766 research outputs found
Privacy Preserving Threat Hunting in Smart Home Environments
The recent proliferation of smart home environments offers new and
transformative circumstances for various domains with a commitment to enhancing
the quality of life and experience. Most of these environments combine
different gadgets offered by multiple stakeholders in a dynamic and
decentralized manner, which in turn presents new challenges from the
perspective of digital investigation. In addition, a plentiful amount of data
records got generated because of the day to day interactions between these
gadgets and homeowners, which poses difficulty in managing and analyzing such
data. The analysts should endorse new digital investigation approaches to
tackle the current limitations in traditional approaches when used in these
environments. The digital evidence in such environments can be found inside the
records of logfiles that store the historical events occurred inside the smart
home. Threat hunting can leverage the collective nature of these gadgets to
gain deeper insights into the best way for responding to new threats, which in
turn can be valuable in reducing the impact of breaches. Nevertheless, this
approach depends mainly on the readiness of smart homeowners to share their own
personal usage logs that have been extracted from their smart home
environments. However, they might disincline to employ such service due to the
sensitive nature of the information logged by their personal gateways. In this
paper, we presented an approach to enable smart homeowners to share their usage
logs in a privacy preserving manner. A distributed threat hunting approach has
been developed to permit the composition of diverse threat classes without
revealing the logged records to other involved parties. Furthermore, a scenario
was proposed to depict a proactive threat Intelligence sharing for the
detection of potential threats in smart home environments with some
experimental results.Comment: In Proc. the International Conference on Advances in Cyber Security,
Penang, Malaysia, July 201
Robust gap repair in the contractile ring ensures timely completion of cytokinesis.
Cytokinesis in animal cells requires the constriction of an actomyosin contractile ring, whose architecture and mechanism remain poorly understood. We use laser microsurgery to explore the biophysical properties of constricting rings in Caenorhabditis elegans embryos. Laser cutting causes rings to snap open. However, instead of disintegrating, ring topology recovers and constriction proceeds. In response to severing, a finite gap forms and is repaired by recruitment of new material in an actin polymerization-dependent manner. An open ring is able to constrict, and rings repair from successive cuts. After gap repair, an increase in constriction velocity allows cytokinesis to complete at the same time as controls. Our analysis demonstrates that tension in the ring increases while net cortical tension at the site of ingression decreases throughout constriction and suggests that cytokinesis is accomplished by contractile modules that assemble and contract autonomously, enabling local repair of the actomyosin network. Consequently, cytokinesis is a highly robust process impervious to discontinuities in contractile ring structure.This project has received funding from the European Research Council
(grants 640553, 260892, and 338410), Fundo Europeu de
Desenvolvimento Regional (FED ER) funds through the Operational
Competitiveness Program (COM PETE), national funds through
Fundação para a Ciência e a Tecnologia (FCT) under the project
FCO MP-01-0124-FED ER-028255 (PTDC/BEX-BCM/0654/2012),
Fundação Luso-Americana para o Desenvolvimento Life Science
2020, and the Louis-Jeantet Young Investigator Award to H. Maiato.
A.X. Carvalho, R. Gassmann, and I.A. Telley have FCT Investigator
positions funded by FCT and cofunded by the European Social Fund
through Programa Operacional Temático Potencial Type 4.2 promotion
of scientific employment. A.M. Silva holds an FCT fellowship
(SFRH/BPD/95707/2013). D.S. Osório was cofunded by the Programa
Operacional Regional do Norte under the Quadro de
Downloaded from jcb.rupress.org on February 27, 2018
Laser microsurgery in the contractile ring • Silva et al. 799
Referência Estratégico Nacional through FED ER and by FCT grant
NOR TE-07-0124-FED ER-000003 (Cell Homeostasis Tissue Organization
and Organism Biology)
Evidence for the classical integrability of the complete AdS(4) x CP(3) superstring
We construct a zero-curvature Lax connection in a sub-sector of the
superstring theory on AdS(4) x CP(3) which is not described by the
OSp(6|4)/U(3) x SO(1,3) supercoset sigma-model. In this sub-sector worldsheet
fermions associated to eight broken supersymmetries of the type IIA background
are physical fields. As such, the prescription for the construction of the Lax
connection based on the Z_4-automorphism of the isometry superalgebra OSp(6|4)
does not do the job. So, to construct the Lax connection we have used an
alternative method which nevertheless relies on the isometry of the target
superspace and kappa-symmetry of the Green-Schwarz superstring.Comment: 1+26 pages; v2: minor typos corrected, acknowledgements adde
Beliefs about others' intentions determine whether cooperation is the faster choice
Is collaboration the fast choice for humans? Past studies proposed that cooperation is a behavioural default, based on Response Times (RT) findings. Here we contend that the individual’s reckoning of the immediate social environment shapes her predisposition to cooperate and, hence, response latencies. In a social dilemma game, we manipulate the beliefs about the partner’s intentions to cooperate and show that they act as a switch that determines cooperation and defection RTs; when the partner’s intention to cooperate is perceived as high, cooperation choices are speeded up, while defection is slowed down. Importantly, this social context effect holds across varying expected payoffs, indicating that it modulates behaviour regardless of choices’ similarity in monetary terms. Moreover, this pattern is moderated by individual variability in social preferences: Among conditional cooperators, high cooperation beliefs speed up cooperation responses and slow down defection. Among free-riders, defection is always faster and more likely than cooperation, while high cooperation beliefs slow down all decisions. These results shed new light on the conflict of choices account of response latencies, as well as on the intuitive cooperation hypothesis, and can help to correctly interpret and reconcile previous, apparently contradictory results, by considering the role of context in social dilemmas
Thinking about Later Life: Insights from the Capability Approach
A major criticism of mainstream gerontological frameworks is the inability of such frameworks to appreciate and incorporate issues of diversity and difference in engaging with experiences of aging. Given the prevailing socially structured nature of inequalities, such differences matter greatly in shaping experiences, as well as social constructions, of aging. I argue that Amartya Sen’s capability approach (2009) potentially offers gerontological scholars a broad conceptual framework that places at its core consideration of human beings (their values) and centrality of human diversity. As well as identifying these key features of the capability approach, I discuss and demonstrate their relevance to thinking about old age and aging. I maintain that in the context of complex and emerging identities in later life that shape and are shaped by shifting people-place and people-people relationships, Sen’s capability approach offers significant possibilities for gerontological research
A novel asynchronous access method with binary interfaces
© 2008 Silva et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Persistent Cell Motion in the Absence of External Signals: A Search Strategy for Eukaryotic Cells
Eukaryotic cells are large enough to detect signals and then orient to them
by differentiating the signal strength across the length and breadth of the
cell. Amoebae, fibroblasts, neutrophils and growth cones all behave in this
way. Little is known however about cell motion and searching behavior in the
absence of a signal. Is individual cell motion best characterized as a random
walk? Do individual cells have a search strategy when they are beyond the range
of the signal they would otherwise move toward? Here we ask if single,
isolated, Dictyostelium and Polysphondylium amoebae bias their motion in the
absence of external cues. We placed single well-isolated Dictyostelium and
Polysphondylium cells on a nutrient-free agar surface and followed them at 10
sec intervals for ~10 hr, then analyzed their motion with respect to velocity,
turning angle, persistence length, and persistence time, comparing the results
to the expectation for a variety of different types of random motion. We find
that amoeboid behavior is well described by a special kind of random motion:
Amoebae show a long persistence time (~10 min) beyond which they start to lose
their direction; they move forward in a zig-zag manner; and they make turns
every 1-2 min on average. They bias their motion by remembering the last turn
and turning away from it. Interpreting the motion as consisting of runs and
turns, the duration of a run and the amplitude of a turn are both found to be
exponentially distributed. We show that this behavior greatly improves their
chances of finding a target relative to performing a random walk. We believe
that other eukaryotic cells may employ a strategy similar to Dictyostelium when
seeking conditions or signal sources not yet within range of their detection
system.Comment: 15 pages, 11 figures, accepted for publication in PLOS On
Distinct Regions of the Large Extracellular Domain of Tetraspanin CD9 Are Involved in the Control of Human Multinucleated Giant Cell Formation
Multinucleated giant cells, formed by the fusion of monocytes/macrophages, are features of chronic granulomatous inflammation associated with infections or the persistent presence of foreign material. The tetraspanins CD9 and CD81 regulate multinucleated giant cell formation: soluble recombinant proteins corresponding to the large extracellular domain (EC2) of human but not mouse CD9 can inhibit multinucleated giant cell formation, whereas human CD81 EC2 can antagonise this effect. Tetraspanin EC2 are all likely to have a conserved three helix sub-domain and a much less well-conserved or hypervariable sub-domain formed by short helices and interconnecting loops stabilised by two or more disulfide bridges. Using CD9/CD81 EC2 chimeras and point mutants we have mapped the specific regions of the CD9 EC2 involved in multinucleated giant cell formation. These were primarily located in two helices, one in each sub-domain. The cysteine residues involved in the formation of the disulfide bridges in CD9 EC2 were all essential for inhibitory activity but a conserved glycine residue in the tetraspanin-defining ‘CCG’ motif was not. A tyrosine residue in one of the active regions that is not conserved between human and mouse CD9 EC2, predicted to be solvent-exposed, was found to be only peripherally involved in this activity. We have defined two spatially-distinct sites on the CD9 EC2 that are required for inhibitory activity. Agents that target these sites could have therapeutic applications in diseases in which multinucleated giant cells play a pathogenic role
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