Experimental Realization of the Fuse Model of Crack Formation

In this work, we present an experimental investigation of the fuse model. Our main goal was to study the influence of the disorder on the fracture process. The experimental apparatus used consisted of an $L\times L$ square lattice with fuses placed on each bond of the lattice. Two types of materials were used as fuses: copper and steel wool wires. The lattice composed only by copper wires varied from a weakly disordered system to a strongly disordered one. The lattice formed only by steel wool wires corresponded to a strongly disordered one. The experimental procedure consisted of applying a potential difference V to the lattice and measuring the respective current I. The characteristic function $I(V)$ obtained was investigated in order to find the scaling law dependence of the voltage and the current on the system size $L$ when the disorder was changed. Our results show that the scaling laws are only verified for the disordered regime.Comment: 4 pages, 8 figures.ep

PAI-1 Expressa no Infiltrado Inflamatório Intratumoral em Pacientes com Carcinoma Epidermoide de Cavidade Oral

PAI-1 Expressa no Infiltrado Inflamatório Intratumoral em Pacientes com Carcinoma Epidermoide de Cavidade Ora

Microscopic mechanism for mechanical polishing of diamond (110) surfaces

Mechanically induced degradation of diamond, as occurs during polishing, is studied using total--energy pseudopotential calculations. The strong asymmetry in the rate of polishing between different directions on the diamond (110) surface is explained in terms of an atomistic mechanism for nano--groove formation. The post--polishing surface morphology and the nature of the polishing residue predicted by this mechanism are consistent with experimental evidence.Comment: 4 pages, 5 figure

Introspection dynamics: a simple model of counterfactual learning in asymmetric games

Social behavior in human and animal populations can be studied as an evolutionary process.Individuals often make decisions between different strategies, and those strategies that yield afitness advantage tend to spread. Traditionally, much work in evolutionary game theory considerssymmetric games: individuals are assumed to have access to the same set of strategies, and theyexperience the same payoff consequences. As a result, they can learn more profitable strategies byimitation. However, interactions are oftentimes asymmetric. In that case, imitation may beinfeasible (because individuals differ in the strategies they are able to use), or it may be undesirable(because individuals differ in their incentives to use a strategy). Here, we consider an alternativelearning process which applies to arbitrary asymmetric games,introspection dynamics. Accordingto this dynamics, individuals regularly compare their present strategy to a randomly chosenalternative strategy. If the alternative strategy yields a payoff advantage, it is more likely adopted. Inthis work, we formalize introspection dynamics for pairwise games. We derive simple and explicitformulas for the abundance of each strategy over time and apply these results to severalwell-known social dilemmas. In particular, for the volunteer’s timing dilemma, we show that theplayer with the lowest cooperation cost learns to cooperate without delay

Feeding and Feedback in the Inner Kiloparsec of the Active Galaxy NGC2110

We present two-dimensional gaseous kinematics of the inner 1.1 x 1.6kpc^2 of the Seyfert 2 galaxy NGC2110, from optical spectra obtained with the GMOS integral field spectrograph on the Gemini South telescope at a spatial resolution of 100pc. Gas emission is observed over the whole field-of-view, with complex - and frequently double - emission-line profiles. We have identified four components in the emitting gas, according to their velocity dispersion (sigma), which we refer to as: (1) warm gas disk (sigma = 100-220km/s); (2) cold gas disk (sigma = 60-90km/s); (3) nuclear component (sigma = 220-600km/s); and (4) northern cloud (sigma = 60-80km/s). Both the cold and warm disk components are dominated by rotation and have similar gas densities, but the cold gas disk has lower velocity dispersions and reaches higher rotation velocities. We attribute the warm gas disk to a thick gas layer which encompasses the cold disk as observed in some edge-on spiral galaxies. After subtraction of a rotation model from the cold disk velocity field, we observe excess blueshifts of 50km/s in the far side of the galaxy as well as similar excess redshifts in the near side. These residuals can be interpreted as due to nuclear inflow in the cold gas, with an estimated ionized gas mass inflow rate of 2.2 x 10^(-2)Msun/yr. We have also subtracted a rotating model from the warm disk velocity field and found excess blueshifts of 100km/s to the SW of the nucleus and excess redshifts of 40km/s to the NE, which we attribute to gas disturbed by an interaction with a nuclear spherical outflow. This nuclear outflow is the origin of the nuclear component observed within the inner 300pc and it has a mass outflow rate of 0.9Msun/yr. In a region between 1" and 4" north of the nucleus we find a new low sigma component of ionized gas which we attribute to a high latitude cloud photoionized by the nuclear source.Comment: 17 pages, 13 figures, 1 table; accepted for publication in MNRA

Metodologia para utilização de teste Elisa na diagnose de murcha bacteriana em batata (Solanum tuberosum)

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Monitoramento de viroses em lavouras de batata-doce no Rio Grande do Sul.

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Analysis of drugs returned by inpatient services after unit dose distribution in a portuguese public hospital

Unit-dose has been considered the most effective dispensing system in hospital pharmacy, however not all drugs are administered, are then returned to the pharmacy. The analysis of non-administered drugs might provide important data regarding pharmacotherapeutic follow-up, but also regarding pharmacy management decisions. The present study aims at depicting the drugs returned to the pharmacy following their previous unit-dose dispensing. Methods: During a period of 45 days, the unused returned drugs of five different inpatient clinical services were analyzed regarding the state of conservation, justification for return, inpatient clinical service provenance, and dosage regimen. Of a total of 65280 unit-dose dispensed drugs, 25.2% were returned (n=16431) and 74.9% of SOS (i.e. medications prescribed as needed) drugs (n=6583) were unused. Excluding SOS drugs, more than a half of the returned drugs (52.4%, n=4967), were probably returned due to unintended omission of administration, after excluding patients that were not physically on the unit and patients whose treatments were modified. The large majority of returned drugs (98.6%, n=16201) were suitable for reintroduction in the medication circuit. In order to accomplish the basic principles of unit-dose dispensing genesis, the returned drugs must be kept to a minimum. Therefore, the suspension of dispensing SOS drugs by unit-dose should be considered. Additionally, the careful analysis of returned drugs should be promoted, in order to avoid, as much as possible, the omission of administration.info:eu-repo/semantics/publishedVersio

Citations, funding and influence in Energy-Policy research on Developing Economies

Energy research seeking to influence policy in low- and -middle-income countries (LMICs) is often funded by – and conceptualised by authors in - institutions from high-income countries (HICs). Research agendas and policy recommendations determined in HICs potentially yield the most influence on policymaking for LMICs. This leaves a multidimensional gap in how LMICs frame, contextualise, evidence and enact policy processes. The unique contribution of this paper is analysing the dynamics of prevalent energy research on LMICs through a multi-method approach using bibliometric, network science and regression-based techniques. An innovative data-driven framework was established using a sample of 6,636 papers from the Web of Science database, combined with journal impact data from Scimago Journal Ranking and country economic data from the World Bank. Results show the existence of a cycle of imbalances across research practices. Most papers recommending energy policy for LMICs have a first author based in a HIC, funded by a HIC institution. Total citations of articles on energy policy in LMICs increase with the GDP of the first author’s country (a 1% increase in GDP is correlated with a 0.68% increase in total citations). Funders support authors based in countries of the same income band as them, or higher. Therefore, we recommend revising research practices and HIC funding policies to place local actors and knowledge at the heart of energy policy research, enabling high-impact policymaking in LMICs