A spatial stochastic model for rumor transmission

We consider an interacting particle system representing the spread of a rumor by agents on the $d$-dimensional integer lattice. Each agent may be in any of the three states belonging to the set {0,1,2}. Here 0 stands for ignorants, 1 for spreaders and 2 for stiflers. A spreader tells the rumor to any of its (nearest) ignorant neighbors at rate \lambda. At rate \alpha a spreader becomes a stifler due to the action of other (nearest neighbor) spreaders. Finally, spreaders and stiflers forget the rumor at rate one. We study sufficient conditions under which the rumor either becomes extinct or survives with positive probability

Temperature dependent carrier lifetime studies of Mo in crystalline silicon

The capture cross sections of both electronsσn and holes σp were determined for interstitialmolybdenum in crystalline silicon over the temperature range of −110 to 150 °C. Carrier lifetimemeasurements were performed on molybdenum-contaminated silicon using a temperature controlled photoconductance instrument. Injection dependent lifetime spectroscopy was applied at each temperature to calculate σp and σn. This analysis involved a novel approach that independently determined the capture cross sections at each temperature assuming a known defect density and thermal velocity. Since the energy state is in the lower half of the bandgap, the determination of σp is unaffected by the defect energy at all temperatures, and σp is found to decrease with temperature in a fashion consistent with excitonic Auger capture. At temperatures below 0 °C, the determination of σn is also unaffected by the defect energy due to the suppression of thermal emission, and σn decreases with temperature as well. It is shown that a projection of σn to higher temperature suggests the defect has an energy of 0.375 eV above the valance band edge of silicon.D.M. likes to thank the Australian Research Council for fellowship and G.C. likes to thank “CrystalClear Integrated Project” Contract No. SES6-CT_2003-502583 funded by the European Commission

A Dutch book coherence condition for conditional completely alternating Choquet expectations

Stemming from de Finetti’s coherence for finitely additive (conditional) probabilities, the paradigm of coherence has been extended to other uncertainty calculi. We study the notion of coherence for conditional completely alternating Choquet expectations, providing an avoiding Dutch book like condition

MYOGENIC DIFFERENTIATION AND MUSCLE HOMEOSTASIS: NOVEL ROLES OF VASOPRESSIN

The neurohypophyseal nonapeptide arg-vasopressin (AVP) and related peptides constitute a novel family of positive regulators of terminal differentiation of myogenic cell lines and primary satellite cells. By interacting with V1 type receptor, AVP induces activation of phospholipases C and D, regulates cAMP levels, increases cytosolic Ca2+ concentration and up-regulates Myf-5 and myogenin expression, both at the mRNA and at the protein level. In a chemically defined medium, which eliminates the interference of serum components, AVP activates both the calcineurin and the CaMK signaling pathways, whose combined activation leads to the formation of multifactor complexes and is required for the full expression of the differentiated phenotype in vitro. To better clarify the physiological role of AVP in skeletal muscle, we analyzed the AVP effects on muscle regeneration induced by cardiotoxin injection. In particular, to increase skeletal muscle sensibility to circulating AVP, in the absence of systemic effects related to administration of the hormone itself, we over-expressed the V1a AVP receptor in mouse tibialis anterior muscle by electroporation-mediated gene delivery in vivo. The local over-expression of the V1aR in injured muscle results in enhanced regeneration. V1aR over-expressing muscle exhibits: early activation of satellite cells and regeneration markers, accelerated differentiation, increased cell population expressing hematopoietic stem cell markers and its conversion to the myogenic lineage. We demonstrate that V1aR over-expressing muscle increases calcineurin and IL-4 expression levels, and induces the phosphorylation of FOXO trascription factors, inhibiting the expression of atrophic genes. This study highlights a novel in vivo role for the AVP-dependent pathways which may represent a potential gene therapy approach for many diseases affecting muscle homeostasis

Direct evidence for efficient ultrafast charge separation in epitaxial WS₂/graphene heterostructures

We use time- and angle-resolved photoemission spectroscopy (tr-ARPES) to investigate ultrafast charge transfer in an epitaxial heterostructure made of monolayer WS2 and graphene. This heterostructure combines the benefits of a direct-gap semiconductor with strong spin-orbit coupling and strong light-matter interaction with those of a semimetal hosting massless carriers with extremely high mobility and long spin lifetimes. We find that, after photoexcitation at resonance to the A-exciton in WS2, the photoexcited holes rapidly transfer into the graphene layer while the photoexcited electrons remain in the WS2 layer. The resulting charge-separated transient state is found to have a lifetime of ∼1 ps. We attribute our findings to differences in scattering phase space caused by the relative alignment of WS2 and graphene bands as revealed by high-resolution ARPES. In combination with spin-selective optical excitation, the investigated WS2/graphene heterostructure might provide a platform for efficient optical spin injection into graphene

Direct evidence for efficient ultrafast charge separation in epitaxial WS2_2/graphene heterostructure

We use time- and angle-resolved photoemission spectroscopy (tr-ARPES) to investigate ultrafast charge transfer in an epitaxial heterostructure made of monolayer WS$_2$ and graphene. This heterostructure combines the benefits of a direct gap semiconductor with strong spin-orbit coupling and strong light-matter interaction with those of a semimetal hosting massless carriers with extremely high mobility and long spin lifetimes. We find that, after photoexcitation at resonance to the A-exciton in WS$_2$, the photoexcited holes rapidly transfer into the graphene layer while the photoexcited electrons remain in the WS$_2$ layer. The resulting charge transfer state is found to have a lifetime of $\sim1$\,ps. We attribute our findings to differences in scattering phase space caused by the relative alignment of WS$_2$ and graphene bands as revealed by high resolution ARPES. In combination with spin-selective excitation using circularly polarized light the investigated WS$_2$/graphene heterostructure might provide a new platform for efficient optical spin injection into graphene.Comment: 28 pages, 14 figure

Salophen and salen oxo vanadium complexes as catalysts of sulfides oxidation with H 2O 2: Mechanistic insights

The application of V(V) catalysts in oxidation of sulfides with peroxides offers an efficient procedure, that is compatible with different functional groups, and leads to good yields and selectivities. However, the understanding of the factors affecting the reactivity of different catalysts is still far to be complete. An experimental and theoretical study on a series of V(V) complexes containing variously substituted salen and salophen ligands is reported with the aim to correlate the activity of the catalysts with the electronic character of the vanadium center. The results obtained indicate that steric factors play a major role in determining the outcome of the reaction, often overcoming the electronic effects. Theoretical results suggest the intervention in the catalytic cycle of an hydroperoxo vanadium species

Investigation of VO-salophen complexes electronic structure

Vanadyl N,N'-bis(salicylidene)-o-phenylenediamine (salophen) complexes have been extensively investigated by cyclic voltammetry, UV-visible spectroscopy and theoretical calculations in MeCN, THF (tetrahydrofuran) and DMF (N,N-dimethylformamide), in order to elucidate the overall factors that influence the electronic density of the metal and therefore the properties of these complexes in various applications. Different substituents were introduced into the salophen skeleton to change the vanadium electron density. Results obtained and here presented showed that the substituents influence the metal electronic character in a way that cannot be easily predicted by considering only the electronic effect. Similarly, the solvent polarity or coordination ability affects the metal complex properties in an unpredictable way. Therefore, experimental and theoretical data here collected are a powerful tool to a priori design salophen ligands to obtain vanadyl complexes having the specific electronic properties suitable for desired applications

A Better Approach for Mishandled Bags Industry Measure

Since 1987, the US Department of Transportation (DOT) has ordered US airlines to report baggage handling statistics. The Code of Federal Regulations (CFR), requests each U.S. carrier to report monthly the total number of passengers enplaned, and the total number of mishandled baggage reports (MBR), including lost, pilfered, damaged and delayed baggage. The U.S. DOT also created a mishandled-baggage rate, which represents the total number of MBRs divided by 1,000 passengers enplaned. This KPI is monthly published at the Air Travel Consumer Report. And it is used worldwide to make comparisons between regions, airports, and airlines, characterizing efficiency and consistency in service and setting a benchmark for the industry. The problem with this indicator created in 1987 is that it only considers passengers, not checked baggage. The customer\u27s behavior has changed a lot after airlines started charging for the checked baggage, influencing KPI results. Therefore, in January 2019 US DOT proposed a new mishandled bags KPI for the airline industry, instead of dividing the original KPI per 1,000 passengers, the new KPI proposes dividing the total number of mishandled baggage report per 1,000 checked baggage. This KPI considers checked bags, correcting this flaw, and creates a more accurate and reliable indicator, avoiding incorrect investment decisions and loss of money. Desde 1987, o Departamento de Transportes dos Estados EUA (DOT) ordena que as companhias aéreas dos EUA reportem as estatísticas de manuseio de bagagem. O Código de Regulamentos Federais (CFR) solicita a cada transportadora dos EUA que reporte mensalmente o número total de passageiros embarcados e o número total de relatórios de bagagem extraviada (MBR), incluindo bagagem perdida, furtada, danificada e atrasada. O DOT dos EUA também criou um índice de bagagem extraviadas, que representa o número total de MBRs dividido por 1.000 passageiros embarcados. Este KPI é publicado mensalmente no Air Travel Consumer Report. E é usado em todo o mundo para fazer comparações entre regiões, aeroportos e companhias aéreas, caracterizando eficiência e consistência no serviço e estabelecendo uma referência para o setor. O problema com esse indicador criado em 1987 é que ele considera apenas passageiros, não bagagem despachada. O comportamento do cliente mudou muito depois que as companhias aéreas começaram a cobrar pela bagagem despachada, influenciando os resultados do KPI. Portanto, este estudo propõe um novo KPI de malas mal manejadas para o setor aéreo. Esse KPI considera as malas despachadas, corrigindo essa falha e cria um indicador mais preciso e confiável, evitando decisões incorretas de investimento e perda de dinheiro