bluuebunny/crossref_metadata_2025_split huggingface dataset:
PERIDINIUM PENARDII (LEMM.) LEMM. FO. CALIFORNICUM, FORMA NOVA1
Authors: Javornický Pavel 
Published: August 2007

SUMMARYA new forma of Peridinium penardii (Lemm.) Lemm. (Dinophyceae) is described from Clear Lake, California, based upon the morphology of a theca. The forma californicum Javorn. is believed to be a connecting link between P. penardii and P. berolinense Lemm. A nomenclatural survey of the species, as well as a key to its formae, are given.
RESULTS OF AN ATTEMPT TO OBTAIN PYRENOIDS OF ZYGNEMA BY BULK‐ISOLATION METHODS1,2
Authors: Rosowski James R. , Hoshaw Robert W. 
Published: August 2007

SUMMARYFilaments of Zygnema were blended 3 min in a buffered sucrose solution, and a pyrenoid‐rich cell fraction was obtained by filtration through a 10‐μ filter. The filtrate was placed on a 35%/40%/50% (wt/wt) discontinuous sucrose density gradient and was spun at approximately 50,000 × g for 1/2–1 hr. Pyrenoids, which were collected at the 40%/50% interface, appeared with light microscopy to be firm, intact, spherical, colorless refractive bodies. Although in situ pyrenoids stained with propionocarmine, isolated pyrenoids would not stain, indicating a change in the chemical properties of pyrenoids during the isolation procedure.
EFFECTS OF SOME PROTEIN AND NUCLEIC ACID SYNTHESIS INHIBITORS ON FERTILIZATION IN VOLVOX CARTERI1
Authors: Hutt William , Kochert Gary 
Published: August 2007

SUMMARYThe fertilization process in Volvox involves a series of events described as follows. A sperm bundle produced by the male colony attaches to the female colony. The bundle then dissociates to a cluster of individual sperm prior to formation of a fertilization pore in the sheath of the female colony. Sperm subsequently enter the matrix of the female colony and presumably fertilize the eggs.The protein synthesis inhibitors cycloheximide, chloramphenicol, and puromycin each, blocked fertilization pore formation. The nucleic acid synthesis inhibitors actinomycin D and 5‐fluorouracil were also tested. Actinomycin D completely blocked fertilization pore formation, whereas 5‐fluorouracil appeared to have no effect. A proposed mechanism of fertilization pore formation is discussed.
YELLOW‐GREEN ALGAE WITH CHLOROPHYLLIDE C1,2
Authors: Guillard Robert R. L. , Lorenzen Carl J. 
Published: August 2007

SUMMARYChlorophyllide c (chlorophyll c) wax found in axenic or unialgal cultures of 5 members of the class Xanthophyceae and in 2 members of the class Raphidophyceae (Chloromonadophyceae).Two other algae contained no chl c; neither had chl b. One of these plants, Pleurochloris magna, is presumably a member of the newly named class Eustigmatophyceae (Hibberd and Leedale). The other alga, clone GSB Sticho, is of uncertain, systematic position.Although, the xanthophyll pigments were not critically studied, there is enough evidence, to permit the conclusion that the xanthophyll suites of the chloromonads, the xanthophytes, P. magna, and clone GSB Sticho all differ in at least one respect.
RETENTION OF DISSOLVED COMPOUNDS BY MEMBRANE FILTERS AS AN ERROR IN THE 14C METHOD OF PRIMARY PRODUCTION MEASUREMENT1
Authors: Nalewajko C. , Lean D. R. S. 
Published: August 2007

SUMMARYMembrane filters retain 14C bicarbonate, 14C glycollate, and other 14C labeled substances from filtrates of algal cultures and lake water. By refiltering different volumes of the filtrate from algal cultures and from lake water after incubation with 14C bicarbonate, it was shown that the labeled material retained was not proportional to volume but showed a saturation effect with increasing volume filtered. When the radioactivity retained by a filter is divided by the volume filtered, decreasing values are obtained with increased volume filtered. This radioactivity may represent a significant addition to the radioactivity in particulate material on the filters, resulting in a similar type of curve when different volumes of lake water or cultures are filtered.Values of radioactivity per milliliter were constant using Chlorella in Chu 10 medium. However, the curve could, be obtained by increasing pH and bicarbonate concentrations in the medium and on resuspending the algae in Lake Ontario (winter) filtrate. The values of cpm/ml retained from filtrates were low in Cryptomonas cultures and the curve was not obtained unless population density was reduced, thus increasing the relative contribution to the radioactivity on the filters.The curve was not always obtained in lake water. It was significant in 10 out of 14 experiments in Lake Ontario and in 2 out of 5 experiments in Grenadier Pond. Changes in lake water rather than in experimental techniques were probably responsible. On 2 occasions when values of cpm/ml were constant in Lake Ontario, addition of sodium bicarbonate without a pH change resulted, in a significant curve.Our experiments do not disprove the possibility of cell damage during Millipore filtration, however, it has been shown that 14C labeled substances retained from solutions can account for the entire range of decreasing values as a function of volume filtered.
A POSSIBLE VIRUS INFECTION IN THE GREEN ALGA OEDOGONIUM1
Authors: Pickett‐Heaps J. D. 
Published: August 2007

SUMMARYDeveloping germlings of the green alga Oedogonium have been sectioned and some were found to contain particles presumed to be those of a virus. Fully formed particles were hexagonal in a 2‐dimensional section, about 240 nm in diameter with a densely stained surface layer and core; what appear to be different stages in their assembly were also seen. Many of the particles were clustered together in groups surrounded by aggregations of ribosomes. In cells containing many of the particles, the germlings' cytoplasm and organelles showed considerable evidence of disruption and breakdown. These particles have only been detected in germlings, so infection by this presumed virus was probably initiated in the naked, motile zoospore.
ORGANIC EXCRETION BY DUNALIELLA TERTIOLECTA1
Authors: Huntsman Susan A. 
Published: August 2007

SUMMARYExcretion of C14‐labeled organic material by Dunaliella tertiolecta was observed under a variety of conditions. In healthy cultures, percent excretion tints related to cell density bill independent of light and preconditioning of the medium. Exaction was lower in nutrient‐limited culture than in an enriched medium, and in both cases was minimal during logarithmic growth. Increases in dissolved carbohydrate during stationary phase represented an accumulation of high molecular weight compounds.The general composition of labeled excretory products was similar in both actively growing and stationary cultures. The data suggest that excretion may involve different processes at high and low cell densities.
AMINO ACID TRANSPORT IN NITZSCHIA OVALIS ARNOTT1,2
Authors: North Barbara B. , Stephens Grover C. 
Published: August 2007

SUMMARYThe marine diatom Nitzschia ovalis possesses at, least 3 amino acid uptake systems, specific for transport of acidic, polybasic, and, neutral amino acids. Maximum uptake velocity (Vmax) for each, site is inversely related to the nitrogen content of the cell, and to the nitrogen available in the culture medium. Transport, of polybasic amino acids occurs throughout the course of growth in batch, culture, but the Vmax increases dramatically as the culture ages and nitrogen/cell reaches a low value. Ks does not, change significantly. Acidic and neutral amino acids are taken up only by cells harvested from nitrogen‐poor culture. It appears that amino acid transport is repressed by high concentrations of nitrogen in the medium. Under natural conditions, where nitrogen concentrations are low, the contribution of amino acid uptake to the nitrogen economy of Nitzschia populations may be significant.
RADIOISOTOPIC STUDY OF CALCIFICATION IN THE ARTICULATED CORALLINE ALCA BOSSIELLA ORBIGNIANA1
Authors: Pearse Vicki Buchsbawn 
Published: August 2007

SUMMARYCalcification in Bossiella orbigniana (Corallinaceae) is characterized by a series of features which, vary according to the age of the segment (intergeniculum). From the youngest segment at the branch tip to older, more basal segments: (1) weight and degree of mineralization increase, while rate of weight gain decreases; (2) rate and stability of calcium‐45 labeling decrease; (3) effect of light on calcium‐45 labeling rate decreases, while effect of light on stability of label increases; however, for all segments, calcium‐45 labeling is more rapid and more stable in the light than in the dark; (4) rate of calcium‐45 labeling in killed controls decreases. Comparative studies with the tropical coralline alga Amphiroa yielded similar results. Characteristics of the gradients in calcification and effect of light in these coralline algae are very similar to those found, in a reef‐building coral containing symbiotic algae, and the data suggest that organic products of photosynthesis may be of general importance to calcification.
THE PRODUCTION OF EXTRACELLULAR POLYSACCHARIDE BY THE UNICELLULAR RED ALGAPORPHYRIDIUM AERUGINEUM1,2
Authors: Ramus J. 
Published: August 2007

SUMMARYThe unicellular red algaPorphyridium aerugineumwas shown to be encapsulated by an amorphous, water‐soluble, polyanionic polysaccharide of high molecular weight. The encapsulating polysaccharide is qualitatively identical with polysaccharide found dissolved in large quantity in the culture medium. The kinetics of extracellular polysaccharide production as a function of cell age was studied. Rates of production (on a per cell basis) of both encapsulating and dissolved polysaccharides are greatest in stationary phase light‐grown cultures.Dissolved polysaccharide was quantitatively isolated by precipitation with cetyl pyridinium chloride, conversion to the calcium salt, and reprecipitation with ethanol. The procedure yields a spectrally pure product, which is composed of glucose, galactose, xylose, and 2 undetermined, sugar components, and has a sulfate content of 7.6% by weight.Electron microscopy ofPorphyridiumrevealed that Golgi vesicles transport, polymerized polysaccharides to and through the cell membrane. Similar vesicles were observed in the multicellularPseudogloiophloea, indicating that the Golgi complex plays a crucial role in the production of extracellular polysaccharides by the red algae.H14CO3‐pulse‐label experiments resulted in labeled extracellular polysaccharide in which all the constituent components contained14C. Rates of excretion of polysaccharide were found, to follow a cyclic pattern, correlated generally with the division cycle, of the cell.
ERUMPENT CEPHALODIA, AN APPARENT CASE OF PHYCOBIAL INFLUENCE ON LICHEN MORPHOLOGY1,2,3
Authors: Jordan William Paul 
Published: August 2007

SUMMARYOn the upper surface of some specimens of the lichen Lobaria cf. crosa (Eschw.) Nyl. there are shrub‐like growths which have a morphology similar to that of a free‐living fruticose lichen, Polychidium umhausense (Auersw.) Henss., and contain a cyanophyte phycobiont, Nostoc. A few growths also contain scattered colonies of a chlorophyte phycobiont, in which case the lichen tissue locally assumes the foliose form characteristic of the parent Lobaria thallus. The differentiation of dorsiventral lichen cortices and the formation of a lax medulla and distinct algal layer are correlated with the presence of the green phycobiont. The lichen substances atranorin, gyrophoric acid, and 4‐0‐methylgyrophoric acid occur in both, the foliose L. erosa thallus and the fruticose tissue. It is suggested that the fruticose structures are erumpent cephalodia which are derived from the outgrowth of internal, cephalodia and should not be considered, to be epiphytic colonies of the lichen Polychidium.
FIVE NEW SPECIES OF CHLAMYDOMONAS1,2
Authors: King Joe M. 
Published: August 2007

SUMMARYFive new species of Chlamydomonas, C. isabeliensis, C. pallidostigmatica, C. fottii, C. pseudomicrosphaera, and C. texensis are described. Supplementary attributes of these organisms are considered as possible taxonomic aids.
DICHOTOMOSIPHON IN FLORIDA SPRINGS1
Authors: Davis J. S. , Gworek W. F. 
Published: August 2007

SUMMARY Dichotomosiphon tuberosus occurs abundantly in the outflows, pools, and streams of at least 5 hard, freshwater springs of north central Florida. This tubular alga produces extensive bright green mats which harbor epiphytes, unicellular algae, ciliates, and amphipods. Within the spring, most tubes remain in the vegetative condition. After 12–15 days under certain laboratory conditions, the tubes produce highly characteristic, sex organs and akinetes.
THE BIOCHEMICAL ANALYSIS OF SOME ESTUARINE PHYTOPLANKTON SPECIES. I. FATTY ACID COMPOSITION12
Authors: DeMort Carole L. , Lowry Robert , Tinsley Ian , Phinney H. K. 
Published: August 2007

SUMMARYThe fatty acid composition of 10 species of estuarine phytoplankton was determined using gas‐liquid chromatography. Nine of the species were isolated from Yaquina Bay, Oregon. These species were common components of the phytoplankton of the bay. The tenth species, Isochrysis galbana, was obtained from the Culture Collection of Algae at Indiana University. The 10 organisms comprised 3 species of Chlorophyta, 1 species of Cryptophyta, and 6 species of Chrysophyta.Twenty‐eight fatty acids were found in the 10 species. The fatty acids common to all species were 14:0, 16:0, 16:1, 13:0, 18:1, and 18:2. The Chlorophyta were distinguished by a high content of linolenic acid, 18:3. The diatoms were distinguished by very low amounts of C18 acids and high proportion of 20:5. All species contained a high proportion of palmitic acid, 16:0.
THE UPTAKE OF UREA BY MARINE PHYTOPLANKTON1
Authors: McCarthy James J. 
Published: August 2007

SUMMARYHalf‐saturation constants for urea uptake by 4 clones of neritic diatoms capable of utilizing urea were determined from short‐term uptake studies with15N‐labeled urea.K8values obtained were similar to those determined, earlier for ammonium, and since ammonium and urea concentrations are similar in the marine environment, it was concluded that these species are capable of utilizing ecologically significant concentrations of urea. Two of 3 species unable to grow on urea showed patterns of short‐term uptake not unlike those of species capable of utilizing urea, which implies that, their assimilatory rather than uptake processes are defective with, regard to urea utilization. The third species initially took15N (supplied as urea) into the cells but subsequently released it back into the medium.
SOME OBSERVATIONS ON COLONIES AND ULTRASTRUCTURE OF THE FRUSTULE OF COENOBIODISCUS MURIFORMIS AND ITS TRANSFER TO PLANKTONIELLA1
Authors: Round F. E. 
Published: August 2007

SUMMARYThe marine planktonic diatom Coenobiodiscus muriformis has been reinvestigated using light microscopy and scanning and transmission electron microscopy; as a result it is proposed, to transfer the species to the genus Planktoniella. The structure and formation of colonies are discussed and compared with data from an earlier study. Further details of valve and girdle baud structure have been ascertained and the exact form of the central and peripheral tubes has been described. The relationship of the present taxon to Thalassiosira and Coscinodiscus is discussed.
POLYMORPHISM IN THE DESMID MICRASTERIAS LATICEPS AND ITS TAXONOMICAL IMPLICATIONS1
Authors: de Mattos Bicudo Carlos Eduardo , Sormus Laine 
Published: August 2007

SUMMARYThis paper refers to a case of polymorphism in the desmid Micrasterias laticeps Nordst. It is based on material collected from an artificial pond in the state of São Paulo, Brazil.A detailed examination of almost 400 specimens permitted the authors to give a detailed description of 13 main morphological forms of the alga and allowed them to draw the following conclusions: (1) For delimitation of genera and infrageneric taxa in desmids it is often necessary to examine sample populations; (2) the morphological characteristics presently used for delimitation of varieties in M. laticeps Nordst. seem to have no considerable taxonomic significance if isolated individuals are studied; (3) it is necessary to take into consideration Cosmarium arthrodesmiforme Borge and C. arthrodesmiforme var. latius Krieg. & Gerl., as well as M. laticeps Nordst. var. ampliata Krieg., when further studies are undertaken, because they may prove to be merely distinct morphological expressions of M. laticeps Nordst var. laticeps.
THE ULTRASTRUCTURE AND MORPHOLOGICAL VARIABILITY OF THE FRUSTULE OF STEPHANODISCUS INVISITATUS HOHN AND HELLERMAN1
Authors: Lowe Rex L. , Crang Richard E. 
Published: August 2007

SUMMARY Stephanodscus invisitatus Hohn and Hellerman, studied by means of light, transmission, and scanning electron microscopy, shows a range of frustule diameters from 6.4 to 13.3 μ. Variation in valve ornamentation can be correlated with specimen diameter. The striae number ranges from 16 to 20 in 10 μ. Various processes difficult to observe by light microscopy alone are described which arise from the inside and outside of the frustules.2
NITROGEN METABOLISM OF AQUATIC ORGANISMS. II. THE ASSIMILATION OF NITRATE, NITRITE, AND AMMONIA BYBIDDULPHIA AURITA1
Authors: Lui Nan S. T. , Roels Oswald A. 
Published: August 2007

SUMMARYBiddulphia aurita, a centric diatom, can grow on either nitrate, nitrite, or ammonia as its sole nitrogen, source.Cells remove ammonium nitrogen from the medium 2.3–2.4 times faster than either nitrate or nitrite nitrogen and, when grown for 24 hr in the ammonium medium, contain higher levels of non‐protein nitrogen than cells grown in the nitrate or nitrite medium for the same period of time.The nitrogenous compounds in the nonprotein nitrogen fraction from cells grown in the nitrate, nitrite, or ammonium medium contain the same level of soluble‐free amino nitrogen, combined amino nitrogen, and ammonium nitrogen. The high level of soluble nonprotein nitrogen in the medium of the cells grown in the ammonium medium is due to soluble amide nitrogen which represents 18% of the total soluble nitrogen present in these cells, whereas it represents only 2% in cells from the nitrite medium, and its level is negligible in cells from the nitrate medium.Cells grown in the nitrate medium have both nitrate‐ and nitrite‐reductase activity. Cells grown in the nitrite medium have only nitrite‐reductase activity in significant levels, while cells grown in the ammonium medium lack both enzymes.
DNA‐BINDING PROTEIN AND THE CELL CYCLE INCRYPTOTHECODINIUM COHNII.I. ON THE RESOLUTION OF METABOLICALLY STABLE COMPONENTS1
Authors: Franker Colin K. 
Published: August 2007

SUMMARYA soluble protein extract, obtained after35S labeling exponential cultures ofCryptothecodinium cohniifor 4–5 generations, was fractionated on DNA‐cellulose. The protein eluted at high salt concentrations from this homologous DNA‐containing matrix was then separated, by chromatography on BioGel P150 and P200 sieve gels. Two prominent chromatographic species of 22,000 and 35,000 daltons plus a substantial amount of material in the molecular weight range of 80,000–140,000 were resolved. The application of this analytical procedure to the study of transcriptional control in the cell cycle is discussed.
RESPONSE OF CHLORELLA PYRENOIDOSA TO ALUMINUM AND LOW pH12
Authors: Foy C. D. , Gerloff G. C. 
Published: August 2007

SUMMARY Chlorella pyrenoidosa, a green alga which has no measurable Ca requirement, tolerated much higher Al concentrations in solution than higher plants which require considerable Ca. This alga also gave significant positive yield responses to Al concentrations between 1.5 and 12 ppm (added at pH 4.6). The positive Al response was not attributable to V, Cr, Ni, Co, W, or Ti contaminants in the Al salt.A strain of C. pyrenoidosa having even greater Al tolerance was isolated, by subjecting the original Strain I (Fitzgerald) culture to increasing Al stress. This strain, I‐Al, grew in stagnant cultures containing 48 ppm Al at an initial pH of 4.2. Its yield also was not significantly decreased by 48 ppm Al in aerated cultures when both inoculum and solution pH were 4.6. Under the same conditions the original Strain I organism was injured by 3 and 6 ppm Al and was killed by 12 ppm.Algal strains which differ in Al tolerance may be useful in (1) studies on the mechanism of Al toxicity and mineral nutrition in general; and (2) in raising the pH, precipitating Al, and thereby detoxifying Al‐containing acid mine drainage water and commercial wastes.
THALASSIOSIRA ECCENTRICA (EHRENB.) CLEVE, T. SYMMETRICA SP. NOV., AND SOME RELATED CENTRIC DIATOMS1
Authors: Fryxell Greta A. , Hasle Grethe R. 
Published: August 2007

SUMMARYExamination of original material from the Ehrenberg collection plus clonal cultures from the Gulf of Mexico and net hauls from widely separated stations in the world's oceans confirms that Coscinodiscus eccentricus is correctly placed as Thalassiosira eccentrica (Ehrenb.) Cleve. A closely related species, T. symmetrica, is described, with, the main differences being found in the value processes and distribution patterns. The former species is more abundant in inshore waters; the latter has been found in oceanic waters. Comparisons are drawn between these 2 species, T. mendiolana and Planktoniella sol.
THE RELATIONSHIP OF LIGHT, TEMPERATURE, AND CURRENT TO THE SEASONAL DISTRIBUTION OF BATRACHOSERMUM (RHODOPHYTA)12
Authors: Rider David E. , Wagner Richard H. 
Published: August 2007

SUMMARYObservations of the 2 growth sites and the laboratory experiments performed on B. vagum and B. moniliforme indicate that B. moniliforme is better suited to higher intensity illumination than is B. vagutn. B. vagnm was found growing year‐round in a dark‐water stream protected from high intensity light by the filtering effect of the bog‐dark water. B. moniliforme was found growing in a clear water stream. Without the protection of dark water, the B. moniliforme disintegrated under the high light intensities of summer. In the laboratory, B. moniliforme retained a healthy macroscopic condition over a full range of light‐intensity treatments; above 250 ft‐c B. vagum was increasingly distintegrated.Light intensity, however, was not the only factor regulating the growth, of Batrachospermum in the 2 growth sites. The pattern of growth of B. vagum in Sinking Creek varied with the depth of the water and, therefore, with the light intensity it received. However, it was found that where all Conditions were the same, the greatest percent cover of the algae was in the center of the stream where the current was the greatest. Thus it was found that within the limitations caused by water depth, current velocity can become limiting to the growth of B. vagum. Although the evidence for environmental factors affecting the growth of B. moniliforme in Smay's Run is less extensive, light intensity and current velocity in this site also appear to interact to control the growth pattern of the algae.
ULTRASTRUCTURE OF SPERMATIAL DEVELOPMENT IN THE PARASITIC RED ALGAE LEVRINGIELLA GARDNERI AND ERYTHROCYSTIS SACCATA12
Authors: Kugrens Paul , West John A. 
Published: August 2007

SUMMARYMorphologically, the development of spermatia in Levringiella gardneri and Erythrocystis saccata is identical, although cytologically several differences are evident. Mature spermatia contain 1 or 2 large spermatial vesicles that contain fibrous material, several small mitochondria, some proplastids, and are surrounded by a wall, either single‐layered as in Erythrocystis or triple‐layered as in Levringiella. Spermatial vesicles are formed by aggregations of endoplasmic reticulum in Levringiella, whereas concentric membrane bodies and dictyosomes may be involved in Erythrocystis. In addition to being fibrillar, the contents of the vesicle assume a convoluted appearance in Levringiella. Several spermatia are formed per mother cell and are connected by small pit connections which rupture to allow spermatial release from the spermatangial branch.