Experiments on the respiration of the trigger fish (Balistes capriscus)

Zusammenfassung Druck- und Bewegungsregistrierungen haben gezeigt, dass die Kiemenventilation beim plectognathen FischBalistes capriscus primär denselben doppelten Pumpmechanismus benützt, wie andere Knochenfische. Messungen des Ventilationsvolumens wurden durch Zufuhr von Wasser unter konstantem Druck zur Mundöffnung durch einen Gummischlauch, der an der steifen Haut des Fisches festgekblet wurde, vorgenommen. Es wurden Sauerstoffausnützungen von 90% beobachtet.     

A facile approach to dihydrojasmone

Résumé La dihydrojasmone a été synthétisée en trois étapes à partir du pentanedione-2,4.

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This research was supported by NRCC, Ottawa.     

A mathematical approach to cognitive processes

Summary A mathematical formalization of cognitive processes based on concepts previously given in Experientia¹ is presented. Cognitive processes are described as a set of exponentially decaying interaction probabilities determined by previous interactions between different elements and an association parameter, the inverse of the cognitive stability. The interactions occur in a cognitive string surrounded by a cognitive plasma which carries the contextual information. The complexity of a cognitive process is proportional to time.     

A mathematical approach to cognitive processes

A mathematical formalization of cognitive processes based on concepts previously given in Experientia is presented. Cognitive processes are described as a set of exponentially decaying interaction probabilities determined by previous interactions between different elements and an association parameter, the inverse of the cognitive stability. The interactions occur in a 'cognitive string' surrounded by a 'cognitive plasma' which carries the contextual information. The 'complexity' of a cognitive process is proportional to time.     

A choice-semantical approach to theoretical truth

A central topic in the logic of science concerns the proper semantic analysis of theoretical sentences, that is sentences containing theoretical terms. In this paper, we present a novel choice-semantical account of theoretical truth based on the epsilon-term definition of theoretical terms. Specifically, we develop two ways of specifying the truth conditions of theoretical statements in a choice functional semantics, each giving rise to a corresponding logic of such statements. In order to investigate the inferential strength of these logical systems, we provide a translation of each truth definition into a modal definition of theoretical truth. Based on this, we show that the stronger notion of choice-semantical truth captures more adequately our informal semantic understanding of scientific statements.     

In vivo effects of Sumithion on tissue respiration and enzyme activity in the fish,Etroplus maculatus

Summary LD₅₀ exposure of a teleost fish.Etroplus maculatus, to Sumithion depressed the rate of oxygen consumption, concomitantly with an inhibition in succinate dehydrogenase activity in the tissues, in the order gill>brain>liver>muscle. The effect of the same pesticide on the activity of acetylcholinesterase was quite interesting, with a maximal inhibitory effect on the brain followed by liver, muscle and gill, suggesting a tissue specificity, and a differential sensitivity of the enzyme towards the pesticide.I wish to express may gratitude to Dr K. Sasira Babu and Dr J. Hemalatha for their valuable discussions and encouragement.     

A Helmholtzian approach to space and time

A slight modification of Helmholtz’s metrical approach to the foundations of geometry leads to the locally Euclidian character of space without restriction of the curvature. A bolder generalization involving time measurement leads to the locally Minkowskian character of spacetime. Some philosophical consequences of these results are drawn.     

A bayesian approach to modelling stochastic cycles

This article deals with a fully Bayesian approach to describe the cyclical behaviour of a univariate time series. A damped sine wave where both the period and the damping factor are time varying is assumed as the underlying mathematical model for the cyclical component. The model is applied to two real data sets; the annual rainfall observations in Fortaleza, Brazil, and the annual Wolf sunspot numbers.     

A mid-level approach to modeling scientific communities

This paper provides an account of mid-level models which calibrate highly theoretical agent-based models of scientific communities by incorporating empirical information from real-world systems. As a result, these models more closely correspond with real-world communities, and are better suited for informing policy decisions than extant how-possibly models. I provide an exemplar of a mid-level model of science funding allocation that incorporates bibliometric data from scientific publications and data generated from empirical studies of peer review into an epistemic landscape model. The results of my model show that on a dynamic epistemic landscape, allocating funding by modified and pure lottery strategies performs comparably to a perfect selection funding allocation strategy. These results support the idea that introducing randomness into a funding allocation process may be a tractable policy worth exploring further through pilot studies. My exemplar shows that agent-based models need not be restricted to the abstract and the apriori; they can also be informed by empirical data.     

A new approach to analysis of human sweating

In human skin transplanted to the back of 3 strains of immuno-deficient mice the functin of the eccrine sweat glands of the human transplant was tested by topical intradermal application of pilocarine, adrenaline and atropine+pilocarpine. Sweat responses were observed in pre-selected fields of observation by means of video macroscope. The iodine strarch reaction served as an indicator for the appearance of seat sport and permitted the evaluation of areas wetted by sweat in the field of observation. Among 9 animals tested, the hybrids between the CB-17-scid mouse and the BALB/cA-nu mouse (BALB/cA-nu,scid) seemed to exhibit the most consistent seweating response to local pharmacological stimulation. According to histological examination, eccrine sweat glands were preserved in human skin trasplanted into the back skin of the BALB/cA-nu,scid mouse strain. the heterologous, human skin graft provides a novel model permitting, independent of the normal sweat gland innervation, the analysis of moecular receptors of sweat gland cells by which the actions of natural transmitters and pharmacological agents are transduced.     

Rate of respiration in relation to autogamy inParamecium aurelia

Zusammenfassung Die Atmung einzelner Pantoffeltierchen (Paramecium aurelia) aus Serien-isolierten Kulturen wurde mit Hilfe eines Cartesischen Tauchers gemessen. Die Messungen an Individuen vor und nach Autogamie (Selbstbefruchtung) zeigten, dass die Atmung nach Autogamie in signifikanter Weise ansteigt.Da die Autogamie für das überleben der Kulturen eine grosse Wichtigkeit besitzt, ergeben sich Parallelen zwischen den Stoffwechselveränderungen beiParamecium und der Alterung der somatischen Zellen von Metazoen.     

A latent variable approach to forecasting the unemployment rate

A forecasting model for unemployment is constructed that exploits the time series properties of unemployment while satisfying the economic relationships specified by Okun's law and the Phillips curve. In deriving the model, we jointly consider the problem of obtaining estimates of the unobserved potential rate of unemployment consistent with Okun's law and the Phillips curve, and associating the potential rate of unemployment with actual unemployment. The empirical example shows that the model clearly outperforms alternative forecasting procedures typically used to forecast unemployment. Copyright © 2011 John Wiley & Sons, Ltd.     

A bayesian decision approach to model monitoring and cusums

Cumulative Sum techniques are widely used in quality control and model monitoring. A single-sided cusum may be regarded essentially as a sequence of sequential tests which, in many cases, such as those for the Exponential Family, is equivalent to a Sequence of Sequential Probability Ratio Tests. The relationship between cusums and Bayesian decisions is difficult to establish using conventional methods. An alternative approach is proposed which not only reveals a relation but also offers a very simple formulation of the decision process involved in model monitoring. This is first illustrated for a Normal mean and then extended to other important practical cases including Dynamic Models. For V-mask cusum graphs a particular feature is the interpretation of the distance of the V vertex from the latest plotted point in terms of the prior precision as measured in ‘equivalent’ observations.     

Disaggregation of annual time-series data to quarterly figures: A comparative study

In this paper we consider some of the prominent methods that are available in the literature for the problem of disaggregating annual time-series data to quarterly figures. The procedures are briefly described and illustrated through a real data set. The performances of the methods are compared in a Monte Carlo study. The results indicate that the complicated model-based procedure is usually superior to other non-model-based alternatives in the large sample situations. Based on the simulation results, we make some recommendations regarding the use of these methods.     

Autonomic response of the fish to pyrogen

Summary Lipopolysaccharide (LPS) applied to the anterior brainstem of the carp caused lightening of body colour. This indicates that an increase in set point temperature is responsible for increased cutaneous autonomic activity following LPS-administration.We express thanks to Dr S. Kanoh, National Institute of Hygenie Sciences, Osaka, Japan, for suppling the LPS.     

Mitochondrial respiration depressed by camphor: A possible aid in radiotherapy

Summary Camphor has been found to decrease the rate of oxygen consumption by rat kidney mitochondria. The rate of oxygen consumption is nearly halved by the addition of 8×10^–3 M camphor. It is suggested that camphor may be of use in oxygenating tumours prior to radiotherapy.Acknowledgments. We thank the New Zealand Cancer Society, Wellington-Branch, for a maintenance grant to Dr. Guilland-Cumming.     

A hybrid approach with step-size aggregation to forecasting hierarchical time series

Hierarchical time series arise in various fields such as manufacturing and services when the products or services can be hierarchically structured. “Top-down” and “bottom-up” forecasting approaches are often used for forecasting such hierarchical time series. In this paper, we develop a new hybrid approach (HA) with step-size aggregation for hierarchical time series forecasting. The new approach is a weighted average of the two classical approaches with the weights being optimally chosen for all the series at each level of the hierarchy to minimize the variance of the forecast errors. The independent selection of weights for all the series at each level of the hierarchy makes the HA inconsistent while aggregating suitably across the hierarchy. To address this issue, we introduce a step-size aggregate factor that represents the relationship between forecasts of the two consecutive levels of the hierarchy. The key advantage of the proposed HA is that it captures the structure of the hierarchy inherently due to the combination of the hierarchical approaches instead of independent forecasts of all the series at each level of the hierarchy. We demonstrate the performance of the new approach by applying it to the monthly data of ‘Industrial’ category of M3-Competition as well as on Pakistan energy consumption data.