Age-related effects on spatial memory across viewpoint changes relative to different reference frames

Remembering object positions across different views is a fundamental competence for acting and moving appropriately in a large-scale space. Behavioural and neurological changes in elderly subjects suggest that the spatial representations of the environment might decline compared to young participants. However, no data are available on the use of different reference frames within topographical space in aging. Here we investigated the use of allocentric and egocentric frames in aging, by asking young and older participants to encode the location of a target in a virtual room relative either to stable features of the room (allocentric environment-based frame), or to an unstable objects set (allocentric objects-based frame), or to the viewer's viewpoint (egocentric frame). After a viewpoint change of 0$,^{circ}$ (absent), 45$,^{circ}$ (small) or 135$,^{circ}$ (large), participants judged whether the target was in the same spatial position as before relative to one of the three frames. Results revealed a different susceptibility to viewpoint changes in older than young participants. Importantly, we detected a worst performance, in terms of reaction times, for older than young participants in the allocentric frames. The deficit was more marked for the environment-based frame, for which a lower sensitivity was revealed as well as a worst performance even when no viewpoint change occurred. Our data provide new evidence of a greater vulnerability of the allocentric, in particular environment-based, spatial coding with aging, in line with the retrogenesis theory according to which cognitive changes in aging reverse the sequence of acquisition in mental development

The Atlantic bluefin tuna: structure and competitiveness of Italian fishing in the international trade

In this paper after showing the productive and international trade background of the Atlantic bluefin tuna, we analyze the competitive position of Italy, important producer and exporter on world scale, compared with the main trade partners, carried out through competitiveness indexes based on trade data. The results highlight Italy's good competitive performance above all with Japan, which represents the main world reference market for the Italian product, but also with the United States, Malta and Turkey The Italian competitive advantage with these countries is stronger for the product taken into account. On the other hand, we can notice a competitive disadvantage with the traditional markets supplying bluefin tuna, and with Spain in particular The same is reckoned with the Southern Mediterranean countries which, in the last years, have contributed to increasing the world supply thanks to the spread of mariculture systems. In this background, the increasing interest in the Italian Atlantic bluefin tuna, by the United States in particular and by some Mediterranean countries and by Central Western Europe as well, could open new opportunities to the Italian trade

Links of the significant wave height distribution in the Mediterranean sea with the Northern Hemisphere teleconnection patterns

This study analyzes the link between the SWH (Significant Wave Height) distribution in the Mediterranean Sea during the second half of the 20th century and the Northern Hemisphere SLP (Sea Level Pressure) teleconnection patterns. <br></br> The SWH distribution is computed using the WAM (WAve Model) forced by the surface wind fields provided by the ERA-40 reanalysis for the period 1958–2001. The time series of mid-latitude teleconnection patterns are downloaded from the NOAA web site. This study shows that several mid-latitude patterns are linked to the SWH field in the Mediterranean, especially in its western part during the cold season: East Atlantic Pattern (EA), Scandinavian Pattern (SCA), North Atlantic Oscillation (NAO), East Atlantic/West Russia Pattern (EA/WR) and East Pacific/ North Pacific Pattern (EP/NP). Though the East Atlantic pattern exerts the largest influence, it is not sufficient to characterize the dominant variability. NAO, though relevant, has an effect smaller than EA and comparable to other patterns. Some link results from possibly spurious structures. Patterns which have a very different global structure are associated to similar spatial features of the wave variability in the Mediterranean Sea. These two problems are, admittedly, shortcomings of this analysis, which shows the complexity of the response of the Mediterranean SWH to global scale SLP teleconnection patterns

Links of the significant wave height distribution in the Mediterranean sea with the Northern Hemisphere teleconnection patterns

Abstract. This study analyzes the link between the SWH (Significant Wave Height) distribution in the Mediterranean Sea during the second half of the 20th century and the Northern Hemisphere SLP (Sea Level Pressure) teleconnection patterns. The SWH distribution is computed using the WAM (WAve Model) forced by the surface wind fields provided by the ERA-40 reanalysis for the period 1958&amp;ndash;2001. The time series of mid-latitude teleconnection patterns are downloaded from the NOAA web site. This study shows that several mid-latitude patterns are linked to the SWH field in the Mediterranean, especially in its western part during the cold season: East Atlantic Pattern (EA), Scandinavian Pattern (SCA), North Atlantic Oscillation (NAO), East Atlantic/West Russia Pattern (EA/WR) and East Pacific/ North Pacific Pattern (EP/NP). Though the East Atlantic pattern exerts the largest influence, it is not sufficient to characterize the dominant variability. NAO, though relevant, has an effect smaller than EA and comparable to other patterns. Some link results from possibly spurious structures. Patterns which have a very different global structure are associated to similar spatial features of the wave variability in the Mediterranean Sea. These two problems are, admittedly, shortcomings of this analysis, which shows the complexity of the response of the Mediterranean SWH to global scale SLP teleconnection patterns.</p

Stochastic simulation techniques as related to innovation in communications-navigation-surveillance and air traffic management (CNS/ATM)

The design and operational tuning of the instruments and procedures employed in communications-navigation-surveillance (CNS) and air traffic management (ATM) often relies on stochastic simulation techniques. In this paper the application areas of simulation in the CNS/ATM context are reviewed together with the simulation methods that can help solve the main problems encountered, i.e. quick simulation techniques for the simulation of rare events, and the bootstrap technique for the evaluation of the accuracy of the results

ADS-B signals reception: a Software Defined Radio approach

In Air Traffic Control, ADS-B (Automatic Dependent Surveillance - Broadcast) systems provide surveillance information as obtained by the cooperating airplanes. This usage of air-derived data and of a common link opens various issues: performance in dense traffic area, signals validation and security. A Software Defined Radio (SDR) permits the needed flexibility and modularity in order to easily develop prototypal devices for evaluation and test of novel enhancements of ADS-B receivers. In this frame, a multi-channel receiver for 1090 MHz ADS-B signals was implemented, using an array antenna, a specific designed analog front-end and a software defined receiver. The device is useful to test signal processing algorithms and to analyse the channel traffic. The receiver is also jointly used with another SDR device capable to generate 1090 MHz traffic. With this configuration it is possible to generate specific traffic scenarios characterized by interferences from multiple sources and/or by jammer. This paper deals with the hardware and set-up description, the presentation of the developed software receiver and its functions, and, finally, the results achieved using the system

ADS-B/MLAT surveillance system from high altitude platform systems

In this work the potential usage of ADS-Band Wide Area Multilateration(WAM)Surveillance with High Altitude Platform Systems(HAPS)is considered.The paper investigates the possible configuration ofthesystem,thelinkbudget,thege-ometryandthelimitationduetotherandomaccesstothechannelbytheModeSSignals(capacity).ThesurveillanceperformanceoftheproposedarchitectureinaWideAreaMultilaterationcontextisevaluatedbybothsimulationandstatisticalanalysis(CramerRaoLowerBound)

How the COVID-19 pandemic is changing online food shopping human behaviour in Italy

The advent of the Internet has significantly changed consumption patterns and habits. Online grocery shopping is a way of purchasing food products using a web-based shopping service. The current COVID-19 pandemic is determining a rethinking of purchase choice elements and of consumers\u2019 behavior. This work aims to investigate which characteristics can affect the decision of online food shopping during the pandemic emergency in Italy. In particular, the work aims to analyze the effects of a set of explanatory variables on the level of satisfaction for the food online shopping experience. For achieving this aim, the proportional odds version of the cumulative logit model is carried out. Data derive from an anonymous on-line questionnaire administrated during the first months of the pandemic and filled by 248 respondents. The results of this work highlight that people having familiarity with buying food online, that have a higher educational level and consider food online channels easy to use, appear more satisfied for the food online shopping experience. These findings can be crucial for the future green global challenges as online shopping may help to reach competitive advantages for company sustainability

Pollen, Tapetum, and Orbicule Development in Colletia paradoxa

Tapetum, orbicule, and pollen grain ontogeny in Colletia paradoxa and Discaria americana were studied with transmission electron microscopy (TEM). The ultrastructural changes observed during the different stages of development in the tapetal cells and related to orbicule and pollen grain formation are described. The proorbicules have the appearance of lipid globule, and their formation is related to the endoplasmic reticulum of rough type (ERr). This is the first report on the presence of orbicules in the family Rhamnaceae. Pollen grains are shed at the bicellular stage

Quality certifications’ impact on wine industry assets performance

This study analyses the impact of third-party voluntary certifications on the asset of wineries operating in the Southern Italian regions. The study carried out both quantitative and qualitative approaches, with data extracted from the AIDA Bureau van Dijk International Database (including performance indicators). The analysed sector belongs to 11.02 ‘Manufacture of wine from grape’ of the Statistical classification of economic activities in the European Community (NACE). The econometric elaboration (regression) was carried out by means of STATA software 14. Comparing certified and no certified wineries, results show a better asset performance of certified wineries, confirmed by a positive relationship between higher revenues and bigger size. The adoption of voluntary certifications requires the presence of highly qualified people, capable of managing innovations of product or process. Wine managers should consider that the expected impacts of the adoption of voluntary certification are not independent from both targeted business scopes and institutional context where the winery operates, being strictly linked to specific market and seller strategic decisions, including customer centricity approaches. For what in our knowledge, this work is the first attempt in investigating the impact of voluntary certifications in the Sicilian wine industries. Results are thus of relevant importance and originality and able to suggest new insights on business assets management for the wine industry, enabling managers to better approach the decision to get certified through sustainable standards