Nanoplastics in the oceans: Theory, experimental evidence and real world

This review critically analyses >200 papers collected by searching on Pubmed the word \u201cnanoplastics\u201d, a group of emerging contaminants which are receiving growing attention. The present review intends to provide an overview of current knowledge on nanoplastic pollution starting with the theory of polymer degradation, passing to laboratory confirmation of nanoplastic formation and ending with the possible occurrence in sea water samples. Most of the observations proposed focus the attention on polystyrene (PS) because the majority of research knowledge is based on this polymer. Moreover, we thoroughly describe what effects have been observed on different organisms tested in controlled conditions. Nanoplastics formation, fate and toxicity seem to be a very dynamic phenomenon. In light of this, we identify some aspects retained crucial when an ecotoxicological study with nanoplastics is performed and which elements of nanoplastics toxicity could be deeper covered

Generalized vibrational perturbation theory for rotovibrational energies of linear, symmetric and asymmetric tops: Theory, approximations, and automated approaches to deal with medium-to-large molecular systems

Models going beyond the rigid\u2010rotor and the harmonic oscillator levels are mandatory for providing accurate theoretical predictions for several spectroscopic properties. Different strategies have been devised for this purpose. Among them, the treatment by perturbation theory of the molecular Hamiltonian after its expansion in power series of products of vibrational and rotational operators, also referred to as vibrational perturbation theory (VPT), is particularly appealing for its computational efficiency to treat medium\u2010to\u2010large systems. Moreover, generalized (GVPT) strategies combining the use of perturbative and variational formalisms can be adopted to further improve the accuracy of the results, with the first approach used for weakly coupled terms, and the second one to handle tightly coupled ones. In this context, the GVPT formulation for asymmetric, symmetric, and linear tops is revisited and fully generalized to both minima and first\u2010order saddle points of the molecular potential energy surface. The computational strategies and approximations that can be adopted in dealing with GVPT computations are pointed out, with a particular attention devoted to the treatment of symmetry and degeneracies. A number of tests and applications are discussed, to show the possibilities of the developments, as regards both the variety of treatable systems and eligible methods

Turmoil over the crisis: innovation capabilities and firm exit

This work investigates the relationship between the characteristics and survival probabilities of firms, distinguishing between “involuntary” firm exit and exit by merger and acquisition (M&A). More in detail, we study how, and to what extent, innovation capabilities, as proxied by patents and trademarks, are able to shape, together with standard performance variables, the observed dynamics at the firm level. By using comprehensive data on Italian firms from business registers, we separate the administrative procedures leading to “involuntary” exit from those ending up with an event of M&A. We find that while higher productivity is associated with a lower probability of “involuntary” exit, productivity increases the chances of being the target for M&A. As far as intellectual property instruments are concerned, they tend to reduce the probability of both “involuntary” exit and M&A. However, the relative importance of the two instruments differs according to the exit route: patents are more relevant than trademarks in preventing “involuntary” exit, while the opposite is true for M&A. Plain English Summary We investigate firm’s exit after a crisis. Overall innovation plays a positive role, but the relative importance of IP depends on the exit route: patents are more relevant than trademarks against “involuntary” exit, while the opposite is true for M&A. We resort to the virtual universe of Italian limited liability firms from manufacturing, trade, and service to investigate the determinants of firm survival over the period 2010–2014. We scrutinize detailed administrative data on significant events occurring to firms to distinguish between events leading to involuntary exit and to M&A. In addition to the evidence on innovation, our results show that higher productivity decreases the probability of “involuntary” exit, yet productivity increases the chances of being the target for M&A. Taken together, these findings warn against a simplistic perspective on exit: the role of innovation and firm characteristics heavily depends on the exit route

Innovative Features of a Plurilingual Approach in Language Teaching

Language teaching methodologies over the past decade have been gradually moving towards more plurilingual approaches to language teaching (Conteh & Meier, 2014; May, 2014; Taylor & Snoddon, 2013; Lau & Van Viegen, 2020). The call for a multi/plurilingual turn in language education marks the move from language separation to integration of languages in the classroom. In turn, this has been accompanied by the emergence of innovative action-oriented and task-based approaches (Author, 2019; Author, in press; van den Branden, et al., 2009). These important developments may raise ambivalent responses, especially in contexts embracing more traditional approaches to language teaching. To address this ambivalence, this article aims to present the successes of a plurilingual action-oriented approach and outline its innovative features. We present data from multiphase, mixed methods research study (Creswell & Plano Clark, 2011) involving 140 participants (25 teachers; 115 students) from a range of culturally and linguistically diverse classrooms represented by nine languages. The results of the data analysis suggest a number of successful and challenging areas within the project. Defining the innovative features of the adopted methodology and examining ways they were implemented by teachers and embraced by students, we outline the most effective aspects of the research project. Building on a broad view of mediation that encompasses the Vygotskian concept (Lantolf et al., 2015) expanded through an embodied and enactive view of cognition (Love, 2014 ) and the cyclical intersubjective process that characterizes human agency (Author, in press; Raimondi, 2014), while taking into account a set of recently developed mediation descriptors (Council of Europe, 2020), we provided both a conceptual and practical frame for the innovative action-oriented tasks, connection of language and culture, and integration of online and in-class learning via the digital platform LITE (Language Integration Through E-portfolio). Finally, we discuss implications from the LINCDIRE project for teachers, administrators, and policy-makers

A multi-criteria approach for comparing alternative fuels and energy systems for marine applications

This paper presents an algorithm to compare traditional and innovative energy systems for maritime applications, adopting a multi-criteria method. The algorithm includes a large and updated database of market solutions. Two case studies are investigated: (i) a sailing yacht (ii) and a large-size cruise ship. For case (i), Fuel Cells represent a competitive solution, in particular considering navigation in emission control areas; the installation of electrical batteries is also evaluated. For case study (ii) Internal Combustion Engines are the best solution: the evaluation of alternative fuels (LNG, ammonia, methanol) is performed, also in dual-fuel configuration

The ultrasound risk stratification systems for thyroid nodule have been evaluated against papillary carcinoma. A meta-analysis

Thyroid imaging reporting and data systems (TIRADS) are used to stratify the malignancy risk of thyroid nodule by ultrasound (US) examination. We conducted a meta-analysis to evaluate the pooled cancer prevalence and the relative prevalence of papillary, medullary, follicular thyroid cancer (PTC, MTC, and FTC) and other malignancies among nodules included in studies evaluating their performance. Four databases were searched until February 2020. Original articles with at least 1000 nodules, evaluating the performance of at least one TIRADS among AACE/ACE/AME, ACR-TIRADS, ATA, EU-TIRADS, or K-TIRADS, and reporting data on the histological diagnosis of malignant lesions were included. The number of malignant nodules, PTC, FTC, MTC and other malignancies in each study was extracted. For statistical pooling of data, a random-effects model was used. Nine studies were included, evaluating 19,494 thyroid nodules. The overall prevalence of malignancy was 34% (95%CI 21 to 49). Among 6162 histologically proven malignancies, the prevalence of PTC, FTC, MTC and other malignancies was 95%, 2%, 1%, and 1%, respectively. A high heterogeneity was found for all the outcomes. A limited number of studies generally conducted using a retrospective design was found, with possible selection bias. Acknowledging this limitation, TIRADSs should be regarded as accurate tools to diagnose PTC only. Proposed patterns and/or cut-offs should be revised and other strategies considered to improve their performance in the assessment of FTC, MTC and other malignancies

Accelerated Stress Tests for Solid Oxide Cells via Artificial Aging of the Fuel Electrode

Solid Oxide Cells (SOCs) are under intensive development due to their great potential to meet the 2030 targets for decarbonization. One of their advantages is that they can work in reversible mode. However, in respect to durability, there are still some technical challenges. Although the quick development of experimental and modeling approaches gives insight into degradation mechanisms, an obligatory step that cannot be avoided is the performance of long‐term tests. Taking into account the target for a commercial lifetime is 80,000 h, experiments lasting years are not acceptable for market needs. This work aims to develop accelerated stress tests (ASTs) for SOCs by the artificial aging of the fuel electrode via redox cycling, which follows the degradation processes of calendar aging (Ni coarsening and migration). However, it can cause irreversible damage by the formation of cracks at the interface anode/electrolyte. The advantages of the developed procedure are that it offers a mild level of oxidation, which can be governed and regulated by the direct impedance monitoring of the Ni network resistance changes during oxidation/reduction on a bare anode sample. Once the redox cycling conditions are fixed and the anode/electrolyte sample is checked for cracks, the procedure is introduced for the AST in full‐cell configuration. The developed methodology is evaluated by a comparative analysis of current voltage and impedance measurements of pristine, artificially aged, and calendar‐aged button cells, combined with microstructural characterization of their anodes. It can be applied in both fuel cell and electrolyzer mode. The results obtained in this study from the electrochemical tests show that the artificially aged experimental cell corresponds to at least 3500 h of nominal operation. The number of hours is much bigger in respect to the microstructural aging of the anode. Taking into consideration that the duration of the performed 20 redox cycles is about 50 to 60 working hours, the acceleration factor in respect to experimental timing is estimated to be higher than 60, without any damaging of the sample. This result shows that the selected approach is very promising for a large decrease in testing times for SOCs

Bovine PrP expression levels in transgenic mice influence transmission characteristics of atypical bovine spongiform encephalopathy

Until recently, transmissible spongiform encephalopathy (TSE) disease in cattle was thought to be caused by a single agent strain, bovine spongiform encephalopathy (BSE) (classical BSE or BSE-C). However, due to the initiation of a large-scale surveillance programme throughout Europe, two atypical BSE strains, bovine amyloidotic spongiform encephalopathy (BASE, also named BSE-L) and BSE-H have since been discovered. These atypical BSE isolates have been previously transmitted to a range of transgenic mouse models overexpressing PrP from different species at different levels, on a variety of genetic backgrounds. To control for genetic background and expression level in the analysis of these isolates, we performed here a comprehensive comparison of the neuropathological and molecular properties of all three BSE agents (BASE, BSE-C and BSE-H) upon transmission into the same gene-targeted transgenic mouse line expressing the bovine prion protein (Bov6) and a wild-type control of the same genetic background. Significantly, upon challenge with these BSE agents, we found that BASE did not produce shorter survival times in these mice compared with BSE-C, contrary to previous studies using overexpressing bovine transgenic mice. Amyloid plaques were only present in mice challenged with atypical BSE and neuropathological features, including intensity of PrP deposition in the brain and severity of vacuolar degeneration were less pronounced in BASE compared with BSE-C-challenged mice

Soliton dynamics of ring quantum cascade lasers with injected signal

Nonlinear interactions in many physical systems lead to symmetry breaking phenomena in which an initial spatially homogeneous stationary solution becomes modulated. Modulation instabilities have been widely studied since the 1960s in different branches of nonlinear physics. In optics, they may result in the formation of optical solitons, localized structures that maintain their shape as they propagate, which have been investigated in systems ranging from optical fibres to passive microresonators. Recently, a generalized version of the Lugiato-Lefever equation predicted their existence in ring quantum cascade lasers with an external driving field, a configuration that enables the bistability mechanism at the basis of the formation of optical solitons. Here, we consider this driven emitter and extensively study the structures emerging therein. The most promising regimes for localized structure formation are assessed by means of a linear stability analysis of the homogeneous stationary solution (or continuous-wave solution). In particular, we show the existence of phase solitons - chiral structures excited by phase jumps in the cavity - and cavity solitons. The latter can be deterministically excited by means of writing pulses and manipulated by the application of intensity gradients, making them promising as frequency combs (in the spectral domain) or reconfigurable bit sequences that can encode information inside the ring cavity

Prion protein interacts with bace1 and differentially regulates its activity towards wild type and swedish mutant amyloid precursor protein

In Alzheimer disease amyloid-β (Aβ) peptides derived from the amyloid precursor protein (APP) accumulate in the brain. Cleavage of APP by the β-secretase BACE1 is the rate-limiting step in the production of Aβ. We have reported previously that the cellular prion protein (PrP(C)) inhibited the action of BACE1 toward human wild type APP (APP(WT)) in cellular models and that the levels of endogenous murine Aβ were significantly increased in PrP(C)-null mouse brain. Here we investigated the molecular and cellular mechanisms underlying this observation. PrP(C) interacted directly with the prodomain of the immature Golgi-localized form of BACE1. This interaction decreased BACE1 at the cell surface and in endosomes where it preferentially cleaves APP(WT) but increased it in the Golgi where it preferentially cleaves APP with the Swedish mutation (APP(Swe)). In transgenic mice expressing human APP with the Swedish and Indiana familial mutations (APP(Swe,Ind)), PrP(C) deletion had no influence on APP proteolytic processing, Aβ plaque deposition, or levels of soluble Aβ or Aβ oligomers. In cells, although PrP(C) inhibited the action of BACE1 on APP(WT), it did not inhibit BACE1 activity toward APP(Swe). The differential subcellular location of the BACE1 cleavage of APP(Swe) relative to APP(WT) provides an explanation for the failure of PrP(C) deletion to affect Aβ accumulation in APP(Swe,Ind) mice. Thus, although PrP(C) exerts no control on cleavage of APP(Swe) by BACE1, it has a profound influence on the cleavage of APP(WT), suggesting that PrP(C) may be a key protective player against sporadic Alzheimer disease