Translation-invariance of two-dimensional Gibbsian point processes

The conservation of translation as a symmetry in two-dimensional systems with interaction is a classical subject of statistical mechanics. Here we establish such a result for Gibbsian particle systems with two-body interaction, where the interesting cases of singular, hard-core and discontinuous interaction are included. We start with the special case of pure hard core repulsion in order to show how to treat hard cores in general.Comment: 44 pages, 6 figure

Trust and Reputation Modelling for Tourism Recommendations Supported by Crowdsourcing

Tourism crowdsourcing platforms have a profound influence on the tourist behaviour particularly in terms of travel planning. Not only they hold the opinions shared by other tourists concerning tourism resources, but, with the help of recommendation engines, are the pillar of personalised resource recommendation. However, since prospective tourists are unaware of the trustworthiness or reputation of crowd publishers, they are in fact taking a leap of faith when then rely on the crowd wisdom. In this paper, we argue that modelling publisher Trust & Reputation improves the quality of the tourism recommendations supported by crowdsourced information. Therefore, we present a tourism recommendation system which integrates: (i) user profiling using the multi-criteria ratings; (ii) k-Nearest Neighbours (k-NN) prediction of the user ratings; (iii) Trust & Reputation modelling; and (iv) incremental model update, i.e., providing near real-time recommendations. In terms of contributions, this paper provides two different Trust & Reputation approaches: (i) general reputation employing the pairwise trust values using all users; and (ii) neighbour-based reputation employing the pairwise trust values of the common neighbours. The proposed method was experimented using crowdsourced datasets from Expedia and TripAdvisor platforms.info:eu-repo/semantics/publishedVersio

Particulate matter from both heavy fuel oil and diesel fuel shipping emissions show strong biological effects on human lung cells at realistic and comparable in vitro exposure conditions

Background: Ship engine emissions are important with regard to lung and cardiovascular diseases especially in coastal regions worldwide. Known cellular responses to combustion particles include oxidative stress and inflammatory signalling. Objectives: To provide a molecular link between the chemical and physical characteristics of ship emission particles and the cellular responses they elicit and to identify potentially harmful fractions in shipping emission aerosols. Methods: Through an air-liquid interface exposure system, we exposed human lung cells under realistic in vitro conditions to exhaust fumes from a ship engine running on either common heavy fuel oil (HFO) or cleaner-burning diesel fuel (DF). Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling including isotope labelling methods to characterise the lung cell responses. Results: The HFO emissions contained high concentrations of toxic compounds such as metals and polycyclic aromatic hydrocarbon, and were higher in particle mass. These compounds were lower in DF emissions, which in turn had higher concentrations of elemental carbon (“soot”). Common cellular reactions included cellular stress responses and endocytosis. Reactions to HFO emissions were dominated by oxidative stress and inflammatory responses, whereas DF emissions induced generally a broader biological response than HFO emissions and affected essential cellular pathways such as energy metabolism, protein synthesis, and chromatin modification. Conclusions: Despite a lower content of known toxic compounds, combustion particles from the clean shipping fuel DF influenced several essential pathways of lung cell metabolism more strongly than particles from the unrefined fuel HFO. This might be attributable to a higher soot content in DF. Thus the role of diesel soot, which is a known carcinogen in acute air pollution-induced health effects should be further investigated. For the use of HFO and DF we recommend a reduction of carbonaceous soot in the ship emissions by implementation of filtration devices

Inhibition of COX-2 counteracts the effects of diuretics in rats

Inhibition of COX-2 counteracts the effects of diuretics in rat.BackgroundIt is well established that the diuretic- and renin-stimulated effects of loop diuretics can be attenuated by nonselective cyclooxygenase inhibitors. Since it is yet unclear which of the isoforms of cyclooxygenases, COX-1 and COX-2, is relevant in this context, our study aimed to determine the effects of selective COX-2 inhibition on the renal effects of the loop diuretic furosemide, as well as the diuretic hydrochlorothiazide, which acts on the distal tubule.MethodMale Sprague-Dawley rats were treated with furosemide (12 mg/day subcutaneously by osmotic pump) or hydrochlorothiazide (30 mg/kg body weight/day orally by gavage). In addition, parallel groups received rofecoxib (1 to 10 mg/kg body weight/day) for selective inhibition of COX-2. Controls were treated with vehicle.ResultsInduction of COX-2 mRNA expression due to furosemide was paralleled by increased renal excretion of prostanoids. Also, hydrochlorothiazide led to a rise in prostanoid excretion. Rofecoxib blunted the diuretic-induced increase in prostanoid excretion, thus confirming an effective blockade of COX-2. Moreover, the COX-2 inhibitor rofecoxib dose-dependently attenuated diuresis and saluresis, as well as the stimulation of the renin system induced by furosemide. Furthermore, rofecoxib completely reversed diuresis and saluresis and prevented the increase of plasma renin activity induced by hydrochlorothiazide.ConclusionsThese findings suggest that COX-2–derived prostanoids are of major relevance in modulating the renal effects of diuretics. COX-2 inhibitors might be valuable drugs to treat salt and water wasting during Bartter and Gitelman diseases

Privacy in Social Networks: Existing Challenges and Proposals for Solutions

The significant change in our social lives and communication habits caused by the rise of Social Network Sites (SNSs) has not only brought along benefits but is also accompanied by privacy threats. In this paper we present our research efforts on SNS privacy and social identity management. First, we outline the results of an empirical study showing significant discrepancies between Facebook users’ actual privacy settings and their perception as well as their preferences. Based on this evident need for improving privacy, we present a novel conceptualization of privacy that serves as the basis for tackling the challenges. Finally, the paper provides an overview of solutions we developed as part of our research efforts on privacy in SNSs

Particulate matter from both heavy fuel oil and diesel fuel shipping emissions show strong biological effects on human lung cells at realistic and comparable in vitro exposure conditions

Background: Ship engine emissions are important with regard to lung and cardiovascular diseases especially in coastal regions worldwide. Known cellular responses to combustion particles include oxidative stress and inflammatory signalling. Objectives: To provide a molecular link between the chemical and physical characteristics of ship emission particles and the cellular responses they elicit and to identify potentially harmful fractions in shipping emission aerosols. Methods: Through an air-liquid interface exposure system, we exposed human lung cells under realistic in vitro conditions to exhaust fumes from a ship engine running on either common heavy fuel oil (HFO) or cleaner-burning diesel fuel (DF). Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling including isotope labelling methods to characterise the lung cell responses. Results: The HFO emissions contained high concentrations of toxic compounds such as metals and polycyclic aromatic hydrocarbon, and were higher in particle mass. These compounds were lower in DF emissions, which in turn had higher concentrations of elemental carbon (“soot”). Common cellular reactions included cellular stress responses and endocytosis. Reactions to HFO emissions were dominated by oxidative stress and inflammatory responses, whereas DF emissions induced generally a broader biological response than HFO emissions and affected essential cellular pathways such as energy metabolism, protein synthesis, and chromatin modification. Conclusions: Despite a lower content of known toxic compounds, combustion particles from the clean shipping fuel DF influenced several essential pathways of lung cell metabolism more strongly than particles from the unrefined fuel HFO. This might be attributable to a higher soot content in DF. Thus the role of diesel soot, which is a known carcinogen in acute air pollution-induced health effects should be further investigated. For the use of HFO and DF we recommend a reduction of carbonaceous soot in the ship emissions by implementation of filtration devices