Cholinergic control of extracardiac pulsations in insects

Summary The autonomic nerve system which controls extracardiac pulsations of hemolymph pressure appears to be quite susceptible to cholinesterase inhibitors (physostigmine, organophosphorus insecticides). In pupae ofTenebrio molitor L. andGalleria mellonella L., the treatment induced large peaks in hemolymph pressure (over 4 kPa). The peaks were repeated at more-or-less constant, 30-s intervals for several hours or days. Removal of the pupal brain neither affected extracardiac pulsations nor influenced the specific responses to the investigated drugs or insecticides.     

The significance of temperature and barometric pressure changes for the snow surface activity ofIsotoma hiemalis (Collembola)

Summary Temperature is limiting for the snow surface activity ofIsotoma hiemalis: values below a threshold of –2.5° to –3°C are avoided. Changing barometric pressure leads to increased surface activity, thus being responsible for mass appearances. These experiments provide the first evidence for sensitivity to and reaction to barometric pressure changes in insects.The financial support by the Swiss National Science Foundation is highly acknowledged. I thank W. Matthey for the unpublished data onGerris remigis.     

Pseudomonas lectin PA-I detects hybrid product of blood group AB genes in saliva

Summary Pseudomonas aeruginosa galactophilic lectin PA-I exhibits an outstanding affinity for soluble hybrid oligosaccharide products of human A and B genes in saliva of heterozygous AB individuals. Neither A nor B salivas, nor an artificial mixture of them, inhibit PA-I hemagglutinating activity to the same extent as saliva from heterozygotes. Other lectins examined do not exhibit this property.     

Activité protéosynthétique des glandes prothoraciques et titre d'ecdysone chez des larves permanentes deLocusta migratoria obtenues par irradiation sélective du tissu hématopoïétique

Summary The prothoracic glands of permanent fifth instar larvae ofLocusta migratoria (moulting blocked by selective X-ray treatment of the hemocytopoietic tissue) are in a state of high activity as evidenced by the rate of incorporation of a labelled amino-acid into the proteins synthesized in these glands. Such permanent larvae apparently synthesize no ecdysone nor ecdysterone.     

Legend naturalism and scientific progress: An essay on Philip Kitcher's : The advancement of science

Philip Kitcher's The Advancement of Science sets out, programmatically, a new naturalistic view of science as a process of building consensus practices. Detailed historical case studies—centrally, the Darwinian revolutio—are intended to support this view. I argue that Kitcher's expositions in fact support a more conservative view, that I dub ‘Legend Naturalism’. Using four historical examples which increasingly challenge Kitcher's discussions, I show that neither Legend Naturalism, nor the less conservative programmatic view, gives an adequate account of scientific progress. I argue for a naturalism that is more informed by psychology and a normative account that is both more social and less realist than the views articulated in The Advancement of Science.     

Zum Geschmackssinn der Baumwollwanze (Dysdercus intermedius)

Summary The bugDysdercus intermedius has gustatory receptors on the terminal segments of its antennae. Thirsty bugs discriminate between dry and wet cellulose swabs: only if they are stimulated with moist swabs, do they extend the proboscis. The stimulating effectiveness of different mono-, oligosaccharides and glycosides was studied by touching the antennae of hungry bugs and observing the extension of the proboscis. The result, that fructose is completely ineffective, entitles one to the assumption that the sugar receptor cells ofDysdercus possess neither a 1C site nor a furanose site.     

Atoms, complexes, and demonstration: Posterior analytics 96b15-25

There is agreement neither concerning the point that is being made in Posterior analytics 96b15–25 nor the issue Aristotle intends to address. There are two major lines of interpretation of this passage. According to one, sketched by Themistius and developed by Philoponus and Eustratius, Aristotle is primarily concerned with determining the definitions of the infimae species that fall under a certain genus. They understand Aristotle as arguing that this requires collating definitional predictions, seeing which are common to which species. Pacius, on the other hand, takes Aristotle to be saying that a genus is studied scientifically through first determining the infimae species that fall under that genus. This interpretation attributes to Aristotle a distinction between primary and derivative subjects. I argue for Pacius’s interpretation, defending it against Barnes’s objections.     

Estimation of serotonin and its action on oviducts and uteri of some oviparous and viviparous insects

Summary Serotonin was not found in the oviducts ofBlabera gigantea, Clitumnus extradentatus nor in the uterus ofGlossina, but it is present in the uterus ofBlabera. It is also found in the central nervous system of all three insects. In vitro experiments confirm these data by showing that serotonin increases the contractions of the uterus ofBlabera, but has no effect on the uterus ofGlossina.     

An immune response-dependent mechanism for the vertical transmission of an entomopathogen

Summary An exceptionally efficient mechanism for the vertical transmission of a parasitic gregarine is dependent on the insect host's immune response. Gametocysts ofAscogregarina chagasi on the genital accessory glands of adult female sand flies (Lutzomyia longipalpis) become encapsulated through hemocyte-mediated immune reactions. Oocysts ofA. chagasi, ejected into the lumen of the glands owing to pressure exerted by this capsule, become glued to eggshells and are subsequently ingested by larvae. InL. longipalpis with an experimentally suppressed encapsulation reaction, fewer accessory glands contained oocysts ofA. chagasi.     

Sexual isolation betweenDrosophila melanogaster females andD. simulans males. Male mating propensities versus success in hybridization

Genetic variation has been found in males of aD. simulans population for their eagerness to hybridize withD. melanogaster females. In a search for traits involved in this hybridization, males ofD. simulans were tested for mating speed and sexual vigour. Between-male differences were detected in both sexual traits, but no relationship was noticed between them, nor with the frequency of hybridization. Thus male mating propensities appear to be unrelated to the breakdown of sexual isolation between these sibling species.     

Occurrence of ricinoleic acid in submerged cultures of variousClaviceps sp.

Summary Ricinoleic acid was found in differentClaviceps sp., indicating that it is neither specific chemotaxonomic marker ofClaviceps purpurea, nor a specific indicator of peptide alkaloid synthesis.     

Short-run macroeconomic forecasting: The OECD performance

Forecasts for the seven major industrial countries, Canada, France, Germany, Italy, Japan, the United Kingdom and the United States, are published on a regular basis in the OECD's Economic Outlook. This paper analyses the accuracy of the OECD annual forecasts of output and price changes and of the current balance in the balance of payments. As a reference basis, the forecasts are compared with those generated by a naive model, a random walk process. The measures of forecasting accuracy used are the mean-absolute error, the root-mean-square error, the median-absolute error, and Theil's inequality coefficient. The OECD forecasts of real GNP changes are significantly superior to those generated by the random walk process; however, the OECD price and current balance forecasts are not significantly more accurate than those obtained from the naive model. The OECD's forecasting performance has neither improved nor deteriorated over time.     

Proestrous gonadotropin levels in thyroparathyroidectomized female rats

Summary Intact and TPTx animals showed the expected afternoon increase in serum LH, FSH and prolactin levels. But the afternoon increase in serum LH levels in TPTx rats was less than that observed for intact animals (p<0.01). Neither serum prolactin nor FSH levels were altered by TPTx.The excellent technical and secretarial assistance ofS. Hemelt andD. Landman is gratefully acknowledged.     

Sur la pyrolyse d'α-acétoxy cétones. Pyrolyse du tétraacétyl-7,12,15,32 nor-16 glaucanol

Summary The pyrolysis of 7,12,15,32-tetraacetyl 16-nor glaucanol IVb (a degradation product of glaucarubin) leads to the olefin 7,15, 32-triacetyl 11, 16 -bis nor glaucanol VII which has a contracted ring C. A mechanism is proposed for the formation of compound VII.     

Presenza di enteramina o di una sostanza enteraminosimile negli estratti gastrointestinali e splenici dei pesci e negli estratti gastroenterici delle Ascidie

Summary It was possible to demonstrate, by means of chemical and biological reactions, the presence of enteramine or of an enteramine-like substance in gastro-intestinal extracts of twoAscidi, Tethium plicatum andCiona intestinalis.The same substance was also found in gastric and still more in intestinal extracts ofSelacia, but seems not to be present in the spleen ofSelacia nor in the alimentary canal ofTeleostea.     

Der Mitosezyklus im diploiden und triploiden Wurzelmeristem vonScilla sibirica

Summary In meristematic root tip cells ofScilla sibirica (2n=12 and 3n=18) the following results were obtained with the aid of autoradiography: 1. The average duration of the mitotic cycle (2n=12) is 69.5 h. The G₁-phase lasts 36.5 h, the DNA synthetic phase 17.5 h, the G₂-phase 8 h and mitosis 7.5 h. 2. There are no marked differences in the lengths of the cell cycles nor in the duration of the various phases between diploid and triploid plants.     

Aspects of Quantum Non-Locality II: Superluminal Causation and Relativity

In a preceding paper, I studied the significance of Jarrett's and Shimony's analyses of ‘factorisability’ into ‘parameter independence’ and ‘outcome independence’ for clarifying the nature of non-locality in quantum phenomena. I focused on four types of non-locality; superluminal signalling, action-at-a-distance, non-separability and holism. In this paper, I consider a fifth type of non-locality: superluminal causation according to ‘logically weak’ concepts of causation, where causal dependence requires neither action nor signalling. I conclude by considering the compatibility of non-factorisable theories with relativity theory. In this connection, I pay special attention to the difficulties that superluminal causation raises in relativistic spacetime. My main findings in this paper are: first, parameter-dependent and outcome-dependent theories both involve superluminal causal connections between outcomes and between settings and outcomes. Second, while relativistic deterministic parameter-dependent theories seem impossible on pain of causal paradoxes, relativistic indeterministic parameter-dependent theories are not subjected to the same challenge. Third, current relativistic non-factorisable theories seem to have some rather unattractive characteristics.     

Intertidal habitat: does the shore level affect the nutritional condition of the shanny (Lipophrys pholis,Teleostei, Blenniidae)?

The nutritional condition of the shanny (Lipophrys pholis, Teleostei, Blenniidae), an intertidal fish, is affected by the shore level on whihc it dwells. Depending on the altitude within the intertidal, zone access to food is restricted for a certain time. A progressive decrease in the feeding time for an individual remaining on an increasingly higher shore level leads to a poorer nutritional condition compared to an individual staying at a lower shore level. Trade-off mechanisms between the feeding time and competition for space and/or predation pressure seem to be responsible for the still high abundance ofL. pholis on the upper shore. Possible consequences for growth and reproduction as well as distribution patterns are discussed.