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1.
This paper argues that, contrary to the claims of Alan Chalmers, Boyle understood his experimental work to be intimately related to his mechanical philosophy. Its central claim is that the mechanical philosophy has a heuristic structure that motivates and gives direction to Boyle's experimental programme. Boyle was able to delimit the scope of possible explanations of any phenomenon by positing both that all qualities are ultimately reducible to a select group of mechanical qualities and that all explanations of natural phenomena are to be in terms of the operations of machines and are to appeal only to qualities that are already familiar. This is illustrated by his investigations into the Torricellian experiment. Boyle's explanation of the elevation of the mercurial cylinder by appeal to the spring of the air was an intermediate mechanical explanation. Boyle was convinced that the spring of the air was ultimately reducible to the mechanical qualities. This in turn had implications for his research into the cause of respiration. In a move that was both parsimonious and consistent with the broad requirements of the mechanical philosophy, Boyle was able to solve the problem of the cause of the inflow of air into the lungs by appeal to his research in pneumatics. This application of a mechanical explanation in pneumatics to physiology is just what one would expect if the mechanical philosophy was as universal as Boyle claimed it to be. Therefore, far from Boyle's experiments having a life of their own, they were clearly directed by and understood in terms of the mechanical philosophy.  相似文献   

2.
Summary The release of insulin which occurred in response to arginine, in the conscious calf, differed from that which occurs in response to glucose in that it was not significantly affected by either adrenergic or muscarinic blocking agents. Release of pancreatic glucagon was reduced by pretreatment with phentolamine.This work was supported by the British Diabetic Association. It is a particular pleasure to acknowledge the skilled assistance provided by Messrs P. M. M. Bircham and G. P. McGregor.  相似文献   

3.
The aim of the article is to analyse the relationship between Quaternary geology, the idea of land elevation, nationalism and regionalism in Scandinavia, with special regard to the contribution of Swedish geologists at the end of the nineteenth century. From a scientific point of view, the idea of land elevation was connected to the acceptance of the glaciation theory and the elevation theory of Thomas F. Jamieson, but analysed in a wider cultural context it is possible to understand both the professionalization of Quaternary geology and the new theory of shore-line displacement as expressions of Swedish cultural nationalism. As a complement to the specific cultural history, the Quaternary geology enterprise was a way of constituting a unique natural history of the nation. One of the new theories that developed in this process was that of the Highest Marine Border, a complex concept established by the distinguished geologist Gerard De Geer at the end of the 1880s in order to defend the theory of land elevation, which was threatened by the work of Eduard Suess. The line was considered to be a geographical border that both expressed the elevation pattern and sharply divided Sweden into one part that had been covered by water during the post-glacial period and another part that had not. The study continues by looking more closely at the construction of the border in the north of Sweden. Through an account of a subsequent scientific dispute between De Geer and the geologist Arvid Gustaf Hogbom it is clear that the concept of the Highest Marine Border was shaped not only by nationalism but also by regionalism.  相似文献   

4.
A V Edwards  S R Bloom 《Experientia》1986,42(2):158-160
The release of insulin which occurred in response to arginine, in the conscious calf, differed from that which occurs in response to glucose in that it was not significantly affected by either adrenergic or muscarinic blocking agents. Release of pancreatic glucagon was reduced by pretreatment with phentolamine.  相似文献   

5.
Summary The B-subunit of cholera toxin, a nontoxic macromolecule which binds specifically to GM1 ganglioside, was conjugated to colloidal gold and injected into skeletal muscle of the rat. It was taken up rapidly in vesicles in the terminal axons at the neuromuscular junctions. Injection of albumin-colloidal gold conjugates resulted in an insignificant uptake. The results indicate that uptake of extracellular macromolecules into the terminal axon of the neuromuscular junction may be greatly enhanced by binding to gangliosides at the presynaptic membrane, and that it may occur without association with vesicular recycling related to transmitter release.The study was supported by grants from the Swedish Medical Research Council (proj. No. 07122).—Part of this study was performed at INSERM U-153, Paris, headed by Dr M. Fardeau.  相似文献   

6.
William Newman construes the Scientific Revolution as a change in matter theory, from a hylomorphic, Aristotelian to a corpuscular, mechanical one. He sees Robert Boyle as making a major contribution to that change by way of his corpuscular chemistry. In this article it is argued that it is seriously misleading to identify what was scientific about the Scientific Revolution in terms of a change in theories of the ultimate structure of matter. Boyle showed, especially in his pneumatics, how empirically accessible, intermediate causes, as opposed to ultimate, mechanical ones can be explored and identified by experiment. Newman is right to observe that Boyle constantly sought intimate links between chemistry and the mechanical philosophy. However, by doing so he did not thereby significantly aid the cause of attaining experimental knowledge of chemical phenomena and the support that Boyle’s chemistry provided for the mechanical philosophy was weaker than both Boyle and Newman imply. Boyle was intent on articulating and defending a strict, mechanical account of the ultimate structure of matter to be sure, but his contributions to the new experimental science in general, and chemistry in particular, are best seen as distinct from that endeavour.  相似文献   

7.
Summary Cerebral cortical blood flow was measured with the hydrogen clearance technique. It was found that the increase in CoBF induced by amphetamine is blocked by atropine or chlorpromazine.This work was supported by grants from Consejo Nacional de Investigaciones Cientificas y Tecnicas and Consejo de Investigaciones de la Provincia de Santa Fé, Argentina.  相似文献   

8.
Summary The carotenoid crocetin was found to be taken up by normal rat muscle cells grown in vitro, and was found in the ribosomal-microsomal fraction, supporting the hypothesis that crocetin affects cell division enzymatic processes.  相似文献   

9.
Bet3, a transport protein particle component involved in vesicular trafficking, contains a hydrophobic tunnel occupied by a fatty acid linked to cysteine 68. We reported that Bet3 has a unique self-palmitoylating activity. Here we show that mutation of arginine 67 reduced self-palmitoylation of Bet3, but the effect was compensated by increasing the pH. Thus, arginine helps to deprotonate cysteine such that it could function as a nucleophile in the acylation reaction which is supported by the structural analysis of non-acylated Bet3. Using fluorescence spectroscopy we show that long-chain acyl-CoAs bind with micromolar affinity to Bet3, whereas shorter-chain acyl-CoAs do not interact. Mutants with a deleted acylation site or a blocked tunnel bind to Pal-CoA, only the latter with slightly reduced affinity. Bet3 contains three binding sites for Pal-CoA, but their number was reduced to two in the mutant with an obstructed tunnel, indicating that Bet3 contains binding sites on its surface.  相似文献   

10.
Pelis K 《Annals of science》1997,54(4):331-360
Historians have devoted little attention to blood transfusion in the nineteenth century. In part, this neglect reflects the presentist assumption that, before Karl Landsteiner's discovery of blood types, this practice would have failed too often to gain currency. Yet, transfusion was in fact the subject of much debate, and was actively practised, primarily by obstetricians on haemorrhaging women. Examining this practice through the conceptual lens of 'blood clots', both as noun and as observation, I follow transfusors' assumptions about the nature of the blood and the problem of its coagulation. Tracing the medicalization of ideas about blood by the century's end, I map this shift onto changing notions about why transfusion was performed, what substance was best employed, and what instrument best fitted that substance's movement into the circulation. In this way, 'Blood Clots' reconstructs the discourse surrounding transfusion, extending that discourse to material culture in order to illuminate the rationale that guided transfusion's practice in nineteenth-century Britain.  相似文献   

11.
Fractionation of the poisonous secretion of the toad Bufo marinus paracnemis Lutz, by dialysis and chromatography on QAE-Sephadex, led to the isolation of a fraction which was adsorbed to the ion exchanger. This fraction, when incubated with human serum, yielded an anticomplementary effect that was evaluated by measuring the kinetics of lytic activity on sensitized sheep red cells (classical pathway) and unsensitized rabbit cells (alternative pathway).  相似文献   

12.
Theories of familial, racial, and national degeneration in the late nineteenth and early twentieth centuries have been explored by historians in the context of social and moral pathology. At the same time nerve degeneration was studied in the post mortem room and in the laboratory but links to the broader ideology of degeneration have not been investigated by scholars. This paper joins these domains by examining the concept of Wallerian degeneration. It argues that various discourses—including those of the laboratory scientist, the clinician, and the social theorist—employed the term degeneration, and these discourses frequently overlapped demonstrating that degeneration was a ubiquitous fact of Victorian and Edwardian nature.  相似文献   

13.
The carotenoid crocetin was found to be taken up by normal rat muscle cells grown in vitro, and was found in the ribosomal-microsomal fraction, supporting the hypothesis that crocetin affects cell division enzymatic processes.  相似文献   

14.
Summary Amniotic fluid was obtained from 19-day-old rat fetuses by aspiration. Pooled samples measured at 4 different dilutions demonstrated parallelism with standard rat TSH. It is concluded that rat amniotic fluid has TSH immunoactivity.This work was supported by Hong Kong University Research Grant No. 335/034/5727.The authors wish to acknowledge with thanks the gift of rat TSH RIA kit from Dr A. F. Parlow and the Rat Pituitary Programme of NIAMDD.  相似文献   

15.
Experiments on anesthetized dogs and on vascular test-preparations demonstrated that reactive hyperemia (RH) was accompanied by the appearance of vasodilator in the blood, and that the level increased with the duration of occlusion of the artery. Removal of the endothelium of the part of the vascular bed studied using saponin, decreased the RH and relaxation of a test-preparation. A rise of pressure in the vascular bed, and a decrease in the deformability of the endothelium resulting from pretreatment with dimerized glutaraldehyde, affected both the hyperemia and the reaction of the vascular preparation in a similar way. It was concluded that the RH resulted from the secretion of vasoactive substances by the endothelium in response to a fall in intravascular pressure.  相似文献   

16.
I began this study with Laudan's argument from the pessimistic induction and I promised to show that the caloric theory of heat cannot be used to support the premisses of the meta-induction on past scientific theories. I tried to show that the laws of experimental calorimetry, adiabatic change and Carnot's theory of the motive power of heat were (i) independent of the assumption that heat is a material substance, (ii) approximately true, (iii) deducible and accounted for within thermodynamics.I stressed that results (i) and (ii) were known to most theorists of the caloric theory and that result (iii) was put forward by the founders of the new thermodynamics. In other words, the truth-content of the caloric theory was located, selected carefully, and preserved by the founders of thermodynamics.However, the reader might think that even if I have succeeded in showing that laudan is wrong about the caloric theory, I have not shown how the strategy followed in this paper can be generalised against the pessimistic meta-induction. I think that the general strategy against Laudan's argument suggested in this paper is this: the empirical success of a mature scientific theory suggests that there are respects and degrees in which this theory is true. The difficulty for — and and real challenge to — philosophers of science is to suggest ways in which this truth-content can be located and shown to be preserved — if at all — to subsequent theories. In particular, the empirical success of a theory does not, automatically, suggest that all theoretical terms of the theory refer. On the contrary, judgments of referential success depend on which theoretical claims are well-supported by the evidence. This is a matter of specific investigation. Generally, one would expect that claims about theoretical entities which are not strongly supported by the evidence or turn out to be independent of the evidence at hand, are not compelling. For simply, if the evidence does not make it likely that our beliefs about putative theoretical entities are approximately correct, a belief in those entities would be ill-founded and unjustified. Theoretical extrapolations in science are indespensable , but they are not arbitrary. If the evidence does not warrant them I do not see why someone should commit herself to them. In a sense, the problem with empricist philisophers is not that they demand that theoretical beliefs must be warranted by evidence. Rather, it is that they claim that no evidence can warrant theorretical beliefs. A realist philosopher of science would not disagree on the first, but she has good grounds to deny the second.I argued that claims about theoretical entities which are not strongly supported by the evidence must not be taken as belief-worthy. But can one sustaon the more ambitious view that loosely supported parts of a theory tend to be just those that include non-referring terms? There is an obvious excess risk in such a generalisation. For there are well-known cases in which a theoretical claim was initially weakly supported by the evidence  相似文献   

17.
Superoxide dismutase is an enzyme that catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. This superoxide radical is produced by all aerobic cells as a normal metabolic intermediate of molecular oxygen, and is dangerous for the cell because it induces the inactivation of various enzymes, lipid peroxidation and mutations. Superoxide dismutase can therefore be considered as a protective enzyme. The purpose of this work was to determine the level of superoxide dismutase activity in the Spanish population, and to study the factors that influence this activity. The superoxide dismutase activity of 2397 individuals was determined using the method described by Minami and Yoshikawa. The superoxide dismutase activity level in the adult Spanish population was found to be 4.16 +/- 0.89 Units/ml of blood. No significant variations with respect to sex were detected. But it was observed that the superoxide dismutase activity level was 9% higher in the young urban Spanish population.  相似文献   

18.
Summary Superoxide dismutase is an enzyme that catalyzes the dismutation of superoxide radicals to hydrogen peroxide and molecular oxygen. This superoxide radical is produced by all aerobic cells as a normal metabolic intermediate of molecular oxygen, and is dangerous for the cell because it induces the inactivation of various enzymes, lipid peroxidation and mutations. Superoxide dismutase can therefore be considered as a protective enzyme. The purpose of this work was to determine the level of superoxide dismutase activity in the Spanish population, and to study the factors that influence this activity. The superoxide dismutase activity of 2397 individuals was determined using the method described by Minami and Yoshikawa. The superoxide dismutase activity level in the adult Spanish population was found to be 4.16±0.89 Units/ml of blood. No significant variations with respect to sex were detected. But it was observed that the superoxide dismutase activity level was 9% higher in the young urban Spanish population.  相似文献   

19.
UV-irradiation of the vegetal hemisphere of amphibian eggs leads to developmental abnormalities in neural morphogenesis. The possibility that the egg's transient sensitivity to irradiation could be due to pigmentation changes was examined in albino eggs. The tissue specificity of the effects of irradiation was analyzed by exchanging the ectoderm between irradiated and control embryos.  相似文献   

20.
The bipartite metatheory thesis attributes to Rudolf Carnap, Philipp Frank and Otto Neurath a conception of the nature of post-metaphysical philosophy of science that sees the purely formal-logical analyses of the logic of science as complemented by empirical inquiries into the psychology, sociology and history of science. Three challenges to this thesis are considered in this paper: that Carnap did not share this conception of the nature of philosophy of science even on a programmatic level, that Carnap's detailed analysis of the language of science is incompatible with one developed by Neurath for the pursuit of empirical studies of science, and, finally, that Neurath himself was confused about the programme of which the bipartite metatheory thesis makes him a representative. I argue that all three challenges can be met and refuted.  相似文献   

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