17,880 research outputs found
Invariant measures for monotone SPDE's with multiplicative noise term
We study diffusion processes corresponding to infinite dimensional semilinear
stochastic differential equations with local Lipschitz drift term and an
arbitrary Lipschitz diffusion coefficient. We prove tightness and the Feller
property of the solution to show existence of an invariant measure. As an
application we discuss stochastic reaction diffusion equations.Comment: 10 page
Encouraging Reflective Thinking in the High School Classroom: Effective Use of Questioning and Wait Time Strategies
Effective questioning techniques and the use of effective wait time can create a learning environment where all students are encouraged to process information and feel comfortable sharing their opinion. The root of reflective thinking lies in asking good questions and knowing how to ask them and when to ask them. Good questions create classroom interaction which has been found to promote student achievement. However, in our fast-paced classrooms, teachers tend to dominate discussions and often answer their own questions. This is where the effective use of wait time can be so crucial in establishing an atmosphere of inquiry – not inquisition. Too many students are left out or unengaged from the classroom because of the types of questions that are posed and the lack of waiting for responses.
Wouldn’t it be great if students discussed the material in class and were actively involved in their own learning? I believe that reflective thinking can occur in the high school classroom with just a few changes: teachers asking better questions and waiting an appropriate amount of time for the students’ response. If reflective thinking increases student achievement, then students will be able to go beyond “textbook” thinking and cultivate deeper and more creative thinking that will produce success inside and outside of the classroom
Stimulus-induced gamma power predicts the amplitude of the subsequent visual evoked response
The efficiency of neuronal information transfer in activated brain networks may affect behavioral performance. Gamma-band synchronization has been proposed to be a mechanism that facilitates neuronal processing of behaviorally relevant stimuli. In line with this, it has been shown that strong gamma-band activity in visual cortical areas leads to faster responses to a visual go cue. We investigated whether there are directly observable consequences of trial-by-trial fluctuations in non-invasively observed gamma-band activity on the neuronal response. Specifically, we hypothesized that the amplitude of the visual evoked response to a go cue can be predicted by gamma power in the visual system, in the window preceding the evoked response. Thirty-three human subjects (22 female) performed a visual speeded response task while their magnetoencephalogram (MEG) was recorded. The participants had to respond to a pattern reversal of a concentric moving grating. We estimated single trial stimulus-induced visual cortical gamma power, and correlated this with the estimated single trial amplitude of the most prominent event-related field (ERF) peak within the first 100 ms after the pattern reversal. In parieto-occipital cortical areas, the amplitude of the ERF correlated positively with gamma power, and correlated negatively with reaction times. No effects were observed for the alpha and beta frequency bands, despite clear stimulus onset induced modulation at those frequencies. These results support a mechanistic model, in which gamma-band synchronization enhances the neuronal gain to relevant visual input, thus leading to more efficient downstream processing and to faster responses
Phase toxicity of dodecane on the microalga Dunaliella salina
In the so-called milking process of Dunaliella salina carotenoids are extracted and simultaneously produced by the culture, whilst the biomass concentration remains constant. Different theories exist about the extraction mechanisms although none have been proven yet. In this research, direct contact between dodecane and cells during the extraction process was studied microscopically and effects of direct contact were determined during in situ extraction experiments. Our results showed that water– solvent interphase contact resulted in cell death. This cell death and consequent cell rupture resulted in the release and concomitant extraction of the carotenoids. Furthermore, it has been suggested to add a small amount of dichloromethane to the biocompatible dodecane to create an organic phase with more extraction capacity. Our results showed that the addition of dichloromethane resulted in increased cell death and consequently the extraction rate increased. The improved solubility of carotenoids in an organic phase with dichloromethane did not significantly increase the extraction rate
An Inquiry into the Cause of the Increase of Tuberculosis of Swine
The great increase in the number of swine found to be tuberculous presented a problem, the solution of which appeared to be desirable before adequate control measures could be devised or recommended. In the hope that a solution of the problem may be found this station undertook an investigation and attempted by experimental inquiry to determine the infection type of the tuberculosis associated with the animals which constituted the bulk of the retentions. In view of the apparent increased incidence and spread of tuberculosis among poultry in a large hog raising section, of which Nebraska forms a part, the experimental project mentioned was to a large extent so directed as to prove or disprove the hypothesis that avian infection may at least in part be held accountable for the great morbidity rate for tuberculosis among swine and its marked increase during the last fifteen years
The Immunizing Value of Commercial Vaccines and Bacterins Against Hemorrhagic Septicemia
In the course of certain studies having to do with hemorrhagic septicemia, we were particularly struck with the difficulties which we encountered in the immunization of susceptible laboratory animals (rabbits). This difficulty in no small degree excited our curiosity regarding the immunizing value of the considerable number of Hemorrhagic Septicemia bacterins and vaccines which during recent years have become such a prominent article of commerce. In the hope of securing some information relative to the immunizing value of the agents mentioned, we undertook a series of experiments in which the immunity of the bacterin and vaccine injected laboratory animals was definitely tested by subsequent inoculations with B. bipolaris
The Incidence of Avian Tuberculosis in Mammals other than Swine
The recognition of a very widespread and intense distribution of avian tuberculosis on the farms of a wide area of the United States, as well as the involvement of a mammalian species also, brought to the foreground the question whether or not the great prevalence of poultry tuberculosis could be of importance also from a public health point of view. This phase of the problem not only pertains to the people on the farms but likewise is of fundamental importance to the consumers of poultry produce. European authors had already identified the avian tubercle bacillus in human lesions while in this country careless speakers outside the profession of medicine and irresponsible journalists had made more or less sensational statements on the subject. The alleged public health phase of avian tuberculosis was regarded as warrant for an attempt to acquire more definite information on this subject. The importance of the problem arising from the widespread distribution of avian tuberculosis and its demonstrated communicability to at least one mammalian species of economic importance justified an extension of the investigation and hence the Nebraska Agricultural Experiment Station undertook the inquiry, the results of which are set forth in the following account
The Value of Commercial Vaccines and Bacterins Against Fowl Cholera
A great prevalence of the disease known as fowl cholera has naturally stimulated an interest in possible means of prevention and especially in those which may bring about a more or less lasting immunity. Vaccines which were favorably reported by some failed utterly in the hands of others, so that on the whole no substantial advantage has been gained. Vaccines and bacterins are nevertheless constantly urged on poultry owners confronted with disease and the Experiment Station is frequently called upon to give an opinion on their value or to recommend any special preparation. In order to comply with those demands in an intelligent and impartial manner, we have thought it wise to make some experiments with the various preparations offered by the pharmaceutical trade in the hope that this may enable us to recommend all or any preparation for the relief of our poultry raisers
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