bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Party Systems of the Established Liberal Democracies in the 1990s: Is this a Decade of Transformation?
Authors: Ware Alan 
Published: April 2007

DURING THE FIRST HALF OF THE 1990s ABOUT ONE THIRD OF the countries which had been governed continuously by liberal democratic regimes since the mid-1950s experienced major electoral upheavals at a general election. In the case of eight countries an argument could be made that electoral politics was not as it had been, and that the party systems were now experiencing problems that were quite different in scale from those with which they had contended during the previous forty years. The countries concerned were:– Sweden, where the 1991 general election produced a major decline in the share of the vote (5.5 per cent of the total) for the governing Social Democrats; this was the largest change in its vote share between consecutive elections since 1944.
On Cytoplasmic Strands in Gonium pectorale (Volvocales)
Authors: STEIN JANET R. 
Published: April 2007

SUMMARY Cytoplasmic connections between cells of a coenobium in Gonium pectorale have been investigated. Light‐microscope observations have been supplemented with stains considered specific for plasmodesmata.Darkfield illumination, polarized light, and phase‐contrast microscopy have also been employed. Comparative studies of Volvox aureus (with thin cytoplasmic strands) and V. globator (with thick strands) have been made. No plasmodesmata have been demonstrated in G. pectorale; however, the cells are connected to one another by individual, almost transparent cytoplasmic connections, possibly the membrane. In older coenobia the cells become separated; the membrane connections stretch ultimately appearing as fine threads between the cells.
Growth and Metabolism of Chlorella pyrenoidosa
Authors: OSRETKAR ANTHONY , KRAUSS R. W. 
Published: April 2007

SUMMARYChlorella pyrenoidosa Chick, van Niel's strain, grown in a chemically defined medium, in which the potassium was replaced with rubidium, attained only 20%of the growth rate of algae in media containing K. Addition of sodium to K‐deficient media spared Rb uptake. Neither growth nor uptake of Rb were accelerated when glucose was added to media Cells which had been maintained on K‐free media, did not immediately respond to K, indicating that their metabolism had become adjusted to Rb. Free and combined amino acids, nonketo organic acids, polysaccharides, and chlorophylls were similar in K or Rb media. Fewer porphyrins, and in smaller quantity, were found in the cells grown in Rb media. Cells grown in K‐free media, analyzed by X‐ray fluorescence, showed 0.039%of their dry weight to be K contamination. When the K equivalent to the small contamination of the Rb salt was added to a Rb‐free medium, the cells failed to grow. The data indicate that Rb either can replace K entirely in cell metabolism, or that it can spare the K requirement. Substitution of K by Rb does not permit normal growth if rate is the criterion.
TRANSLOCATION IN THE GIANT KELP MACROCYSTIS I. RATES, DIRECTION, QUANTITY OF C14‐LABELED PRODUCTS AND FLUORESCEIN
Authors: Parker Bruce C. 
Published: April 2007

SUMMARY C14 tracer and fluorescein dye experiments on translocation through the stipes of Macrocystis are reported. Both dye and C14‐labeled products move mainly in the sieve tubes acropetally and basipetally in variable amounts and at variable rates, frequently entering young developing blades en route. The maximum rate of transport of organic products of photosynthesis may reach 65‐78 cm/hr, while that of fluorescein rarely exceeds 1.0 cm/hr in intact fronds. By their behavior, fluorescein and the C1J′‐labeled products(s) resemble phloem translocation in vascular plants.
THE EFFECT OF TEMPERATURE ON THE RADIAL SYMMETRY OF STAURASTRUM POLYMORPHUM
Authors: Brandham P. E. , Godward M. B. E. 
Published: April 2007

SUMMARYStaurastrum polymorphum Bréb. is a desmid showing different types of symmetry within a clone. Low temperature favors the formation of the quadriradiate form; high temperature favors the formation of the triradiate form. The change from one form to the other has been observed to occur abruptly in a single division. Possible mechanisms for the effect are discussed. The work is correlated with field observations by a previous writer.
ZOOSPORE INHIBITION IN SPONGIOCHLORIS TYPICA1
Authors: McLean Robert J. , Trainor Francis R. 
Published: April 2007

SUMMARYSpongiochloris typica, grown in a 2‐membered culture with a soil bacterium, did not produce zoospores. The zoospore‐inhibiting effect could be found in the cell‐free filtrate of the bacterial culture grown in complete medium. The phenomenon could not be attributed to a deficiency of Ca or any other component of the medium. Zoospore inhibition could be demonstrated only when the pH was 8.4 or above. Manipulation of the components of complete medium showed that the ammonium ion was necessary for inhibition. Co‐action of any other ion in the complete medium with the ammonium ion could not be demonstrated.
COMPARATIVE IMMUNOLOGY OF THE ALGAL GENERA TETRACYSTIS AND CHLOROCOCCUM1
Authors: Brown R. Malcolm , Lester Richard N. 
Published: April 2007

SUMMARY Antigens of algae in the genera Tetracystis and Chlorococcum have been studied extensively by immunodiffusion techniques. Some antigens were species‐, group‐, or genus‐specific; others were common to both genera. The results largely supported other data from morphology, physiology, and ultrastructure but indicated a probable error in the taxonomic placement of one species. The cross reactivity between genera may be of importance in human inhalant allergy to algae.
HETEROTROPHIC GROWTH OF SELECTED WASTE‐STABILIZATION POND ALGAE1
Authors: Wiedeman Varley E. , Bold Harold C. 
Published: April 2007

SUMMARY Growth of 39 axenic algal isolates from the Austin, Texas, waste‐stabilization pond system and the Colorado River, aerobically and with air excluded, in light and in darkness in a basal inorganic medium supplemented with glucose, mannose, fructose, urea, sodium acetate, casein hydrolysate, and coconut milk, could be classified in 5 categories: (1) inhibition by certain carbon compounds; (2) growth aerobically in light only; (3) growth in light only, either aerobically or with air excluded; (4) growth in light aerobically or with air excluded and in the dark aerobically; and (5) growth in light or darkness, aerobically or with air excluded. Apparently, under conditions of air exclusion or darkness, growth of certain algae can continue provided that the proper organic compounds are present to act as a carbon source and if the algae have the enzymes to metabolize them. In addition, the algae which can metabolize such organic sources are, in effect, able to carry out processes usually associated with the bacteria in sewage treatment in waste‐stabilization ponds. It is suggested that autochthonous development of algae under such conditions may be partially instrumental in “bloom” formation.
TROPICAL MARINE ALGAE: GROWTH IN LABORATORY CULTURE
Authors: Colinvaux Llewellya Hillis , Wilbur Karl M. , Watabe Norimitsu 
Published: April 2007

SUMMARY Mature tropical marine algae were transplanted from Jamaica, Bermuda, and Florida to aquaria at Duke University, North Carolina and The Queen's University of Belfast, Northern Ireland. Genera cultured included: Caulerpa, Halimeda, Penicillus, Udo‐tea, Acetabularia, Batophora, Cymopolia, Dictyosphaeria, Neomeris, and Valonia. Methods of transport and culture are described. The use of adult plants was convenient, as well as essential for those genera and species in which spore or gamete stages are as yet unknown. Since only small amounts of seawater were needed for maintenance of the cultures, studies on these livinng marine algae can be made at institutes far from the sea. The growth of new segments and young plants of Halimeda, Penicillus, and Udotea are described as well as gametangial development, aging and decay in Halimeda. Sequential photographs of Penicillus and Halimeda show development from the time the plants first appeared above the sand to relative maturity. Changes in morphology after a few months’culture are also described.
THOREA RIEKEI SP. NOV. AND RELATED SPECIES1
Authors: Bischoff Harry W. 
Published: April 2007

SUMMARY The morphology and ontogeny of Thorea riekei sp. nov. from a spring‐fed stream in Landa Park, New Braunfels, Texas, are described. The organism was isolated into unialgal culture and grown through its complete life history, stages of which are illustrated by photomicrographs. Comparative studies were made of herbarium specimens of Thorea species from several United States herbaria. A review of the taxonomic literature on the genus Thorea revealed a considerable number of inaccurate and doubtful determinations of herbarium specimens. A brief study of the ultrastructure of T. riekei is included.
AN ULTRASTRUCTURE STUDY OF SPIROGYRA
Authors: Dawes Clinton J. 
Published: April 2007

SUMMARY The fine structure of three species of Spirogyra is presented, utilizing bright field, polarized light, and electron microscopes; x‐ray diffraction; and autoradiographic techniques. The birefringent filament wall consists of an outer amorphous layer covering Cellulose I microfibrils in a multinet growth pattern. Vegetative cytoplasmic fine structure is typical of the Chlorophyta with the exception of karyoids which are described. Autoradiography indicated spots on the conjugating filament walls corresponding to developing conjugation papillae. Conjugation tubes possess a cell wall of microfibrils in a reticulate pattern. During conjugation removal of papillae cross walls was observed. This wall breakdown appears to be controlled by vesicles released from the cytoplasm.
ELECTRON MICROSCOPIC STUDY OF HETEROCYST DEVELOPMENT IN ANABAENA AZOLLAE STRASBURGER1
Authors: Lang Norma J. 
Published: April 2007

SUMMARY Various stages of heterocyst development in Anabaena azollae growing within Azolla filiculoides were viewed with an electron microscope. Developing heterocysts undergo marked internal and external reorganization which cannot be detected with light microscopy. The proposed sequence of developmental stages includes: (1) formation of a thick, two‐layered envelope; (2) contortion of photosynthetic lamellae; (3) loss of granular inclusions and possible loss of or change in nucleoplasms material; and (4) concentration of photosynthetic lamellae toward the poles. These findings are compared with those reported by Wildon and Mercer in 1963.
A CULTURAL STUDY OF SEXUALITY IN SIROGONIUM MELANOSPORUM
Authors: Hoshaw Robert W. 
Published: April 2007

SUMMARY The chlorophytan alga, Sirogonium melanosporum, is a member of the Zygnemataceae and superficially resembles certain species of Spirogyra. Clonal cultures of S. melanosporum were isolated from a natural collection obtained near Guaymas, Mexico. In Pringshei?n's soil‐water medium with a light intensity of 3,500 lux at 22 ± 2 C, cultures of the alga produce a netlike growth which results from the genuflexion of filaments and the onset of the sexual process. The clones studied are homothallic with a totally anisogamous mode of reproduction. The major events of the sexual cycle, including gametangial development, gametic formation, syngamy, and the germination of zygospores, were observed for S. melanosporum and compared with an early account of sexual reproduction in S. sticticum.
DETECTION OF BRISTLES IN SCENEDESMUS SPECIES1
Authors: Trainor Francis R. , Burg Carol Ann 
Published: April 2007

SUMMARY Numerous long and delicate appendages, called bristles, have been detected on several species and strains of Scenedesmus. There are frequently over 100 such processes per coenobium. They are more commonly observed on the spine‐bearing species and are found on coenobia resembling S. quadricauda both in nature and in culture. Only a few S. obliquus cultures have shown these processes. Because they are much more delicate than spines, and because they are removed when coenobia are brought through an alcohol series, the bristles have been observed rarely in the past. A procedure for the detection of the appendages is presented.
A NEW CHLOROSARCINOPSIS FROM THE NEGEV DESERT
Authors: Friedmann I , Ocampo‐Paus Roseli 
Published: April 2007

SUMMARYChlorosarcinopsis negevensis n. sp. f. negevensis and Chi. negevensis f. ferruginea n. f. have been isolated in culture from a desert locality in the Negev. The organisms form regular 3‐dimensional cell packets. Pseudofilamentous groups or a gelatinous matrix are absent. Reserve material is an orange‐colored oil formed in quantities. In old cultures, palmelloid stages appear. Reproduction is by zoospores, autospores, and isogametes. The sensitivity pattern of Chi. negevensis to inhibitory agents differs from that of the other species of the genus.
MATING TYPES OF CHLAMYDOMONAS FROM THE COLLECTION OF GILBERT M. SMITH
Authors: Hoshaw Robert W. 
Published: April 2007

SUMMARY After the death of Dr. Gilbert M. Smith on July 11, 1959, the strains of Chlamydomonas maintained in his collection were sent to the Culture Collection of Algae at Indiana University. Axenic cultures of 29 strains were investigated to determine the nature of their sexual behavior. Mating types for 6 species (C. elliptica var. britannica, C. frankii, C. minutissima, C. moewusii f. microstigmata, C. reinhardtii, C. smithii) produced zygotes when agar cultures were harvested with sterile distilled water or low nitrogen medium and the complementary mating types for each species were mixed. Three species, C. moewusii f. microstigmata, C. reinhardtii, and C. smithii, produced sufficient zygotes to be of value in experimental work. C. smithii is an undescribed species interfertile with C. reinhardtii. The description of C. smithii will be published in a separate paper. Fourteen mating types of Chlamydomonas originally isolated and maintained by Smith are now maintained in the Culture Collection.
PHOTOINDUCTION AND PHOTOREVERSAL OF THE NOSTOCACEAN DEVELOPMENTAL CYCLE1
Authors: Lazaroff Norman 
Published: April 2007

SUMMARY The developmental cycle of Nostoc muscorum, a nitrogen‐fixing blue‐green alga, is controlled by the spectral quality of illumination. Red light with peak activity at 650 mμ induces development of filaments from a nonfilamentous (aseriate) stage of the life cycle. Red‐light photoinduction is reversed by simultaneous or subsequent exposure to light from a broad band in the green region of the spectrum. Photo‐reversibility of the red‐light induction, by green light, decays very slowly, remaining at an appreciable level for over 24 hr after the primary stimulus. Allophycocyanin is indicated to be the photoreceptor for red‐light induction. One or more phyco‐erythrins may operate as photoreceptors for reversal of induction. The dosage response and wavelength dependence of developmental photocontrol in Nostoc muscorum A indicate that a nonphotosynthetic mechanism is involved in both developmental photoinduction and its photor ever sal.
HETEROTROPHY OF FOUR MARINE PHYTOPLANKTERS AT LOW SUBSTRATE CONCENTRATIONS1
Authors: Sloan P. R. , Strickland J. D. H. 
Published: April 2007

SUMMARY Three pelagic marine phytoplankters, Coccolithus huxleyi, Skeletonema costatum, and Thalassiosira ro‐tula, and a facultative heterotroph, Cyclotella cryp‐tica, have been exposed to three organic substrates, viz, glucose, acetate, and glutamate, at low concentrations (organic carbon 0.25 mg/liter). Experiments were performed in the dark and light and the net assimilation of substrate was measured by using radiocarbon. The dark uptake of carbon dioxide was also determined, together with photosynthesis at near optimum light intensity. The expected heterotrophy was detected with Cyclotella cryptica. Thalassiosira rotula was found to assimilate glutamate at an appreciable rate. In all cases, however, the short‐term uptake of carbon dioxide in the dark was the greatest assimilation rate measured. Values are discussed in relation to their ecological significance and it is concluded that heterotrophic survival of these and probably most other algae in the open ocean xuould be impossible unless they were in contact with a high concentration of substrate in the form of particulate matter.
PARASITISM OF ASTERIONELLA FORMOSA HASS. BY A CHYTRID IN TWO LAKES OF THE RAWAH WILD AREA OF COLORADO1
Authors: Koob Derry D. 
Published: April 2007

SUMMARY The populations of Asterionella formosa Hass. in two subalpine lakes in the Rawah Wild Area, Colorado, were composed of colonies of five distinct size classes based on frustule length. The spring bloom in these two lakes was dominated by cells of the Beta or Gamma population, whereas the fall pulse was dominated by cells of the Alpha and Beta, or Alpha populations. The Beta population was physiologically unique in that it was parasitized by the chytrid Rhizophidium planktonicum Canter. The development of the parasite population could not be correlated with the concentration or the growth phase of the host population. The occurrrence of parasitism did not noticeiceably affect the population growth patterns of the Asterionella populations.
A POPULATION OF STAURASTRUM FREEMANII FROM THE CENTRAL HIGHLANDS OF NEW GUINEA
Authors: Brook A. J. , Hine A. E. 
Published: April 2007

SUMMARY An abundant gathering of the desmid Staurastrum freemanii has been collected from a pond located in the highlands of New Guinea. This material shows considerable polymorphism and contains a number of significant dichotypic forms. Examination of this material questions the validity of the varietal rank conferred by earlier investigators to many of the forms of this species. Consequently, a taxonomic revision of these varieties is proposed.
STUDIES ON THE BIOCHEMISTRY AND FINE STRUCTURE OF SILICA SHELL FORMATION IN DIATOMS. II. THE STRUCTURE OF THE CELL WALL OF NAVICULA PELLICULOSA (BRÉB.) HILSE
Authors: Reimann Bernhard E. F. , Leivin Joyce C. , Volcani Benjamin E. 
Published: April 2007

SUMMARY The cell wall of the freshwater diatom Navicula pelliculosa (Bréb.) Hilse is composed of the silica shell and an organic skin which surrounds it. Isolated skins can be prepared by first removing the contents of the cell by mechanical shaking, followed by a posttreatment of these isolated cell walls with HF vapor to remove the silica shell. T h e skins can also be seen in sections, particularly well after the silica shell has been removed B y H. F; vapor. The origin and morphological composition of the shin in N. pelliculosa are not yet completely ascertaincd. As parts of the cell wn11, both the silica shell and the skin are extracellularly located. The growth of the silica shell, however, occurs intracellularly inside a vesicle delimited by a triple‐layered membrane, the silicalemma. This membrane or secondary excreted organic material or both in various proportions may compose the skin.
ECOLOGY AND MORPHOLOGY OF TYDEMANIA EXPEDITIONS, A TROPICAL DEEP‐WATER SIPHONOUS GREEN ALGA1
Authors: Gilmartin Malvern 
Published: April 2007

SUMMARY The morphological relationship between the glomeriferous and flabelloid aspects of Tydemania expeditionis, a rarely collected siphonous green algae, is presented and discussed in relation to the ecological niche it occupies and the phylogenic position of the genus within the Codiaceae. Using SCUBA techniques, the alga was observed and extensively collected at depths in the 40‐65‐m range. It is suggested that seasonal mean in situ light intensities exceeding 0.03 g cal/cm2/min inhibit the development of dense stands of the alga, and that Tydemania is a primitive member of the Codiaceae.
DEVELOPMENT OF THE SYMBIOSIS OF CONVOLUTA ROSCOFFENSIS GRAFF AND PLATYMONAS SP.1
Authors: Oschman James L. 
Published: April 2007

SUMMARY The acoel flatworm Convoluta roscoffensis is infected by the alga Platymonas sp. The ova and young Convoluta do not contain algae, and each generation must be reinfected. The infecting algae undergo morphological alterations when within the worm. Flagella, theca, and eyespot are lost in that order. Flagellar basal bodies and striated rootlets remain. Loss of theca may be the result of a dissolution process, possibly the result of enzymes from the animal or from the algae. Upon loss of theca, the alga assumes an irregularly shaped form. Fingerlike processes of the algal cells penetrate between adjacent animal cells. This form is present in all but the earliest stages of infection, and may be a prerequisite for the establishment of a balanced photosynthetic mutualism.
CARBON DIOXIDE‐INDUCED DELAY OF CELLULAR DEVELOPMENT IN TWO CHLORELLA SPECIES1
Authors: Soeder Carl J. , Strotmann Heinrich , Galloxvay Raymond A. 
Published: April 2007

SUMMARY Two species of Chlorella, C. fusca and C. vannielii, manifest delay in cell development in synchronous cultures when gassed with air enriched with 1.5% vol. C02 or higher. This effect is greater if the final developmental steps proceed in the light rather than in the dark. Despite this, as much as 5% vol. CO2 does not decrease the production of dry matter in continuous light. It is not unlikely that this action of CO2 is restricted to cases in which nitrate serves as the only N source.
SENSITIVITY OF MICROCYSTIS AERUGINOSA AND OTHER BLUE‐GREEN ALGAE AND ASSOCIATED BACTERIA TO SELECTED ANTIBIOTICS1
Authors: Vance B. Divain 
Published: April 2007

SUMMARY Sensitivity of 5 blue‐green algae, especially Microcystis aeruginosa, and associated bacteria to 32 antibiotics was determined. A combination of neomycin and dihydrostrcptomycin was the most useful in inhibiting bacterial growth while allowing some algal growth. An axenic culture of M. aeruginosa maintainable for an extended time was not obtained. This and other studies indicate that a blue‐green chroococcalcan culture should not be reported to be bacteria‐free unless repeated rigorous tests for bacteria prove negative.
ANTIALGAL ACTIVITY OF SOME SIMPLE PHENOLS1
Authors: McLachlan J. , Craigie J. S. 
Published: April 2007

SUMMARY The antialgal activity of a number of simple phenols was examined for their effect on the growth of 7 species of unicellular marine algae. The 3 knoiun algal phenols, 5‐bromo‐3,4‐dihydroxybenzaldehyde; 2,3‐dibromo‐4,5‐dihydroxybenzylalcohol, and 3,4‐dihy‐droxyphenylethylamine, were highly toxic as were other ortho dihydroxy compounds. Monohydroxy compounds were notably less toxic. Skeletonema costatum and Olisthodiscus sp. were the most sensitive organisms examined and Dunaliella tertiolecta was the most resistant. Possible ecological implications of these results are discussed.
LIGHT MICROSCOPE OBSERVATIONS ON CYTOLOGICAL MANIFESTATIONS OF NITRATE, PHOSPHATE, AND SILICATE DEFICIENCY IN FOUR MARINE CENTRIC DIATOMS
Authors: Holmes Robert W. 
Published: April 2007

SUMMARY Cytological changes induced by nitrate or phosphate limitation were reproducible and readily visible by phase contrast microscopy in Coscinodiscus wailesii, Ditylum brightwellii, Rhizosolenia hebetata f. semi‐spina, Skeletonema costatum, and Stephanopyxis turris. These effects included changes in chromatophore number and shape, pyrenoid location, and mitochondrial abundance and appearance. In S. costatum, a diatom containing only 1 chromatophore, only nitrogen‐deficient cells could be recognized. Silicate deficiency prevented cell division almost entirely. When a few cells did divide in the presence of low silicate, abnormalities in valve structure occurred in some cells. Cytological differences with N and P deficiency may permit a rough assessment of the physiological condition of the same or similar species in natural diatom communities.