Eyeblink conditioning during an interstimulus interval switch in rabbits (Oryctolagus cuniculus) using picrotoxin to disrupt cerebellar cortical input to the interpositus nucleus.

The role of the cerebellar cortex in eyeblink classical conditioning remains unclear. Experimental manipulations that disrupt the normal function impair learning to various degrees, and task parameters may be important factors in determining the severity of impairment. This study examined the role of cerebellar cortex in eyeblink conditioning under conditioned stimulus?unconditioned stimulus intervals known to be optimal or nonoptimal for learning. Using infusions of picrotoxin to the interpositus nucleus of the rabbit cerebellum, the authors pharmacologically disrupted input from the cerebellar cortex while training with an interstimulus interval (ISI)-switch procedure. One group of rabbits (Oryctolagus cuniculus) was 1st trained with a 250-ms ISI (optimal) and then switched to a 750-ms ISI (nonoptimal). A 2nd group was trained in the opposite order. The most striking effect was that picrotoxin-treated rabbits initially trained with a 250-ms ISI learned comparably to controls, but those initially trained with a 750-ms ISI were severely impaired. These results suggest that functional input from cerebellar cortex becomes increasingly important for the interpositus nucleus to learn delay eyeblink conditioning as the ISI departs from an optimal interval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensitivities of Band-Edge Selectivities

Many filters have a band-edge selectivity (BES) that is a function of parameters other than filter order. In these cases, the band-edge selectivity can be maximized without increasing the order of the filter. However, in increasing BES, we must keep track of the sensitivity of BES to the parameters. In this paper, we provide sensitivities of BES to filter parameters for a variety of classical filters, these being described by rational functions approximating the ideal filter magnitude response. The results are useful in the design of such filters.     

Proposed criteria for diagnosis of celiac disease in children]

At a seminar arranged in September 1997 by the Swedish Paediatric Working Group for Coeliac Disease, a diagnostic protocol proposed by the working group was approved by a majority of the paediatricians present, representing almost all paediatric units in Sweden. Briefly, a small bowel biopsy is called for in all children, both at presentation and as a control during gluten-free dieting. Subsequent gluten challenge and biopsy are mandatory only in cases of atypical presentation or if the diagnosis is questioned at some future date. Serum antigliadin and anti-endomysial antibody tests are complementary tools. Agreement was also reached regarding the institution of a national coeliac disease registry.     

Effect of Etching and Imaging Mode on the Measurement of Subsurface Damage in Microground Optical Glasses

Microgrinding of optical glass has been under intensive study recently. Characterization of the subsurface damage (SSD) generated by this process is very important because it is one of the criteria used to characterize the quality and efficiency of the microgrinding technique. SEM, as a new method, is applied for a detailed observation of the SSD. Etching with HF solutions of various concentrations is utilized to open the subsurface cracks. The etching condition has a significant influence on the measured SSD value. Using the SEM method, slightly larger SSD values are obtained compared to those obtained using conventional optical microscopy.     

Langmuir–Blodgett films of indandione-l,3 pyridinium betaine. II: Molecular structure and properties of monolayers; simulation and optical absorption data

The molecular structure and optical properties of a monolayer at the air/water interface of novel amphiphilic derivatives of indandione-1,3 pyridinium betaine (IPB) with different lengths of the aliphatic tail, namely C_1lIPB and C₁₇IPB, have been studied using optical absorption techniques and computer simulation approaches. The compression π-A isotherm of the C₁₇IPB monolayer and computer simulation of its molecular structure show that there may exist two energetically stable molecular configurations, one with antiparallel orientation of the dipole moments of the C₁₇IP ‘heads’ in the low-pressure region at π = 5–32 mN m^?1 and the second (after a distinct phase transition at π = 33 mN m^?1) with parallel orientation of the dipoles, with different tilt angles and areas per molecule. For C₁₁IPB only the first structural phase is observable. The compression-induced changes in spectral characteristics of the two structural phases go in diametrically opposite directions. In the low-pressure phase compression induces a red shift and an increase in intensity of the S₁ absorption band, while in the high pressure phase a blue shift and a decrease in the intensity of this band are observed. These spectral changes correlate reproducibly with the compression π-A isotherms. Measurements of absorption dichroism confirm the change in the tilt angle at the phase transition pressure. The compression-induced spectral changes have been substantiated by the results of quantum chemical calculations.     

OPTIMAL PREDICTION OF CATASTROPHES IN AUTOREGRESSIVE MOVING-AVERAGE PROCESSES

Abstract. This paper presents an optimal predictor of level crossings, catastrophes, for autoregressive moving-average processes, and investigates the performance of the predictor. The optimal catastrophe predictor is the predictor that gives a minimal number of false alarms for a fixed detection probability. As a tool for evaluating, comparing and constructing the predictors a method using operating characteristics, i.e. the probability of correct alarm and the probability of detecting a catastrophe for the predictor, is used. An explicit condition for the optimal catastrophe predictor based on linear prediction of future process values is given and compared with a naive catastrophe predictor, which alarms when the predicted process values exceed a given level, and with some different approximations of the optimal predictor. Simulations of the different algorithms are presented, and the performance is shown to agree with the theoretical results. All results indicate that the optimal catastrophe predictor is far better than the naive predictor. They also show that it is possible to construct an approximate catastrophe predictor requiring fewer computations without losing too much of the optimal predictor performance.     

Reviews and summaries of research related to AACN 1980 research priorities: contextual topics

This article reviews and summarizes the research conducted following publication of the 1980s American Association of Critical-Care Nurses' contextual research priorities. Reports of original research conducted on the contextual priority topics between 1981 and 1991 were included. Review articles, doctoral dissertations, theses, and abstracts were excluded unless judged to provide important information on the topic. Following the statement of each priority, progress in the area is summarized. Limitations and measurement issues are discussed as appropriate. Recommendations for future research are provided, and progress in the area is summarized.     

Chronic stimulation of the left vagal nerve in children: effect on swallowing

PURPOSE: To learn whether stimulation of the left vagal nerve would influence swallowing. METHODS: Eight children receiving intermittent left vagal nerve stimulation (VNS) for their pharmacoresistant epilepsy underwent barium swallow studies with their generators off, on, and at maximally tolerated settings. RESULTS: Laryngeal penetration of barium was present in three patients without stimulation, and was caused by VNS in one other patient. Aspiration never occurred. CONCLUSIONS: Stimulation of the left vagal nerve under conditions used to treat epilepsy does not cause aspiration.     

Deposition and characterization of magnetic Ti-Fe-C nanocomposite thin films

Nanocomposite (Ti_1−xFe_x)C_y films with different compositions have been deposited by dc magnetron sputtering at 450 °C. The sputtered films could dissolve as much as 20-30 at.% of Fe on the Ti sites which is far above the maximum solid solubility at equilibrium. The solubility was dependent on the carbon content and more carbon-rich films could dissolve more Fe without the formation of Fe-precipitates. The addition of Fe also reduced the grain size of the carbide particles. Upon annealing, α-Fe starts to precipitate and the amount and size of these precipitates can be controlled by the annealing procedure and from the total composition of the as-deposited films. Mechanical and tribological studies show that some compositions of the (Ti_1−xFe_x)C_y films have very good wear-resistant properties. These results together with magnetization measurements suggest that Ti-Fe-C films can be used as a wear-resistant magnetic thin film material.