218 research outputs found

    Fast filtering and animation of large dynamic networks

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    Detecting and visualizing what are the most relevant changes in an evolving network is an open challenge in several domains. We present a fast algorithm that filters subsets of the strongest nodes and edges representing an evolving weighted graph and visualize it by either creating a movie, or by streaming it to an interactive network visualization tool. The algorithm is an approximation of exponential sliding time-window that scales linearly with the number of interactions. We compare the algorithm against rectangular and exponential sliding time-window methods. Our network filtering algorithm: i) captures persistent trends in the structure of dynamic weighted networks, ii) smoothens transitions between the snapshots of dynamic network, and iii) uses limited memory and processor time. The algorithm is publicly available as open-source software.Comment: 6 figures, 2 table

    Distinguishing Topical and Social Groups Based on Common Identity and Bond Theory

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    Social groups play a crucial role in social media platforms because they form the basis for user participation and engagement. Groups are created explicitly by members of the community, but also form organically as members interact. Due to their importance, they have been studied widely (e.g., community detection, evolution, activity, etc.). One of the key questions for understanding how such groups evolve is whether there are different types of groups and how they differ. In Sociology, theories have been proposed to help explain how such groups form. In particular, the common identity and common bond theory states that people join groups based on identity (i.e., interest in the topics discussed) or bond attachment (i.e., social relationships). The theory has been applied qualitatively to small groups to classify them as either topical or social. We use the identity and bond theory to define a set of features to classify groups into those two categories. Using a dataset from Flickr, we extract user-defined groups and automatically-detected groups, obtained from a community detection algorithm. We discuss the process of manual labeling of groups into social or topical and present results of predicting the group label based on the defined features. We directly validate the predictions of the theory showing that the metrics are able to forecast the group type with high accuracy. In addition, we present a comparison between declared and detected groups along topicality and sociality dimensions.Comment: 10 pages, 6 figures, 2 table

    Upholding a role for EMT in pancreatic cancer metastasis

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    Epithelial-to-mesenchymal transition (EMT) is a cellular program that operates in the context of embryogenesis, wound healing and carcinoma pathogenesis to drive epithelial cells towards a mesenchymal state. During carcinoma progression, EMT enables the cells forming these tumours to acquire the traits of highly malignant cells, notably motility, invasiveness and an ability to disseminate to form distant metastases. Indeed, a number of published reports have associated EMT with a variety of malignant carcinoma cells. Recently, however, Zheng et al.1 reported that in genetically engineered mouse models of pancreatic adenocarcinoma development, carcinoma cells could metastasize without activating EMT programs. Their conclusions, if sustained by the evidence presented, would prompt a major change in how we conceptualize malignant progression and metastasis of carcinoma cells, including the neoplastic cells in human carcinomas

    Power Moderates the Effects of Social Dominance Orientation on Punishment: An Experimental Analysis

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    In this study, it was hypothesized that experimentally manipulated levels of power would moderate the association of dispositional social dominance orientation (SDO) with preferences for harsh punishment. In particular, we expected to detect a stronger effect for dispositional SDO in the low-power condition, relying on the notion that low power enhances sensitivity to threats to the status quo, and that high SDO individuals are particularly motivated to enforce hierarchy-enhancing measures as punishment. SDO scores were measured two months prior to the experiment, and then immediately after the experimental session. As expected, preexperimental SDO interacted with the power manipulation. We found stronger preexperimental SDO effects on punishment among low-power participants. We also anticipated and found that individuals high in SDO increased further their postexperimental SDO scores if assigned to a high-power condition. The discussion focuses on the importance of SDO effects among low-status groups and on how situational roles shape dispositional self-descriptions

    Nutraceutical effects of table green olives: A pilot study with Nocellara del Belice olives

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    Background: The aim of this study was to analyse the nutraceutical properties of table green olives Nocellara del Belice, a traditional Mediterranean food. The Mediterranean Diet has as key elements olives and extra virgin olive oil, common to all Mediterranean countries. Olive oil is the main source of fat and can modulate oxidative stress and inflammation, whereas little is known about the role of olives. Moreover, emerging evidences underline the association between gut microbiota and food as the basis of many phenomena that affect health and delay or avoid the onset of some age-related chronic diseases. Methods: In order to show if table green olives have nutraceutical properties and/or probiotic effect, we performed a nutritional intervention, administering to 25 healthy subjects (mean age 38,3), 12 table green olives/day for 30 days. We carried out anthropometric, biochemical, oxidative stress and cytokines analyses at the beginning of the study and at the end. Moreover, we also collected fecal samples to investigate about the possible variation of concentration of Lactobacilli, after the olives consumption. Result: Our results showed a significant variation of one molecule related to oxidative stress, malondialdehyde, confirming that Nocellara del Belice green olives could have an anti-oxidant effect. In addition, the level of interleukin-6 decreased significantly, demonstrating how this food could be able to modulate the inflammatory response. Moreover, it is noteworthy the reduction of fat mass with an increase of muscle mass, suggesting a possible effect on long time assumption of table olives on body mass variation. No statistically significant differences were observed in the amount of Lactobacilli, although a trend towards an increased concentration of them at the end of the intervention could be related to the nutraceutical effects of olives. Conclusion: These preliminary results suggest a possible nutraceutical effect of daily consumption of green table olives Nocellara del Belice. To best of our knowledge, this is the first study performed to assess nutraceutical properties of this food. Of course, it is necessary to verify the data in a larger sample of individuals to confirm their role as nutraceuticals

    A preferential attachment model with random initial degrees

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    In this paper, a random graph process G(t)t1{G(t)}_{t\geq 1} is studied and its degree sequence is analyzed. Let (Wt)t1(W_t)_{t\geq 1} be an i.i.d. sequence. The graph process is defined so that, at each integer time tt, a new vertex, with WtW_t edges attached to it, is added to the graph. The new edges added at time t are then preferentially connected to older vertices, i.e., conditionally on G(t1)G(t-1), the probability that a given edge is connected to vertex i is proportional to di(t1)+δd_i(t-1)+\delta, where di(t1)d_i(t-1) is the degree of vertex ii at time t1t-1, independently of the other edges. The main result is that the asymptotical degree sequence for this process is a power law with exponent τ=min{τW,τP}\tau=\min\{\tau_{W}, \tau_{P}\}, where τW\tau_{W} is the power-law exponent of the initial degrees (Wt)t1(W_t)_{t\geq 1} and τP\tau_{P} the exponent predicted by pure preferential attachment. This result extends previous work by Cooper and Frieze, which is surveyed.Comment: In the published form of the paper, the proof of Proposition 2.1 is incomplete. This version contains the complete proo

    Avaliação eletrocardiográfica em cães submetidos à pneumonectomia direita

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    O propósito das ressecções pulmonares em cães e gatos, quer sejam por lobectomia ou pneumonectomia, é a cura ou paliação de processos broncopulmonares sempre que os meios conservadores de tratamento clínico sejam considerados ineficientes. Tendo em vista as significativas alterações resultantes da pneumonectomia, novos estudos experimentais devem ser feitos para avaliar as vantagens dessa intervenção cirúrgica e determinar a maneira como aplicá-la com segurança. O presente estudo tem como objetivo avaliar as alterações eletrocardiográficas em dez cães adultos de ambos os sexos, sem raça definida, com 10-30 kg, submetidos à pneumonectomia direita. Foram avaliados diariamente os parâmetros clínicos de cada cão e as alterações em todas as derivações do eletrocardiograma. Todos os cães apresentaram um bom desenlace pós-operatório. Apenas um cão apresentou alteração de relevância clínica, um caso de complexos ventriculares prematuros, possivelmente decorrente da parada cardiorrespiratória, que foi revertido com sucesso. Houve diminuição da amplitude dos complexos QRS nos primeiros 14 dias, retornado ao normal após 60 dias de pós-operatórioThe purpose for using lobectomy or pneumonectomy in dogs and cats, is to cure or palliate of bronchopulmonary diseases whenever conservative clinical treatment proves ineffective. Considering the marked changes caused by pneumonectomy, new experimental studies have to be done to assess the advantages of this surgical intervention allow its performance without any risk. The aim of the current study was to evaluate the electrocardiographic alterations in ten adult mongrel dogs of both sexes with between 10 and 30 Kg that were submitted to right pneumonectomy. The clinical parameters of the dogs were evaluated in a daily basis and the alterations in every electrocardiogram derivation were recorded. All dogs presented a good post-operative outcome. In most cases there were no electrocardiographic alterations; when these alterations were observed they were of no clinical significance and included premature ventricular complexes in one dog, most likely resulting from a cardiorespiratory arrest that was reverted to successfully, and a decreased width in the QRS complex amplitude on the first 0-14 days post surgery which returned to normal after sixty days post surger

    Diagnostic and prognostic potential of the proteomic profiling of serum-derived extracellular vesicles in prostate cancer

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    Extracellular vesicles (EVs) and their cargo represent an intriguing source of cancer biomarkers for developing robust and sensitive molecular tests by liquid biopsy. Prostate cancer (PCa) is still one of the most frequent and deadly tumor in men and analysis of EVs from biological fluids of PCa patients has proven the feasibility and the unprecedented potential of such an approach. Here, we exploited an antibody-based proteomic technology, i.e. the Reverse-Phase Protein microArrays (RPPA), to measure key antigens and activated signaling in EVs isolated from sera of PCa patients. Notably, we found tumor-specific protein profiles associated with clinical settings as well as candidate markers for EV-based tumor diagnosis. Among others, PD-L1, ERG, Integrin-β5, Survivin, TGF-β, phosphorylated-TSC2 as well as partners of the MAP-kinase and mTOR pathways emerged as differentially expressed endpoints in tumor-derived EVs. In addition, the retrospective analysis of EVs from a 15-year follow-up cohort generated a protein signature with prognostic significance. Our results confirm that serum-derived EV cargo may be exploited to improve the current diagnostic procedures while providing potential prognostic and predictive information. The approach proposed here has been already applied to tumor entities other than PCa, thus proving its value in translational medicine and paving the way to innovative, clinically meaningful tools

    All-sky search for gravitational wave emission from scalar boson clouds around spinning black holes in LIGO O3 data

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    This paper describes the first all-sky search for long-duration, quasimonochromatic gravitational-wave signals emitted by ultralight scalar boson clouds around spinning black holes using data from the third observing run of Advanced LIGO. We analyze the frequency range from 20 to 610 Hz, over a small frequency derivative range around zero, and use multiple frequency resolutions to be robust towards possible signal frequency wanderings. Outliers from this search are followed up using two different methods, one more suitable for nearly monochromatic signals, and the other more robust towards frequency fluctuations. We do not find any evidence for such signals and set upper limits on the signal strain amplitude, the most stringent being ≈10−25 at around 130 Hz. We interpret these upper limits as both an “exclusion region” in the boson mass/black hole mass plane and the maximum detectable distance for a given boson mass, based on an assumption of the age of the black hole/boson cloud system
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