98 research outputs found

    Micro- and nano-plastics in edible fruit and vegetables. The first diet risks assessment for the general population.

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    Microplastics (MPs) represent a current public health concern since toxicity has not yet fully investigated. They were found in several foods, but to the best of our knowledge, at this time no data was reported for the edible vegetables and fruits. We focused on diet exposure aiming to evaluate the number and the size (10 μm) of MPs in the most commonly consumed vegetables and fruits, in relation to their recommended daily intake too. MPs extraction and analysis were carried out using an innovative Italian methodology and SEM-EDX, respectively. Finally, we calculated the Estimated Daily Intakes (EDIs) for adults and children for each type of vegetal and fruit. The higher median (IQR) level of MPs in fruit and vegetable samples was 223,000 (52,600-307,750) and 97,800 (72,175-130,500), respectively. In particular, apples were the most contaminated fruit samples, while carrot was the most contaminated vegetable. Conversely, the lower median (IQR) level was observed in lettuce samples 52,050 (26,375-75,425). Both vegetable and fruit samples MPs levels were characterized by wide variability. The smallest size of MPs was found in the carrot samples (1.51 μm), while the biggest ones were found in the lettuce (2.52 μm). Both vegetable and fruit samples had size of the MPs characterized by low variability. We found the highest median level of MPs in samples purchased from the "fruiter 3" (124,900 p/g) and the lowest in those purchased in "supermarket" (87,600 p/g). The median size of the MPs had overlapping dimensions in all the purchase sites, with the exception of the samples purchased at the "shop at km zero 2″ which had slightly smaller size (1.81 μm). The highest adults' (4.62 E+05) and children's (1.41 E+06) EDIs are due the ingestion of apples, instead the lowest are due to the ingestion of carrots (adults: 2.96 E+04; children: 1.15 E+05). We hypothesized that the mechanism of uptake and translocation of MPs can be the same described and reported for carbon-nanomaterials. This may be a possible translocation route of MPs by environment to vegetables permitting, so, the translocation or uptake inside of their biological systems. Based on the results obtained it is urgent important to perform toxicological and epidemiological studies to investigate for the possible effects of MPs on human health

    Learning Potential in Mathematics through Imagination and Manipulation of Building Blocks

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    In line with scientific literature, there is a growing interest in building-block play. In fact, through this kind of play, children acquire both the abilities for abstract thought and symbolic representation and an understanding of rules—all of which are fundamental for mathematical understanding. This study explores the relationship between constructive play, mathematical skills, and mental imagery in children aged 10 to 12 years through the applications of three kinds of test: LEGO® block play, objective mathematical tests for primary school, and mental imagery tests (MITs). Gender did not significantly affect the tests' outcomes with the exception of the MIT visuo-spatial memory subtest, on which males reported better scores. Mental imagery correlated positively and significantly with all the variables involved in this study. Moreover, mental imagery was shown to have a mediating role in the relation between block play and mathematics. The results of this study may be useful for developing teaching and learning techniques based on construction play. DOI: 10.5901/mjss.2015.v6n4s3p15

    Hardness of Learning Problems over Burnside Groups of Exponent 3

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    In this work we investigate the hardness of a computational problem introduced in the recent work of Baumslag et al. In particular, we study the BnB_n-LHN problem, which is a generalized version of the learning with errors (LWE) problem, instantiated with a particular family of non-abelian groups (free Burnside groups of exponent 3). In our main result, we demonstrate a random self-reducibility property for BnB_n-LHN. Along the way, we also prove a sequence of lemmas regarding homomorphisms of free Burnside groups of exponent 3 that may be of independent interest

    Design and integration sensitivity of a morphing trailing edge on a reference airfoil: The effect on high-altitude long-endurance aircraft performance

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    Trailing edge modification is one of the most effective ways to achieve camber variations. Usual flaps and aileron implement this concept and allow facing the different needs related to take-off, landing, and maneuver operations. The extension of this idea to meet other necessities, less dramatic in terms of geometry change yet useful a lot to increase the aircraft performance, moves toward the so-called morphing architectures, a compact version of the formers and inserted within the frame of the smart structures’ design philosophy. Mechanic (whether compliant or kinematic), actuation and sensor systems, together with all the other devices necessary for its proper working, are embedded into the body envelope. After the successful experiences, gained inside the SARISTU (SmARt Intelligent Aircraft STrUctures) project where an adaptive trailing edge was developed with the aim of compensating the weight variations in a mediumsize commercial aircraft (for instance, occurring during cruise), the team herein exploits the defined architecture in the wing of a typical airfoil, used on high-altitude long-endurance aircraft such as the Global Hawk. Among the peculiarities of this kind of aerial vehicle, there is the long endurance, in turn, associated with a massive fuel storage (approximately around 50% of the total weight). A segmented, finger-like, rib layout is considered to physically implement the transition from the baseline airfoil to the target configurations. This article deals with an extensive estimation of the possible benefits related to the implementation of this device on that class of planes. Parametric aerodynamic analyses are performed to evaluate the effects of different architectural layouts (in-plane geometry extension) and different shape envelopes (namely, the rotation boundaries). Finally, the expected improvements in the global high-altitude long-endurance aircraft performance are evaluated, following the implementation of the referred morphing device

    High-resolution aeromagnetic survey of Calabria (Southern Italy)

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    We present a 1:350,000 high-resolution magnetic anomaly map of Calabria (Southern Italy), obtained by merging the results from two low-altitude aeromagnetic surveys performed in southern and northern Calabria. Magnetic anomalies of Calabria are of low intensity, and mostly range from 11 to –9 nT. Northern Calabria is characterized by positive anomalies in the Tyrrhenian margin (Coastal Chain) that turn into negative values moving eastward in the Sila Massif. Southern Calabria is characterized by slightly positive anomaly values, interrupted by a null magnetic anomaly corridor roughly corresponding to the eastern margin of the Gioia Tauro basin. Finally, anomaly values turn systematically negative in the Messina Straits. Due to the unprecedented resolution (low flying height, spatial sampling along the flight line of ∼5 m and 1–2 km flight line spacing), the new map highlights, in detail, the geometry and setting of the upper crustal features. As Calabria is one of the most seismically active regions in Italy, hit by several high-magnitude earthquakes in recent centuries, the interpretation of this new map will hopefully contribute to new insights into the crustal geological setting, location and dimension of the main seismogenic sources.Published116-1231A. Geomagnetismo e Paleomagnetismo3SR. AMBIENTE - Servizi e ricerca per la SocietàJCR Journa

    Alpha Cluster Structure in16O

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    The main purpose of the present work is the investigation of the α-cluster phenomenon in 16 O. The 12 C( 6 Li,d) 16 O reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron-Enge-Spectrograph facility and the nuclear emulsion detection technique. Resonant states around 4α threshold were measured and an energy resolution of 15 keV allows to define states previously unresolved. The angular distributions of the absolute cross sections were determined in a range of 4-40 degree in the center of mass system. The upper limit for the resonance widths was obtained, indicating that the α cluster structure information in this region should be revised

    A Brief Overview of the NEBULA Future Internet Architecture

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    NEBULA is a proposal for a Future Internet Architecture. It is based on the assumptions that: (1) cloud computing will comprise an increasing fraction of the application workload offered to an Internet, and (2) that access to cloud computing resources will demand new architectural features from a network. Features that we have identified include dependability, security, flexibility and extensibility, the entirety of which constitute resilience.NEBULA provides resilient networking services using ultrareliable routers, an extensible control plane and use of multiple paths upon which arbitrary policies may be enforced. We report on a prototype system, Zodiac, that incorporates these latter two features

    Italian natural history museums on the verge of collapse?

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    The Italian natural history museums are facing a critical situation, due to the progressive loss of scientific relevance, decreasing economic investments, and scarcity of personnel. This is extremely alarming, especially for ensuring the long-term preservation of the precious collections they host. Moreover, a commitment in fieldwork to increase scientific collections and concurrent taxonomic research are rarely considered priorities, while most of the activities are addressed to public events with political payoffs, such as exhibits, didactic meetings, expositions, and talks. This is possibly due to the absence of a national museum that would have better steered research activities and overall concepts for collection management. We here propose that Italian natural history museums collaborate to instate a “metamuseum”, by establishing a reciprocal interaction network aimed at sharing budgetary and technical resources, which would assure better coordination of common long-term goals and scientific activities

    Pro-Environmental Behaviors: Determinants and Obstacles among Italian University Students

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    The awareness of citizens concerning the health risks caused by environmental pollution is growing, but studies on determinants of pro-environmental behaviors have rarely examined health-related aspects. In this study, we investigated these determinants using data from a large survey among Italian university students (15 Universities: 4778 filled questionnaires). Besides the health-related aspects, represented by environmental health risk perception and functional health literacy, we considered social and demographic characteristics (gender, area of residence, sources of information, trust in institutional and non-institutional subjects, and students' capacity of positive actions, indicated as internal locus of control). The attitudes towards pro-environmental behaviors were positive for more than 70% of students and positively related with health risk perception, internal locus of control, and health literacy. The correspondence between the positive attitudes towards pro-environmental behaviors and the real adoption of such behaviors was approximately 20% for most behaviors, except for the separate collection of waste (60%). Such a discrepancy can be attributable to external obstacles (i.e., lack of time, costs, lack of support). The health-related aspects were linked to the pro-environmental attitudes, but to a lesser extent to pro-environmental behaviors, owing to the complexity of their determinants. However, they should be taken in account in planning education interventions
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