Prospective elementary teachers\u2019 perceptions of the processes of modeling: A case study

In this paper we discuss a study on the approaches to modeling of students of the 4-year elementary school teacher program at the University of Palermo, Italy. The answers to a specially designed questionnaire are analyzed on the basis of an a priori analysis made using a general scheme of reference on the epistemology of mathematics and physics. The study is performed by using quantitative data analysis methods, i.e. factorial analysis of the correspondences and implicative analysis. A qualitative analysis of key words and terms used by students during interviews is also used to examine some aspects that emerged from the quantitative analysis. The students have been classified on the basis of their different epistemological approaches to knowledge construction, and implications between different conceptual strategies used to answer the questionnaire have been highlighted. The study\u2019s conclusions are consistent with previous research, but the use of quantitative data analysis allowed us to classify the students into three \u201cprofiles\u201d related to different epistemological approaches to knowledge construction, and to show the implications of the different conceptual strategies used to answer the questionnaire, giving an estimation of the classification or implication \u201cstrength.\u201d Some hints on how a course for elementary school physics and mathematics education can be planned to orient the future teachers to the construction of models of explanation are reported

KwaZulu-Natal coastal erosion events of 2006/2007 and 2011: A predictive tool?

Severe coastal erosion occurred along the KwaZulu-Natal coastline between mid-May and November 2011. Analysis of this erosion event and comparison with previous coastal erosion events in 2006/2007 offered the opportunity to extend the understanding of the time and place of coastal erosion strikes. The swells that drove the erosion hotspots of the 2011 erosion season were relatively low (significant wave heights were between 2 m and 4.5 m) but of long duration. Although swell height was important, swell-propagation direction and particularly swell duration played a dominant role in driving the 2011 erosion event. Two erosion hotspot types were noted: sandy beaches underlain by shallow bedrock and thick sandy beaches. The former are triggered by high swells (as in March 2007) and austral winter erosion events (such as in 2006, 2007 and 2011). The latter become evident later in the austral winter erosion cycle. Both types were associated with subtidal shore-normal channels seaward of megacusps, themselves linked to megarip current heads. This 2011 coastal erosion event occurred during a year in which the lunar perigee sub-harmonic cycle (a ±4.4-year cycle) peaked, a pattern which appears to have recurred on the KwaZulu-Natal coast. If this pattern proves true, severe coastal erosion may be expected in 2015. Evidence indicates that coastal erosion is driven by the lunar nodal cycle peak but that adjacent lunar perigee sub-harmonic peaks can also cause severe coastal erosion. Knowing where and when coastal erosion may occur is vital for coastal managers and planners

Hepatic Resection Using a Water Jet Dissector

The mortality and morbidity in major hepatic resection is often related to hemorrhage. A high pressure, high velocity water jet has been developed and has been utilized to assist in hepatic parenchymal transection. Sixty-seven major hepatic resections were performed for solid hepatic tumors. The tissue fracture technique was used in 51 patients (76%), and the water jet dissector was used predominantly in 16 patients (24%). The extent of hepatic resection using each technique was similar. The results showed no difference in operative duration (p = .499). The mean estimated blood loss using the water jet was 1386 ml, and tissue fracture technique 2450 ml (p = .217). Transfusion requirements were less in the water jet group (mean 2.0 units) compared to the tissue fracture group (mean 5.2 units); (p = .023). Results obtained with the new water dissector are encouraging. The preliminary results suggest that blood loss may be diminished

MIDGARD: A Simulation Platform for Autonomous Navigation in Unstructured Environments

We present MIDGARD, an open-source simulation platform for autonomous robot navigation in outdoor unstructured environments. MIDGARD is designed to enable the training of autonomous agents (e.g., unmanned ground vehicles) in photorealistic 3D environments, and to support the generalization skills of learning-based agents through the variability in training scenarios. MIDGARD's main features include a configurable, extensible, and difficulty-driven procedural landscape generation pipeline, with fast and photorealistic scene rendering based on Unreal Engine. Additionally, MIDGARD has built-in support for OpenAI Gym, a programming interface for feature extension (e.g., integrating new types of sensors, customizing exposing internal simulation variables), and a variety of simulated agent sensors (e.g., RGB, depth and instance/semantic segmentation). We evaluate MIDGARD's capabilities as a benchmarking tool for robot navigation utilizing a set of state-of-the-art reinforcement learning algorithms. The results demonstrate MIDGARD's suitability as a simulation and training environment, as well as the effectiveness of our procedural generation approach in controlling scene difficulty, which directly reflects on accuracy metrics. MIDGARD build, source code and documentation are available at https://midgardsim.org/

Reconstructing Bioinvasion Dynamics Through Micropaleontologic Analysis Highlights the Role of Temperature Change as a Driver of Alien Foraminifera Invasion

Invasive alien species threaten biodiversity and ecosystem structure and functioning, but incomplete assessments of their origins and temporal trends impair our ability to understand the relative importance of different factors driving invasion success. Continuous time-series are needed to assess invasion dynamics, but such data are usually difficult to obtain, especially in the case of small-sized taxa that may remain undetected for several decades. In this study, we show how micropaleontologic analysis of sedimentary cores coupled with radiometric dating can be used to date the first arrival and to reconstruct temporal trends of foraminiferal species, focusing on the alien Amphistegina lobifera and its cryptogenic congener A. lessonii in the Maltese Islands. Our results show that the two species had reached the Central Mediterranean Sea several decades earlier than reported in the literature, with considerable implications for all previous hypotheses of their spreading patterns and rates. By relating the population dynamics of the two foraminifera with trends in sea surface temperature, we document a strong relationship between sea warming and population outbreaks of both species. We conclude that the micropaleontologic approach is a reliable procedure for reconstructing the bioinvasion dynamics of taxa having mineralized remains, and can be added to the toolkit for studying invasions

Review of Systemic Antibiotic Treatments in Children with Rhinosinusitis

Antibiotic treatment in paediatric rhinosinusitis is still a matter of debate, as the current guidelines have been drafted mainly based on clinical studies published before 2013. Recent modifications in the epidemiological basis of the disease might mean that current treatments are not completely adequate considering the evolving microbiological profile of the disease. The present paper reviews the role of systemic antibiotics in children with acute (ARS), chronic (CRS), recurrent (RARS), and complicated acute (CoARS) rhinosinusitis. A total of 14 studies (including 3 prospective non-randomised studies, 8 retrospective studies, and 3 prospective randomised studies) of the 115 initially identified papers were included in this review, corresponding to 13,425 patients. Five papers dealt with ARS, four papers with RARS or CRS, and five papers with CoARS; the remaining papers included patients with either ARS or CRS. Data about the effectiveness of antibiotic treatment in children with ARC, CRS, and CoARS is scarce, as only three randomised controlled trials have been published in the last decade, with contrasting results. There is an urgent need for dedicated controlled trials not only to test the actual clinical benefits deriving from the routine use of systemic antibiotics in different categories of patients but also to compare the effectiveness of various therapeutic protocols in terms of the type of antibacterial molecules and the duration of treatment

Intuitive Robot Teleoperation through Multi-Sensor Informed Mixed Reality Visual Aids

© 2021 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/.Mobile robotic systems have evolved to include sensors capable of truthfully describing robot status and operating environment as accurately and reliably as never before. This possibility is challenged by effective sensor data exploitation, because of the cognitive load an operator is exposed to, due to the large amount of data and time-dependency constraints. This paper addresses this challenge in remote-vehicle teleoperation by proposing an intuitive way to present sensor data to users by means of using mixed reality and visual aids within the user interface. We propose a method for organizing information presentation and a set of visual aids to facilitate visual communication of data in teleoperation control panels. The resulting sensor-information presentation appears coherent and intuitive, making it easier for an operator to catch and comprehend information meaning. This increases situational awareness and speeds up decision-making. Our method is implemented on a real mobile robotic system operating outdoor equipped with on-board internal and external sensors, GPS, and a reconstructed 3D graphical model provided by an assistant drone. Experimentation verified feasibility while intuitive and comprehensive visual communication was confirmed through a qualitative assessment, which encourages further developments.Peer reviewe