Reduction in Phencyclidine Induced Sensorimotor Gating Deficits in the Rat Following Increased System Xc − Activity in the Medial Prefrontal Cortex

Rationale: Aspects of schizophrenia, including deficits in sensorimotor gating, have been linked to glutamate dysfunction and/or oxidative stress in the prefrontal cortex. System xc −, a cystine–glutamate antiporter, is a poorly understood mechanism that contributes to both cellular antioxidant capacity and glutamate homeostasis. Objectives: Our goal was to determine whether increased system xc − activity within the prefrontal cortex would normalize a rodent measure of sensorimotor gating. Methods: In situ hybridization was used to map messenger RNA (mRNA) expression of xCT, the active subunit of system xc −, in the prefrontal cortex. Prepulse inhibition was used to measure sensorimotor gating; deficits in prepulse inhibition were produced using phencyclidine (0.3–3 mg/kg, sc). N-Acetylcysteine (10–100 μM) and the system xc − inhibitor (S)-4-carboxyphenylglycine (CPG, 0.5 μM) were used to increase and decrease system xc − activity, respectively. The uptake of 14C-cystine into tissue punches obtained from the prefrontal cortex was used to assay system xc − activity. Results: The expression of xCT mRNA in the prefrontal cortex was most prominent in a lateral band spanning primarily the prelimbic cortex. Although phencyclidine did not alter the uptake of 14C-cystine in prefrontal cortical tissue punches, intraprefrontal cortical infusion of N-acetylcysteine (10–100 μM) significantly reduced phencyclidine- (1.5 mg/kg, sc) induced deficits in prepulse inhibition. N-Acetylcysteine was without effect when coinfused with CPG (0.5 μM), indicating an involvement of system xc −. Conclusions: These results indicate that phencyclidine disrupts sensorimotor gating through system xc − independent mechanisms, but that increasing cystine–glutamate exchange in the prefrontal cortex is sufficient to reduce behavioral deficits produced by phencyclidine

Assessing Executive Dysfunction in Neurodegenerative Disorders: A Critical Review of Brief Neuropsychological Tools

Executive function (EF) has been defined as a multifaceted construct that involves a variety of high-level cognitive abilities such as planning, working memory, mental flexibility, and inhibition. Being able to identify deficits in EF is important for the diagnosis and monitoring of several neurodegenerative disorders, and thus their assessment is a topic of much debate. In particular, there has been a growing interest in the development of neuropsychological screening tools that can potentially provide a reliable quick measure of EF. In this review, we critically discuss the four screening tools of EF currently available in the literature: Executive Interview-25 (EXIT 25), Frontal Assessment Battery (FAB), INECO Frontal Screening (IFS), and FRONTIER Executive Screen (FES). We first describe their features, and then evaluate their psychometric properties, the existing evidence on their neural correlates, and the empirical work that has been conducted in clinical populations. We conclude that the four screening tools generally present appropriate psychometric properties, and are sensitive to impairments in EF in several neurodegenerative conditions. However, more research will be needed mostly with respect to normative data and neural correlates, and to determine the extent to which these tools add specific information to the one provided by global cognition screening tests. More research directly comparing the available tools with each other will also be important to establish in which conditions each of them can be most useful.info:eu-repo/semantics/publishedVersio

Visibility and verifiability in port governance transparency: exploring stakeholder expectations

Transparency remains an under-analyzed topic in port research, and previous research has shown that port decision-making and governance reporting are inconsistent across countries. While transparency might be imposed through legislation or voluntarily adopted, effective transparency also includes (a) an organization’s willingness to consistently communicate and make transparent information available to internal or external stakeholders and (b) the stakeholder`s expectations on the visibility and verifiability of information. This paper focuses primarily on the second of these, extending an earlier study that explored the availability of information accessible to the public and port stakeholders through a port’s most public face—its website (Brooks et al. 2020). This research examines a subset of 27 governance variables from Brooks et al. (2020), who explored 59 separate items to identify transparency practices by ports, revealing uneven levels of port transparency. The scope is to identify what different port stakeholders expect to be visible and readily available in terms of board meeting openness, board director conflict of interest, board provided information, and board reports/publications. Stakeholders also provided their perceptions of how trustworthy board reporting was perceived. The data set includes 134 usable responses from 38 countries and this paper analyzes similarities and differences across stakeholders and countries. The responses from the survey are also considered in the light of the results from Brooks et al. (2020) and the extent that ports currently make these variables visible and available. The study concludes by discussing a further research agenda towards a more transparent and thus better port industry. © 2021, World Maritime University

Position paper: Inland waterways classification for South America: Core concepts and initial proposals

South America, as of yet, has not been able to take full advantage of its extensive system of naturally navigable waterways and in making them an integrated part of the region’s transport network to cater for the ever increasing demand for cargo and human mobility. Infrastructure limitations are one of the major obstacles for the development of inland navigation in the region and, to a certain extent, they are being addressed in most national and regional transport plans and projects. However, this effort, in most cases, remain isolated, and the potential and role of inland shipping as a “natural resource” in itself, but also for transporting the region’s natural resources is, in general, absent as an integral part of the countries transport, mobility and or logistics policies. In this sense the economic and social value of the region’s inland waterway system is still underestimated. A common classification of the inland waterways (rivers, canals and lakes), which currently does not exist in the region, could be instrumental for achieving greater, better and more sustainable use and governance of inland navigation. The experiences of other regions in the world demonstrate that inland waterway classifications, far from being public sector formality or a purely academic exercise, are an essential, powerful and dynamic tool for supporting and implementing inland waterways policies and projects inasmuch as they allow to identify the limitations and the economic potential of navigable waterways in the region and to encourage and monitor the development of their capacity for transport of goods and people. Against this backdrop and in order to encourage reflection on a potential inland waterways classification for the South American region, this document uses the example of the European system of classification to demonstrate the role of classifications in the inland navigation development. Specifically, it looks at the 1996 European Agreement on Main Inland Waterways of International Importance (AGN Agreement). Signed in 1996 and ratified by 18 European countries, the AGN Agreement continues to be one of the main instruments for inland water transport development in Europe, as demonstrated by the growing number of ratifications by the countries of the region.1 This Working Document describes the main elements of the European classification system of navigable waterways (Section I) and existing mechanisms for the monitoring and use of the established network of inland waterways (Section II) and then analyses the role of the classification in the development of inland water transport in Europe (Section III). It goes on to discuss lessons learned and presents a preliminary proposal for the establishment of a regional classification for South America (Section IV). The concluding section addresses the institutional processes and next steps needed to develop a classification of this kind. Bearing in mind that the process for the elaboration of the South American classification is still at an early stage and several open question still remain, the overall goal of the document is to highlight and illustrate relevant issues, which have to be discussed at national level and among the experts of the South American countries to identify and implement a harmonized scheme of classification on a regional basis