Bedford College

About: Bedford College is a education organization based out in Bedford, United Kingdom. It is known for research contribution in the topics: Sieve tube element & Metamorphism. The organization has 656 authors who have published 839 publications receiving 25538 citations.

The earliest fossil conifer from the Westphalian B of Yorkshire

Abstract: Small charred (fusainized) leaves and leafy shoots, prepared by maceration of an Upper Carboniferous (Westphalian B) shale from Yorkshire are illustrated and described as Swillingtonia denticulata gen. et sp. nov. Examination by s. e. m. has yielded details of stomatal structure and distribution, and some internal anatomy. The uncompressed nature of the epidermal and hypodermal cells, with their open lumina, we attribute to the rigidity of the charcoalified cell walls, that result from exposure to wild fire before fossilization. Most of the leaves are triangular-lanceolate with a denticulate margin and single vascular strand; but a few of the leaves fork, with accompanying dichotomy of the vascular strand. The stomata are sunken and paracytic, and form two bands on the lower (abaxial) face. The leafy shoots show superficial similarity to both conifers and lycopods, but resemble most closely and significantly the conifer Lebachia Florin. Swillingtonia is accordingly assigned to the Lebachiaceae of the Coniferales, and consti­tutes the earliest record of a conifer.

Pollen stigma interactions in Brassica oleracea.

Abstract: Recent studies on the mechanism of self-incompatibility in Brassica indicate the location, nature and mode of action of the molecules involved. Characteristics of the pollen surface and the stigma surface are described in detail, together with new information pertaining to the recognition molecules located therein. A sequence of events is outlined leading from pollination, through adhesion, hydration, germination, and tube growth to acceptance and ultimate compatibility. The characteristics of rejection of incompatible grains are described for each stage of the pollen-stigma interaction. It is proposed that recognition of proteins from the coating of self-pollen by the molecules in the pellicle results in the formation of a biologically-active complex which inhibits water supply to the incompatible grain, and that all other manifestations of incompatibility are a consequence of this initial response.

Statics and Stability of Small Cluster Nuclei

Abstract: This article describes the chief geometrical features of the clustering of small numbers of interacting particles. The approach is quite different from others which consider the problem as one of finding dense packings of spheres.

Citric acid‐sodium citrate‐glucose mixtures for blood storage

Abstract: 1. Certain citric acid-sodium citrate-glucose mixtures have been tested and found to be satisfactory for use as blood preservatives. The use of these solutions is recommended for the following reasons:— (a) Red cells stored in these solutions survive better in the recipient's circulation after transfusion than when stored in any other solution yet tested. (b) The whole mixtures can be autoclaved with the production of little or no caramel. (c) The transfusion of blood stored in these solutions has not been accompanied by the production of any untoward results. (d) The amount of methaemoglobin formed when blood is stored with these solutions is not significantly greater than the amount formed when the usual trisodium citrate-glucose solution is used. 2. The rates of release of inorganic phosphorus, of potassium shift, of glycolysis, of haemolysis and of alteration in the osmotic fragility of blood stored in these solutions and in the Rous-Turner and standard M. R. C. citrate-glucose solutions were investigated. The changes observed were not found to be correlated with the ability of the erythrocytes to survive In Vivo after transfusion, except that in this series delay in haemolysis was associated with improved survival in vivo. We should like to thank Mr. R. J. Bromfield, Dr. C. H. Gray, and Miss M. Heppenstall for carrying out some of the tests in this investigation; Dr. M. Maizels and Dr. M. M. Murray for advice; the Medical Superintendents of Kingston County and St. Helier Hospitals for access to suitable cases; and British Drug Houses Ltd. for supplies of reagents.