On the definition of temperature in FPU systems

It is usually assumed, in classical statistical mechanics, that the temperature should coincide, apart from a suitable constant factor, with the mean kinetic energy of the particles. We show that this is not the case for \FPU systems, in conditions in which energy equipartition between the modes is not attained. We find that the temperature should be rather identified with the mean value of the energy of the low frequency modes.Comment: 12 pages, 4 Figure

Discrete Matter, Far Fields, and Dark Matter

We show that in cosmology the gravitational action of the far away matter has quite relevant effects, if retardation of the forces and discreteness of matter (with its spatial correlation) are taken into account. The expansion rate is found to be determined by the density of the far away matter, i.e., by the density of matter at remote times. This leads to the introduction of an effective density, which has to be five times larger than the present one, if the present expansion rate is to be accounted for. The force per unit mass on a test particle is found to be of the order of 0.2cH_0. The corresponding contribution to the virial of the forces for a cluster of galaxies is also discussed, and it is shown that it fits the observations if a decorrelation property of the forces at two separated points is assumed. So it appears that the gravitational effects of the far away matter may have the same order of magnitude as the corresponding local effects of dark matter.Comment: 16 pages, 1 figure. LaTex documen

Composting, anaerobic digestion and biochar production in Ghana: environmental-economic assessment in the context of voluntary carbon markets

In some areas of Sub-Saharan Africa appropriate organic waste management technology could address development issues such as soil degradation, unemployment and energy scarcity, while at the same time reducing emissions of greenhouse gases. This paper investigates the role that carbon markets could have in facilitating the implementation of composting, anaerobic digestion and biochar production, in the city of Tamale, in the North of Ghana. Through a life cycle assessment of implementation scenarios for low-tech, small scale variants of the above mentioned three technologies, the potential contribution they could give to climate change mitigation was assessed. Furthermore an economic assessment was carried out to study their viability and the impact thereon of accessing carbon markets. It was found that substantial climate benefits can be achieved by avoiding landfilling of organic waste, producing electricity and substituting the use of chemical fertilizer. Biochar production could result in a net carbon sequestration. These technologies were however found not to be economically viable without external subsidies, and access to carbon markets at the considered carbon price of 7 EUR/ton of carbon would not change the situation significantly. Carbon markets could help the realization of the considered composting and anaerobic digestion systems only if the carbon price will rise above 75-84 EUR/t of carbon (respectively for anaerobic digestion and composting). Biochar production could achieve large climate benefits and, if approved as a land based climate mitigation mechanism in carbon markets, it would become economically viable at the lower carbon price of 30 EUR/t of carbon.Industrial Ecolog

Quasi-Homogeneous Thermodynamics and Black Holes

We propose a generalized thermodynamics in which quasi-homogeneity of the thermodynamic potentials plays a fundamental role. This thermodynamic formalism arises from a generalization of the approach presented in paper [1], and it is based on the requirement that quasi-homogeneity is a non-trivial symmetry for the Pfaffian form $\delta Q_{rev}$. It is shown that quasi-homogeneous thermodynamics fits the thermodynamic features of at least some self-gravitating systems. We analyze how quasi-homogeneous thermodynamics is suggested by black hole thermodynamics. Then, some existing results involving self-gravitating systems are also shortly discussed in the light of this thermodynamic framework. The consequences of the lack of extensivity are also recalled. We show that generalized Gibbs-Duhem equations arise as a consequence of quasi-homogeneity of the thermodynamic potentials. An heuristic link between this generalized thermodynamic formalism and the thermodynamic limit is also discussed.Comment: 39 pages, uses RevteX. Published version (minor changes w.r.t. the original one

Overview of the marine litter status in the Atlantic Area: floating litter

CleanAtlantic is an INTERREG Atlantic Area Programme project that aimed at protecting biodiversity and ecosystem services in the Atlantic Area by improving capabilities to monitor, prevent and remove (macro) marine litter. Besides, the project also contributed to raise awareness and change attitudes among stakeholders and to improve marine litter managing systems. To achieve these aims, the work was organised in 8 work packages. The present deliverable aims at synthesizing the main results achieved on the frame of the action 1 of work package 4, which focused on the Regional characterisation of marine litter in the Atlantic Area. More specifically, this report deals with the assessment of the floating litter data available in this area. Additionally, the major key findings, gaps on monitoring and research as well as potential improvements and recommendations are identified

Liquid biopsy is a promising tool for genetic testing in idiopathic pulmonary fibrosis

Liquid biopsy, which allows the isolation of circulating cell-free (ccf) DNA from blood, is an emerging noninvasive tool widely used in oncology for diagnostic and prognosis purposes. Previous data have shown that serum cfDNA discriminates idiopathic pulmonary fibrosis (IPF) from other interstitial lung diseases. Our study aimed to measure plasma levels of ccfDNA in 59 consecutive therapy-naive and clinically stable IPF patients. The single nucleotide polymorphism (SNP) of the MUC5B gene promoter (rs35705950), associated with increased susceptibility of developing IPF, has been sought in plasma cfDNA and genomic DNA for comparison. Thirty-five age-and sex-matched healthy volunteers were recruited as the control group. Our results show that concentrations of small-size ccfDNA fragments were significantly higher in IPF patients than in controls and inversely correlated with lung function deterioration. Moreover, the median level of 104 ng/mL allowed discriminating patients with mild disease from those more advanced. The rs35705950 polymorphism was found in 11.8% of IPF patients and 8% of controls, with no differences. Complete concordance between ccfDNA and genomic DNA was detected in all control samples, while four out of seven IPF cases (57%) carrying the rs35705950 polymorphism were discordant from genomic DNA (7% of total IPF). Liquid biopsy is a suitable tool with optimistic expectations of application in the field of IPF. In analogy with cancer biology, finding some discrepancies between ccfDNA and genomic DNA in IPF patients suggests that the former may convey specific genetic information present in the primary site of the disease

Biological notes on a fungus-growing ant, Trachymyrmex cf. zeteki (Hymenoptera, Formicidae, Attini) attacked by a diverse community of parasitoid wasps (Hymenoptera, Diapriidae)

A number of wasps in the family Diapriidae, subfamily Diapriinae (Proctotrupoidea), are parasitoids that specialize on ant larvae. These wasps are abundant and diverse in the Neotropics, but little is known about their biology. We studied parasitism rates by an array of diapriine wasps that attack the larvae of fungus-growing ants, Trachymyrmex cf. zeteki, in a single population (near Gamboa, Panama). Relatively little is known about the biology and natural history of these ants, so we also present data on colony size and nest architecture. We excavated 136 colonies in central Panama from June to September 2006, and 20 nests from July 2009. We reared six wasp morphotypes; two of them in the genus Mimopriella Masner and Garcia, one Oxypria Kieffer, two Szelenyiopria Fabritius and one Acanthopria Ashmead. The mean intensity of larval parasitism per ant colony was 33.9% (2006), and its prevalence across all ant populations was 27.2% (2006 and 2009). Parasitism rates were not positively correlated with host colony size. A single case of super-parasitism was documented in which two Oxypria males were reared from the same host larva.Museo de La Plat

Platelet serotonin levels are associated with plasma soluble leptin receptor concentrations in normoglycemic women

Most peripheral serotonin (5-hydroxytryptamine (5HT)) is synthetized in the gut with platelets being its main circulating reservoir. 5HT is acting as a hormone in key organs to regulate glucose and lipid metabolism. However, the relation between platelet 5HT levels and traits related to glucose homeostasis and lipid metabolism in humans remains poorly explored. The objectives of this study were (a) to assess the association between platelet 5HT levels and plasma concentration of nonesterified fatty acids (NEFAs) and some adipokines including leptin and its soluble leptin receptor (sOb-R), (b) to assess the association between platelet 5HT levels and anthropometric traits and indexes of insulin secretion/sensitivity derived from oral glucose tolerance test (OGTT), and (c) to evaluate changes in platelet 5HT levels in response to OGTT. In a cross-sectional study, 59 normoglycemic women underwent a standard 2-hour OGTT. Plasma leptin, sOb-R, total and high molecular weight adiponectin, TNFα, and MCP1 were determined by immunoassays. Platelet 5HT levels and NEFAs were measured before and after OGTT. The free leptin index was calculated from leptin and sOb-R measurements. Insulin sensitivity indexes derived from OGTT (HOMA-S and Matsuda ISICOMP) and plasma NEFAs (Adipose-IR, Revised QUICKI) were also calculated. Our data show that among metabolic traits, platelet 5HT levels were associated with plasma sOb-R (r = 0 39, p = 0 003, corrected p = 0 018). Platelet 5HT levels were reduced in response to OGTT (779 ± 237 vs 731 ± 217 ng/109 platelets, p = 0 005). In conclusion, platelet 5HT levels are positively associated with plasma sOb-R concentrations and reduced in response to glucose intake possibly indicating a role of peripheral 5HT in leptin-mediated appetite regulation