi, el instrumento ha pasado a través de varias colecciones italianas antes de llegar a su presente lugar en Roma hacia el final del siglo xix. El texto investiga también cómo en el transcurso de su largo viaje a través de diferentes contextos históricos y regímenes de valores, el hueso trabajado continuó estimulando una serie de discursos sobre la alteridad cultural. Proponemos además que la agencia del objeto se debe a su « contemporaneidad perdurable » (enduring coevalness), una cualidad que permite a los objetos antiguos de ser vistos siempre como contemporáneos y significativos aun frente a contextos culturales cambiantes

Detection of muons in the LHCb experiment: the aging of RPC detectors and the study of Z0→μ+μ−Z^0 \to \mu^+ \mu^-

The LHCb experiment will take place at the future LHC accelerator at CERN and will start in 2007. It is a single arm spectrometer dedicated to precision measure- ments of CP violation and rare decays in the b quark sector . Recent experimental results have shown that CP violation is large in this sector . LHCb is designed with a robust and exible trigger , in order to extensively gain access to a wide spread of different physical processes involving the beauty particles. This will allow to over-constrain the Standard Model predictions about CP violation, and to discover any possible inconsistency , which would reveal the presence of ìNew Physicsî. The work presented in this thesis has two main parts: the development of the Resistive Plate Chambers, proposed for the detection of muons in LHCb, and the study of the detector performances in the physical channel Z 0 -> u + u -. The LHCb experiment has nished its R&D at the end of 2002. We have par- ticipated in the development of a suitable detector for the outer part of the Muon system. Because of the large surface to cover (more than 200 m ) and the high time resolution requested for triggering, the Resistive Plate Chambers (RPC) ap- peared to represent a valid technology , and their industrial implemented produc- tion would have allowed to reduce the costs. The efforts have then been concen- trated on the aging effects, to verify that the RPC detectors are able to satisfy the LHCb requirements for a period of ten years working. The results of a compre- hensive aging test carried through three years are presented in the rst part of the thesis. As we shall see the detectors have showed important aging effects and have been abandoned. The design values of the center-of -mass energy and luminosity at LHC repre- sent new limits, never reached by hadron colliders. As a result, high production cross-sections will be attained and high statistics data samples are foreseen to be collected, for a large variety of processes. In the second part of the thesis is reported a complete study of the the process pp -> Z 0 -> u + u -, a marginal channel respect to main LHCb physics program. However it has recently gained interest, since its the theoretical cross-section has been determined with a good accuracy . New physics results can thus arise from the comparison of the predicted value and a precise experimental measurement. A particular focus has been put on the detection performances of LHCb, and on off - line and on-line event selections. Three possible physics elds of interest have been individuated and discussed: the application as an absolute luminosity monitor , the efcacy in a precise calibration of the LHCb spectrometer , and the study of the proton structure functions

Samba de Roda and the Threat of Epistemicide on the North Coast of Bahia

This paper presents an ethnography of samba de roda in the north coast of Bahia from the point of view of its mestres [chief practitioners]. We highlight the network of community activities that support samba as a multivocal and singular cultural practice. Emerging in a rural context with profound association to religious and labour practices of communities, samba de roda developed a vast choreographic and musical repertoire. However, it now faces challenges in maintaining its aesthetic and poetic richness, in the face of a new context brought on by the tourism industry. We ponder the extent to which samba de roda can (and cannot) withstand such socioeconomic transformations. At the same time, we consider that these activities should be included in the samba de roda safeguard policies. As the objectification of cultural practices is a harmful factor that can result from safeguard policies, this study can simultaneously serve as a cautionary tale for Recôncavo Baiano and its own safeguarding policies.Cet article présente une ethnographie de la samba de roda de la côte nord de Bahia du point de vue de ses mestres (meilleurs praticiens). Nous mettons en exergue le réseau des activités communautaires qui soutiennent la samba en tant que pratique culturelle multi-vocale et singulière. Apparue dans un milieu rural, en étroite association avec les pratiques religieuses et de travail des communautés, la samba de roda a développé un immense répertoire musical et chorégraphique. Cependant, elle doit à présent relever de nombreux défis pour conserver sa richesse poétique et esthétique, devant le nouveau contexte imposé par l’industrie du tourisme. Nous évaluons dans quelle mesure la samba de roda peut (et ne peut pas) résister à de telles transformations socioéconomiques. En même temps, nous pensons que ces activités devraient être incluses dans les politiques de protection de la samba de roda. Puisque la réification des pratiques culturelles est un facteur nuisible qui peut résulter de politiques de protection, cette étude peut servir de conte de mise en garde pour le Recôncavo bahianais et ses propres politiques de préservation du patrimoine