Petri Net Plans A framework for collaboration and coordination in multi-robot systems

Programming the behavior of multi-robot systems is a challenging task which has a key role in developing effective systems in many application domains. In this paper, we present Petri Net Plans (PNPs), a language based on Petri Nets (PNs), which allows for intuitive and effective robot and multi-robot behavior design. PNPs are very expressive and support a rich set of features that are critical to develop robotic applications, including sensing, interrupts and concurrency. As a central feature, PNPs allow for a formal analysis of plans based on standard PN tools. Moreover, PNPs are suitable for modeling multi-robot systems and the developed behaviors can be executed in a distributed setting, while preserving the properties of the modeled system. PNPs have been deployed in several robotic platforms in different application domains. In this paper, we report three case studies, which address complex single robot plans, coordination and collaboration

The influence of salinity on the effects of Multi-walled carbon nanotubes on polychaetes

Salinity shifts in estuarine and coastal areas are becoming a topic of concern and are one of the main factors influencing nanoparticles behaviour in the environment. For this reason, the impacts of multiwalled carbon nanotubes (MWCNTs) under different seawater salinity conditions were evaluated on the common ragworm Hediste diversicolor, a polychaete species widely used as bioindicator of estuarine environmental quality. An innovative method to assess the presence of MWCNT aggregates in the sediments was used for the first time. Biomarkers approach was used to evaluate the metabolic capacity, oxidative status and neurotoxicity of polychaetes after long-term exposure. The results revealed an alteration of energy-related responses in contaminated polychaetes under both salinity conditions, resulting in an increase of metabolism and expenditure of their energy reserves (lower glycogen and protein contents). Moreover, a concentration-dependent toxicity (higher lipid peroxidation, lower ratio between reduced and oxidized glutathione and activation of antioxidant defences and biotransformation mechanisms) was observed in H. diversicolor, especially when exposed to low salinity. Additionally, neurotoxicity was observed by inhibition of Cholinesterases activity in organisms exposed to MWCNTs at both salinities.publishe

Is Promiscuity Associated with Enhanced Selection on MHC-DQα in Mice (genus Peromyscus)?

Reproductive behavior may play an important role in shaping selection on Major Histocompatibility Complex (MHC) genes. For example, the number of sexual partners that an individual has may affect exposure to sexually transmitted pathogens, with more partners leading to greater exposure and, hence, potentially greater selection for variation at MHC loci. To explore this hypothesis, we examined the strength of selection on exon 2 of the MHC-DQα locus in two species of Peromyscus. While the California mouse (P. californicus) is characterized by lifetime social and genetic monogamy, the deer mouse (P. maniculatus) is socially and genetically promiscuous; consistent with these differences in mating behavior, the diversity of bacteria present within the reproductive tracts of females is significantly greater for P. maniculatus. To test the prediction that more reproductive partners and exposure to a greater range of sexually transmitted pathogens are associated with enhanced diversifying selection on genes responsible for immune function, we compared patterns and levels of diversity at the Class II MHC-DQα locus in sympatric populations of P. maniculatus and P. californicus. Using likelihood based analyses, we show that selection is enhanced in the promiscuous P. maniculatus. This study is the first to compare the strength of selection in wild sympatric rodents with known differences in pathogen milieu

Uno strumento per la conoscenza dell’Area Archeologica Centrale di Roma: il modello ligneo del quartiere Alessandrino e del Foro Romano (1871)

The wooden model was constructed in 2017 by the Department of Architecture of Roma Tre University and is now on display in the permanent exhibition at the Museum of Rome (Palazzo Braschi). It represents the diversified landscape of a part of the city at the end of the Papal State control. The new Institutions of the Italian State, in the following years, promoted many actions of strong urban discontinuity. At this moment, the Roman Forum was in a transitional phase. It had been excavated almost exclu¬sively near the Capitoline Hill, and there were fences around the monuments which had already been restored; the complexity of the ancient level would only come to light a few years later. The Alessan¬drino district, around via Alessandrina and via Bonella, was still intact. The preparatory research for the construction of the model has philologically reconstructed the urban fabric of the Alessandrino district and the archeological landscape as it was before the radical changes undertaken during the Fascist period. The model aims to virtually restore the demolished urban settlement and to make intelligible the obliterated meanings of the original Alessandrino district. The model is therefore conceived as a contribution to the knowledge of the urban history of Rome and also as a tool to inform both future enhancement programs and concrete design proposals for the Central Archeological Area

Water sorption by anhydrous ionic liquids

The kinetics of water vapour sorption by several anhydrous hydrophobic and hydrophilic ionic liquids (ILs) were gravimetrically determined at 25 degrees C and two levels of humidity, namely 43 and 81%. A simple equation was used to fit the data. The kinetic parameters obtained from the different ILs were compared and the differences were related to the IL structures. Results showed that even hydrophobic ILs absorb water at an unexpected speed

Zebrafish Larval Melanophores Respond to Electromagnetic Fields Exposure

Groups of zebrafish (Danio rerio) embryos receive radiations of different frequencies and intensities by means of new prototype devices. They are exposed to static (B0, 0 Hz), extremely low-frequency (ELF, 0.2 Hz), low-frequency (LF, 270 kHz), very-high-frequency (VHF, 100 MHz), and ultra-high-frequency (UHF, 900 MHz) field irradiations. The applied magnetic field intensities are 40 mT at 0 Hz, 40 mT at 0.2 Hz, 470 μT at 270 kHz, 240 nT at 100 MHz, and 240 nT at 900 MHz. Such combinations are meant to cover environmental radiations from geomagnetic fields and cosmic magnetism to electromagnetic radiation of electronic instruments such as GSM and UMTS transmission-mode mobile systems. For each frequency, fish are monitored for up to 5 days. Unexposed embryos are used as controls. Notably, exposure to the different radiations brings alterations of body pigmentation in zebrafish embryos and larvae in terms of total number, area, and morphology of (black) melanophores. This research may contribute to evaluating the roles and effects of magnetic radiation on living matter

[Doppler echocardiographic evaluation of the new mechanical bileaflet Sorin Bicarbon valve prosthesis compared with St. Jude Medical].

BACKGROUND: Despite the Bicarbon valve has been marketed for more than two years, no systematic Doppler evaluation of its normal functioning has yet been published. Therefore, the aims of this study were to establish the normal flow characteristics for the Bicarbon bileaflet prosthetic heart valve and to compare them with those obtained from the St. Jude Medical valve prosthesis. METHODS: Doppler echocardiographic characteristics of normally functioning Bicarbon prostheses were prospectively assessed in 76 consecutive patients (44 males and 32 females, mean age 60 +/- 10 years) with 79 valves in mitral (n = 29) and aortic (n = 50) position whose function was considered normal by clinical and echocardiographic evaluation. In addition, Doppler characteristics of the Bicarbon valves in aortic position were compared to those of 27 normal functioning St. Jude Medical implanted during the same period. RESULTS: For the mitral valve prostheses, we found non significant difference among prosthesis sizes in terms of transprosthetic gradients or pressure half time. Peak and mean gradients were similar in the 27-mm and 31-mm size valves (from 11 +/- 4 to 11 +/- 2 mm Hg and from 5 +/- 2 to 5 +/- 1 mm Hg, respectively; p = NS for both). Similarly, the pressure half time was similar in the 27-mm and in the 31-mm size valve (85 +/- 16 and 76 +/- 13 msec; p = NS). Conversely, for the aortic valve prostheses, there was a significant decrease in transprosthetic gradients and an increase in effective orifice areas as prosthesis size increased. Mean gradient was 13 +/- 1 mm Hg in 19-mm size valves, and it decreased to 6 +/- 2 mm Hg in the 29-mm size. Effective prosthetic valve area calculated using the continuity equation, ranged between 1.0 +/- 0.3 cm2 for 19-mm size valves to 3.5 +/- 0.7 cm2 for 29-mm size. With analysis of variance, effective prosthetic aortic valve area differentiated various valve sizes (F = 23.3; p < 0.0001) better than peak (F = 3.2; p = 0.017) or mean (F = 4.19; p = 0.0035) gradients alone did. Furthermore, effective prosthetic aortic valve area correlated better than peak and mean gradients with prosthetic size (r = 0.87, r = -0.58 and r = -0.57; respectively). In addition, peak and mean transprosthetic gradients and effective prosthetic aortic valve areas did not show any statistically significant difference between the Bicarbon and the St. Jude Medical valves in aortic position, either in 19 and 21 mm (25 +/- 8 mm Hg, 13 +/- 4 mm Hg, 1.3 +/- 0.3 cm2 and 32 +/- 11 mm Hg, 17 +/- 6 mm Hg, 1.2 +/- 0.4 cm2, respectively; p = NS), or in 23 and 25 mm (21 +/- 8 mm Hg, 11 +/- 4 mm Hg, 2.1 +/- 0.5 cm2 and 24 +/- 11 mm Hg, 12 +/- 5 mm Hg, 1.8 +/- 0.4 cm2, respectively; p = NS) or in 27 and 29 mm (12 +/- 2 mm Hg, 7 +/- 1 mm Hg, 2.8 +/- 0.9 cm2 and 16 +/- 5 mm Hg, 7 +/- 2 mm Hg, 2.6 +/- 0.4 cm2, respectively; p = NS). CONCLUSIONS: This study suggest that the Bicarbon valve prosthesis offers relatively little resistance to forward flow except at a small anulus diameter. Furthermore, these is no statistically significant difference between the Bicarbon and the St. Jude Medical in aortic position with regard to early hemodynamic performances