On the characterization of isotropic Gaussian fields on homogeneous spaces of compact groups

Let T be a random field invariant under the action of a compact group G We give conditions ensuring that independence of the random Fourier coefficients is equivalent to Gaussianity. As a consequence, in general it is not possible to simulate a non-Gaussian invariant random field through its Fourier expansion using independent coefficients

The Effect of Coupled Dark Energy on the Alignment between Dark Matter and Galaxy Distributions in Clusters

We investigate the effects of a coupled Dark Energy (cDE) scalar field on the alignment between satellites and matter distributions in galaxy clusters. Using high-resolution N-body simulations for LCDM and cDE cosmological models, we compute the probability density distribution for the alignment angle between the satellite galaxies and underlying matter distributions, finding a difference between the two scenarios. With respect to LCDM, in cDE cosmologies the satellite galaxies are less preferentially located along the major axis of the matter distribution, possibly reducing the tension with obersevational data. A physical explanation is that the coupling between dark matter and dark energy acts as an additional tidal force on the satellite galaxies diminishing the alignments between their distribution and the matter one. Through a Wald test based on the generalized chi-square statistics, the null hypothesis that the two probability distributions come from the same parent population is rejected at the 99 % confidence level. It is concluded that the galaxy-matter alignment in clusters may provide a unique probe of dark sector interactions as well as the nature of dark energy.Comment: Accepted for publication in ApJ, published version, all minor typos corrected, 5 figure

WATCAT: a tale of wide-angle tailed radio galaxies

We present a catalog of 47 wide-angle tailed radio galaxies (WATs), the WATCAT; these galaxies were selected by combining observations from the National Radio Astronomy Observatory/Very Large Array Sky Survey (NVSS), the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST), and the Sloan Digital Sky Survey (SDSS), and mainly built including a radio morphological classification. We included in the catalog only radio sources showing two-sided jets with two clear "warmspots" (i.e., jet knots as bright as 20% of the nucleus) lying on the opposite side of the radio core, and having classical extended emission resembling a plume beyond them. The catalog is limited to redshifts z $\leq$ 0.15, and lists only sources with radio emission extended beyond 30 kpc from the host galaxy. We found that host galaxies of WATCAT sources are all luminous (-20.5 $\gtrsim$ Mr $\gtrsim$ -23.7), red early-type galaxies with black hole masses in the range $10^8\lesssim$ M$_{\rm BH} \lesssim 10^9$ M$_\odot$. The spectroscopic classification indicates that they are all low-excitation galaxies (LEGs). Comparing WAT multifrequency properties with those of FRI and FRII radio galaxies at the same redshifts, we conclude that WATs show multifrequency properties remarkably similar to FRI radio galaxies, having radio power of typical FRIIs

New flaring of an ultraluminous X-ray source in NGC 1365

We have studied a highly variable ultraluminous X-ray source (ULX) in the Fornax galaxy NGC 1365, with a series of 12 Chandra and XMM-Newton observations between 2002 and 2006. In 2006 April, the source peaked at a luminosity ~ 3 x 10^{40} erg/s in the 0.3-10 keV band (similar to the maximum luminosity found by ASCA in 1995), and declined on an e-folding timescale ~ 3 days. The X-ray spectrum is always dominated by a broad power-law-like component. When the source is seen at X-ray luminosities ~ 10^{40} erg/s, an additional soft thermal component (which we interpret as emission from the accretion disk) contributes ~ 1/4 of the X-ray flux; when the luminosity is higher, ~ 3 x 10^{40} erg/s, the thermal component is not detected and must contribute < 10% of the flux. At the beginning of the decline, ionized absorption is detected around 0.5-2 keV; it is a possible signature of a massive outflow. The power-law is always hard, with a photon index Gamma ~ 1.7 (and even flatter at times), as is generally the case with bright ULXs. We speculate that this source and perhaps most other bright ULXs are in a high/hard state: as the accretion rate increases well above the Eddington limit, more and more power is extracted from the inner region of the inflow through non-radiative channels, and is used to power a Comptonizing corona, jet or wind. The observed thermal component comes from the standard outer disk; the transition radius between outer standard disk and Comptonizing inner region moves further out and to lower disk temperatures as the accretion rate increases. This produces the observed appearance of a large, cool disk. Based on X-ray luminosity and spectral arguments, we suggest that this accreting black hole has a likely mass ~ 50-150 Msun (even without accounting for possible beaming).Comment: 14 pages, to appear in MNRA

Long-term disease-free survival of patients with radically resected thymomas: relevance of cell-cycle protein expression

BACKGROUND. Despite radical Surgical resection, thymomas often recur. The objective of the current retrospective Study was to investigate the prognostic relevance of the expression of cell-cycle proteins in these neoplasms to formulate a possible therapeutic Surveillance strategy for the prevention of recurrence. METHODS. The authors retrospectively reviewed the main clinicopathologic factors, including the World Health Organization (WHO) classification, of patients with thymoma who had undergone radical surgical resection. Specimens were studied using immunohistochemistry and the expression of cell-cycle proteins (i.e., p21, p27, and p53) was assessed. Univariate and multivariate analysis of predicting survival prognostic factors were performed. RESULTS. The authors analyzed 88 patients with thymoma who underwent radical surgical resection at the study institution. According to the Masaoka staging system, 41 patients had Stage I disease, 31 patients had Stage II disease, and 16 patients had Stage III disease. There were 24 tumor recurrences (27.3%), 4 of which were local, 16 of which were distant intrathoracic, and 4 of which were extrathoracic. The second radical resection provided a disease-free Survival rate that was similar to the first. Only Masaoka stage (P=0.001), WHO classification (P=0.001), high expression of p53 (P=0.03), and low expression of p21 (P=0.02) and p27 (P=0.001) were found to he correlated with a reduced disease-free survival. Low p27 expression was found to be the most significant predictive factor of a short disease-free Survival (P=0.001), especially when associated with low p21 expression and high p53 expression (P=0.0001). CONCLUSIONS. Long-term disease-free survival in thymoma patients treated with radical surgical resection Was found to be correlated with Masaoka stage, WHO classification, and expression of cell-cycle proteins, with the latter found to be the most significant predictive factor. Functional cooperation between cell-cycle proteins might constitute another level of regulation in tumor growth. More careful surveillance should be adopted whenever there is negative cell-cycle protein expression. (c) 2005 American Cancer Society

A Logical Modeling of Severe Ignorance

In the logical context, ignorance is traditionally defined recurring to epistemic logic. In particular, ignorance is essentially interpreted as “lack of knowledge”. This received view has - as we point out - some problems, in particular we will highlight how it does not allow to express a type of content-theoretic ignorance, i.e. an ignorance of φ that stems from an unfamiliarity with its meaning. Contrarily to this trend, in this paper, we introduce and investigate a modal logic having a primitive epistemic operator I, modeling ignorance. Our modal logic is essentially constructed on the modal logics based on weak Kleene three-valued logic introduced by Segerberg (Theoria, 33(1):53–71, 1997). Such non-classical propositional basis allows to define a Kripke-style semantics with the following, very intuitive, interpretation: a formula φ is ignored by an agent if φ is neither true nor false in every world accessible to the agent. As a consequence of this choice, we obtain a type of content-theoretic notion of ignorance, which is essentially different from the traditional approach. We dub it severe ignorance. We axiomatize, prove completeness and decidability for the logic of reflexive (three-valued) Kripke frames, which we find the most suitable candidate for our novel proposal and, finally, compare our approach with the most traditional one

Handling oversampling in dynamic networks using link prediction

Oversampling is a common characteristic of data representing dynamic networks. It introduces noise into representations of dynamic networks, but there has been little work so far to compensate for it. Oversampling can affect the quality of many important algorithmic problems on dynamic networks, including link prediction. Link prediction seeks to predict edges that will be added to the network given previous snapshots. We show that not only does oversampling affect the quality of link prediction, but that we can use link prediction to recover from the effects of oversampling. We also introduce a novel generative model of noise in dynamic networks that represents oversampling. We demonstrate the results of our approach on both synthetic and real-world data.Comment: ECML/PKDD 201

Reasoning about constitutive norms in BDI agents

This is a pre-copyedited, author-produced PDF of an article accepted for publication in Logic Journal of the IGPL following peer review. The definitive publisher-authenticated version: Criado Pacheco, N.; Argente Villaplana, E.; Noriega, P.; Botti Navarro, VJ. (2014). Reasoning about constitutive norms in BDI agents. Logic Journal of the IGPL. 22(1):66-93 is available online at: http://dx.doi.org/1093/jigpal/jzt035Software agents can be members of different institutions along their life; they might even belong to different institutions simultaneously. For these reasons, agents need capabilities that allow them to determine the repercussion that their actions would have within the different institutions. This association between the physical word, in which agents interactions and actions take place, and the institutional world is defined by means of constitutive norms. Currently, the problem of how agents reason about constitutive norms has been tackled from a theoretical perspective only. Thus, there is a lack of more practical proposals that allow the development of software agents capable of reasoning about constitutive norms. In this article we propose an information model, knowledge representation and an inference mechanism to enable Belief-Desire-Intention agents to reason about the consequences of their actions on the institutions and making decisions accordingly. Specifically, the information model, knowledge representation and inference mechanism proposed in this article allows agents to keep track of the institutional state given that they have a physical presence in some real-world environment. Agents have a limited and not fully believable knowledge of the physical world (i.e. they are placed in an uncertain environment). Therefore, our proposal also deals with the uncertainty of the environment.Criado Pacheco, N.; Argente Villaplana, E.; Noriega, P.; Botti Navarro, VJ. (2014). Reasoning about constitutive norms in BDI agents. Logic Journal of the IGPL. 22(1):66-93. doi:10.1093/jigpal/jzt035S6693221Baldi, P., Brunak, S., Chauvin, Y., Andersen, C. A. F., & Nielsen, H. (2000). Assessing the accuracy of prediction algorithms for classification: an overview. Bioinformatics, 16(5), 412-424. doi:10.1093/bioinformatics/16.5.412Bloch, I. (1996). Information combination operators for data fusion: a comparative review with classification. IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Humans, 26(1), 52-67. doi:10.1109/3468.477860Casali, A., Godo, L., & Sierra, C. (2011). A graded BDI agent model to represent and reason about preferences. Artificial Intelligence, 175(7-8), 1468-1478. doi:10.1016/j.artint.2010.12.006Criado, N., Julián, V., Botti, V., & Argente, E. (2010). A Norm-Based Organization Management System. Lecture Notes in Computer Science, 19-35. doi:10.1007/978-3-642-14962-7_2Governatori, G., & Rotolo, A. (2008). BIO logical agents: Norms, beliefs, intentions in defeasible logic. Autonomous Agents and Multi-Agent Systems, 17(1), 36-69. doi:10.1007/s10458-008-9030-4Grossi, D., Aldewereld, H., Vázquez-Salceda, J., & Dignum, F. (2006). Ontological aspects of the implementation of norms in agent-based electronic institutions. Computational & Mathematical Organization Theory, 12(2-3), 251-275. doi:10.1007/s10588-006-9546-6Hübner, J. F., Boissier, O., Kitio, R., & Ricci, A. (2009). Instrumenting multi-agent organisations with organisational artifacts and agents. Autonomous Agents and Multi-Agent Systems, 20(3), 369-400. doi:10.1007/s10458-009-9084-yJONES, A. J. I., & SERGOT, M. (1996). A Formal Characterisation of Institutionalised Power. Logic Journal of IGPL, 4(3), 427-443. doi:10.1093/jigpal/4.3.427Rawls, J. (1955). Two Concepts of Rules. The Philosophical Review, 64(1), 3. doi:10.2307/2182230Da Silva, V. T. (2008). From the specification to the implementation of norms: an automatic approach to generate rules from norms to govern the behavior of agents. Autonomous Agents and Multi-Agent Systems, 17(1), 113-155. doi:10.1007/s10458-008-9039-

Tumor Necrosis Factor-alpha Levels In Blood Cord Is Directly Correlated With The Body Weight Of Mothers

Obesity has emerged as major public health problem leading to increased morbidity and mortality. Epidemiological studies indicate that in many regions of the world, children and teenagers are increasingly affected by obesity, which contributes for a pessimistic projection for the near future. Maternal obesity has been implicated in metabolic disorders of the offspring, but there are no biological markers that can be detected early on life that predict the development of obesity in the offspring. Objective To evaluate the expression of inflammatory markers in the umbilical cord blood of babies of mothers with obesity/overweight, and correlate these markers with the body weight at age 9 months. Methods Anthropometric data of mothers and babies were obtained during prenatal evaluation, at birth and 9 months after birth. Cord blood was collected during delivery of 54 babies from mothers with obesity/overweight and of 50 babies from lean mothers. Tumour necrosis factor-alpha (TNF-alpha), transforming growth factor 1 beta, monocyte chemoattractant protein-1 and 2 (MCP-1/MCP-2) were determined in serum samples using enzyme-linked immunosorbent assay methods. Correlations were evaluated using the Spearman correlation coefficient, and comparisons were evaluated using the non-parametric Mann-Whitney U-test. Results Cord blood TNF-a was positively correlated with maternal body mass index. There was an inverse correlation between cord blood transforming growth factor 1 beta and baby body weight at birth. There was no biological marker that predicted body weight at age 9 months. Conclusion Although we have not found a biological marker to predict increased body weight at 9 months of age, the study shows that maternal obesity exposes the baby to higher TNF-a level in the early stages of life, and this can affect metabolic and inflammatory parameters during adulthood.2221021