SIGNAL MANIPULATION EFFECTS ON RESPONDING MAINTAINED WITH DELAY OF REINFORCEMENT

O objetivo foi avaliar a manipulação da duração da sinalização (luz) sobre o responder mantido com atraso de reforço sinalizado. Quinze ratos foram utilizados, sendo o estudo dividido em duas fases. Na Fase 1, a duração da luz era manipulada até cobrir todo o atraso (Grupo Encadeado III) ou ficar completamente ausente (Grupo Encadeado II). Com outros dois grupos, a luz ou não era apresentada ou sua duração cobria todo o atraso, mas não houve a manipulação gradual. Houve um aumento de 4 s na duração do atraso com o inicio da Fase 2, idêntica à anterior. Observou-se um aumento na taxa de emissões e de reforços produzidos pelos sujeitos dos grupos com manipulação da luz. Os resultados são discutidos focando as propriedades reforçadoras da sinalização. Palavras-chave: Atraso de reforço, atraso de reforço sinalizado, duração da sinalização, reforçador condicionado, hipótese da redução do atraso e pressão à barra, ratos.Evaluate the manipulation of the signal (light) duration upon the response frequency maintained by delayed reinforcement was the purpose of the study. Fifteen rats were assigned and the study was divided into two phases. On Phase 1, the light duration was gradually increased until covered all the delayed period (Chained Group III) or was gradually decreased until disappeared (Chained Group II). With two other groups, the light or was not presented, or its duration covered the entire period. There was an increase of 4 s of the delay duration in Phase 2, identical to the previous. There was an increase in the rate of responding and reinforces with the light duration manipulation. The results are discussed focusing the conditioned reinforcer properties of the signal. Key words: Delayed reinforcement, delay-signal, signal duration, conditioned reinforcement, delay reduction theory and lever press

Dispersive stabilization of the inverse cascade for the Kolmogorov flow

It is shown by perturbation techniques and numerical simulations that the inverse cascade of kink-antikink annihilations, characteristic of the Kolmogorov flow in the slightly supercritical Reynolds number regime, is halted by the dispersive action of Rossby waves in the beta-plane approximation. For beta tending to zero, the largest excited scale is proportional to the logarithm of one over beta and differs strongly from what is predicted by standard dimensional phenomenology which ignores depletion of nonlinearity.Comment: 4 pages, LATEX, 3 figures. v3: revised version with minor correction

Guest editorial special issue on increasing the socio-cultural diversity of electrical and computer engineering and related fields

Universities and colleges struggle to achieve their diversity goals in disciplines including electrical engineering, computer science, and computer engineering. Even if entering students are sufficiently diverse, programs are challenged to provide appropriate support and develop engagement opportunities that enable these students to succeed. Some students from minority populations may have had schooling less well funded than that of their mainstream peers, and while capable of succeeding, may be differently equipped than their peers. This special issue asks: How can efforts to increase success of minority students be designed and implemented? How can programs help faculty to understand challenges diverse students face? How can they change their teaching methods

Is it possible to make a diagnosis of raw, heated and baked egg allergy in children using cut-offs? A systematic review

The diagnosis of IgE-mediated egg allergy lies both on a compatible clinical history and on the results of skin prick tests (SPTs) and IgEs levels. Both tests have good sensitivity but low specificity. For this reason, oral food challenge (OFC) is the ultimate gold standard for the diagnosis. The aim of the present paper is to systematically review the literature in order to identify, analyze and synthesize the predictive value of SPT and specific IgEs both to egg white and main egg allergens and to review the cut-offs suggested in the literature

Effect of lifestyle factors on Staphylococcus aureus gut colonization in Swedish and Italian infants

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Nondestructive Characterization of Aged Components

It is known that high energy radiation can have numerous effects on materials. In metals and alloys, the effects include, but may not be limited to, mechanical property changes, physical property changes, compositional changes, phase changes, and dimensional changes. Metals and alloys which undergo high energy self-irradiation are also susceptible to these changes. One of the greatest concerns with irradiation of materials is the phenomenon of void swelling which has been observed in a wide variety of metals and alloys. Irradiation causes the formation of a high concentration point defects and microclusters of vacancies and interstitials. With the assistance of an inert atom such as helium, the vacancy-type defects can coalesce to form a stable bubble. This bubble will continue to grow through the net absorption of more vacancy-type defects and helium atoms, and upon reaching a certain critical size, the bubble will begin to grow at an accelerated rate without the assistance of inert atom absorption. The bubble is then said to be an unstably growing void. Depending on the alloy system and environment, swelling values can reach in excess of 50% !V/Vo where Vo is the initial volume of the material. Along with dimensional changes resulting from the formation of bubbles and voids comes changes in the macroscopically observed speed of sound, moduli, electrical resistivity, yield strength, and other properties. These effects can be detrimental to the designed operation of the aged components. In situations where irradiation has sufficient time to cause degradation to materials used in critical applications such as nuclear reactor core structural materials, it is advisable to regularly survey the material properties. It is common practice to use surveillance specimens, but this is not always possible. When surveillance materials are not available, other means for surveying the material properties must be utilized. Sometimes it is possible to core out a small sample which may be used for material properties measurements. A more appealing solution is to use nondestructive evaluation (NDE) methods

Nondestructive Characterization of Aged Components

It is known that high energy radiation can have numerous effects on materials. In metals and alloys, the effects include, but may not be limited to, mechanical property changes, physical property changes, compositional changes, phase changes, and dimensional changes. Metals and alloys which undergo high energy self-irradiation are also susceptible to these changes. One of the greatest concerns with irradiation of materials is the phenomenon of void swelling which has been observed in a wide variety of metals and alloys. Irradiation causes the formation of a high concentration point defects and microclusters of vacancies and interstitials. With the assistance of an inert atom such as helium, the vacancy-type defects can coalesce to form a stable bubble. This bubble will continue to grow through the net absorption of more vacancy-type defects and helium atoms, and upon reaching a certain critical size, the bubble will begin to grow at an accelerated rate without the assistance of inert atom absorption. The bubble is then said to be an unstably growing void. Depending on the alloy system and environment, swelling values can reach in excess of 50% !V/Vo where Vo is the initial volume of the material. Along with dimensional changes resulting from the formation of bubbles and voids comes changes in the macroscopically observed speed of sound, moduli, electrical resistivity, yield strength, and other properties. These effects can be detrimental to the designed operation of the aged components. In situations where irradiation has sufficient time to cause degradation to materials used in critical applications such as nuclear reactor core structural materials, it is advisable to regularly survey the material properties. It is common practice to use surveillance specimens, but this is not always possible. When surveillance materials are not available, other means for surveying the material properties must be utilized. Sometimes it is possible to core out a small sample which may be used for material properties measurements. A more appealing solution is to use nondestructive evaluation (NDE) methods

How Do Climate Change Experiments Alter Plot-Scale Climate?

To understand and forecast biological responses to climate change, scientists frequently use field experiments that alter temperature and precipitation. Climate manipulations can manifest in complex ways, however, challenging interpretations of biological responses. We reviewed publications to compile a database of daily plot-scale climate data from 15 active-warming experiments. We find that the common practices of analysing treatments as mean or categorical changes (e.g. warmed vs.unwarmed) masks important variation in treatment effects over space and time. Our synthesis showed that measured mean warming, in plots with the same target warming within a study, differed by up to 1.6 Celsius degrees (63% of target), on average, across six studies with blocked designs. Variation was high across sites and designs: for example, plots differed by 1.1Celsius degrees (47% of target) on average, for infrared studies with feedback control (n = 3) vs. by 2.2 Celsius degrees (80% of target) on average for infrared with constant wattage designs (n = 2). Warming treatments produce non-temperature effects as well, such as soil drying. The combination of these direct and indirect effects is complex and can have important biological consequences. With a case study of plant phenology across five experiments in our database, we show how accounting for drier soils with warming tripled the estimated sensitivity of budburst to temperature. We provide recommendations for future analyses, experimental design,and data sharing to improve our mechanistic understanding from climate change experiments, and thus their utility to accurately forecast species' responses

The Extreme Energy Events HECR array: status and perspectives

The Extreme Energy Events Project is a synchronous sparse array of 52 tracking detectors for studying High Energy Cosmic Rays (HECR) and Cosmic Rays-related phenomena. The observatory is also meant to address Long Distance Correlation (LDC) phenomena: the network is deployed over a broad area covering 10 degrees in latitude and 11 in longitude. An overview of a set of preliminary results is given, extending from the study of local muon flux dependance on solar activity to the investigation of the upward-going component of muon flux traversing the EEE stations; from the search for anisotropies at the sub-TeV scale to the hints for observations of km-scale Extensive Air Shower (EAS).Comment: XXV ECRS 2016 Proceedings - eConf C16-09-04.