707 research outputs found
Interspecific aggression and food competition between the global invader Palaemon macrodactylus and the native Palaemon elegans
The impact of invasive alien species on native communities can act at different levels both
by affecting the ecosystem’s structure (i.e., mainly in the case of vegetation) and through direct
interactions (i.e., competition for food or space). Behavioral studies under controlled conditions can
provide relevant information on both the invasive potential of alien species and the potential impact
of the invaders on the local native species. In the laboratory, the competition for food resources
between the invasive oriental shrimp Palaemon macrodactylus, Rathbun, 1902, and the Mediterranean
native shrimp Palaemon elegans, Rathke, 1836, was analyzed. These species are typical residents of
coastal transitional and estuarine waters, so the experiments were carried out using two salinity
conditions that characterize the coastal lagoon of Venice. Although at both salinity treatments the
alien species tended to be more aggressive than the native one, significant differences between the
two species were mainly observed at a salinity of 30. In particular, at a salinity of 30, P. macrodactylus
spent more time attending to the food source than the native species. The results are discussed in
light of the potential inter-specific competition between the two species within the conditions of the
Venice lagoon
Energetic cost of running with and without the ball in male basketball players
This study aimed to assess the energetic cost ( C) at different running conditions (RC) with/without the ball (1000m at 80% of VO(2)max) during: Linear running, Shuttle running (180 degrees), Linear running with stop and restart, between two groups according to the position/role (guards: n=15; forwards/centres: n=15). Experimental approach to the problem required the following tests/devices: a portable Metabolimeter was used to assess the metabolic parameters for each RC, Squat Jump (OptoJump) to assess the strength's decrease differences of the lower limbs before/ after each test and Ratings of Perceived Exertion (RPE) after each RC to assess the training load, while the Global Navigation Satellite System (GNSS-IMU) was used to assess the body inclinations and Acceleration/ Deceleration for each RC. The T-test was used for independent samples and Two-way repeated measures ANOVA was used to assess the significant differences for each variable between each RC. The results of this study could be useful not only for coaches to optimize basketball training load related to the RC (with and without the ball), but also to optimize the motor learning in young basketball players and to optimize the load of work in relation to the position and energetic capacities of players. The main evidence of this study has confirmed initial hypothesis, showing a different metabolic expenditure in the six running conditions ( Linear Running, Linear Running & Stop and restart, Shuttle run with and without ball) and between the two groups taken in consideration (Guards and Forwards/Centres). In addition, different energetic cost between the two groups increases even more during the running with the ball compared to running without the ball
Data-driven design: The new challenges of digitalization on product design and development
Digitalization and the momentous role being assumed by data are commonly viewed as pervasive phenomena whose impact is felt in all aspects of society and the economy. Design activity is by no means immune from this trend, and the relationship between digitalization and design is decades old. However, what is the current impact of this 'data revolution' on design? How will the design activity change? What are the resulting research questions of interest to academics? What are the main challenges for firms and for educational institutions having to cope with this change? The paper provides a comprehensive conceptual framework, based on recent literature and anecdotal evidence from the industry. It identifies three main streams: namely the consequences on designers, the consequences on design processes and the role of methods for data analytics. In turn, these three streams lead to implications at individual, organizational and managerial level, and several questions arise worthy of defining future research agendas. Moreover, the paper introduces relational diagrams depicting the interactions between the objects and the actors involved in the design process and suggests that what is occurring is by no means a simple evolution but a paradigmatic shift in the way artefacts are designed
Physical education teaching in Italian primary school: theoretical lines and operational proposals
Background and Study Aim For the new reform to be applied in the best possible way, it is a priority and useful to promote the development of knowledge on the organization and methods of teaching/learning in physical education in primary school. This study aims to search for a new didactic organizational model for physical education in primary school, starting from the theoretical lines, showing the contrasts of the significant aspects and the uniqueness of heuristic learning, with a consequent theoretical and argumentative elaboration of operational proposals.Material and Methods For this purpose, an accurate survey of the scientific literature has been analyzed, highlighting the critical issues that characterized the various proposals and attempt to implement physical activity and sports education courses in primary school over the years, up to the recent legislative innovation.Results The path of the definition of physical education in primary school was marked by stages that did not always enhance the educational and training dimension of the motor and sports experience, making the school discipline assume a marginal and optional role in the face of an extracurricular practice characterized by a widespread organization and more capable of intercepting and responding to the physical exercise and sport needs of society. This complex situation has only generated confusion without solving the problem of the absence of physical and sporting activity in the 5-10 age group, as required by the World Health Organization and the European Union, by adequately and uniquely qualified teachers. It is now useful to promote the development of knowledge on the didactic organization of the primary school, on the different teaching/learning methods in physical education, to contextualize the scope of the new legal provision to the current legal framework.Conclusions The study highlights the value of a new approach in teacher training that aims to ensure the acquisition of key competence, according to the Recommendation of the European Parliament. This perspective can be easily realized by using a core curriculum uniformly applied at the national level
Heuristic Learning as a Method for Improving Students’ Teamwork Skills in Physical Education
Transversal skills are the knowledge, skills, and personal qualities that are currently needed to meet the demands of the working world and everyday life. Schools have the task of equipping students with these skills, working not only on disciplinary goals but also on operational–behavioral goals. In 2018, the European Union adopted new recommendations on eight key competencies for lifelong learning and asked schools to implement new methods to develop these recommendations. To be successful, it is necessary to stimulate students’ development of these competences, which are also called soft skills, from the earliest years of the school experience. Physical education (PE) is called upon to make its contribution. In Italy, the two teaching methods used during PE classes are prescriptive teaching and heuristic learning. It is not clear which of the two methods is the most effective in improving soft skills, especially the skills involved in teamwork. The objective of this article was to compare the effects of these two teaching methods on students’ teamwork skills during PE classes in primary schools. After verifying the normality of the data, a Student’s t-test for dependent samples was performed to assess pre-test and post-test differences in each of two groups, while a Student’s t-test for independent samples was performed to compare the two groups after 3 months. Heuristic learning proved to be the most effective method for improving teamwork skills. The results may make an important contribution to future teacher training on the most effective teaching methods for developing students’ soft skill
Melanocortins and the cholinergic anti-inflammatory pathway.
Experimental evidence indicates that small concentrations of inflammatory molecules produced by damaged tissues activate afferent signals through ascending vagus nerve fibers, that act as the sensory arm of an "inflammatory reflex". The subsequent activation of vagal efferent fibers, which represent the motor arm of the inflammatory reflex, rapidly leads to acetylcholine release in organs of the reticuloendothelial system. Acetylcholine interacts with α7 subunit-containing nicotinic receptors in tissue macrophages and other immune cells and rapidly inhibits the synthesis/release of tumor necrosis factor-α and other inflammatory cytokines. This neural anti-inflammatory response called "cholinergic anti-inflammatory pathway" is fast and integrated through the central nervous system. Preclinical studies are in progress, with the aim to develop therapeutic agents able to activate the cholinergic anti-inflammatory pathway. Melanocortin peptides bearing the adrenocorticotropin/α-melanocyte-stimulating hormone sequences exert a protective and life-saving effect in animals and humans in conditions of circulatory shock. These neuropeptides are likewise protective in other severe hypoxic conditions, such as prolonged respiratory arrest, myocardial ischemia, renal ischemia and ischemic stroke, as well as in experimental heart transplantation. Moreover, experimental evidence indicates that melanocortins reverse circulatory shock, prevent myocardial ischemia/reperfusion damage and exert neuroprotection against ischemic stroke through activation of the cholinergic anti-inflammatory pathway. This action occurs via stimulation of brain melanocortin MC3/MC4 receptors. Investigations that determine the molecular mechanisms of the cholinergic anti-inflammatory pathway activation could help design of superselective activators of this pathway
Below-elbow or above-elbow cast for conservative treatment of extra-articular distal radius fractures with dorsal displacement: A prospective randomized trial
Background: Distal radial fractures are common traumatic injuries, but their management remains controversial also in case of conservative treatment regarding the type of immobilisation. Hence, we conducted a two-arm, parallel-group, prospective randomised trial to compare the capacity of long casts (above-elbow) and short casts (below-elbow) to maintain the reduction of extra-articular distal radius fractures with dorsal displacement (AO/OTA classification: 2R3A2.2). Methods: Seventy-four eligible patients with AO/OTA 2R3A2.2 fractures treated with closed reduction and cast immobilisation were randomised to the long cast group (n°= 37) or to the short cast group (n°= 37). Baseline radiological parameters, radial inclination (RI), radial height (RH), ulnar variance (UV) and palmar tilt (PT) were taken, and compared with clinical (DASH, Mayo Wrist and Mayo Elbow) and radiological scores taken at 7-10 days, 4 weeks and 12 weeks. Furthermore, to evaluate correlations between radiological parameters and functional outcomes, patients were divided into two groups according to whether or not their radiological parameters at Follow-ups 2 and 3 were acceptable, i.e. within the range 11-12 mm for RH, 16°-28° for RI, - 4-+ 2 mm for UV and 0°-22° for PT. Results: Patient demographic and baseline radiological parameters were similar between groups. At follow-up, there were no statistically significant differences between the two types of cast in terms of RI, RH, UV or PT, or Mayo wrist or DASH scores. Short cast group patients displayed better Mayo elbow score at follow-up 2 (4 weeks), but this difference was no longer statistically significant at follow-up 3 (12 weeks). No statistically significant differences in clinical outcomes were found between patients who presented acceptable radiographic parameters at follow-up and those who did not. Conclusion: As there were no significant differences between short casts and long casts in terms of fracture reduction maintenance or clinical outcomes, short casts are an effective method of post-reduction immobilisation in AO/OTA 2R3A2.2 fracture of the radius. Radiological parameters outside the range conventionally considered acceptable do not preclude a satisfactory clinical outcome. Trial registration: ClinicalTrials.gov PRS, NCT04062110. Registred 20 August 2019
Field emission properties of as-grown multiwalled carbon nanotube films
Multiwalled carbon nanotubes have been produced by ethylene catalytic
chemical vapor deposition and used to fabricate thick and dense freestanding
films ("buckypapers") by membrane filtering. Field emission properties of
buckypapers have been locally studied by means of high vacuum atomic force
microscopy with a standard metallic cantilever used as anode to collect
electrons emitted from the sample. Buckypapers showed an interesting linear
dependence in the Fowler-Nordheim plots demonstrating their suitability as
emitters. By precisely tuning the tip-sample distance in the submicron region
we found out that the field enhancement factor is not affected by distance
variations up to 2um. Finally, the study of current stability showed that the
field emission current with intensity of about 3,3*10-5A remains remarkably
stable (within 5% fluctuations) for several hours.Comment: 18 pages, 5 figure
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