8,074 research outputs found

    Symposium on Intracellular pH, PCOā‚‚ and POā‚‚: Introductory Remarks

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    It is a pleasure to welcome the three authorities who will carry the major load of presentations in our symposium today. They are Dr. Frans Jƶbsis of Duke University School of Medicine, Dr. Eugene Robin of The University of Pittsburgh School of Medicine, and Dr. Norman Carter of The University of Texas Southwestern Medical School. We are also grateful for the presence of Dr. Lutz Kiesow of the Naval Medical Research Institute, Bethesda, Maryland. Dr. Kiesow will assist in the discussions to be held after each major presentation. Each of these men is an international authority in his field, and we are more than fortunate to have this group with us today

    Experiments and other methods for developing expertise with design of experiments in a classroom setting

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    The only way to gain genuine expertise in Statistical Process Control (SPC) and the design of experiments (DOX) is with repeated practice, but not on canned problems with dead data sets. Rather, one must negotiate a wide variety of problems each with its own peculiarities and its own constantly changing data. The problems should not be of the type for which there is a single, well-defined answer that can be looked up in a fraternity file or in some text. The problems should match as closely as possible the open-ended types for which there is always an abundance of uncertainty. These are the only kinds that arise in real research, whether that be basic research in academe or engineering research in industry. To gain this kind of experience, either as a professional consultant or as an industrial employee, takes years. Vast amounts of money, not to mention careers, must be put at risk. The purpose here is to outline some realistic simulation-type lab exercises that are so simple and inexpensive to run that the students can repeat them as often as desired at virtually no cost. Simulations also allow the instructor to design problems whose outcomes are as noisy as desired but still predictable within limits. Also the instructor and the students can learn a great deal more from the postmortum conducted after the exercise is completed. One never knows for sure what the true data should have been when dealing only with real life experiments. To add a bit more realism to the exercises, it is sometimes desirable to make the students pay for each experimental result from a make-believe budget allocation for the problem

    Slow, Continuous Beams of Large Gas Phase Molecules

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    Cold, continuous, high flux beams of benzonitrile, fluorobenzine, and anisole have been created. Buffer-gas cooling with a cryogenic gas provides the cooling and slow forward beam velocities. The beam of benzonitrile was measured to have a forward velocity peaked at 67 Ā±5\pm 5 m sāˆ’1^{-1}, and a continuous flux of 101510^{15} molecules sāˆ’1^{-1}. These beams provide a continuous source for high resolution spectroscopy, and provide an attractive starting point for further spatial manipulation of such molecules, including eventual trapping

    On the admissibility of unboundedness properties of forced deterministic and stochastic sublinear Volterra summation equations

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    In this paper we consider unbounded solutions of perturbed convolution Volterra summation equations. The equations studied are asymptotically sublinear, in the sense that the state--dependence in the summation is of smaller than linear order for large absolute values of the state. When the perturbation term is unbounded, it is elementary to show that solutions are also. The main results of the paper are mostly of the following form: the solution has an additional unboundedness property UU if and only if the perturbation has property UU. Examples of property UU include monotone growth, monotone growth with fluctuation, fluctuation on R\mathbb{R} without growth, existence of time averages. We also study the connection between the times at which the perturbation and solution reach their running maximum, and the connection between the size of signed and unsigned running maxima of the solution and forcing term.Comment: 45 page

    Blow-up and superexponential growth in superlinear Volterra equations

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    This paper concerns the finite-time blow-up and asymptotic behaviour of solutions to nonlinear Volterra integrodifferential equations. Our main contribution is to determine sharp estimates on the growth rates of both explosive and nonexplosive solutions for a class of equations with nonsingular kernels under weak hypotheses on the nonlinearity. In this superlinear setting we must be content with estimates of the form limā”tā†’Ļ„A(x(t),t)=1\lim_{t\to\tau}A(x(t),t) = 1, where Ļ„\tau is the blow-up time if solutions are explosive or Ļ„=āˆž\tau = \infty if solutions are global. Our estimates improve on the sharpness of results in the literature and we also recover well-known blow-up criteria via new methods.Comment: 24 page

    Subexponential Growth Rates in Functional Differential Equations

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    This paper determines the rate of growth to infinity of a scalar autonomous nonlinear functional differential equation with finite delay, where the right hand side is a positive continuous linear functional of f(x)f(x). We assume ff grows sublinearly, and is such that solutions should exhibit growth faster than polynomial, but slower than exponential. Under some technical conditions on ff, it is shown that the solution of the functional differential equation is asymptotic to that of an auxiliary autonomous ordinary differential equation with righthand side proportional to ff (with the constant of proportionality equal to the mass of the finite measure associated with the linear functional), provided ff grows more slowly than l(x)=x/logā”xl(x)=x/\log x. This linear--logarithmic growth rate is also shown to be critical: if ff grows more rapidly than ll, the ODE dominates the FDE; if ff is asymptotic to a constant multiple of ll, the FDE and ODE grow at the same rate, modulo a constant non--unit factor.Comment: 10 page

    Online mentoring and peer support: Using learning technologies to facilitate entry into a community of practice

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    A vital aspect of any professional education is the opportunity for students to engage in meaningful practical experiences. In preā€service teacher education in Australia, this vital teaching practice component has undergone challenges in recent years due to increasing student numbers (linked to the increasing demand for new teachers) and limited resources in university and school sectors. As such, initiatives to enhance the practical component of this professional degree have been sought. This paper details the methodology and outcomes associated with a pilot project that utilized asynchronous Webā€based communication tools to facilitate mentoring and peer support through the teaching practice experience. Analysis of the online discussions and interviews with participants provides an indication of the nature of the interactions and the perceived value of the intervention, and informs the potential for largerā€scale implementation
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