On the PSPACE-completeness of Peg Duotaire and other Peg-Jumping Games

Peg Duotaire is a two-player version of the classical puzzle called Peg Solitaire. Players take turns making peg-jumping moves, and the first player which is left without available moves loses the game. Peg Duotaire has been studied from a combinatorial point of view and two versions of the game have been considered, namely the single- and the multi-hop variant. On the other hand, understanding the computational complexity of the game is explicitly mentioned as an open problem in the literature. We close this problem and prove that both versions of the game are PSPACE-complete. We also prove the PSPACE-completeness of other peg-jumping games where two players control pegs of different colors

Experimental investigation on CO2methanation process for solar energy storage compared to CO2-based methanol synthesis

The utilization of the captured CO2 as a carbon source for the production of energy storage media offers a technological solution for overcoming crucial issues in current energy systems. Solar energy production generally does not match with energy demand because of its intermittent and non-programmable nature, entailing the adoption of storage technologies. Hydrogen constitutes a chemical storage for renewable electricity if it is produced by water electrolysis and is also the key reactant for CO2 methanation (Sabatier reaction). The utilization of CO2 as a feedstock for producing methane contributes to alleviate global climate changes and sequestration related problems. The produced methane is a carbon neutral gas that fits into existing infrastructure and allows issues related to the aforementioned intermittency and non-programmability of solar energy to be overcome. In this paper, an experimental apparatus, composed of an electrolyzer and a tubular fixed bed reactor, is built and used to produce methane via Sabatier reaction. The objective of the experimental campaign is the evaluation of the process performance and a comparison with other CO2 valorization paths such as methanol production. The investigated pressure range was 2–20 bar, obtaining a methane volume fraction in outlet gaseous mixture of 64.75% at 8 bar and 97.24% at 20 bar, with conversion efficiencies of, respectively, 84.64% and 99.06%. The methanol and methane processes were compared on the basis of an energy parameter defined as the spent energy/stored energy. It is higher for the methanol process (0.45), with respect to the methane production process (0.41–0.43), which has a higher energy storage capability

a library for the simulation of smart energy systems the case of the campus of the university of parma

Abstract Smart energy systems are complex systems (i.e. composed of windmills, PV panels, solar collectors, heat pumps, CHP systems, etc) in which synergies rise through the ICT (Information and Communications Technology) based management and control of the whole system. In the development of efficient smart energy systems, a fundamental step is the optimization of total energy conversion, transmission and utilization processes within the whole system. To this extent, mathematical models can represent very useful tools for the simulation of the behavior of the system. In this paper, a library for the dynamic simulation of smart energy systems is presented. The library is implemented in Matlab ® /Simulink ® and each component (i.e. the energy conversion and distribution systems and the end-users) is developed through a modular approach. Therefore, the modules are designed by considering a standardized input/output and causality structure. Finally, the capabilities of this approach are evaluated through the application to the district heating and cooling network of the Campus of the University of Parma. The case study is based on a branch which feeds twelve buildings with a total heating volume of about 150 000 m 3 and peak thermal power demand of about 8 MW. Results reported in the paper demonstrate the effectiveness of this approach and the capability in term of system optimization

Dipping prism modelling of subduction plates in view of an improved GOCE Global Moho: The Tonga example

The study of subduction zones, i.e. the process occurring at convergent boundaries by which one tectonic plate moves under another and sinks into the mantle, is a fundamental topic in many Earth−related sciences. Since usually important density variations occur in the correspon− dence of subduction zones, a proper modelling of these regions is fundamental when studying the Earth crust from gravity field observations. In the present work, we investigate the possibility to characterize a subduction zone by exploiting GOCE gravity gradients. The main ob− jective of the work is to find a simple way to model subducting plates in view of a global inversion of the gravity field to recover the main features of the Earth crust. In particular, GOCE along−orbit filtered data are firstly reduced for the effects of the bathymetry, upper−sedi− ments, middle−sediments, and lower−sediments. After that, the residual signal is further reduced for the effect of a “regular crust” by means of a Kriging procedure, isolating, in this way, the gravitational effect of the subducting plate. The signal is thus fitted, by means of a sim− ulated annealing (SA) procedure, with the gravitational effect of a dipping prism, characterized by a set of parameters that define the prism position, size, density, and its strike and dipping angles. The methodology has been firstly assessed in a closed−loop experiment to test the performance of the SA algorithm in detecting the parame− ters used to best fit the isolated gravitational signal of the subduction plate. Then, the Tonga subduction plate has been chosen as a natural lab− oratory to perform some numerical experiments. The closed−loop simulations have shown the capability of the proposed approach to estimate the parameters with a relative error smaller than 10%, even in the presence of observation noise. As for the Tonga subduction, the estimated model well−fit the observed gravitational signal and its geometric parameters are highly−consistent with the values available in the literature

Origin, evolution, and distribution of the molecular machinery for biosynthesis of sialylated lipooligosaccharide structures in Campylobacter coli

Campylobacter jejuni and Campylobacter coli are the most common cause of bacterial gastroenteritis worldwide. Additionally, C. jejuni is the most common bacterial etiological agent in the autoimmune Guillain-Barre syndrome (GBS). Ganglioside mimicry by C. jejuni lipooligosaccharide (LOS) is the triggering factor of the disease. LOS-associated genes involved in the synthesis and transfer of sialic acid (glycosyltranferases belonging to family GT-42) are essential in C. jejuni to synthesize ganglioside-like LOS. Despite being isolated from GBS patients, scarce genetic evidence supports C. coli role in the disease. In this study, through data mining and bioinformatics analysis, C. coli is shown to possess a larger GT-42 glycosyltransferase repertoire than C. jejuni. Although GT-42 glycosyltransferases are widely distributed in C. coli population, only a fraction of C. coli strains (1%) are very likely able to express ganglioside mimics. Even though the activity of C. coli specific GT-42 enzymes and their role in shaping the bacterial population are yet to be explored, evidence presented herein suggest that loss of function of some LOS-associated genes occurred during agriculture niche adaptation.Peer reviewe

A Review of Significant European Foodborne Outbreaks in the Last Decade.

ABSTRACT Foodborne diseases remain a global public health challenge worldwide. The European surveillance system of multistate foodborne outbreaks integrates elements from public and animal health and the food chain for early detection, assessment, and control. This review includes descriptions of the significant outbreaks that occurred in Europe in the last decade. Their significance and relevance to public health is derived from the changes, improvements, and novelties that pushed toward building a safer food system in the European Union, certainly driven by the One Health approach. In 2011, a point source monoclonal outbreak of infections caused by Escherichia coli serotype O104:H4 in sprouted seeds resulted in hundreds of cases of hemolytic uremic syndrome and several fatalities. In 2015, a prolonged outbreak of Listeria monocytogenes infections caused by contamination of frozen corn in Europe resulted in 47 cases and nine deaths. In 2016, a persistent polyclonal outbreak of Salmonella Enteritidis was linked to the consumption of eggs and was associated with hundreds of cases. The outbreak evaluations highlight the importance of rapid sharing of data (e.g., sequencing and tracing data) and the need for harmonizing bioinformatics outputs and computational approaches to facilitate detection and investigation of foodborne illnesses. These outbreaks led to development of a legal framework for a European collaboration platform for sharing whole genome sequence data and enabled the enforcement of existing hygiene and food safety provisions and the development of new hygiene guidelines and best practices. This review also briefly touches on the new trends in information technologies that are being explored for food traceability and safety. These technologies could enhance the traceability of food throughout the supply chain and redirect the conventional tracing system toward a digitized supply chain. HIGHLIGHT