bluuebunny/crossref_metadata_2025 huggingface dataset:
INVESTIGATION OF A DIATOM POPULATION FROM MINE TAILINGS IN NYE COUNTY, NEVADA, U. S. A.1
Authors: VanLandingham S. L.
Published: April 2007

A diatom population consisting of 31 taxonomic entries was found in tailings from an abandoned mine near Ichthyosaur Paleontologic State Monument, Nye County, Nevada, U.S.A. The diatom population of the mine tailings resembled those found in dry lakes of the vicinity which are similar to some soil diatom populations. The mine tailings population was very similar to some Quaternary diatom assemblages in the vicinity and in other parts of the conterminous United States. The diatom population indicated that alkaline and oligohalobous conditions were prevalent with associated “indifference” with respect to the current spectrum.
CONTROL OF COLONY AND UNICELL FORMATION IN A SYNCHRONIZED SCENEDESMUS12
Authors: Trainor Francis R. , Rowland Helen L.
Published: April 2007

Colony formation in a synchronized Scenedesmus could be controlled by the addition of 0.05% Na3 citrate or 85 μM EDTA to modified Bristol's medium. No unicells were formed; only S. quadricauda‐like or S. longispina‐type colonies were observed in young cultures grown in that medium. A colony population could be made completely unicellular in 2 days if grown in soil‐Bristol's medium and transferred daily.

The pleomorphic Scenedesmus was examined in synchronized culture. When the organism was grown in a defined medium in a 15‐hr light /9‐hr dark cycle on a roller tube rotator at 2‐6 rpm and transferred daily, synchrony of cell division and release of the products were achieved. In a synchronized culture 2 doublings/day were recorded, with most cytoplasmic cleavages and all releasing of daughter cells taking place in the dark period. In many observations with several synchronized strains of Scenedesmus, no fixed pattern of release of daughter products from mother cells or colonies was detected. Colonies or unicells had their full spine complement at the time of release. As a cell or colony aged the spines sometimes increased in thickness.

Other Scenedesmus strains were examined to provide supporting data.
REPRODUCTION OF THE ARTICULATED CORALLINE AMPHIROA EPHEDRAEA1
Authors: Johansen H. William
Published: April 2007

Developmental events in the formation of reproductive structures in tetrasporangial, male, and female plants of Amphiroa ephedraea from South Africa were studied. An early step in the formation of a conceptacle is the elongation of a stratum of cortical cells, the cavity cells, to form a dome surmounted by an a cellular cap. Atrophy of the cavity cells to form a conceptacular cavity accompanies the subsequent development of reproductive structures. Tetrasporangial conceptacles differ from sexual conceptacles in that the reproductive cells develop in a peripheral ring and in the fact that the tissue lateral to these cells does not overgrow the fertile area. Finally, a comparison of some of the features of reproduction in A. ephedraea is made zuith. comparable features in other corallines.
SOME OBSERVATIONS ON THE VERTICAL MIGRATION OFDINOFLAGELLATES 12
Authors: Eppley R. W. , Holm‐Harisen O. , Strickland J. D. H.
Published: April 2007

The technique of measuring chlorophyll concentration in vivo by fluorometric analysis has been adapted to studying the diurnal migration of dino‐flagellates in the sea and also in a deep tank (3 m in diameter by 10 m deep).

The downward migration of Ceratium furca was followed during a bloom off the California coast. The main band of cells migrated from the upper 2 m to a depth of 5 m about 2 hr after sunset, and was dispersed between 5 and 16 m 4.5 hr after sunset.

Cultures of Gonyaulax polyedra and Cachonina niei both migrated to the surface of the deep lank during illumination and migrated downward during darkness at a rate of 1‐2 mjhr. The downward migration was observed to begin before the light was turned off, indicating that migration is correlated with a cellular periodicity which is to some extent independent of the light regime. Further evidence for such a periodicity was afforded by observations that C. niei start to migrate up in the water column before start of the light period.

Nitrogen‐limited cells of G. polyedra showed no diurnal migration, but within 1 day after addition of a nitrogen source they recovered their full migratory ability. Cells of C. niei, however, continued to migrate during 5 days of N‐starvation, although they did not concentrate in the upper 1/2 m as did the control cells.
SULFONAMIDE INHIBITION IN MONOCHRYSIS LUTHERP1
Authors: Ukeles Ravenna
Published: April 2007

The effect of sulfonamides on growth of the chry‐somonad, Monochrysis lutheri, in a synthetic sea‐water medium was examined over a period of 14 days. The population increased at all sulfonamide concentrations during the first several days of incubation before inhibition became apparent. Inhibitory concentrations ranged from 0.01 to 1.0 mg%. Inhibition luas most pronounced in sulfathiazole; sulfamethazine, sulfapyridine, and sulfanilamide followed in decreasing order. p‐Arninobenzoic acid (0.001‐1.0 mg%) competitively reversed inhibition. Folic acid, thymine, adenine, and vitamin B12 neither reversed the inhibition nor spared the requirement for p‐aminobenzoic acid. The significance of the inhibition pattern and the potential use of antimetabolites in the marine environment were discussed.
STRUCTURE AND REPRODUCTION OF NEOARDISSONEA KYLIN (RHODOPHYTA‐NACCARIACEAE)1
Authors: Womersley H. B. S. , Abbott Isabella A.
Published: April 2007

Neoardissonea naccarioides (J. Ag.) Kylin, the type and only species of its genus, is shown to be referable to Naccaria Endlicher, to which genus it is transferred as Naccaria naccarioides (J. Ag.) comb. nov.
TAXONOMIC CONFUSION CONCERNING CERTAIN FILAMENTOUS BLUE‐GREEN ALGAE1
Authors: Brock Thomas D.
Published: April 2007

Throughout a long history many filamentous bacteria may have been identified in natural collections as blue‐green algae. This problem has been especially acute regarding the thermophilic species of hot springs, especially at the higher temperatures. It is suggested that in the absence of pure cultures, the minimal criteria for distinguishing filamentous bacteria from blue‐green algae microscopically should be: (1) observation of the chlorophyll fluorescence with a fluorescent microscope and (2) demonstration of light‐dependent 14CO2 fixation autoradiographically. Pure cultures of a number of filamentous thermophiles have been obtained from habitats at temperatures above 60 C. These cultures resemble microscopically the natural material, grow only heterot rophically, and do not contain chlorophyll.
CHLOROPLAST DEVELOPMENT AND ULTRESTRUCTURE IN THE FRESHWATER RED ALGA BATRACHOSPERMUM1
Authors: Brown D. L. , Weier T. E.
Published: April 2007

Chloroplast development and ultrastructure of the freshwater red alga Batrachospermum moniliforme are described. Chloroplasts develop from proplastids which have a double‐membraned chloroplast envelope and a parallel double‐membraned outer photo‐synthetic lamella. Of these 2 double‐membraned structures of the proplastid, only the outermost pho‐tosynthetic lamella functions in production of further lamellae. The mature chloroplast consists of 2 or more concentric lamellae and a variable number of nonconcentric lamellae. These lamellae are not dense, uninterrupted sheets as described for other red algae, but are largely constructed of tubules, lying side by side, that form interrupted lamellar sheets. The possible physiological significance of lamellar interruptions in providing path‐ways for movement of materials in the chloroplast stroma is discussed.
XYLULOSE, AN ALGAL GROWTH INHIBITOR12
Authors: Wu Madeline , Alston Ralph E. , Mabry Tom J.
Published: April 2007

The growth of Chlorococcum echinozygotum was previously known to be inhibited by an autoclaved solution of xylose in Bold's modified Bristol's medium. We now report the isolation of 2 inhibitory compounds derived from xylose during autoclaving, and the identification of one of them as xylulose. Two strains of C. echinozygotum were isolated, one of which had physiologically adapted to xylulose. The growth rates of both strains were studied using varying amounts of xylulose. Cell counting studies indicated that the zoospores of the unadapted strain were most severely affected by xylulose inhibition and that the zygospores were most resistant.
OBSERVATIONS ON THE FINE STRUCTURE OF OEDOGONIUM. V. EVIDENCE FOR THE DE NOVO FORMATION OF PYRENOIDS IN ZOOSPORES OF OE. CARDIACUM123
Authors: Hoffman Larry R.
Published: April 2007

Ultrastructural studies of the chloroplasts of zoospores and developing zoospores of Oedogonium carcliacum have disclosed the occurrence of numerous incipient pyrenoids. A single developing zoospore may possess several score of these structures which appear to arise de novo in the chloroplast stroma and seem to lack any direct association with mature pyrenoids which are also present in the cells. The incipient pyrenoids lack the associated starch grains and the membrane‐limited channels characteristic of mature pyrenoids, but they are readily recognized in the chloroplasts since they demonstrate a greater granularity and electron density than the surrounding chloroplast stroma. The granularity and electron density of the incipient pyrenoids match the ultra‐structural appearance of the matrix of mature pyrenoids. The smallest of the incipient pyrenoids examined from serial sections had a maximum diameter of less than 0.3 μ. This may be compared with the size of mature pyrenoids, many with a maximum diameter of over 5.0 μ. In all the zoospores and developing zoospores examined, only one mature pyrenoid was observed in an apparent stage of division.
DEOXYRIBONUCLEIC ACID CONTENT OF THE THREE CELL TYPES OF PHAEODACTYLUM TRICORNUTUM BOHLIN1
Authors: Darley W. Marshall
Published: April 2007

There is no significant difference in the DNA content of the oval, fusiform, and triradiate cell types of Phaeodactylum tricornutum, suggesting that they do not represent an alternation of haploid and diploid generations. The triradiate cells have a shorter generation time than the oval or fusiform cells.
ELECTRON MICROSCOPY OF THE LICHEN PHYSCZA AZPOLIA (EHRH.) NYL.1,2
Authors: Brown R. Malcolm , Wilson Rick
Published: April 2007

The ultrastructure of the lichen Physcia aipolia was studied in the desiccated and hydrated states. No significant structural variation between these 2 states was noted for the fungus. The fungus contains unusual ellipsoidal structures heretofore unobserved. Their possible role in the formation of membrane is discussed. The plasmalemma of the fungus is convoluted while that of the alga is smooth. The convoluted projections have a “double‐unit membrane” structure similar to fingerlike projections of the ellipsoidal bodies. With OsO4 fixation crystals are pre‐served, enclosed in unit membrane sacs which extend to the convoluted surface. The pyrenoid of the associated alga does not produce starch in the desiccated condition, and electron‐dense granules are present in the matrix associated with chloroplast lamellae which enter this area. In the hydrated condition, the alga contains abundant starch in the pyrenoid region, and the electron‐dense granules are displaced to the preriphery of the pyrenoid starch. Mitochondria, endo‐plasmic reticulum, and ribosomes are not clearly defined in the desiccated state while they are more so in the hydrated condition. Golgi bodies were not observed in the either lichen component. Finally, no fine structural basis for indicating an exchanged of materials between the alga and fungus was observed except, possibly, the convoluted plasmalemma of the fungus and the smooth plasmalemma of the alga.
THE DISCOLORATION OF ROOFS IN THE UNITED STATES AND CANADA BY ALGAE1
Authors: Brook Alan J.
Published: April 2007

Roof shingles are often colonized and discolored by blue‐green and green algae. The former are mostly subaerial species and the latter are soil algae most frequently recovered from the atmosphere.
LIGHT AND ELECTRON MICROSCOPE OBSERVATIONS ON THE TUBE‐DWELLING DIATOM AMPHIPLEURA RUTILANS (TRENTEPOHL) CLEVE
Authors: Drum Ryan W.
Published: April 2007

The tubular sheath of Amphipleura rutilans is composed of small fibrils 20–25 A in diameter. The endotubular environment is further partitioned by individual cell sheath formation. The tube boundary seems to be an effective barrier against damage from extreme salinity changes, but does not prevent passage of EDTA, neutral red, surfactants, or caffeine. Terminal swellings develop on growing tips during extremely cold periods. These give rise to 2 or more separate growing tips which proceed to form regular tubes. There was no evidence for sexual reproduction or auxospore formation within the terminal swellings, even though adjacent swellings fused. Bacterial, algal, and fungal epiphytes were abundant on the extratubular surface. Hollow lipid bodies occurred in many cells. A rimring strand of presumed DNA occurs in the chloroplast. It is proposed that the tube material serves not only as a protective boundary but also functions as an active nutrient trap.
FATTY ACIDS IN LOTIC PERIPHYTON: ANOTHER MEASURE OF COMMUNITY STRUCTURE1
Authors: McIntire C. David , Tinsley Ian J. , Lowry Robert R.
Published: April 2007

The fatty acid spectra of 6 periphyton communities developed in laboratory streams at different combinations of light intensity and current velocity were determined by gas‐liquid chromatography and silver nitrate thin‐layer chromatography. Differences in species composition of the communities apparently had no striking effect on proportions of palmitic and stearic acids, whereas concentrations of myristic, palmitoleic, oleic, linoleic, and linolenic acids and a C20:5 acid were more closely related to taxonomic differences. In general, communities dominated by blue‐green algae exhibited relatively high proportions of oleic, linolenic, and linolenic acids and low proportions of palmitoleic acid and a C20:5 acid, as compared to communities consisting primarily of diatoms. The data also indicated an inverse relationship between fatty acid redundancy and species diversity.
REJUVENATION OF SENESCENT CELLS OF SPONGIOCHLORIS TYPICA2
Authors: McLean Robert J.
Published: April 2007

Thick‐walled, oil‐filled akinetes of the green alga Spongiochloris typica, long in the stationary phase of growth, were transferred to fresh media. Ultra‐structural changes were observed during a 51‐hr period after transfer. Akinetes, when transferred to fresh media, may follow 1 of 3 pathways:

Remain unchanged; these cells appear to be moribund perhaps due to an over‐accumulation of lipid.

Undergo immediate zoosporogenesis; seems to occur in cells with 4, 8, or more nuclei.

Return to the vegetative state; this was common in smaller cells with less than 4 nuclei; however, zoosporogenesis eventually did occur when 4, 8, or more nuclei were present.
OBSERVATIONS ON PHOTOHETEROTROPHY IN A MARINE DIATOM1
Authors: Bunt John S.
Published: April 2007

An unidentified species of the diatom genus Cocconeis has been isolated from the sediments of Biscayne Bay, Florida. The organism is capable of utilizing a range of organic substrates, including lactate, in the light but not in the dark, as shown by growth studies. Information is included on changes in cell carbon, nitrogen, and chlorophyll a during growth in batch culture. Data obtained on the kinetics of uptake of lactate and glucose raise questions on the possible ecological significance of photoheterotrophy among marine microalgae, particularly those in estuaries.
SOME CHROMOSOME NUMBERS OF DRAPARNALDIA
Authors: Carroll Jackie Wayne , Deason Temd R.
Published: April 2007

The variability exhibited by Draparnaldia both in nature and in the laboratory makes it difficult to identify the species. The natural variability of Draparnaldia was amplified by the environmental conditions and the media used in this study.

With the hope that chromosome studies would aid in taxonomic characterization by providing additional differentiating criteria, special attention was devoted to adapting techniques which could be used to determine chromosome numbers of Draparnaldia isolates. The chromosome numbers reported herein are as follows: (1) Draparnaldia glomerata, Isolate #1, isolated from Davis Falls, Montevallo, Alabama, was found to have a chromosome number of 13. (2) Draparnaldia Isolate #2, an unidentified species obtained from Anniston, Alabama, was found to have a chromosome number of 13. (3) Draparnaldia acuta, Isolate #3 from Northwood Lake, Northport, Alabama, exhibited 26 chromosomes. (4) Draparnaldia plumosa strain 423 (Indiana Culture Collection), 418/a (Cambridge) was observed to have a chromosome number of 13.
A COMPOSITE RATING OF ALGAE TOLERATING ORGANIC POLLUTION2
Authors: Palmer C. Mervin
Published: April 2007

From information on pollution‐tolerant algae compiled from reports from 165 authors, the genera and species most often referred to as significant fall into a relatively stable series. Diatoms, pigmented flagellates, green, and blue‐green algae are all well represented among the pollution‐tolerant genera and species. The top 8 genera are Euglena, Oscillatoria, Chlamydomonas, Scenedesmus, Chlorella, Nitzschia, Navicula, and Stigeoclonium, and the top 5 species, Euglena viridis, Nitzschia palea, Oscillatoria limosa, Scenedesmus quadricauda, and Oscillatoria tennis. In some genera, e.g., Euglena, a single species is far more significant than all others as a pollution‐tolerant form. In other genera, e.g., Oscillatoria, only a slight difference distinguishes the pollution tolerance of 2 or more species. Algal genus and species pollution indices arc presented for use in rating water samples with high organic pollution.
QUANTITATIVE CATION REQUIREMENTS OF SEVERAL GREEN AND BLUE‐GREEN ALGAE2
Authors: Gerloff G. C. , Fishbeck K. A.
Published: April 2007

In contrast with studies which have based essential element requirements of algae on nutrient solution concentrations, in this investigation the requirements of each of 6 species of green and blue‐green algae for calcium, magnesium, and potossium were quantitatively evaluated in terms of critical cell concentrations of the 3 cations. A critical cell concentration was considered the minimum cell content of an element which permitted maximum or near maximum total growth of an organism. In comparison with the needs of angiosperm crop plants, the requirements of all 6 species for calcium were extremely low (critical cell contents of 0.06% or less, oven‐dry basis); requirements for magnesium were equal to or only slightly less than in higher plants (0.15–0.30%) with the exception of Scenedesmus quadricauda (0.05%); and the requirements for potassium varied greatly, from critical levels less than the average values established for higher plants (0.25–0.50%) to values equal to or in excess of higher plant averages (0.80–2.40%). The nutrition of S. quadricauda was of particular interest because of extremely low requirements for all 3 cations. The results provide a more precise and meaningful expression of the essential cation requirements of algae than have previous data. The results also suggest differences in the physiology and functions of cations in the algae studied and in angiosperms which seem worthy of further investigation.
NOTES ON CLADOPHORA (CHLOROPHYCEAE). II. CLADOPHORA CATENATA (LINNAEUS) KÜTZ., 1843, EMEND. V. D. HOEK, 1963
Authors: van den Hoek C.
Published: April 2007

The species name Cladophora catenata (L.) Kütz. emend, van den Hoek has priority over Cladophora fuliginosa Kütz.
N‐METHYL‐N'‐NITRO‐N‐NITROSOGUANIDINE AS A MUTAGEN FOR BLUE‐GREEN ALGAE: EVIDENCE FOR REPAIR1
Authors: Stevens S. E. , Van Baalen C.
Published: April 2007

Survival and mutagenesis have been examined in the marine coccoid blue‐green alga, Agmenellum quadruplicatum, after treatment with the chemical mutagen, N‐methyl‐N'‐nitro‐N‐nitrosoguanidine (NTG). When cells were immediately returned to growth conditions following NTG treatment, the survival level was consistently low and essentially independent of the treatment conditions. The types of mutants found paralleled those previously described in the freshwater coccoid, Anacystis nidulans. If, however, cells were kept under very low light intensity, a nongrowth condition, following NTG treatment, viable cell recovery was dramatically increased. This “dim light” repair in A. quadruplicatum has characteristics similar to those reported for the dark repair systems of bacteria and yeast.
EXPERIMENTAL OBSERVATIONS ON THE INFLUENCE OF TEMPERATURE, LIGHT, AND SALINITY ON CELL DIVISION OF THE MARINE DIATOM, DETONULA CONFERVACEA (CLEVE) GRAN2
Authors: Smayda Theodore J.
Published: April 2007

The influence of 116 combinations of temperature (2, 7, 12, 16 C), salinity (5–35‰ at 5‰ intervals) and light (5 levels) on the mean daily cell division rate (K) of the Narragansett Bay clone of Detonula confervacea was examined following appropriate preconditioning. Growth did not occur at 16 C, but was excellent (K = 1.2–1.5) under certain combinations of light and salinity at 2, 7, and 12 C, being somewhat better at the 2 highest temperature levels. At 32%, and 1100–1200 ft‐c, K increased approximately 2.5 fold from 0.6 to 1.5 between 2 and 12 C.

A light‐temperature relationship was found which had the general trend of an increased optimal light intensity with increasing temperature. Within the optimal salinity range of 15–30‰, the optimal light intensity was 200–600 ft‐c at 2 C, 600–1200 ft‐c at 7 C, and 1200–1800 ft‐c at 12 C. The light‐temperature relationship was most pronounced at 2 and 12 C. At 2 C, K decreased with increasing light intensity, but was independent of this factor at higher temperatures. The optimal salinity range of 15–30‰ was independent of temperature negligible growth occurred at 5‰.

In situ and in vitro responses of Detonula confervacea to salinity were in general agreement but its pronounced cryophilic preference in nature (usually reaching maximum abundance below 1 C) contrasts with its excellent growth at 12 C in culture. The experiments suggest that termination of the bloom of Detonula confervacea in Narragansett Bay and elsewhere is not solely temperature‐dependent. Temperature does not satisfactorily account for its apparent exclusion from waters contiguous to Narragansett Bay and from other more northerly portions of the northeastern coast of the U.S, or, together with light, for its equally surprising apparent unimportance in Norwegian coastal waters.
PAPENFUSSIELLA CALLITRICHA: NEW OBSERVATIONS ON A LITTLE‐KNOWN ENDEMIC BROWN ALGA FROM SOUTHWEST GREENLAND2
Authors: Wilce R. T.
Published: April 2007

Papenfussiella callitricha(Rosenv.) Kylin, of the Myriogloia group (Chordariaceae), is an endemic species of west Greenland with a very restricted distribution; it is known from only 3 localities. The collections from which my own description of the plant is taken constitute the first records of the species since Rosenvinge's original collections of 1886. My cytological data are taken from living plants and ecological notes are based upon observations made while I dived with the aid of Scuba equipment. Zoospores liberated in culture medium germinated to produce microthalli, the second microthallus to be described for this algal group. The life history was not completed in culture. However, motile cells released from the plurilocular sporangia of the microthalli continued to produce more microthalli. I suspect that under natural conditions, the microthalli remain vegetative at the close of the daylight season, to resume reproduction late the following spring, giving rise to the next generation of macrothalli.
SCENEDESMUS MORPHOGENESIS. TRACE ELEMENTS AND SPINE FORMATION1
Authors: Trainor Francis R.
Published: April 2007

When Scenedesmus culture 16, a soil organism with numerous long spines, was grown in axenic culture in a dilute laboratory medium (with approximately 30 mg/liter total salts), spines were not formed. In this medium the organism resembled S. bijugatus, whereas S. longus and S. abundans colonies were typically formed in more concentrated media.

Spines were formed on daughter colonies upon transfer to the dilute medium plus additional Fe EDTA or Ca EDTA. No other individual components of the medium did this. Spineless colonies were healthy and green with a well‐defined chloroplast, provided the culture was transferred often.

In addition to the absence of spines, cultures in the dilute medium had a linear arrangement of cells within a colony, along with terminal cells 20% shorter than median cells. With 4‐celled spiny colonies all cells were the same length and were alternately arranged.
BONNEMAISONIA HAMIFERAHARIOT IN NATURE AND IN CULTURE23
Authors: Chen L. C.‐M. , Edelstein T. , McLachlan J.
Published: April 2007

In culture tetraspores of the sporophyte(Trailliella intricata)ofSonnemaisonia hamiferagave rise to male gametophytes only. In the Gulf of St. Lawrence tetrasporangia occur annually during the autumn, but mature gametophytes have not been recorded. However, gametophytes with antheridia were found during the winter on the Atlantic coast of Nova Scotia. Both phases are capable of vegetative propagation, and this is probably the usual method of reproduction in nature.
A REMARKABLE NEW RED SEAWEED FROM NEW ZEALAND
Authors: Chapman V. J.
Published: April 2007

A remarkable new sublittoral red alga is described from New Zealand. A detailed account of its morphology is provided. A new genus, Pseudoanemonia, is proposed for it and the specific epithet P. tentacula. It is placed in a new family, Pseudoanemoniaceae.
CELL DIVISION IN SPIROGYRA. II. CYTOKINESIS
Authors: Fowke L. C. , Pickett‐Heaps J. D.
Published: April 2007

Cytokinesis in cells of Spirogyra sp. was studied with both light and electron microscopes. Early formation of the cross wall was achieved by annular ingrowth of a septum; the cross wall was completed by a phragmoplast containing Golgi vesicles, longitudinally aligned microtubules, and associated electron‐dense material. Spirogyra may represent an intermediate stage in the evolution of the phragmoplast seen in higher plants.
SEXUAL REPRODUCTION IN CHAETOSPHAERIDIUM GLOBOSUM (NORDST.) KLEBAHN (CHLOROPHYCEAE) AND DESCRIPTION OF A SPECIES NEW TO SCIENCE
Authors: Thompson R. H.
Published: April 2007

Developmental morphology and sexual reproduction of Chaetosphaeridium globosum are described. Dicoleon nordstedtii is reduced to synonymy with C. globosum. A species new to science, C. gemmatum, is described. Descriptions are given of material collected of C. ovalis and C. pringsheimii accompanied by a key to the 4 species of the genus. The species C. huberi is relegated to species dubium.
PHOSPHORUS CONTENT AND RATE OF GROWTH IN THE DIATOMS CYCLOTELLA NANA AND THALASSIOSIRA FLUVIATILIS
Authors: Fuhs G. Wolfgang
Published: April 2007

Cyclotella nana and Thalassiosira fluviatilis were grown in chemostat and turbidostat units in 1/3 strength artificial seawater supplemented with nutrients and vitamin B12 in excess except for phosphorus (P) which in concentrations of 50 or 100 μg/liter was limiting. Different chemostat and turbidostat settings produced different cell numbers per unit volume which, since external P was practically nil, corresponded to varying amounts of bound P per cell. Growth rate plotted vs. P per cell follows a saturation curve. While no growth occurs at a certain minimum content of bound P, half the maxi‐mum growth rate is observed at twice the minimum level of P,3/4 of the maximum at 3 times the minimum level, etc., the maximum growth rate being defined as that observed during growth unrestricted by P supply at a given set of conditions (light, temperature, salinity, etc.). Temperature and light were varied from 13.5 to 24 C and from 2000 to 6000 lux (continuous and intermittent). An abnormal growth curve was found with C. nana at 24 C and 6000 lux continuous light.

Any change in P content of the cells significantly alters cell composition as reflected in P distribution in acid‐soluble, lipid, and acid‐insoluble fractions and in organic carbon content.

External P does not immediately enter our equation for growth rate but is one of the factors deter‐mining rate of P uptake and therefore bound P per cell. Conditions governing uptake, however, cannot be adequately controlled in a chemostat and there fore should be determined in a different experimental approach.
CHLOROPLAST INHERITANCE IN COSMARIUM TURPINII BRÉB.
Authors: Korn Robert W.
Published: April 2007

Chloroplast inheritance was studied in Cosmarium turpinii Bréb. with respect to both vegetative and zygotic transmission. Analyses were carried out on (1) reciprocal haploid x diploid crosses with respect to the number and size of the zygotic chloroplasts, (2) differential survival of chloroplasts in hypnospores of different mating type strains, and (3) the position of the chloroplasts in diploid zygotes. Morphological evidence indicates that the chloroplasts in the mature zygote are derived from the (+) mating type gamete with an infrequent contribution from the (–) mating type gamete. Additional evidence suggests that the chloroplast material of each of 2 Bones arising from the zygote is derived from the plastid material of a semicell of a gamete. Differential survival of the chloroplasts is interpreted as a result of physiological differences between cells of complementary mating types.
SYMBIODINIUM MICROADRIATICUM FREUDENTHAL, A REVISED TAXONOMIC DESCRIPTION, ULTRASTRUCTURE
Authors: Kevin Monica J. , Hall William T. , McLaughlin John J. A. , Zahl Paul A.
Published: April 2007

The ultrastructure of Symbiodinium microadriaticum in vitro and in the type host Condylactis and Casseopeia is described and contrasted with previous observations on symbionts from Anemonia sulcata and the Pacific Tridacnidae. Its type description is emended with new electron microscopic observations and with a list of alternate hosts, including their distributions.
THE THERMOPHILIC CYANOPHYTES OF ICELAND AND THE UPPER TEMPERATURE LIMIT1
Authors: Castenholz Richard W.
Published: April 2007

The upper temperature limit for the growth of chlorophyllous cyanophytes was estimated at about 63–64 C by observations of field populations and by the growth of culture isolates at that temperature. Several isolates of Mastigocladus laminosus were made from different Iceland springs and temperatures. A few continued to grow at 62 C and one at 64 C. M. laminosus was the cyanophyte in Iceland tolerant of the highest temperature. The several species or races of narrow‐cell‐form Synechococcus, which almost exclusively inhabit North American and other springs above 62 C and up to about 74 C, were not found in Iceland. According to my observations and those of others, a maximum of 6–8 cyanophyte species occur in waters over 45 C in all of Iceland. Many times this number has been reported from continental regions of great thermal activity. The low number of species and the absence of particular thermophilic cyanophytes may result from inadequate dispersal from other thermal areas since the end of the last glaciation. Environmental inadequacies (e.g., winter darkness, or minimum‐maximum concentrations of nutrients or other solutes) may also be factors in the absence of certain species.
COMPARISON OF HALF‐SATURATION CONSTANTS FOR GROWTH AND NITRATE UPTAKE OF MARINE PHYTOPLANKTON 2
Authors: Eppley Richard W. , Thomas William H.
Published: April 2007

Growth rates and rates of nitrate uptake by N‐depleted cells were measured for an oceanic diatom, Chaetoceros gracilis, and a neritic diatom, Asterionella japonica, as functions of nitrate concentration of the medium. Both growth and N‐uptake rates appeared to be hyperbolic with nitrate concentration and could be fit to an equation of Michaelis‐Menten form:

where v is rate, Vm. is the maximum rate, S is nitrate concentration, and Ksis the half‐saturation constant. Ksvalues for uptake and growth were similar if not identical for each species. Uptake experiments can provide a presumptive measure of Ksfor growth, thought to be an ecologically significant characteristic of a species.
ADAPTATION OF PHOTOSYNTHESIS IN LAMINARIA SACCHARINA (PHAEOPHYTA) TO CHANGES IN GROWTH TEMPERATURE1
Authors: Davison Ian R.
Published: April 2007

The effect of growth temperature on photosynthetic metabolism was studied in the kelp Laminaria saccharina (L.) Lamour. Photosynthesis was subject to phenotypic adaptation, with almost constant photosynthetic rates being achieved at growth temperatures between 0 and 20° C. This response involved: (1) an inverse relationship between growth temperature and photosynthetic capacity, (2) a reduction in the Q10 value for photosynthesis of L. saccharina grown at 0 and 5° C compared with 10, 15 and 20° C grown sporophytes, and (3) an acquired tolerance of photosynthesis to temperatures between 15–25° C (which inhibited photosynthesis in 0 and 5° C grown L. saccharina) in sporophytes grown at 10, 15 and 20° C. The physiological basis of these adaptations is discussed in terms of observed changes in activities and kinetics of the Calvin cycle enzyme ribulose‐1, 5‐bisphosphate carboxylase (oxygenase) and efficiency of light harvesting‐electron transport systems.
Donor retention as a function of donor reactions to whole‐blood and automated double red cell collections
Authors: Rader Aaron W. , France Christopher R. , Carlson Bruce
Published: April 2007

BACKGROUND: Although reactions to whole‐blood (WB) donation are known to decrease donor retention, potential effects of reactions to automated double red cell (2RBC) donation upon retention have not been investigated.

STUDY DESIGN AND METHODS: The authors investigated effects of donor status (first‐time, experienced) and reactions (absent, present) upon retention of all male allogeneic WB and 2RBC donors (n = 45,296) donating within the American Red Cross Central Ohio Region during a 12‐month period. Donor age, race, and status (first‐time, experienced); phlebotomist's reaction rating; and phlebotomy procedure (WB, 2RBC) were collected for the initial donation by each donor. Dates of any donation attempts in the 12 months starting from the donor's first eligible date after the initial donation were also collected.

RESULTS: On average, WB donors were less likely to react and more likely to donate again and returned more quickly to donate than 2RBC donors, even after accounting for differential delays in eligibility. Reactions decreased the likelihood of repeat donation among all first‐time donors regardless of initial phlebotomy procedure. Among experienced donors, however, reactions depressed retention of WB donors by 27.6 percent, whereas reactions lowered retention of 2RBC donors by just 3.6 percent.

CONCLUSION: Although 2RBC donors were more likely to react, first‐time 2RBC donors were no more affected by reactions than first‐time WB donors. Experienced WB donors suffered a larger drop in retention as a function of reactions, in fact, than did experienced donors who gave 2RBC donations. Potential reasons for this data pattern require further investigation.
Identification of a DREB‐related gene in Triticum durum and its expression under water stress conditions
Authors: Latini A. , Rasi C. , Sperandei M. , Cantale C. , Iannetta M. , Dettori M. , Ammar K. , Galeffi P.
Published: April 2007

Genes from the DREB family are involved in plant’s responses to dehydration and possibly play a role in their ability to tolerate water stress. Understanding the relationship between water stress tolerance and expression of specific genes requires the isolation and characterisation of the sequences that may be involved. We report the isolation and characterisation of a gene in Triticum durum, namely TdDRF1, which belongs to the DREB gene family and produces three forms of transcripts through alternative splicing. The relationship between the expression profile of the TdDRF1 gene and water stress was assessed by real‐time reverse transcription–polymerase chain reaction in a time‐course experiment up to 7 days. Water stress experimental conditions were selected to relate changes in gene expressions during a time frame reflecting as closely as possible those during which water stress starts having a visible effect under field conditions. Among the three isoforms of TdDRF1, the truncated form TdDRF1.2 was at all times the most expressed. Its expression, together with the TdDRF1.3 transcript, increased sharply after 4 days of dehydration, but then decreased at 7 days. The TdDRF1.1 transcript was the least expressed overall and varied least with the duration of dehydration. Genotypic differences in TdDRF1 gene expression are currently under investigation.
Characterization and NMR Solution Structure of a Novel Cyclic Pentapeptide Inhibitor of Pathogenic Hantaviruses
Authors: Hall Pamela R. , Malone LaDonna , Sillerud Laurel O. , Ye Chunyan , Hjelle Brian L. , Larson Richard S.
Published: April 2007

Hantavirus‐induced diseases such as hantavirus cardiopulmonary syndrome and hemorrhagic fever with renal syndrome are a global health concern. Hantavirus cardiopulmonary syndrome caused by Sin Nombre virus lacks specific therapy and its high mortality makes Sin Nombre virus a potential bioweapon agent. Sin Nombre virus entry into susceptible cells requires expression of αvβ3 integrin. We recently reported the sequence of a cyclic nonapeptide that inhibited Sin Nombre virus entry into Vero E6 cells at a level comparable to ReoPro, a Fab fragment of the anti‐β3 antibody c7E3. Here, we refine the parental peptide, cyclo‐[CPFVKTQLC], using alanine scanning and amino acid deletions, by optimizing for viral inhibition. The IC50 of the resulting peptide, cyclo‐[CPFVC], was 267 μm compared with 263 μm for the parental peptide. The solution structure of cyclo‐[CPFVC] was determined by two‐dimensional nuclear magnetic resonance spectroscopy, revealing the Phe ring in an extended conformation stacked against the Pro ring and containing a β‐turn encompassing Val‐4 through Cys‐1. As an initial step in identifying interactions between cyclo‐[CPFVC] and its target cellular receptor, the refined peptide structure was docked into the ReoPro binding site of integrin β3. This structure will provide the basis for designing more potent peptidomimetic therapeutics to prevent Sin Nombre virus entry and treat hantavirus cardiopulmonary syndrome.
Gandhi, The Mahatma: Evolving Narratives and Native Discourse in Gandhi Studies
Authors: Howard Veena Rani
Published: April 2007

The scholarship on Gandhi tends to situate him in one of three camps: political leader, nonviolent revolutionary, or spiritual figure. But for Gandhi, his methods ofAhis(nonviolence) andSatygraha(passive resistance or Soul Force) were interconnected with his asceticism. The overwhelming focus in recent years is on Gandhi's nonviolent strategy in solving personal, social and political conflicts; Gandhi's ascetic practices are dismissed as nonessential or contradictory to political processes. It is difficult for most modern peace activists and scholars, as it was for Gandhi's contemporaries, to understand the native discourse of his paradoxical ideology. Today, there is an emerging debate in the search for alternative responses to war. Gandhi's methods are being deliberated as a possible way to resolve modern problems. But the question remains: Can the modern world borrow Gandhi's political strategies and begin to succeed at the level he did without accepting renunciation, the core of Gandhi's personal and political philosophy?
Association Officers and Executive Council
Authors: Dalgleish R. C. , Branch Ernest A. , Cady Frank C. , Irwin Vern D.
Published: April 2007

Roster Of Active Members ‐ April, 1941

Roster Of Associate Members ‐ April, 1941
REVIEW BOOKS AND ARTICLES
Authors: Russell A. L.
Published: April 2007

Martin, D. J, The Evanston dental caries study. I. Determination of fluorine in foods, bones, and teeth.

Van Huysen, Grant, and Kuhler, Joseph C. Enamel solubility reducing effect of flavored low concentration stannous fluoride solution.

Fulton, J. T. Community economic status and the distribution of dentists.

Progress in the control of dental caries. Health Bul. for Teachers (Metropolitan Life Insurance Co.)

Cheyne, V. D., Home, E. V., The Value of the Roentgenograph in the Detection of Carious Lesions
REVIEW OF BOOKS AND ARTICLES
Authors: Russell A. L.
Published: April 2007

Pelton, W. J., and Wisan, J. M., eds. Dentistry in public health.

Bertrand, A. L., and Hitt, H. L. Parental attitudes and dental care for children in selected rural areas of Louisiana.

Henschel, C. J., and Lieber, Leon. Carries incidence reduction by unsupervised use of 27.5 per cent ammonium therapy dentifrice.

Diebert, A. V. The dentist in the national program of cancer control.

Toverud, Guttorm. Decrease in caries frequency in Norwegian children during World War II.

Robinson, H. G. B. The metabolism of minerals and vitamins and the effect of systemic conditions on dental caries.

Nadler, W. H. Dental infection and extraoral disease.

Keyes, P. H. and Shourie, K. L. Dental caries in the syrian hamster.

Kipkin, Isadore, and Mc Clure, F. J. Inhibitory effect of fluoride on tooth decalcification by citrate and lactate in vivo.

Manly, R. S., and Bibby, B. G. Substances capable of decreasing the acid solubility of tooth enamel.

Straub, J., and Adler, P. Fluoride saturation rate of human enamel.

Russell, A. L. Dental effects of exposure to fluoride‐bearing Dakota sand‐stone waters at various ages and for various lengths of time.

Hill, T. J., White, B., Matt, M., and Peariman, S. A biologically active salivary fraction possibly related to caries susceptibility.

Mc Cauley, H. B., Likins, R. C., and Arnold, F. A., Jr. Relation between caries experience and poliomyelitis in Minneapolis school children (1946 epidemic).

Banti, Lorenzo. The action of blood on germs presumably killed by antiseptics.

Easlick, K. A. Ten “musts” in planning for dental health.
MASS REFERRAL AND QUESTIONNAIRE ON DENTAL CARE; A REPORT ON PILOT STUDIES IN TWO SUBURBAN COMMUNITIES
Authors: Marsh T. L.
Published: April 2007

Manitoba, with indifferent results, tries a mass‐referral technic for modifying the dental care of children prior to entering school.
PREVENTIVE DENTISTRY OR ORAL PUBLIC HEALTH?
Authors: Di Pasquale Dra. Chaja
Published: April 2007

What is in a name?– An Argentinian raises the question. She agreed to the publication of her statement while studying for a year in Paris, France.
FLUORIDATION AND PATTERNS IN COMMUNITY POLITICS
Authors: Hahn Harlan D.
Published: April 2007

A political scientist scrutinizes political behavior as a hazard to fluoridation.
THE ROLE OF THE SCHOOL ORAL HYGIENIST IN AIDING DENTISTRY TO BECOME A PREVENTIVE PROFESSION*
Authors: Harris Norman O.
Published: April 2007

Norman Harris states with conviction from a background of experience, “A startling reduction in incremental carious lesions in school children can be achieved by a dental hygienist trained in my technics.”
THE PURCHASE OF DENTAL CARE; THE EFFECT OF TRENDS ON THE FUTURE PRACTICE OF DENTAL PUBLIC HEALTH*
Authors: Lusk Edward W.
Published: April 2007

A resident presents his look at the implications of denta1 prepayment.
PRICES AND PRODUCTIVITY IN DENTAL CARE*
Authors: Hann Harry J.
Published: April 2007

This analysis of the effect of dental manpower, productivity, work‐week, and income on the costs and availability of dental services makes for interesting reading.
THE AMOUNT OF DENTAL CARE REQUIRED BY THE DENTALLY INDIGENT ELEMENTARY SCHOOL CHILD IN TRENTON, NEW JERSEY*
Authors: Mumma Kichard D.
Published: April 2007

Step by step, here is how procedures for dental indigents were planned in Trenton, New Jersey.
THE DENTAL STATUS OF MENTALLY RETARDED CHILDREN
Authors: Butts John E.
Published: April 2007

An initial public health approach to the development of treatment of retarded children.
ENVIRONMENTAL CHARACTERISTICS; THEIR IMPLICATION FOR THE TEACHING AND PRACTICE OF DENTISTRY
Authors: Menendez Otto R.
Published: April 2007

Doctor Menendez presents his estimate of ecological and cultural impact on the education of dental students and the practice of dentistry in Guatemala from the viewpoint of dental public health.
THE PEDODONTIC ASPECTS OF MEDICAID: THE IMPLICATIONS FOR DENTAL PUBLIC HEALTH *
Authors: Godfrey Richard C.
Published: April 2007

Dr. Godfrey, tracing the development of Medicaid in this country, points out the problems that exist for the dentist in public health who gets the administration of dental coverage.
A CLINICAL FIELD‐EXPERIENCE FOR FOURTH‐YEAR DENTAL STUDENTS†
Authors: Podshadley Arlon G. , Burkett Hugh N. , Kleier Donald J.
Published: April 2007

The enthusiasm of the writers of this report may stimulate comparable projects at other schools of dentistry
REPORT ON THE AMERICAN DENTAL ASSOCIATION'S CONFERENCE ON THE CLINICAL TESTING OF CARIOSTATIC AGENTS*
Authors: Horowitz Herschel S.
Published: April 2007

Dr. Horowitz in his report presents some idea to the Association of the updating of guidelines for comparable research on the effect of anti‐cariogenic agents.
IMPENDING DEMANDS UPON DENTAL MANPOWER AND EDUCATION*
Authors: Mecklenburg Robert E.
Published: April 2007

The Committee on Manpower and Education predicts some of the impact of comprehensive health planning in the various states.
THE EFFECT ON DENTAL CARIES‐ACTIVITY OF SUPPLEMENTING DIETS WITH PHOSPHATES; A REVIEW*
Authors: Gilmore Neville D.
Published: April 2007

Dr. Gilmore has completed a comprehensive survey of the literature on the utilization of phosphates to reduce the effect of dental caries, and has attempted an evaluation of the information reviewed.
MANDATORY FLUORIDATION IN ILLINOIS*
Authors: Pokorney Robert L. , Sebelius Carl L.
Published: April 2007

Dr. Pokorney presents, step by step, the problems that arise and their solution after the passage of a law for state‐wide fluoridation.
DENTAL CARE FOR MENTALLY RETARDED PERSONS; THE PROFESSION MEETS A CHALLENGE
Authors: Latimer Ruth
Published: April 2007

Miss Latimer reports a survey of dental services for handicapped persons that could be utilized by any public health dentist.
EXPANDING SERVICES BY DENTAL AUXILIARIES; WHY? WHERE? HOW?*
Authors: Weinstein Frances M. , Hansen Robert G.
Published: April 2007

Miss Weinstein, with guidance from Dr. Hansen, has gone forward vigorously to learn more about the acceptance of an intraoral technical assistant by the dental profession.
FORMULA GRANTS TO SCHOOLS OF PUBLIC HEALTH*
Authors: Wegman Myron E.
Published: April 2007

The Editor is pleased to find a dean of a school of public health willing to present so forthrightly the problems now facing educators of public health personnel.
NEW FORMS FOR DENTAL HEALTH EDUCATION*
Authors: Weir John M.
Published: April 2007

A health educator ably presents social challenges to the dental profession and some notions about how to respond.
PROGRAMMED COURSE IN DENTAL ETHICS COMPARED WITH TWO OTHER METHODS OF INSTRUCTION
Authors: Miller Sidney L. , Ramirez Albert , Pelton Walter J.
Published: April 2007

After reading this report of Dr. Miller and his group, some still may wonder whether programmed instruction always provides sound teaching or sometimes exercise with a fad.
DENTAL NEEDS OF THE CHRONICALLY ILL AND AGED
Authors: Drake Claude W.
Published: April 2007

The writer does not find a very happy solution for the oral conditions of inmates in the nursing homes of North Carolina.
THOUGHTS OF CHILDREN ABOUT THEIR TEETH AND DENTAL HEALTH
Authors: Keevil Joan M.
Published: April 2007

Miss Keevil deserves credit for working out a new approach in dental health education and initiating it in a school system.
INTEREXAMINER VARIABILITY WHEN USING VIEGAS' SIMPLIFIED CARIES INDEX
Authors: Lopes Eymar Sampaio , Filho Halim Nagem , Chiodi Jose , Tavano Orivaldo
Published: April 2007

This group from a university in Brazil concludes that the examination of three selected teeth (index of Viegas) improves the comparability of findings by examiners over that of a complete examination for DMF.
SMALL COMMUNITIES AND FLUORIDATION; THREE CASE‐STUDIES*
Authors: Lantos Joseph , Marsh Lois A. , Schultz Ronald P.
Published: April 2007

Two senior dental students and a graduate student of Sociology at the University of Buffalo have teamed together to complete case‐studies of the problems in gaining fluoridation for three small communities in New York.