On the epistemological foundations of the law of the lever

In this paper I challenge Paolo Palmieri’s reading of the Mach—Vailati debate on Archimedes’ proof of the law of the lever. I argue that the actual import of the debate concerns the possible epistemic (as opposed to merely pragmatic) role of mathematical arguments in empirical physics, and that construed in this light Vailati carries the upper hand. This claim is defended by showing that Archimedes’ proof of the law of the lever is not a way of appealing to a non-empirical source of information, but a way of explicating the mathematical structure that can represent the empirical information at our disposal in the most general way.     

Melatonin decreases the amplitude of the b-wave of the human electroretinogram

In a double-blind placebo crossover study of 13 healthy volunteers, the pineal hormone melatonin (10 mg) was given at 4 pm, and the electroretinogram measured under conditions of dark and light adaptation. A significant diminution of b-wave amplitude was found under both photopic (=5.4 V, p<0.05) and scotopic conditions (=7.4 V, p<0.01). These data indicate that melatonin may transduce the dark signal at the level of the retina as well as the pineal. Acute administration of melatonin decreases sensitivity to light.     

Statistical analysis of the relation between the length of the genoma and the diploid number of the chromosomes inCercopithecus

Riassunto Utilizzando metodiche statistiche è stato analizzato l'incremento della lunghezza totale del genoma rispetto al numero dei cromosomi in piastre a diversa ploidia nel genereCercopithecus. È stato riscontrato che la relazione numero dei cromosomi e lunghezza del genoma è significativamente lineare. È supposto un meccanismo adittivo per interpretare l'incremento del numero dei cromosomi.     

Computing the variance of the forecast error for the holt-winters seasonal models

This paper presents expressions for the variance of the forecast error for arbitrary lead times for both the additive and multiplicative Holt-Winters seasonal forecasting models. It is shown that even when the smoothing constants are chosen to have values between zero and one, when the period is greater than four, the variance may not be finite for some values of the smoothing constants. In addition, the regions where the variance becomes infinite are almost the same for both models. These results are of importance for practitioners, who may choose values for the smoothing constants arbitrarily, or by searching on the unit cube for values which minimize the sum of the squared errors when fitting the model to a data set. It is also shown that the variance of the forecast error for the multiplicative model is nonstationary and periodic.     

Development of the innervation of the urogenital complex in the fetal mouse

Summary The developing urogenital complex of the fetal mouse was studied by means of silver impregnation and electron microscopy. These studies showed that: 1) the mesonephric field is innervated during prenatal stages (Wolffian nerve); 2) nerve penetration precedes the differentiation of the gonads and related ducts; and 3) the Wolffian nerve arises during the earliest stages from the first pair of abdominal rami communicantes. The identity between the fetal Wolffian nerve and the nerve of the suspensory ligament (higher pathway) of the adult is discussed.     

Continuous light abolishes the maternal entrainment of the circadian activity rhythm of the pups in the field mouse

Summary 1212-h cycles of presence and absence of mother mouse act as a zeitgeber and entrain the circadian rhythm of locomotor activity in the pups ofMus booduga under continuous darkness or continuous dim light. Continuous higher illumination of 15–25 lx abolishes this impressive maternal entrainment.Acknowledgment. We are grateful to the DST, Government of India, for financial support under their IRHPA scheme. N.V. is the recipient of a Senior Research Fellowship of CSIR, New Delhi. We thank Dr. R. Subbaraj for discussions.     

On the irreversible agglutination of the sperm of the sea-urchins caused by the sperm extract

Zusammenfassung Eine neue Methode der Extrahierung von «Antifertilizin» aus den Samenzellen von Seeigeln,Paracentrotus lividus undArbacia lixula, wurde beschrieben. Der Extrakt zeigte folgende Wirkungen: Neutralisierung des Fertilizins, nicht umkehrbare Agglutinierung der Samenfäden und der Eier bei beiden Seeigelarten.     

Modelling the daily banknotes in circulation in the context of the liquidity management of the European Central Bank

The main focus of this paper is to model the daily series of banknotes in circulation. The series of banknotes in circulation displays very marked seasonal patterns. To the best of our knowledge the empirical performance of two competing approaches to model seasonality in daily time series, namely the ARIMA‐based approach and the Structural Time Series approach, has never been put to the test. The application presented in this paper provides valid intuition on the merits of each approach. The forecasting performance of the models is also assessed in the context of their impact on the liquidity management of the Eurosystem. Copyright © 2008 John Wiley & Sons, Ltd.     

On the adenosintriphosphatase activity of the particulates of the egg of the sea urchinParacentrotus lividus

Riassunto I particolati delle uova vergini di riccio di mare possono essere separati, a mezzo della centrifugazione differenziale, in due frazioni, una fortemente ed una scarsamente pigmentata. La prima mostra una attività ATPasica attivata da Mg con un massimo a pH 8.2; il massimo della seconda è invece a pH 6.4. Nelle preparazioni contenenti i due tipi di particolati si ritrovano i due massimi.     

Whewell on the classification of the sciences

Despite deserving a place amongst the historic milestones of the philosophy of disciplines, the system of the sciences put forward by Whewell has so far received little interest. Yet his ideas had a significant impact on the researches subsequently carried out on the topic, exerting in particular a decisive influence on Peirce and Spencer. The present paper aims to display the innovatory nature of the philosophical foundations of the Whewellian classification of the sciences. In this respect, we will argue that the most striking feature of his disciplinary system lies in a heuristic categorization of the sciences according to their “methods of discovery”. This represents a double departure from both the Aristotelian and the Baconian disciplinary paradigms, which are instead underpinned by ontological and epistemological criteria, respectively. Next, we will explore the pivotal role of Whewell's classification of the sciences for his overall project of a philosophy of scientific discovery.