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Network Security Supported by Arguments
Get PDFArgumentation has been proved as a simple yet powerful approach to manage conflicts in reasoning with the purpose to find subsets of ?surviving? arguments. Our intent is to exploit such form of resolution to support the? administration of security in complex systems, e.g., in case threat countermeasures are in conflict with non-functional requirements. The proposed formalisation is able to find the required security controls and explicitly provide arguments supporting this selection. Therefore, an explanation automatically comes as part of the suggested solution, facilitating human comprehension
Geo Data Annotator: a Web Framework for Collaborative Annotation of Geographical Datasets
No full textIn this paper we illustrate the Geo Data Annotator (GDA), a framework which helps a user to build a ground-truth dataset, starting from two separate geographical datasets. GDA exploits two kinds of indices to ease the task of man- ual annotation: geographical-based and string-based. GDA provides also a mechanism to evaluate the quality of the built ground-truth dataset. This is achieved through a col- laborative platform, which allows many users to work to the same project. The quality evaluation is based on annotator agreement, which exploits the Fleiss? kappa statistic.?
Social Cognitive Heuristics for adaptive data dissemination in Opportunistic Networks
Get PDFIn typical Opportunistic Networking (OppNets) scenarios, mobile devices collaborate to cooperatively disseminate data toward interested nodes. However, the limited resources and knowledge available at each node, compared to possibly vast amounts of data to be delivered, makes it difficult to devise efficient dissemination schemes. Recent solutions propose to use data dissemination algorithms built on human information processing schemes, modelled in cognitive sciences as Cognitive Heuristics. In general, they are methods used by the human brain to quickly assess relevance of information so to drop what is irrelevant. Recent solutions for data dissemination in OppNets based on these heuristics proved to be effective and efficient in terms of network overhead. However, to the best of our knowledge, none takes into consideration the structure of users\u27 social relationships, which is known to determine movement patterns and thus contact opportunities between nodes. In this paper we propose a social-based data dissemination scheme, built on the Social Circle Heuristic (SCH). SCH exploits the structure of the social environment of users to infer the relevance of discovered information for the individual and their social communities. We compare the proposed scheme against state-of-the-art solutions based on non-social cognitive heuristics, both in terms of effectiveness (i.e., bringing messages to users that request it) and efficiency (i.e., doing so minimising the network traffic). We show that the scheme based on SCH significantly outperforms non-social cognitive schemes along both dimensions. In particular, the difference becomes more and more evident as scenarios becomes more and more dynamic. We finally show that in scenarios where new content is generated over time, the scheme based on SCH is the only one able to bring content to the interested users, while non-social schemes fail to do so while at the same time generating significant higher network traffic
A new method for discovering disease-specific miRNA-target regulatory networks
Get PDFGenes and their expression regulation are among the key factors in the comprehension of the genesis and development of complex diseases. In this context, microRNAs (miRNAs) are post-transcriptional regulators that play an important role in gene expression since they are frequently deregulated in pathologies like cardiovascular disease and cancer. In vitro validation of miRNA - targets regulation is often too expensive and time consuming to be carried out for every possible alternative. As a result, a tool able to provide some criteria to prioritize trials is becoming a pressing need. Moreover, before planning in vitro experiments, the scientist needs to evaluate the miRNA-target genes interaction network. In this paper we describe the miRable method whose purpose is to identify new potentially relevant genes and their interaction networks associate to a specific pathology. To achieve this goal miRable follows a system biology approach integrating together general-purpose medical knowledge (literature, Protein-Protein Interaction networks, prediction tools) and pathology specific data (gene expression data). A case study on Prostate Cancer has shown that miRable is able to: 1) find new potential miRNA-targets pairs, 2) highlight novel genes potentially involved in a disease but never or little studied before, 3) reconstruct all possible regulatory subnetworks starting from the literature to expand the knowledge on the regulation of miRNA regulatory mechanisms
Alkaline Phosphatase-Positive Immortal Mouse Embryo Fibroblasts Are Cells in a Transitional Reprogramming State Induced to Face Environmental Stresses
Get PDFIn this study, we report that immortal mouse embryonic fibroblasts (I-MEFs) have a baseline level of cells positive for alkaline phosphatase (AP?) staining. Environmental stresses, including long-lasting growth in the absence of expansion and treatment with drugs, enhance the frequency of AP? I-MEFs. By adapting fast red AP staining to the sorting procedure, we separated AP? and AP? I-MEFs and demonstrated that the differentially expressed genes are consistent with a reprogrammed phenotype. In particular, we found that sestrin 1 is upregulated in AP? I-MEFs. We focused on this gene and demonstrated that increased sestrin 1 expression is accompanied by the growth of I-MEFs in the absence of expansion and occurs before the formation of AP? I-MEFs. Together with sestrin 1 upregulation, we found that AP? I-MEFs accumulated in the G1 phase of the cell cycle, suggesting that the two events are causally related. Accordingly, we found that silencing sestrin 1 expression reduced the frequency and G1 accumulation of AP? I-MEFs. Taken together, our data suggested that I-MEFs stressed by environmental changes acquire the AP? phenotype and achieve a quiescent state characterized by a new transcriptional network
Progettazione e Realizzazione di un Contenitore per Telecamera ad alta velocit? per Visualizzazioni Subacquee
No full textTechnical Report for Underwater Hi Speed Camer
A 13000 year environmental history of Lake Colbricon Inferiore (Trentino, Italia)
Get PDFLake sediments have long been used as an archive for paleoclimatic-paleoenvironmental reconstructions, with more and more refined techniques developed in the late 40 years. This work is an attempt to reconstruct with a multiproxy paleolimnological technique the ecosystem response in Colbricon Inferiore, a small high-mountain lakes located in the Paneveggio-Pale di S. Martino Natural Park(Trento, Italy). A ca. 360cm long core was retrieved with a piston core; a gravity corer was used for the most recent sediment. Chronology was established by a combination of 210Pb and 14C isotopes. Diatom assemblages show changes in species composition that could be associated to an initial warm phase (Allerod), a following colder one (YD) and a progressive amelioration of climate until the optimum (8500-3500). During the transition period (10000-8000) carotenoids point out to an increase of cyanobacteria (Echinenone and myxoxanthophyll) associated with an increase of fire frequency and the first settlement around Lake Colbricon. Along the climatic optimum, algal pigment are rather stable and Chryptophytes (alloxanthin) are well represented pointing to a high and stable water level. Diatom assemblages are dominated by the planktonic Discostella stelligeroides. At ca. 3500 yrs. B.P., a new phase begins with a decrease of D. stelligeroides and an increase of the small benthic fragilariaceae (Staurosira and Pseudostaurosira species) typical of cold-water conditions. At this level, there is a general increase of carotenoids and a shift in the ratio CD:TC. This suggest, rather than an increase in productivity, a change in the preservation conditions associated with the worsening of climate. After 2000 cal yr BP the lake seems quite stable: diatom assemblages are dominated by Staurosira and Pasudostaurosira species. Algal pigment are also quite stable apart myxoxanthophyll that increase in the more recent phase
Single culture and co-culture of two Synechococcus phylotypes respond differently to nanoflagellate grazing
Get PDFCyanobacteria belonging to the genus Synechococcus are found in lake waters typically as planktonic single cells and monospecific microcolonies. In oligotrophic lakes, single cells dominate in spring, while microcolonies are mostly found in late summer-autumn when the large colonial cyanobacteria increase in number. Since grazing activity is known as one of the major factors inducing microbial phenotypical changes, the formation of Synechococcus microcolonies was proposed as an efficient defence strategy against sizeselective predators. To better understand this ecological interaction, we explored the effect of grazing by the mixotrophic nanoflagellate Poteriochromonas sp. on the aggregation of two freshwater Synechococcus strains belonging to different phylogenetic clades (phycoerythrin-rich cells, PE, Group A; phycocyanin-rich cells, PC, Group I). During four days of incubation, we followed the dynamics of single-cells, microcolonies, and flagellates in semicontinuous cultures under different treatments (single culture and co-culture, with and without predators) by flow cytometry, epifluorescence microscopy and PhytoPAM. In single culture with the addition of Poteriochromonas, we observed the formation of grazing-induced monoclonal PE microcolonies, conversely limited in PC. In co-culture, there was an interaction between PE and PC, with an active microcolony formation by both PE and PC, and an increase of PC photosynthetic fitness (Fv/Fm). In co-culture, the microenvironment, generated by the formation of PE microcolonies, PC cells, bacteria and Poteriochromonas, can be the site of a beneficial "communication signalling" among Synechococcus cells for attaining the best spatial distribution for the fitness of the group
Long-term research to understand impact of perturbations on lakes: the example of Lake Maggiore
Get PDFPerturbations linked to the direct and indirect impacts of human activities during the so-called Anthropocene, affect the structure and functioning of lake ecosystems to varying degrees. To understand the patterns and mechanisms of these anthropogenic effects and the extent to which they may drive irreversible changes in ecosystem services, long-term research is required. Studies on the long-term dynamics of plankton may be particularly useful for large and deep lakes whose overall productivity is dominated by pelagic processes. In the open-waters of such lakes, planktonic organisms link and interact with both abiotic and biotic compartments. Here we will analyze 60 years of data on the plankton of the large, deep, subalpine, Lake Maggiore, tracing changes in the pelagic food web which occurred during different phases of the lake\u27s recent evolution. We will document short- to- medium response times by different trophic levels, from microbes, to primary producers and secondary consumers. We will revisit results of past studies based on contemporary and paleolimnological studies and present new analyses to: i) identify any tipping points of the lake trophic evolution, ii) discern effects of recent climatic change, iii) quantify whether inter-annual variability has changed perhaps in responses to changes in thermal stratification regime and warming. By supplementing structural with functional descriptions of long term changes in phyto- and zooplankton communities, we aim to test competing mechanisms underpinning the decade-scale changes we observed
The terrestrial Isopoda (Crustacea, Oniscidea) of Rapa Nui (Easter Island), with descriptions of two new species
Get PDFNine species of terrestrial isopods are reported for the Polynesian island of Rapa Nui (Easter Island) based upon museum materials and recent collections from field sampling. Most of these animals are non-native species, but two are new to science: Styloniscusmanuvaka sp. n. and Hawaiiosciarapui sp. n. Of these, the former is believed to be a Polynesian endemic as it has been recorded from Rapa Iti, Austral Islands, while the latter is identified as a Rapa Nui island endemic. Both of these new species are considered \u27disturbance relicts\u27 and appear restricted to the cave environment on Rapa Nui. A short key to all the oniscidean species presently recorded from Rapa Nui is provided. We also offered conservation and management recommendations for the two new isopod species