The Early Development of the Algebraic Theory of Semigroups

In the history of mathematics, the algebraic theory of semigroups is a relative new-comer, with the theory proper developing only in the second half of the twentieth century. Before this, however, much groundwork was laid by researchers arriving at the study of semigroups from the directions of both group and ring theory. In this paper, we will trace some major strands in the early development of the algebraic theory of semigroups. We will begin with the aspects of the theory which were directly inspired by, and were analogous to, existing results for both groups and rings, before moving on to consider the first independent theorems on semigroups: theorems with no group or ring analogues. Dedicated to the memory of Professor W. Douglas Munn. This article was begun when the author was an EPSRC-funded research student at the University of York, UK, and completed at CAUL under FCT post-doctoral research grant SFRH/BPD/34698/2007.     

Kinetic study of carcinogenesis. The immune barrier and the stability of microcancer states]

We show that cancerisation presents some similarities with first order phase transitions. We analyze the barrier opposed by cytoxic cells against the proliferation of cancer cells.     

Focal brain hyperthemia. I. The cerebellar cortex

Summary Focal brain hyperthemic methodology has been described and data presented on the cerebellum which show that enhancement of electrical activity of cerebellar cortex occurs when this method is used with careful monitoring of temperature. The duration of electrically induced cerebral after-discharges is shortened when cerebellar warming reaches 39.5–42.0°C. Since these effects are repeatable over many hours, there appears to be little, if any, resultant damage. Such induced changes in the cerebrum resemble those previously reported in which electrical stimuli were applied to the cerebellar cortex.We sincerely thank the United States Public Health Service for financial support from grant No. NS11929.     

Focal brain hyperthermia. I. The cerebellar cortex

Focal brain hyperthermic methodology has been described and data presented on the cerebellum which show that enhancement of electrical activity of cerebellar cortex occurs when this method is used with careful monitoring of temperature. The duration of electrically induced cerebral after-discharges is shortened when cerebellar warming reaches 39.5--42.0 degrees C,. Since these effects are repeatable over many hours, there appears to be little, if any, resultant damage. Such induced changes in the cerebrum resemble those previously reported in which electrical stimuli were applied to the cerebellar cortex.     

Studies on benzene mutagenesis. I. The micronucleus test

Summary The mutagenic action of benzene was studied by means of the micronucleus test performed on mice. A linear dose effect relationship was found for the percentage of micronucleated erythrocytes, against the benzene-dose logarithms. A significant dose effect correlation was found either after the standard 30-h experiments or after a prolonged 54-h one. A higher effect was found in the prolonged experiments, suggesting the induction of a delay in the cell cycle by benzene.     

Greek astronomical calendars I. The parapegma of Euctemon

Summary In view of the striking similarities noted in the subsection A, B, C we are bound to conclude that Euctemon was influenced by Babylonian astronomy. However, his parapegma was not just a translation of a Babylonian text: it was an improvement in many respects. His dates of annual risings and settings were more accurate than the Babylonian dates. In most cases he recorded true risings, or he recorded both the true and the visible phaenomena. This distinction is not made in the text MUL APIN.     

Excited complexes in photosensitized processes. Kinetic characteristics

Zusammenfassung Die Kinetik homogener Photoreaktionen, welche über einen Excimer-Komplex verlaufen, wird untersucht. Es ergibt sich, dass in Übereinstimmung mit zahlreichen Beobachtungen eine Konzentrationsabhängigkeit ähnlich der vonLangmuir-Hinshelwood für die heterogene Katalyse abgeleiteten zu erwarten ist.     

The effect of methallibure (I.C.I. 33,828) on the steriodogenesis in the ovary and testis of a fresh water teleost, Cyprinus carpio

Methallibure treatment of mature Cyprinus carpio causes a marked reduction in the steroidogenesis, as indicated by the fall in 3beta-HSD activity in the gonads. Significance of these results is discussed.     

Tissue culture ofNigella sativa I. The behaviour of nucleus

Zusammenfassung In Kallusgewebekulturen vonNigella sativa nimmt mit der Zeit der Anteil der diploiden Zellen ab, während sich die Anteile von aneupliden, von 2n abweichenden Zellen vermehren.     

多组分可燃性气体爆炸影响研究

通过对多种可燃性气体爆炸上、下限进行实验,用Matlab模拟实验数据,绘制了爆炸三角形,并研制出本安型二次测爆仪。对科研人员研制便携式爆炸性气体检测仪提供了理论依据并对煤矿救护人员进行井下救援具有指导意义。     

Studies on the Dd antigen-antibody system. I. The nature of antigen Dd and its antibodies

Summary The nature of antigen Dd, an antigen present in the extracts of human dandruff which precipitates human sera selectively, and antibodies reacting with it are reported.This work was supported through U.G.C. Grant No. F.23-230/75/SR II. H.K. participated in this study, first as J.R.F. of U.G.C. and then as S.R.F. of I.C.M.R. We are grateful to Dr Baruch S. Blumberg for his invaluable suggestions and to Professor H. Walter for the gift of IgG, IgM and IgA immune sera.     

The effect of methallibure (I.C.I. 33, 828) on the steroidogenesis in the ovary and testis of a fresh water teleost,Cyprinus carpio

Summary Methalibure treatment of matureCyprinus carpio causes a marked reduction in the steroidogenesis, as indicated by the fall in 3-HSD activity in the gonads. Significance of these results is discussed.K.K. is thankful to University Grants Commission for a fellowship. Thanks are also due to I.C.I. England for the supplies of methallibure.     

Newton,Gases, and Daltonian chemistry: The foundations of combination in definite proportion

This study deals with the relationship between Newton's gas model in the Principia (Book II, Proposition xxiii) and Dalton's theorizing. Dalton's first theory of mixed gases is an elegant extension of the Newtonian gas model which, in turn, led Dalton to a general model of chemical combination. The views on combination are contrasted with those of Arnold Thackray. Interestingly, the model of combination was knowingly based on a falsified theory.