bluuebunny/crossref_metadata_2025 huggingface dataset:
Space and sustainability: an exploratory essay on the production of social spaces through city‐work
Authors: TAYLOR PETER J
Published: August 2007

The purpose of this essay is to locate the making of social spaces as a particularly salient approach for understanding sustainability. Castells’ spaces of places and spaces of flows are interpreted generically and a new social theory, Jacobs’ moral syndromes, is introduced to underpin the production of these two spatial forms: commercial agents through their network practices make spaces of flows; guardian agents through their territorial practices make spaces of places. Both spaces are considered to be the outcome of city‐work. A new division of labour is devised: four primary types of city‐work are identified: hinter‐work, net‐work, territorial‐work and hierarch‐work. These ideas are considered as tools for thinking about developing spatial policies for sustainability. In conclusion, Jacobs’ theory is used to discuss what the general strategy has to be for tackling sustainability.
Azerbaijan's resource wealth: political legitimacy and public opinion
Authors: O’LEAR SHANNON
Published: August 2007

After considering how well Azerbaijan's economy follows the trajectory of a ‘resource curse’ state, this paper investigates the political dimensions of the resource curse evident in Azerbaijan. Of particular interest is how Azerbaijan appears to establish external and internal political legitimacy. These dimensions of sovereignty are not necessarily balanced or present in equal measure. The paper assesses the recent transition in leadership in Azerbaijan as well as Azerbaijan's interactions with, and assessment by, the international community. Additionally, national survey data provide insights into public concerns, satisfaction with government policy, and views on democracy and freedom of expression. The paper concludes that at present there appears to be sufficient public expectation for future benefits, combined with institutional stability, to stave off widespread political instability for the time being.
Mating structure and male production inVespa analisandVespa simillima(Hymenoptera: Vespidae)
Authors: TAKAHASHI Jun‐ichi , INOMATA Yutaka , MARTIN Stephen J.
Published: August 2007

We estimated queen mating frequency, genetic relatedness between workers and worker reproduction in the hornetsVespa analisandVespa simillimausing microsatellite DNA genotyping. The 20V. analiscolonies studied each contained a queen inseminated by a single male. Of the 15V. simillimacolonies studied, nine had a queen inseminated by a single male, four had a queen inseminated by two males, and two had a queen inseminated by three males. The estimated effective number of matings was 1.33 ± 0.74 (mean ± SD), with 75–85% of the offspring of the six multiply mated queens sired by single males. The values for genetic relatedness between the workers ofV. analisandV. simillimawere 0.739 ± 0.004 and 0.698 ± 0.013 (mean ± SD), respectively. We conclude thatV. analisandV. simillimacolonies are genetically monogynous and monandrous. When high relatedness between the workers occurs within colonies, kin selection theory predicts a potential conflict between queens and workers over male production. To determine whether males were derived from queens or workers, males fromV. analisandV. simillimacolonies were genotyped at four microsatellite loci and the level of ovary activation in workers was determined. None of the 787V. analisworkers and only 15 of 3520V. simillimaworkers had developed ovaries. Furthermore, the genotyping identified no worker‐produced males in any colony. The presence of reproductive workers correlated positively with the number of workers within the colony. These results suggest that eusocial colonies with an annual life cycle tend to break down socially when they become large and are close to dying.
Effect of rainfall on the long‐term population dynamics of the aquatic firefly Luciola cruciata
Authors: YUMA Masahide
Published: August 2007

Long‐term observations of adult populations of the aquatic Genji firefly, Luciola cruciata (Coleoptera: Lampyridae), were conducted using a simple flash counting method from 1975 to 2006 at four locations in Kyoto City, Japan. The relative population sizes of adult L. cruciata at these sites fluctuated almost synchronously, indicating the influence of large‐scale environmental phenomena such as weather conditions on population dynamics. Rainfall in September and the latter half of July caused a significant decrease in the population size. The frequent rainfall during these months may have caused considerable drift in the emergence of early instars of firefly larvae and a decrease in their foraging activity.
Redefinition of Ptycta Enderlein (Psocodea: “Psocoptera”: Psocidae) and taxonomic revision of the Japanese species
Authors: BESS Emilie C. , YOSHIZAWA Kazunori
Published: August 2007

The genera Ptycta Enderlein, 1925, and Copostigma Enderlein, 1903, are defined as a monophyletic complex based on the morphology of the male terminalia. Ptycta is redefined as those species of the Copostigma–Ptycta complex with forewing veins Rs+M fused for a short distance. Two new species of Ptycta from Japan are described, P. recava sp. nov. and P. johnsoni sp. nov., increasing the number of Japanese species to four, along with P. parvidentata Tsutsumi, 1964, and P. micromaculata Thornton, Lee, and Chui, 1972. Distributional information and illustrations of each species, and a key to Japanese species of Ptycta are included.
CHLOROPLAST DIVISION AND PYRENOID FORMATION IN CHLAMYDOMONAS REINHARDI1
Authors: Goodenough Ursula W.
Published: August 2007

The process of chloroplast division during mitosis in Chlamydomonas reinhardi is followed with the electron microscope. The pyrenoid and the chloroplast reproduce by fission. The dividing chloroplast contains regions of dense material that superficially resemble pyrenoids, but it is concluded that the formation of the dense material is not related to pyrenoid formation in C. reinhardi. The dense material appears to be localized over regions of chloroplast DNA.
DISSOLVED ORGANIC PHOSPHORUS EXCRETION BY MARINE PHYTOPLANKTON1,2
Authors: Kuenzler Edward J.
Published: August 2007

The amounts of extracellular dissolved organic phosphorus (DOP) produced by 8 species of marine planktonic algae under various conditions of light, salinity, and nutrition were compared. Large amounts, more than 20% of the total P in the system, were excreted by Cyclotella cryptica, Thalassiosira fluviatilis, Dunaliella tertiolecta, and Synechococcus under 1 or more of the experimental conditions. Excretion of DOP was proportional to light intensity in Dunaliella, Rhodomonas, Chlorella sp., and Coccolithus huxleyi. Phosphorus limitation reduced DOP production by Cyclotella and Thalassiosira, nitrogen limitation reduced DOP production by Phaeodactylum, Dunaliella, and Rhodomonas, and lack of iron reduced DOP levels in Cyclotella cultures. Salinity affected growth, but no clear relationship to DOP excretion was evident. The DOP eliminated during growth was reassimilated by the species that produced it and by other species, but lack of alkaline phosphatase reduced the amount of DOP that was available to certain algae.
ULTRASTRUCTURE OF THE CONCHOCELIS STAGE OF THE MARINE RED ALGA PORPHYRA LEUCOSTICTA1
Authors: Lee Robert Edward , Fultz Sara A.
Published: August 2007

The ultrastructure of the Conchocelis or filamentous stage of Porphyra leucosticta was investigated. Each cell contains 1 or 2 parietal, stellate chloroplasts with a single pyrenoid in each chloroplast. The centrally located nucleus is irregularly shaped and contains 1–2 nucleoli. The cytoplasm has typical floridean starch grains and nonmernbrane‐bound lipid bodies. The cell wall is divided into an outer and an inner wall. Many lomasomes are associated with the cell membrane. Pit connections are found between cells, and their taxonomic significance is discussed.
OBSERVATIONS ON THE FINE STRUCTURE OF THE CRYPTOPHYCEAE. I. THE GENUS CRYPTOMONAS1,2
Authors: Lucas I. A. N.
Published: August 2007

The fine structure of 3 members of the genus Cryptomonas, C. rostrella, C. reticulata, and C. calceiformis, has been examined. These species exhibit the features typical of the class Cryptophyceae. The presence of subpellicular trichocysts causes a regular folding of the periplast, and larger trichocysts are present within the gullet. The plastid contains thylacoids arranged in pairs and a prominent pyrenoid; both structures are enclosed in 4 membranes, the outermost of which is a rough endoplasmic reticulum. The nucleus, Golgi apparatus and the Corps de Maupas occupy characteristic positions within the cell, and are the most characteristic features. All these structures indicate that this algal class occupies a unique phylogenetic position.
GROWTH PATTERNS AND MOTILITY OF SPIROGYRA SP. AND CLOSTERIUM ACEROSUM1,2
Authors: Yeh Pao‐Zun , Gibor A.
Published: August 2007

Spirogyra and Closterium exhibit active motility. This motility is associated with the secretion of pectic mucilage from the cells. The gliding of these cells is not directed toward light but photosynthesis is the energy source for it. The secretion of mucilage causes older Closterium cultures to become thick gelatinous clusters. Spirogyra filaments when undisturbed grow to form thick multistranded rings. This growth pattern might result from the tendency of the filaments to rotate on their long axis.
ON THE MECHANISM OF THE INHIBITION OF GROWTH BY XYLULOSE IN CHLOROCOCCUM ECHINOZYGOTUM1,2
Authors: Wu M. , Alston R. E. , Mabry T. J.
Published: August 2007

We previously established that xylulose inhibits the growth of the green alga Chlorococcum echinozygotum. Utilizing experiments involving exposure of the alga to NaHC14O3, it was possible to show by counting the C14 activity of methanolic extracts of the algal cells that xylulose inhibited CO2 uptake. Subsequently it was shown that xylulose does not inhibit or otherwise influence the Hill reaction in this alga.

Several enzymes related to xylulose metabolism were investigated. It was found that xylulokinase was active in C. echinozygotum while phosphoketolase activity was absent. Transketolase was present but its activity was not notably affected by xylulose. Crude carboxydismutase preparations were found to be inhibited by xylulose and xylulose 5‐phosphate. However, as carboxydismutase was purified further, this inhibition was relatively less. When xylulose 1,5‐diphosphate was prepared synthetically, this compound was found to be the most effective inhibitor of purified algal carboxydismutase. We conclude that d‐xylulose enters the cells of C. echinozygotum where it is converted to d‐xylulose 1,5‐diphosphate which acts as a competitive inhibitor of carboxydismutase.
COMPARATIVE STUDIES IN THE GENUS PORPHYRIDIUM NAEG.1,2
Authors: Sommerfeld Milton R. , Nichols H. Wayne
Published: August 2007

Seven isolates of Porphyridium from 2 species were compared. P. cruentum Naeg. isolates were similar in size and pigmentation; differences were observed among the P. aerugineum Geit. isolates. Differences were detected among isolates in reproduction, rate of movement, growth rate, and sensitivity to CuSO4 and crystal violet. No isolate grew heterotropically; however, growth differences were apparent on various carbon sources.
REQUIREMENTS FOR THE MAINTENANCE AND GROWTH OF APHANIZOMENON FLOS‐AQUAE IN CULTURE1,2
Authors: O'Flaherty Larrance M. , Phinney Harry K.
Published: August 2007

Aphanizomenon flos‐aquae has been introduced into unialgal culture in a completely defined medium and maintained for more than 3 years in the colonial flake form found in nature. The color and size of the flake and general appearance of the cells are substantially improved over those found in the original material at the time of collection from Upper Klamath Lake, Klamath County, Oregon. The alga readily forms both akinetes and heterocysts in culture Bacteria‐free cultures have not been obtained.

A precipitate‐free medium designated ASM No. 8a has been developed from the ASM of McLachlan and Gorham. Their medium was altered by modifying the concentration of certain elements and by the addition of sodium bicarbonate, a 1/25 dilution of Arnon's trace element solutions B7 and C13, hydrogen ferric ethylenediamine di‐o‐hydroxyphenylacetate (EDDHA), and disodium ethylene dinitrilotetra‐acetate (Na2EDTA).
DISTRIBUTION AND TAXONOMIC REAPPRAISAL OF CTENOCLADUS (CHLOROPHYCEAE: CHAETOPHORALES)1,2
Authors: Blinn Dean W. , Stein Janet R.
Published: August 2007

The distribution of the rare filamentous green alga Ctenocladus Borzi was examined on a world‐wide basis. All the collection sites are restricted to specific inland habitats. Most of these locations are in arid regions of North America with a few scattered sites in Peru, Sicily, and Siberia. This alga has been referred to 2 genera, either Ctenocladus or Lochmiopsis Woronochin & Popova, for the past 45 years. Based on field observations, laboratory cultures, and herbarium material, Lochmiopsis is considered synonymous with Ctenocladus.

The response of vegetative cell dimensions to seasonal changes (i.e., osmotic potential and temperature) in 3 saline habitats in British Columbia was also investigated. Results from the study, along with laboratory dilutions of natural saline waters, showed that cell dimensions arc not valid criteria for separating species of Ctenocladus as proposed by some authors. Consequently Ctenocladus is considered a monotypic genus with physiological variants responding to seasonal environmental conditions.
SUCCESSION AND CURRENT DEMAND RELATIONSHIPS OF DIATOMS ON ARTIFICIAL SUBSTRATES IN PRATER'S CREEK, SOUTH CAROLINA1,2
Authors: Reisen William K. , Spencer Deirdre J.
Published: August 2007

A study concerning the colonization of glass slides by diatoms was conducted in Prater's Creek, Pickens County. S. C., to observe qualitatively and quantitatively the responses of the periphytic community to current velocities for varied lengths of time. Over short time periods (1, 2 and 4 weeks) diatoms seemed to adhere best at slow current velocities. Over longer periods (6 weeks) growth, of the initial colonizers seemed to be the density governing factor; consequently, the highest diatom densities developed at the higher current, velocities. The interaction of time and current resulted in a reversal of the diatom deposition phenomenon.
MORPHOLOGY AND TAXONOMY OF THE EURYHALINE CHRYSOPHYTE, SPHAERIDIOTHRIX COMPRESSA1
Authors: Andrews Hollings T.
Published: August 2007

Sphaeridiothrix compressa was found in a. saline pond in central Kansas in 1966. Studies in culture have shown that it reproduces readily by zoosporogenesis when grown in media of 12–21 ppt (%0) total salt. Its taxonomic position in the Chrysophyceae and synonymy with S. globulosa, S. brunea, and Chrysodictyon indicum are discussed. This is the first report of Sphaeridiothrix in the Western Hemisphere, and the first account of zoosporogenesis in the genus.
CHANGES IN ABSORBANCE SPECTRUM OF THE DIATOM PHAEODACTYLUM TRICORNUTUM UPON MODIFICATION OF PROTEIN STRUCTURE1,2
Authors: Margulies Maurice M.
Published: August 2007

Changes in the absorbance spectrum, of the diatom Phaeodactylum tricornutum which are brought about by heat, urea, stilt, and formaldehyde have been studied. The changes brought about by all agents are similar. Each converts cell suspensions from orange‐brown to yellow‐green. This color change results from an increase in absorbance in the blue and a decrease in absorbance in the green. All agents, except salt, also bring about an increase in absorbance in the red at wavelengths below that of the red peak of chlorophyll, and a decrease in absorbance at longer wavelengths. On heating cells, the absorbance change in the green occurs more rapidly than the changes in the blue and red. The converse is true when cells are treated with 4 M NaCl. Heat or formaldehyde treatments chemically modify chlorophyll pigments which are present in untreated cells. The change in absorbance in the green is probably due to changes in the molecular environment of fucoxanthin which, results from protein modification. The changes in the blue and red are at least partly due to chemical changes in chlorophylls, but may also be due, in part, to protein modification.
STUDIES ON THE PHOTOBIOLOGY OF BANGIA FUSCOPURPUREA1
Authors: Richardson Norman
Published: August 2007

In the Rhodophyta there are few reports of light‐mediated responses. In Bangia fuscopurpurea the formation of the fertile cell rows by the Conchocelis phase meets criteria established for the definition of photoperiodism in higher plants. Throughout the life history of the alga maintained in culture, cell fate and cell function fire under photoperiodic regulation. Maintenance and conversion photoperiods are established. Sequential induction studies suggest the absence of metabolic effects operative in the induction, response of fertile cell row formation. Preliminary studies of non‐24‐hr photoperiods suggest the absence of short‐term endogenous rhythms involved in spore formation. A phytochrome response involved in the formation of the fertile cell rows is demonstrated.
CULTIVATION OF A FILAMENTOUS ALGA IN QUANTITY ON AGAR PLATES1,2
Authors: Rosowski James R. , Hoshaw Robert W.
Published: August 2007

A method for the cultivation of Zygnema in quantity on agar plates is described. Axenic filaments were chopped with razor blades, and 4 ml of the suspension of short filaments in nutrient medium were transferred with a syringe to 1% agarized nutrient medium plates. Filamentous growth uniformly covered agar plates in 10 days or less.
ZOOSPOROGENESIS IN THE CHLOROCOCCALEAN ALGA RADIOSPHAERA NEGEVENSIS OCAMPO‐PAUS AND FRIEDMANN1
Authors: Ocampo‐Paus Roseli
Published: August 2007

A simple method is described to demonstrate zoospore formation in a chlorococcalean alga.
KINETICS OF GLUCOSE TRANSPORT AND GROWTH OF CYCLOTELLA CRYPTICA REIMANN, LEWIN AND GUILLARD1,2
Authors: Hellebust Johan A.
Published: August 2007

Growth rate as well as rate of glucose uptake of C. cryptica depends on glucose concentration in the medium according to saturation kinetics. The Kg for growth is 1.9 × 10−5 M, and the Kt, for glucose transport is 5.8 × 10−5 M. The maximum growth rate in the dark on glucose is considerably slower than the light‐saturated growth rate at the same temperature, and does not appear to be determined by the capacity of the cell for glucose uptake.

The glucose transport process is highly specific, and depends on energy metabolism. The Q10 for the process is 2.2 (15–2.5 C). Glucose taken up by the cells is almost, quantitatively phosphorylated within 10 min, either through the transport process itself or by a high affinity kinase system in the cells.
SPHEROPLAST FORMATION AND ASSOCIATED ULTRASTRUCTURAL CHANGES IN A SYNCHRONOUS CULTURE OFANACYSTIS NIDULANSTREATED WITH LYSOZYME1,2
Authors: Lindsey Jerri K. , Vance B. Dwain , Keeter Joe S. , Scholes Vernon E.
Published: August 2007

Cells ofAnacystis nidnlanswere grown in synchronous culture using a light‐dark alternation to obtain synchronization. Two synchronous cycles were obtained with, decay of synchrony beginning with the third cycle. Cells of various ages in the growth cycle were treated with lysozyme to form spheroplasts. The percentage of spheroplast formation varied with age of the cells. After extended periods of lysozyme treatment, up to 90% of the cells of all ages showed spheroplast formation. Some cells were resistant to the action of lysozyme regardless of age or length of treatment. An ultrastructure study of the spheroplast was made. The electron‐dense inner layer of the cell wall was removed by the action of lysozyme on the glucosamine residues of the cell wall, indicating true spheroplast formation. The photosynthetic apparatus became more pronounced with extended treatment with lysozyme.
COMPARATIVE ULTRASTRUCTURE OF THE PRIMARY NUCLEUS IN BRYOPSIS AND ACETABULARIA1,2
Authors: Burr Frances A. , West John A.
Published: August 2007

The fine structure of the primary nucleus in Bryopsis hypnoides was compared with that of the primary nucleus in Acetabularia calyculus and Batophora oerstedii. In Bryopsis the mature primary nucleus contains a peripheral reticulum composed of 4–6 layers of 200 A diameter fibrils. The nuclear membrane has numerous nuclear pores that are located adjacent to the openings in the layers of the reticulum. Each nuclear pore is constituted of peripheral globular elements and a central granule. Although pores of similar structure are present in the nuclear envelope of Acetabularia and Batophora, a fibrillar reticulum is absent.
OBSERVATIONS ON THE FINE STRUCTURE OF DICTYOCHA FIBULA EHRENBERG. II. THE PROTOPLAST1
Authors: Van Valkenburg Shirley D.
Published: August 2007

Dictyocha fibula in exponential phase cultures displays a range of morphological variants of which the “sunburst” is most common. In this form, the perinuclear cytoplasm (perikaryon) contains an average of 72 dictyosomes, assorted vesicles, mitochondria, endoplasmic reticulum, and ribosomes. Cytoplasmic processes, globose to irregular, extend on fine cytoplasmic strands from the perikaryon into an extensive, viscous wall, structureless in electron micrographs except for scattered electron‐opaque leaflets near the perikaryon. Mitochondria with tubular cristae occur within the globose process and occasionally within the connecting strands. Chloroplasts, with 3‐disk lamellar bands and with pyrenoids not crossed by lamellae, are confined to the cytoplasmic processes in the sunburst from. A structure which may be the “flagellum” occasionally occurs attached to the perikaryon. However, no flagellar structures containing microtubules, nor flagellar root structures, have been found.
GLIDING MOTILITY IN THE BLUE‐GREEN ALGA OSCILLATORIA PRINCEPS1
Authors: Halfen Lawrence N. , Castenholz Richard W.
Published: August 2007

Gliding is an active movement displayed by a microorganism in contact with a solid substrate where there is no evidence of a motility organelle or of a conformational change in the organism. Gliding may be accompanied by rotations, reversals, flectional activity, and mucilage sheath production, as well as linear translation. Previous explanations of the mechanism responsible did not consider all these aspects of behavior.

The gliding behavior and ultrastructure of the blue‐green alga Oscillatoria princeps Vaucher were examined. O. princeps has a maximum observed gliding rate of 11.1 μm/sec. The trichomes can glide in either longitudinal direction following rapid and occasionally frequent reversals. Right‐handed trichome rotation was always observed, which means that any surface point on these trichomes traces a 60‐deg right‐handed helix. A mucilage sheath envelopes the moving trichomes. The rate of gliding was reduced by viscous substrates, extreme pH, lysozyme, DNP, and cyanide, while sustained darkness had no inhibitory effect.

Ultrastructurally, the cell wall is composed of an L‐1 layer which is 10 nm thick and often ill‐defined. The L‐2 layer which is outside this is 200 nm thick and participates in septum formation. The L‐3 layer is outside the L‐2 and is continuous over the trichome surface. The L‐4 “membrane” lies outside the L‐3 layer. Grazing surface sections and freeze‐etch replicas show a parallel and tight array of 6–9 nm wide continuous fibrils in the cell wall on the surface of the distinctive L‐2 layer. Isolated wall fragments were tightly coiled inside out with the fibrils on the inside. The angle of orientation for the fibrils was to the right in a helix with a pitch of 60 deg. O. animalis, a blue‐green alga with a movement tracing a left‐handed helix, showed a similar array of fibrils oriented in a left‐handed helix with a pitch of 60 deg.

It is proposed that gliding is produced by unidirectional waves of bending in the fibrils which, act against the sheath or substrate, tints displacing the trichome.
OBSERVATIONS ON THE GENUS BLIDINGIA (CHLOROPHYTA) IN CALIFORNIA1
Authors: Norris James N.
Published: August 2007

The green algal genus Blidingia (Ulvales), reported for the first time in California only 4 years ago, is now found to be fairly widely distributed there as B. minima (Nägeli ex Kützing) Kylin var. minima. B. minima var. subsalsa (Kjellman) Seagal is now recorded for California. Ulva vexata Setchell and Gardner [Enteromorpha vexata (Setch. & Gardn.) Doty] is reduced to varietal status as B. minima var. vexata, and is reported, to be found in 2 ecological forms. Forms with expanded, ulvoid blades are common to exposed localities and is the form described by Setchell & Gardner. Smaller, narrower, enteromorphoid forms are found near river mouths and are the kind referred to by Doty. There are many intermediate forms of this variety.

Characters which are used to separate Blidingia from Enteromorpha are critically evaluated.
COMPARATIVE ULTRASTRUCTURE OF CULTURED SPECIES OF TREBOUXIA1,2
Authors: Fisher K. A. , Lang N. J.
Published: August 2007

Five species of cultured Trebouxia—T. anticipata, T. decolorans, T. erici, T. gelatinosa, and T. impressa—were examined with the electron microscope. A comparative examination of their pyrenoids revealed pyrenoglobuli associated with single pyrenoid thylakoids. The pyrenoids of T. decolorans, T. erici, and T. gelatinosa possess single thylakoids that cross or deeply penetrate the pyrenoid matrix and are often disposed in parallel arrays. T. anticipata possesses both single and double pyrenoid thylakoids within the matrix. T. impressa possesses vesiculate invaginations of thylakoid membranes into the pyrenoid matrix.

The phycobiont. T. erici was examined in detail at the light and electron microscopic levels for pyrenoid alterations associated, with varied environmental regimes and with cell division. A greater amount of starch is present in cells grown in organic culture at 215 lux light intensity than in cells of similar size grown at 1075 or 3600 lux. Pyrenoglobuli are present throughout the life cycle and occur both in aplanospores and in zoospores.
DIVISION SYNCHRONY IN PRIMARY CULTURES OF AN ENDOZOIC DINOFLAGELLATE1
Authors: Franker Colin K.
Published: August 2007

Division cysts of zooxanthellae harbored by Anthopleura elegantissima were isolated from random host‐associated populations by their preferential attachment to plastic surfaces. By selecting cysts at similar stages in the cell cycle, synchronous division, excystation, and daughter cell reencystment were obtained in a medium enriched with amino acids. The interval of DNA synthesis in a single growth cycle was determined by pulse‐labeling with radioactive thymidine. Analysis of the sequence of morphologic changes within such cycles suggested that the initial selection procedure isolates G2 cells. The transit time from first generation G2 division cysts to subsequent reentry into G2 was about 70 hr.
STIMULATORY PROPERTIES OF FILTRATE FROM THE GREEN ALGAHORMOTILA BLENNISTA.II. FRACTIONATION OF FILTRATE1,2
Authors: Monahan Thomas J. , Trainor Francis R.
Published: August 2007

This investigation reports on the fractionation of filtrate from the green algaHormotilablennista known to contain autostimulatory properties. Acid, basic, and volatile acid filtrate extracts reduced the lag time ofH. blennistaat low concentrations. Whole filtrate did not express those lag time reducing capacities which were demonstrated in filtrate extracts. Glycolic acid was identified in both the acid and volatile acid extracts. Growth rate stimulation could not be demonstrated with any filtrate extract. Stimulatory properties of filtrate were shown to be dialyzable and heat labile. It was suggested that heat‐labile low molecular weight organic extracellular products are responsible for the growth rate stimulatory property of filtrate. Although dialysis and heat treatments of filtrate removed growth rate stimulation, filtrate properties capable of extending final population levels were retained. High molecular weight heat‐stable extracellular products appear to be at least partially responsible for these extended growth levels.
MICROMORPHOLOGY OF THE PERIPLAST OF CHROOMONAS SP. (CRYPTOPHYCEAE)1,2
Authors: Gantt E.
Published: August 2007

An ultrastructural examination of the periplast of Chroomonas sp. revealed a surface pattern composed of rows of plate areas. The plate areas are delineated by a series of ridges, which emanate from a common line at the posterior cell end, and lateral grooves which intersect the anterior‐posterior ridges. Small ejectosomes (trichocysts) are generally located at the intersection of the lateral grooves and the ridges. Size of the plate areas varies, being smallest at the posterior and anterior ends and largest in the midregion of the cell. The average plate area is 1 μ in length and 0.7 μ in width. In section the periplast is seen to consist of 3 intimately attached layers of which the middle (plasma membrane) layer is continuous with the gullet region, flagella, and ejectosome chambers. Trypsin digestion resulted in the disappearance of the inner and outer layers, and in the loss of periplast stiffness.
PERIDINIUM GREGARIUM, A NEW SPECIES OF DINOFLAGELLATE1,2
Authors: Lombard Eugene H. , Capon Brian
Published: August 2007

A dinoflagellate has been found in tidepools on the coast of the Palos Verdes Peninsula in southern California. It is described as a new species, Peridinium gregarium. In the tidepool habitat, great numbers of the organism form cloud‐like masses held together by a mucous matrix. The gregarious cloud formation seems to be shared by only one other species of dinoflagellate, Peridinium sociale (Henneguy ex Labbé) Biecheler, 1935.
PREDAEA WELDII, A NEW SPECIES OF RHODOPHYTA FROM HAWAII, WITH AN EVALUATION OF THE GENUS1
Authors: Kraft Gerald , Abbott Isabella A.
Published: August 2007

A new species of Predaea (Gigartinales, Rhodophyta) is described from Hawaii. It is compared in important morphological details with other species of the genus, all of which are distributed in the subtropics. Predaea is likewise compared to the genera of Nemastomataceae, and should be included in that family. The genus Yadranella Ercegovic (Nemaliales, Rhodophyta) is placed in synonymy with Predaea.
CAPITATE APPENDAGES ON SCENEDESMUS CULTURE 16 WALLS1
Authors: Massalski Andrzej , Trainor Francis R.
Published: August 2007

A capitate appendage was detected on the cell wall of Scenedesmus strain 16 with the electron microscope, using the negative staining technique. The mushroom‐like structures, from 450 to 650 mμ long, possessed an elongate stipe and a circular cap. These are attached to ridges or the cell wall of both spiny and spineless colonies.
OBSERVATIONS SUR LES BESOINS EN VITAMINES DES DESMIDIÉES (CHLOROPHYCÉES‐ZYGNEMATALES)1
Authors: Tassigny Michel
Published: August 2007

The minimal nutrient requirements of 61 strains of desmids belonging to 18 different genera were investigated within 16 axenic cultures and 45 contaminated cultures. Thirty‐nine strains were autotrophic: they included all 30 strains belonging to the genera Cosmarium, Staurastrum, and Micrasterias. Twenty‐two strains were auxotrophic; they included all 14 strains belonging to the genus Closterium. Of the 22 auxotrophic strains, 13 required only vitamin B12; the specific requirements of the other 9 strains were not determined.
INFLUENCE OF SALINITY ON THE FORM OF ASTEROCYTIS IN PURE CULTURE1
Authors: Lewin Ralph A. , Robertson Jack A.
Published: August 2007

The growth form of an isolate of Asterocytis ornata in pure culture changed from filamentous in a full‐strength seawater medium to a unicellular or bicellular form closely resembling the genus Chroothece in a medium of quarter‐strength seawater. The alga did not grow in media of lower salinities, or in media in which seawater was replaced by KCl, NaCl, or CaCl2. The formation of filaments from single cells could not be attributed to osmolarity. The controlling factors seemed to be the concentrations of cations, notably Na+ and Mg++. However, the filaments produced experimentally in a defined medium, were never as extensively developed as those occurring in seawater, an indication that further studies should be done. The occurrence of the Asterocytis form, in freshwater habitats remains to be explained. There may be distinct physiological races, if not true species, within the genus.
ECOLOGY OF THE EPIPELIC ALGAL COMMUNITIES IN MARION LAKE, BRITISH COLUMBIA1,2
Authors: Gruendling Gerhard K.
Published: August 2007

Studies of the seasonal and spatial distribution of the epipelic algal standing crop and primary productivity were conducted in Marion Lake, British Columbia. Possible biological, chemical, and physical factors controlling the epipelic algal community dynamics were also investigated. The epipelic algal flora of the lake was very diverse, however, it can be generally considered as acidophilic associations of algae. The vertical distribution of the epipelic algae is partially influenced by the amount of light reaching the sediment, but also strongly influenced by the grazing of animals and erosion by wave action. Temperature, light, and grazing by animals all appear to influence the seasonal fluctuations in the algal standing crop. Concentrations of nutrients immediately above the sediment surface appear to be less important as controlling factors. The most important variables influenceing the primary productivity of the epipelic community are temperature, total algal standing crop, and light. Nutrients, again, appear to be less important as controlling factors. The study supports the idea that epipelic algal growth is high in shallow, low nutrient lakes and that the epipelic algal productivity is extremely important to the total energy budget of the lake.
ENERGY EXPENDITURE FOR GLIDING MOTILITY IN A BLUE‐GREEN ALGA1
Authors: Halfen Lawrence N. , Caslenholz Richard W.
Published: August 2007

The energy required to overcome viscous drag in a gliding trichome of a blue‐green alga advancing and rotating through a medium of known viscosity (67 poise at 25 C) has been calculated to be about 0.05% of the energy available from oxidative phosphorylation (based on respiration measurements), whereas 0.2–5% are possible figures for the amount actually expended. These values represent a low energy demand for a function of probable high survival value, but are comparable to estimates for motility in flagellated cells.
AN EXOCELLULAR POLYSACCHARIDE FROM THE DIATOM GOMPHONEMA OLIVACEUM1,2
Authors: Huntsman Susan A. , Sloneker J. H.
Published: August 2007

An acidic polysaccharide produced by Gomphonema olivaceum was extracted with hot water after conversion to its potassium form. Recovered in 2–3% yield, the β‐linked polysaccharide was composed primarily of d‐galactose, d‐xylose, and an alkalistable sulfate ester in the ratio of 1:1:1.2. Several other minor components including a uronic acid were observed but not further identified. Periodate oxidation was complete in 40 hr at 4 C with the consumption of 0.88 mole of oxidant and production of 0.26 mole of acid per sugar residue. Half of the d‐galactose in the polysaccharide was not oxidized by periodate: the remainder was cleaved between C2 and C3. Of the d‐oxylose residues, 35% were not oxidized; 15% were cleaved beetween C2 and C3; and 50%, presumbably a nonreducing side‐chain moiety, afforded formic acid. From these data two possible structures have been proposed.
NEW ALGAL SPECIES RECORD FOR COLORADO1
Authors: Todd Darryl J.
Published: August 2007

Colonies of the alga Nostoc parmeloides Kützing 1843, containing midge larvae, were collected from Bellows Creek in the southwestern mountains of Colorado near Creede, Mineral County, on February 27, 1970. G. W. Prescott verified the algal identification and confirmed it as a new species record for Colorado. The Nostoc‐midge combination has been definitely identified in 8 other Colorado mountain streams. The streams are located in various sections of Colorado above 2333 m; distribution may be statewide.
CYTOKINESIS AND PLASMODESMATA IN ULOTHRIX1
Authors: Floyd Gary L. , Stewart Kenneth D. , Mattox Karl R.
Published: August 2007

Cytokinesis essentially similar to that of vascular plants occurs in Ulothrix, an unbranched filamentous green alga. Plasmodesmata, similar to those of vascular plants, but different from those of many other algae, are also present. Cell plate formation and plasmodesmata also occur in Stigeoclonium, a branched green alga.
BIPHASIC TIME COURSE OF SOLUBILIZATION OF NITROGENASE DURING CAVITATION OF AEROBICALLY GROWN ANABAENA CYLINDRICA1
Authors: Wolk C. Peter , Wojciuch Elizabeth
Published: August 2007

The nitrogenase activity of extracts from aerobically grown. Anabaena cylindrica is proportional to the cube of the concentration of extract over a wide range of activities. This relationship is changed to one of direct proportionality, approximately, when reaction mixtures are supplemented with a constant amount of extract from algae starved for molybdenum in the presence of tungstate. The time course of solubilization of nitrogenase during cavitation is reevaluated in the light of these results. The finding that solubilization occurs at first rapidly and subsequently much more slowly is discussed with reference to the hypothesis that nitrogenase is localized in heterocysts.
GLUCOSE UPTAKE BY CYCLOTELLA CRYPTICA: DARK INDUCTION AND LIGHT INACTIVATION OF TRANSPORT SYSTEM1,2
Authors: Hellebust Johan A.
Published: August 2007

Glucose transport capacity of C. cryptica increases in an exponential manner over 24 hr after transfer of the cells from light to complete darkness with little simultaneous increase in cell number. The transport system is rapidly inactivated when cells are transferred back to continuous light. Most of the inactivation takes place while there is still little changes in cell number. When grown on a continuous light regime, the capacity for glucose transport per cell depends on the light intensity. At intensities sufficient to saturate photosynthesis the glucose transport system is only about 5% that of dark‐grown cells, while cells grown at intensities close to the light compensation point have about 30% of the capacity of dark‐grown cells. The action spectrum for inactivation of glucose transport is identical to that for photosynthesis.

Cells, whether grown under continuous light, in the dark in the presence of glucose, or kept in the dark without glucose, contain high levels of glucokinase and phosphofructokinase. The glucose transport system is highly specific for glucose; only galactose inhibits the uptake of glucose by about 50% when present at 10 times the concentration of glucose. The glucokinase is even more specific for glucose and is not inhibited by galactose. The phosphofructokinase is inhibited by high concentrations of ATP in cells grown under all conditions. cycloheximide inhibits the induction of glucose transport in the dark, but not the inactivation of the system in the light.
A LIGHT AND ELECTRON MICROSCOPIC STUDY OF RHIZOID DEVELOPMENT IN POLYSIPHONIA LANOSA (L.) TANDY1,2
Authors: Rawlence David J. , Taylor A. R. A.
Published: August 2007

The ontogeny of P. lanosa rhizoids was investigated by light and electron microscopy. A series of distinct, changes was recognized. Prior to penetration of the host, Ascophyllum nodosum, starch reserves were depleted and a large number of dictyosome vesicles accumulated in the cell. These appeared to have been discharged immediately prior to or during host, penetration with a concomitant increase in rhizoid wall thickness. Following initial penetration, the tip became highly convolute and dominated by ER, ribosomes, and mitochondria. Senescence was marked by almost complete, vacuolation of the cytoplasm, degeneration of most organelles, and the loss of color. These ultrastructural changes are correlated wth the habit of P. lanosa.
DISTRIBUTION OF PHYTOPLANKTON IN A POLLUTED SALINE LAKE, ONONDAGA LAKE, NEW YORK1,2,3
Authors: Sze Philip , Kingsbury John M.
Published: August 2007

Onondaga Lake, possibly the most polluted lake in New York State, supports an algal flora characteristic of a eutrophic lake with an admixture of saline species. Floral diversity is noteworthy under the circumstances. Seasons in the lake may be identified by the succession of flora. High salinity of lake water results in layering at the outfall (as in an estuary, in reverse) such that river water may enter the lake at the outlet despite continuous net outflow. Certain species of algae appeared first at the outflow station and then spread through the lake. Phosphorus and nitrogen are never limiting, although seasonal diminution in the latter may influence the composition of the flora. Silica diminution was related to blooms of diatoms and may then be limiting for further growth of diatom populations. No obvious controlling relationship exists between herbivores and phytoplankton populations. The euphotic layer is typically much shallower than the thermocline. Therefore turbulence and mixing may play an important role in controlling certain populations. A brief midsummer clearing in 1969, characteristic for the lake, resulted in serious oxygen depletion and cannot be accounted for with the available data. Among metals, chromium and copper are high in the lake as the result of industrial discharges. The former may be inhibiting, the latter probably is inhibiting to algal growth. Consequently, measures underway to “clean up” the lake may result in increased blooms. Biomass calculations have been made for the major phytoplankters, and a list of 82 species is presented.
OBSERVATIONS ON THE ULTRASTRUCTURE OF THE MALI GAMETES OF BIDDULPHIA LEVIS EHR.1
Authors: Heath I. Brent , Darley W. Marshall
Published: August 2007

The marine centric diatom Biddulphia levis produced uniflagellate fusiform male gametes completely within the parent cell frustule. These gametes lacked both a central pair of microtubules in the flagellar axoneme and chloroplasts but did contain a cone of microtubules which passed posteriorly from the base of the kinetosome along the nuclear envelope. The gametes were released through a specialized pore in the girdle band leaving behind a cytoplasmic mass which contained chloroplasts and other cytoplasmic components. Tubules which resembled the flimmer hairs on the gamete flagellum occurred in cisternae of the cytoplasmic reticulum in the residual cytoplasm and in the nuclear envelope of the gametes. Gametogenesis in B. levis is compared with similar processes in other centric diatoms.
ACID PHOSPHATASE ACTIVITY AND ULTRASTRUCTURE OF AGED CELLS OF EUGLENA GRANULATA1,2
Authors: Palisano John R. , Walne Patricia L.
Published: August 2007

Ultrastructure and acid phosphatase activity of aged calls of Euglena granulata are reported. Cells are spherical, quiescent, and nonflagellated. The most conspicuous attribute of aged cells is the accumulation of cyloplasmic vacuoles and lysosome‐like structures containing heavily stained, pigmented bodies and membrane fragments. In chloroplasts, portions of whorled lamellae arc abscised and subsequently incorporated into lysosome‐like structures; osmiophilic granules increase in number. Membranes surrounding eyespot granules disappear and the granules themselves become diffuse; the usual association with microtubules is not seen in aged cells. Acid phosphatase precipitation accumulates largely at the maturing face of dictyosomes and associated vesicles; there is also activity in multivesicular and lysosome‐like vacuoles.
THE FINE STRUCTURE OF MITOSIS AND CELL DIVISION IN THE CHRYSOPHYCEAN ALGA OCHROMONAS DANICA1
Authors: Slankis T. , Gibbs Sarah P.
Published: August 2007

At the ultrastructural level, cell division in Ochromonas danica exhibits several unusual features. During interphase, the basal bodies of the 2 flagella replicate and the chloroplast divides by constriction between its 2 lobes. The rhizoplast, which is a fibrous striated root attached to the basal body of the long flagellum, extends under the Golgi body to the surface of the nucleus in interphase cells. During proprophase, the Golgi body replicates, apparently by division, and a daughter rhizoplast, appears. During prophase, the 2 pairs of flagellar basal bodies, each with their accompanying rhizoplast and Golgi body, begin to separate. Three or 4 flagella are already present at this stage. At the same time, there is a proliferation of microtubules outside the nuclear envelope. Gaps then appear in the nuclear envelope, admitting the microtubules into the nucleus, where they form a spindle. A unique feature of mitosis in O. danica is that the 2 rhizoplasts form the poles of the spindle, spindle microtubules inserting directly onto the rhizoplasts. Some of the spindle microtubules extend from pole to pole; others appear to attach to the chromosomes. Kinetochores, however, are not present. The nuclear envelope breaks down, except, in the regions adjacent, to the chloroplasts; chloroplast ER remains intact throughout mitosis. At late anaphase the chromosomes come to lie against part of the chloroplast ER. This segment of the chloroplast ER appears to be incorporated as part of the reforming nuclear envelope, thus reestablishing the characteristic nuclear envelope—chloroplast ER association of the interphase cell.
GROWTH AND EXCRETION IN PLANKTONIC ALGAE AND BACTERIA1
Authors: Nalewajko C. , Lean D. R. S.
Published: August 2007

In short‐term experiments using cultures ofChlorella pyrenoidosa, Anabaena flos‐aquae, Asterionella formosa, andNavicula pelliculosa, both the proportion of photosynthetic products released from cells and the composition of these products altered, with age. In the first 3 species, percentage extracellular release values increased with increasing growth rates but the reverse trend was shown byNavicula.

Fractionation of filtrates using Sephadex indicated that, in general, larger molecular weight compounds became predominant as cultures aged. Also a time‐dependent shift in a similar direction occurred in cultures of all ages.

In several lakes a predominance of large molecular weight compounds was apparent in filtrates even from short‐term experiments. Filtrates of mixed cultures of planktonic bacteria growing on14C glycolate were found to contain, large molecular weight organic compounds.

It was demonstrated that in nonaxenic cultures of algae and in lake water, bacteria utilize low molecular weight extracellular metabolites of algal origin and larger molecular weight compounds are formed.
ULTRASTRUCTURE OF TETRASPOROGENESIS IN THE PARASITIC RED ALGA LEVRINGIELLA GARDNERI (SETCHELL) KYLIN12
Authors: Kugrens Paul , West John A.
Published: August 2007

Ultrastructural studies on tetraspore formation in Levringiella gardneri revealed that 3 stages may be recognized during their formation. The youngest stage consists of a uninucleate tetraspore mother cell with synaptonemal complexes present during early prophase of meiosis I. Mitochondria are aggregated around the nucleus, dictyosome activity is low, and chloroplasts occur in the peripheral cytoplasm. A 4‐nucleate tetraspore mother cell is formed prior to tetrahedral cell cleavage, and an increase in the number of chloroplasts and mitochondria occurs. Small straight‐profiled dictyosomes secrete vesicles into larger fibrous vesicles or contribute material to the developing tetraspore wall. During the second stage of tetraspore formation, striated vesicles form within endoplasmic reticulum, semicircular profiled dictyosomes secrete vesicles for fibrous vesicles or wall material, and starch formation increases. The final stage is characterized by the disappearance of striated vesicles, presence of straight, large dictyosomes which secrete cored vesicles, and an abundance of starch grains. Cleavage is usually complete at this stage and the tetraspore wall consists of a narrow outer layer of fibrillar material and an inner, electron transparent layer. These spores are surrounded by a tetrasporangial wall which was the original wall surrounding the tetraspore mother cell.