Using a distributed Shapley-value based approach to ensure navigability in a social network of smart objects

The huge number of nodes that is expected to join the Internet of Things in the short term will add major scalability issues to several procedures. A recent promising approach to these issues is based on social networking solutions to allow objects to autonomously establish social relationships. Every object in the resulting Social IoT (SIoT) exchanges data with its friend objects in a distributed manner to avoid the need for centralized solutions to implement major functionalities, such as: node discovery, information search and trustworthiness management. However, the number and types of established friendship affects network navigability. This paper addresses this issue proposing an efficient, distributed and dynamic strategy for the objects to select the right friends for the benefit of the overall network connectivity. The proposed friendship selection model relies on a Shapley-value based algorithm mapping the friendship selection process in the SIoT onto the coalition formation problem in a corresponding cooperative game. The obtained results show that the proposed solution is able to ensure global navigability, measured in terms of average path length among two nodes in the network, by means of a distributed and wise selection of the number of friend objects a node has to handle

Naturalness in Cosmological Initial Conditions

We propose a novel approach to the problem of constraining cosmological initial conditions. Within the framework of effective field theory, we classify initial conditions in terms of boundary terms added to the effective action describing the cosmological evolution below Planckian energies. These boundary terms can be thought of as spacelike branes which may support extra instantaneous degrees of freedom and extra operators. Interactions and renormalization of these boundary terms allow us to apply to the boundary terms the field-theoretical requirement of naturalness, i.e. stability under radiative corrections. We apply this requirement to slow-roll inflation with non-adiabatic initial conditions, and to cyclic cosmology. This allows us to define in a precise sense when some of these models are fine-tuned. We also describe how to parametrize in a model-independent way non-Gaussian initial conditions; we show that in some cases they are both potentially observable and pass our naturalness requirement.Comment: 35 pages, 8 figure

Cellulose Acetate and Cardanol Based Seed Coating for Intraspecific Weeding Coupled with Natural Herbicide Spraying

Abstract: Agricultural pesticides can become persistent environmental pollutants and their use is destined to be reduced. Consequently, weed control is shifting to green products and strategies. A combined approach, made of pelargonic acid based herbicide spraying and interspecific competition (i.e. seeding of plants species competing for growth against weeds) could boost the weeding effect. In case of the contemporary seeding and spraying, needed to reduce costs, seed coating is necessary as barrier to herbicide toxic effects but, at the same time, the coating has to be endowed with the right features to allow germination. This work aims to verify the feasibility of using cellulose acetate/cardanol (CA/Card) as seed coating polymer–plasticizer blend and to identify possible relationship between material features and germination rate. For these purposes, untreated and pelargonic acid herbicide treated coated seeds coated through solvent evaporation methods (CA/Card ratios from 0/0 to 100/0) were subjected to germination test. Coatings were characterized through SEM, EDX, media uptake, DSC and mechanical analysis with and without conditioning in seeding conditions. Germination test showed that 70/30 seeds, treated and untreated with herbicide, presented the best germination rate. Germination assays showed that coating presence reduced and slowed (without stopping) seeds germination equally with and without herbicide treatment. Consequently, was possible to conclude that CA/Card coatings allowed germination and presented a barrier effect against herbicide. Thus coating resulted suitable for seed coating in herbicide spraying/interspecific combined applications. No strong correlations were found between material features and germination, but it is plausible to hypothesize that both water absorption and mechanical properties of the coating play an important role and have to be optimized to improve germination rate avoiding difficulty in sprouting. Finally, the study opened a new perspective in the use of cellulose acetate for seed coating from waste sources such as cigarette filters. Graphic Abstract: [Figure not available: see fulltext.]

D2 or non D2-lymphadenectomy in gastric cancer

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Coarsening in surface growth models without slope selection

We study conserved models of crystal growth in one dimension [$\partial_t z(x,t) =-\partial_x j(x,t)$] which are linearly unstable and develop a mound structure whose typical size L increases in time ($L = t^n$). If the local slope ($m =\partial_x z$) increases indefinitely, $n$ depends on the exponent $\gamma$ characterizing the large $m$ behaviour of the surface current $j$ ($j = 1/|m|^\gamma$): $n=1/4$ for $1< \gamma <3$ and $n=(1+\gamma)/(1+5\gamma)$ for $\gamma>3$.Comment: 7 pages, 2 EPS figures. To be published in J. Phys. A (Letter to the Editor

Polycrystalline diamond films grown by MWPECVD technique and application in photocathodes

Diamond is an extremely interesting material for photoemission applications, due to the negative electron affinity which can be obtained after suitable surface treatments. In the present work, two sets of polycrystalline diamond films, characterized by dif-ferent thickness and deposition conditions, are ana-lyzed. In particular, the relationship among the grain size, the amount of non-diamond carbon (sp2) located at the grain boundaries and the film sensitivity as a photocathode has been found and carefully investi-gated. The photoemission yield in the UV range has been evaluated for all the samples, before and after hydrogenation process, and after air exposure. The critical parameter for the photocathode performances has been found not to be the film thickness, but the properties of polycrystalline diamond films, tunable with the plasma modulation and the methane percent-age in the gas mixture

HO-1 induction in cancer progression: A matter of cell adaptation

The upregulation of heme oxygenase-1 (HO-1) is one of the most important mechanisms of cell adaptation to stress. Indeed, the redox sensitive transcription factor Nrf2 is the pivotal regulator of HO-1 induction. Through the antioxidant, antiapoptotic, and antinflammatory properties of its metabolic products, HO-1 plays a key role in healthy cells in maintaining redox homeostasis and in preventing carcinogenesis. Nevertheless, several lines of evidence have highlighted the role of HO-1 in cancer progression and its expression correlates with tumor growth, aggressiveness, metastatic and angiogenetic potential, resistance to therapy, tumor escape, and poor prognosis, even though a tumor-and tissue-specific activity has been observed. In this review, we summarize the current literature regarding the pro-tumorigenic role of HO-1 dependent tumor progression as a promising target in anticancer strategy

Mechanical properties of MWPECVD diamond coatings on Si substrate via nanoindentation

The mechanical properties of polycrystalline diamond coatings with thickness varying from 0.92 to 44.65 μm have been analysed. The tested samples have been grown on silicon substrates via microwave plasma enhanced chemical vapour deposition from highly diluted gas mixtures CH4–H2 (1% CH4 in H2). Reliable hardness and elastic modulus values have been assessed on lightly polished surface of polycrystalline diamond films. The effect of the coating thickness on mechanical, morphological and chemical-structural properties is presented and discussed. In particular, the hardness increases from a value of about 52 to 95 GPa and the elastic modulus from 438 to 768 GPa by varying the coating thickness from 0.92 to 4.85 μm, while the values closer to those of natural diamond (H=103 GPa and E=1200 GPa) are reached for thicker films (N5 μm). Additionally, the different thickness of the diamond coatings permits to select the significance of results and to highlight when the soft silicon substrate may affect the measured mechanical data. Thus, the nanoindentation experiments were made within the range from 0.65% to 10% of the film thickness by varying the maximum load from 3 to 80 mN. © 2010 Elsevier B.V. All rights reserve

Modulation of CYP1A1 by PKC Inhibitors and TPA Pre-Treatments in MH1C1 Rat Hepatoma Cells Exposed to 3 -Methylcholanthrene

Cytochrome P4501A1 (CYP1A1), an enzyme known to metabolize polycyclic aromatic hydrocarbons, is regulated by the aryl hydrocarbon receptor (AhR). The involvement of protein kinase C (PKC) in the regulation of AhR signal transduction pathway, has been widely studied but the role of specific PKC isoform(s) involved in this process it is not well clarified. To study which PKC isoform(s) is implicated in the regulation of CYP1A1, in the poorly tumorigenic MH1C1 rat hepatoma cells, we examined the effects of some PKC pharmacological inhibitors, Calphostin C (CAL), Staurosporine (STA) and H7, and of 12-0-tetradecanoyl phorbol 13-acetate (TPA), a PKC activator, on basal and 3- methylcholanthrene (MC)-induced CYP1A1 protein expression and mediated ethoxyresorufin O-deethylation (EROD) activity. In parallel, the activities of PKC-α, -βI, -δ and -ε isoforms, the most expressed in MH1C1 cells, were monitored. After pre-treatment with CAL, STA and H7, the MC-induced CYP1A1 protein and EROD activity were rapidly reduced with temporal profile similar to the profile of the activity of α and β1 PKC isoforms. Moreover, TPA pre-treatment induced a biphasic effect on EROD activity, and a decline of PKC -βI and -α, in first instance, and -δ and -ε activities later on. These findings clearly show that, in MH1C1 cells, PKC is involved in CYP1A1 regulation and that α and βI classic PKC isoforms play an active role in modulating this process