The estimative functions of physical theory

Attention is drawn to two closely related functions served by scientific theory (called here ‘mensurative’ and ‘reconstructive estimation’) which are of fundamental importance in physical science but as yet little discussed in philosophy. As indicated by their names, they constitute the theoretical basis of physical measurements.After analysing some historically important examples and sketching the historical development of these ideas, this paper examines the similarities and differences between the estimate functions of theory and such well-known functions as prediction and explanation. The pervasiveness of the estimative functions even when theory is but poorly developed is noted; and some of the problems raised by the physical equivalence of the measuring instrument to the object measured are discussed. The relations of estimation to ‘reductive logic’ are also considered.We then apply this understanding of estimative functioning to distinguishing experimental errors from those genuine anomalies which result in discovery. It is also shown that there can be no facts established nor any verification of predictions except on the basis of valid estimates derived, in turn, from antecedently accepted theories.     

Seasonal changes in the uptake capacity of the suprachiasmatic nucleus for3H-serotonin

Summary The suprachiasmatic nucleus, a hypothalamic center important in mediation of circadian and estrous cycles, is shown in adult rats to have seasonal changes in its uptake capacity in vitro for³H-serotonin.Supported in part by grants from the National Institute of Mental Health (MH-25091), the National Institute of Health (HD-10263, HD-03352, 5-T01-HD00104-10), USPHS, and the Ford Foundation (grant No. 630-0505 B, C).     

Young organic matter as a source of carbon dioxide outgassing from Amazonian rivers

Rivers are generally supersaturated with respect to carbon dioxide, resulting in large gas evasion fluxes that can be a significant component of regional net carbon budgets. Amazonian rivers were recently shown to outgas more than ten times the amount of carbon exported to the ocean in the form of total organic carbon or dissolved inorganic carbon. High carbon dioxide concentrations in rivers originate largely from in situ respiration of organic carbon, but little agreement exists about the sources or turnover times of this carbon. Here we present results of an extensive survey of the carbon isotope composition (13C and 14C) of dissolved inorganic carbon and three size-fractions of organic carbon across the Amazonian river system. We find that respiration of contemporary organic matter (less than five years old) originating on land and near rivers is the dominant source of excess carbon dioxide that drives outgassing in medium to large rivers, although we find that bulk organic carbon fractions transported by these rivers range from tens to thousands of years in age. We therefore suggest that a small, rapidly cycling pool of organic carbon is responsible for the large carbon fluxes from land to water to atmosphere in the humid tropics.     

Adrenal dopamine-β-hydroxylase activity: 24-hour rhythmicity and evidence for pineal control

Summary Adrenal medullary dopamine--hydroxylase activity was found in male rats to have a 24-hour rhythm, with an approximately 6-fold increase at about the time of the onset of darkness. This nocturnal rise in enzyme activity did not occur when lights were kept on, nor did it occur in animals that had been pinealectomized.Supported in part by grants from the Ford Foundation (No. 630-05050A), National Institutes of Health (No. HD-03352) and National Institute of Mental Health (No. MH-25019) USPHS.     

Spontaneous adenomata of the hypophyseal anterior lobe in aged pinealectomized rats

Zusammenfassung Es wurden Vorkommen und Eigenschaften des Hypophysenadenoma bei altersschwachen Ratten nach Pinealektomie beschrieben. Trotzdem in Tumoren zirbeldrüsenloser Tiere grössere Parenchymbildung und grösserer Blutgehalt erscheinen, können die vorliegenden Ergebnisse keinen entscheidenden Unterschied bestätigen.

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This investigation was supported in part by PHS research grant No. GM-05219 from the National Institute of General Medical Sciences, NIH, Public Health Service, USA, and the Miller Institute for Basic Research in Science, University of California, Berkeley (California).