Coral successions in Upper Tortonian reefs in SE Spain

Martin, Jose M., Braga, Juan C. & Rivas, Pascual 1989 07 15: Coral successions in Upper Tortonian reefs in SE Spain. Lethaia , Vol. 22, pp. 271–286. oslo. ISSN 0024–1164,
During the Upper Tortonian (Upper Miocene), the Almanzora river corridor, a small Neogene basin in SE Spain, harboured coral reefs growing in three different environments: in fan deltas, beyond the influence of coarse terrigenous sedimentation; in the abandoned lobes of a delta complex; and on coastal margins. All of these reefs are composed of several successive beds, each of which may be made up mainly of Porites embedded in silt or of an initial Porites level followed by a silt-free Tarbellastraea level on top. Porites may be associated with corallines. This structure is interpreted as being the result of an ecological succession repeated over and over again. A pioneer association consisting mainly of Porites . by colonizing the substrate and continuing to grow through relatively adverse silt-deposition conditions, prepares the ground for Tarbellastraea to take over. A return to the previous conditions halts the growth of the Tarbellastraea colonies and the Porites association once more establishes itself in the silt, or else the renewed rate of deposition is sufficiently heavy to suffocate the whole bioconstruction.* Ecological succession. coral reefs, Tortonian, southeast Spain .     

An Indirect Radiolabelled Antibody Staining Technique for the Rapid Detection and Identification of Bacteria

Small numbers of Bacillus subtilis var. niger spores, Serratia marcescens and Francisella tularensis can be detected and identified in an hour using an indirect radiolabelled antibody staining technique with homologous rabbit antibacterial antibody and radiolabelled goat anti-rabbit globulin. Tritium is better than ¹²⁵I, ¹⁴C and ³⁵S for labelling the globulin. The reagent obtained is sensitive and adequately stable.     

Isolation of <Emphasis Type="Italic">Plasmodium berghei</Emphasis> (Malaria) Parasites by Ammonium Chloride Lysis of Infected Erythrocytes

IMMUNOLOGICAL, biochemical and other studies of intra-erythrocytic parasites, such as malaria, would be greatly facilitated if the parasites could be obtained free from erythrocytes. To lyse infected erythrocytes, hypotonic shock¹, sonication², rapid pressure release obtained with the French press³, proteolytic enzyme digestion^4,5, saponin^6,7 and antibody-induced lysis^8,9 have been tried, but these either fail to remove erythrocyte debris completely, or cause structural damage to the organisms.     

Evidence for Subpopulation of Mature Lymphocytes within Mouse Thymus

THERE is increasing evidence that thymus cells migrate from the thymus to the peripheral lymphoid tissues where they make up most, if not all, of the thymus-dependent population of lymphocytes^1–3. The term “thymus-derived” is thus appropriately applied to this population. Yet most thymocytes are different from peripheral lymphocytes, both in immunological competence and in surface antigenic characteristics. For example, thymocytes have more theta (θ)⁴ and less H2 antigen⁵ than do peripheral lymphocytes and in TL-positive strains of mice only thymocytes normally express the TL antigen⁶. Recently, Lance et al.⁷ found that injected thymocytes which had migrated to lymph nodes and spleen were progressively less susceptible to anti-TL and more susceptible to anti-H2 serum over the first 24 h. I report here experiments in which thymus cells injected intravenously into irradiated syngeneic mice and harvested as early as 3 h later from the peripheral lymphoid tissues can be shown to have the surface antigenic properties of peripheral thymus-derived lymphocytes rather than thymocytes. A second experiment demonstrates that at least part of the differentiation from thymocyte to thymus-derived lymphocyte seems to occur within the thymus.     

Decay Rates of Different mRNA in <Emphasis Type="Italic">E. coli</Emphasis> and Models of Decay

THE basis for messenger RNA instability in bacteria is not understood. Both functional capacity^1,2 and mass of messages for a given protein are lost at constant exponential rates which can differ, indicating independent processes³.     

The fungitoxicities of plant furocoumarins

A mixture of the furocoumarins pimpinellin, isopimpinellin, isobergapten and sphondin isolated from Heracleum sphondylium root was toxic to Gloeosporium limetticola, Botryis cinerea, Sclerotinia fructigena and Stereum purpureum at 200 p.p.m. or less in nutrient medium. The extractive of the leaves of plants that contain furocoumarins suppressed in vivo growth of G. limetticola and B. cinerea at concentrations lower than the contents of the extractive in the leaves. Furocoumarins may form an important class of natural defensive agents against fungi; this possibility is discussed.     

Phylogenetic Relationships of Blepharisma Americanum and Colpoda Inflata Within the Phylum Ciliophora Inferred From Complete Small Subunit Rrna Gene Sequences

ABSTRACT The complete small subunit rRNA gene sequences of the heterotrich Blepharisma americanum and the colpodid Colpoda inflata were determined to be 1719 and 1786 nucleotides respectively. the phylogeny produced by comparisons with other ciliates indicated that C. inflata is allied more closely with the nassophoreans and oligohymenophoreans than the spirotrichs. This is consistent with the placement of the colpodids in the Class Copodea. Blepharisma americanum was not grouped with the hypotrichs but instead was placed as the earliest branching ciliate. the distinct separation of B. americanum supports the elevation to class status given the heterotrichs based on morphological characters.