bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF LIGHT AND TEMPERATURE INTERACTIONS ON GROWTH OFCRYPTOMONAS EROSA(CRYPTOPHYCEAE)1
Authors: Morgan Keith C. , Kalff Jaap
Published: August 2010

Cryptomonas erosaSkuja, a planktonic alga, was grown in batch culture at different combinations of light intensity and temperature, under nutrient saturation. Growth was maximal (1.2 divisions · day−1) at 23.5 C and 0.043 ly · min−1, declining sharply with temperature (0.025 divisions‐day−1at 1 C). With decreasing temperature, the cells showed both light saturation and inhibition at much reduced light intensities. At the same time the compensation light intensity for growth declined towards a minimum of slightly above 0.4 × 10−4ly · min−1(~1 ft‐c) at 1 C or <0.1 ly · day−1(PAR). Cell division was more adversely affected by low temperature than carbon uptake, and the resulting excess production of photosynthate was both stored and excreted. Extreme storage of carbohydrates resulted in cell volumes and carbon content ca. 22 and 30 × greater, respectively, than the maxima observed for cells incubated in the dark, whereas, at growth inhibitory light levels, as much as 57% of the total assimilated carbon was excreted. A marked increase in cell pigment was observed at the lowest light levels (<10−3ly · min−1), at high temperature. The growth response ofC. erosain culture provides insight into the abundance and distribution of cryptomonads and other small algal flagellates in nature.
ULTRASTRUCTURE OF MALE GAMETOGENSIS IN FUCUS SERRATUS (PHAEOPHYCEAE)1
Authors: Berkaloff Claire , Rousseau Bernard
Published: August 2010

The main structural features of male gametogenesis in Fucus serratus L. are described. The antheridial parent cells exhibit meristematic characteristics: large nucleus, dense cytoplasm, chloroplasts with few thylakoids. Synaptonemal complexes are frequently observed in the nuclei at the same time that microtubules are very abundant around the centrioles. Meiotic spindles are intranuclear, as are the mitotic spindles of the subsequent synchronous karyokineses. A nuclear membrane is present in all stages observed. Antheridial maturation is accompanied by multiplication of mitochondria and plastids as well as development of two major kinds of “vacuoles.” Cytokinesis proceeds with the progressive fusion of one of these types of vacuoles: this mode of cytoplasmic cleavage is unique among algae. Formation and differentiation of characteristic spermatozoid organelles (flagella, eyespot, proboscis) are also described.
GAS VACUOLE COLLAPSE IN MARINE OSCILLATORIA (TRICHODESMIUM) THIEBAUTII (CYANOPHYTA) AND THE EFFECT ON NITROGENASE ACTIVITY AND PHOTOSYNTHESIS1
Authors: Carpenter Edward J. , Walsby A. E.
Published: August 2010

Photosynthesis and nitrogenase activity (acetylene reduction) in Oscillatoria (Trichodesmium) thiebautii were significantly reduced after its gas vesicles were collapsed by pressurizing to 6·2 MPa (62 bars). The reduction in nitrogenase activity was observed with both intact and disrupted colonies, and under both aerobic and microaerobic conditions. It is unlikely, therefore, that the reduction in either process results solely from loss of gas diffusion pathways, and may simply originate from disturbance of the cellular architecture as gas vesicles are destroyed. Since nitrogenase activity of the samples was affected by gas vesicle collapse, the process presumably resides in the gas vacuolate organism (Oscillatoria) rather than in any associated bacteria which might be present.
DUDRESNAYA PATULASP. NOV., AN UNUSUAL DEEP‐WATER RED ALGA FROM FLORIDA1
Authors: Eiseman Nathaniel J. , Norris James N.
Published: August 2010

Dudresnaya patulasp. nov. is described from 30–60 m depth on the east coast of Florida. The plant grows to a height of at least 10 cm, has flattened axes and main branches to 2 cm wide and 3 mm thick, and has unusually long female reproductive branches. The new species is compared to otherDudresnayaspecies in habitat, vegetative structure, and reproductive morphology.
CHEMICAL COMPOSITION AND STRUCTURE OF THE CELL WALLS OF THE CONCHOCELIS AND THALLUS PHASES OF PORPHYRA TENERA (RHODOPHYCEAE)1,2
Authors: Mukai Leonard S. , Craigie James S. , Brown Robert G.
Published: August 2010

Purified cell walls were prepared from both the conchocelis and thallus phases of Porphyra tenera (Kjellm.). The nitrogen content of cell walls from the conchocelis was significantly greater than that for the thallus cell walls, being 3.35 ± 0.26% and 2.39± 0.03%, respectively. Amino acid analysis revealed important differences. The conchocelis cell wall hydrolyzates were richer in aspartic acid, glutamic acid, methionine, and basic amino acids. The thallus cell wall hydrolyzates, however, contained much more glycine and alanine than did those of the conchocelis. Hydroxyproline was not detected in cell walls of either phase. The neutral sugar content of cell wall hydrolyzates from the thallus was more than double that from the conchocelis being 83.6% and 34.5%, respectively. The former contained predominantly mannose which accounted for 72.2% of the neutral sugars while the latter was principally galactose (49.9%) and glucose (36.4%). Methylation analysis confirmed the presence of cellulose microfibrils in the conchocelis in contrast to xylan microfibrils in the thallus. The results establish that the conchocelis and thallus phases of P. tenera differ markedly in the structure and composition of the cell walls.
EFFECTS OF THE ENCRUSTING BRYOZOAN, MEMBRANIPORA MEMBRANACEA, ON THE LOSS OF BLADES AND FRONDS BY THE GIANT KELP, MACROCYSTIS PYRIFERA (LAMINARIALES)1
Authors: Dixon John , Schroeter Stephen C. , Kastendiek Jon
Published: August 2010

Juvenile sporophytes of the giant kelp, Macrocystis pyrifera (L.) C. A. Agardh, were transplanted from local kelp beds to stations located various distances from the outfall from an electrical generating station that was known to cause an increase in the settlement of fouling organisms. Plants near the outfall became heavily fouled by the encrusting bryozoan, Membranipora membranacea (L.), and lost about one‐third of their blades during the course of the experiment. Blade loss was significantly correlated with amount of fouling. To test the hypothesis that fouling causes blade loss, we paired fouled and unfouled plants of about the same age, overall length, and number of fronds and placed them at stations in nearby kelp beds and near the outfall. At the stations in the kelp beds, the fouled plants lost blades more rapidly than the unfouled controls. However, at the station near the outfall the “control” plants quickly became fouled so there was little difference in treatments and there was no significant difference in blade loss. Plants fouled by Membranipora suffered greater blade loss than clean plants probably because fouled blades are fragile and break off easily and because fish bite off chunks of blade while foraging on the attached bryozoans.
TEMPERATURE‐GROWTH RESPONSES OF ALGAL ISOLATES FROM ANTARCTIC OASES1
Authors: Seaburg Kenneth G. , Parked Bruce C. , Wharton Robert A. , Simmons George M.
Published: August 2010

Thirty‐five taxa (128 clonal cultures) of Antarctic algae isolated from various habitats were assayed for growth over a range of 2–34°C. Isolates, all unialgal and two axenic, varied markedly in their temperature‐growth responses. Only four taxa belonging to either the Chlamydomonadaceae or Ulotrichaceae were obligately cold‐adapted and incapable of growth at ≥20°C. All isolates grew at temperatures ranging from 7.5 to 18°C, and a few were incapable of growth at ≤5°C. Over one‐third of the isolates grew at 30°C, but none grew at 34°C.

Percentages of cold‐adapted clones correlated well with the more stable low temperature habitats. Four chlamydomonad isolates displayed optimum temperatures for growth near their maximum temperatures for growth, both temperatures being well above those of the native habitats. This temperature‐growth response suggests a closer relationship to algae from more moderate thermal regions than one might have supposed. However, the ability to grow at low temperatures and the inability to grow at 34°C suggest that these Antarctic algae are cold temperature adapted. Growth capability at low in situ temperatures is considered more useful ecologically than physiologically‐defined categories for algae based on their maximum temperature for growth.
DIEL OSCILLATIONS IN THE PHOTOSYNTHESIS‐IRRADIANCE RELATIONSHIP OF A PLANKTONIC MARINE DIATOM1
Authors: Harding Lawrence W. , Prézelin Barbara B. , Sweeney Beatrice M. , Cox James L.
Published: August 2010

The amplitude of diel oscillations in photosynthesis as a function of irradiance varied with the growth phase in a marine phytoplankton species. The common centric diatom (Bacillariophyta), Ditylum brightwellii (West) Grun., showed strong periodicity in the photosynthesis‐irradiance (P‐I) relationship, which damped progressively from early to late exponential and stationary phase. These findings suggest that short‐term temporal characteristics of phytoplankton production depend on factors which affect growth, and that the amplitude is most enhanced at maximal growth rates likely to be encountered in the natural environment.
GAMETOPHYTIC GROWTH BY MACROCYSTIS PYRIFERA (PHAEOPHYTA) IN RESPONSE TO VARIOUS IRON AND ZINC CONCENTRATIONS1
Authors: Kuwabara James S.
Published: August 2010

Batch culturing experiments were conducted to examine effects on Macrocystis pyrifera (L.) C. A. Agardh gametophytic growth of various iron and zinc concentrations in the chemically defined, artificial seawater medium, Aquil. A least squares fit of experimental data represented the relative importance of these micronutrient effects. Optimal iron and zinc concentrations in Aquil were estimated at 340 nM (7 × 10−11 nM as [Fe3+]) and 135 nM (6 × 10−2 nM as [Zn2+]), respectively.
TEMPORAL AMMONIUM PATCHINESS AND GROWTH RATE IN CODIUM AND ULVA (ULVOPHYCEAE)1
Authors: Ramus J. , Venable Melissa
Published: August 2010

The growth rates of two chlorophyte macroalgae, Codium fragile and Ulva curvata, are compared in response to varied, but non‐random, NH4+ enrichments (pulses). The species were chosen to contrast radically different morphologies. Pulse frequency and pulse duration were varied independently; however, an equivalent mass of NH4+ was added in each treatment. The growth rate of Codium varied neither as a function of pulse frequency nor duration; the growth rate of Ulva varied with pulse frequency, but not pulse duration. These data are combined with life form and physiological characters, and are discussed in the context of the “function form” hypothesis. From the evidence we argue that by virtue of its life form, Ulva is capable of utilizing transiently high NH4+ concentrations and is capable of high growth rates, attributes contributing to its role as a ruderal species. In contrast, Codium's life form does not allow utilization of transiently high NH4+ concentrations or high growth rates, thereby contributing to its role as a persistent species.
TIME‐LAPSE ANALYSES OF SEXUAL ISOLATION BETWEEN TWO CLOSELY RELATED MATING GROUPS OF THE CLOSTERIUM EHRENBERG SPECIES COMPLEX (CHLOROPHYTA)1
Authors: Ichimura Terunobu , Kasai Fumie
Published: August 2010

Sexual isolation between Groups A and B of Closterium ehrenbergii, two closely related species, was studied by a multiple‐choice mating method, as well as the nochoice mating method which has been used in previous work on microalgae. Time lapse photomicrographs and the difference in cell shape and size between the two mating groups allowed identification of a given cell in the mixture as either Group A or B, even when certain morphological changes occurred during the several day culture required for sexual induction. When plus and minus mating types of Group A were mixed with those of Group B (multiplechoice mating), no intergroup hybrid zygospores were formed. However, many intragroup zygospores of either Group A or B were formed. When one plus strain of Group A was mixed with one minus strain of Group B or when one plus strain of Group B was mixed with one minus strain of Group A (no‐choice mating), intergroup sexual interactions took place resulting in a small number of hybrid zygospores; however, the process took much longer than intragroup sexual interactions. It was also shown that cell size difference itself hardly affects sexual interactions between haploid and autodiploid strains of Group A. It is suggested that sexual isolation between Groups A and B would be complete in nature, although they may interact sexually in the laboratory.
VARIATIONS IN ENVELOPE MORPHOLOGY AND MINERALIZATION IN TRACHELOMONAS LEFEVREI (EUGLENOPHYCEAE)1
Authors: Dunlap John R. , Walne Patricia L.
Published: August 2010

The mineralized envelope surrounding the trachelomonad cell is a complex of organic and inorganic components, anastomosed to form a structure that is characteristic of the species. Although there may be considerable morphological variability in envelope size, shape and ornamentation, its microarchitecture is characterized by two basic components: granular and needle‐like deposits. The present study documents for the first time that manipulation of the culture conditions results in predictable changes in envelope ultrastructure, color and elemental composition. Supplemental iron (Fe) in the culture medium results in an increase of granular components in the envelope, whereas supplemental managanese (Mn) results in an increase of needle‐like components; with nitrogen (N) supplements there is an increase of both granular and needle‐like components in the envelope. It is also shown here that autoxidation of Fe may occur, resulting in the accumulation of Fe deposits along strands of unmineralized envelope mucilage. Autoxidation and deposition of Mn do not occur.
ALGAL ASSEMBLAGES IN ANTARCTIC PACK ICE AND IN ICE‐EDGE PLANKTON1
Authors: Garrison David L. , Buck Kurt R. , Fryxell Greta A.
Published: August 2010

A significant amount of the primary production in the Southern Ocean and other ice‐covered oceans takes place in localized ice edge plankton blooms. The dynamics of these blooms appear to be closely related to seasonal melting of sea ice. Algal cells released from the ice are a possible source of ice edge planktonic assemblages, but evidence for this “seeding” has been equivocal. We compared algal assemblages in ice and water in the Weddell Sea during the austral spring of 1983 at a receding ice edge with a well‐developed ice edge bloom. The high degree of similarity between ice and water column assemblages, the spatial and temporal patterns in the distribution and abundances of species, and preliminary evidence for the viability and growth of ice‐associated species provide evidence for seeding from sea ice of some species in Antarctica.
ULTRASTRUCTURE OF A NEW INTRACELLULAR SYMBIOTIC ALGA FOUND WITHIN PLANKTONIC FORAMINIFERA1
Authors: Gastrich Mary Downes
Published: August 2010

A small intracellular eukaryotic algal symbiont, 1.5–3.5 μm in diameter, occurs abundantly and persistently in nine planktonic Foraminifera host species. This alga is different from the dinoflagellate, from 8–12 μm in diameter, known to occur in the four spinose species Orbulina universa, Globigerinoides sacculifer, G. ruber, and G. conglobatus. Transmission and epifluorescent microscopy were used to confirm the presence cophyta. The evidence supporting this classification includes the presence of a chloroplastic endoplasmic reticulum surrounding the plastids and tubular cristae, as opposed to flattened cristae, in the mitochondria. Three classes of algae may be represented including the Chrysophyceae, Bacillariophyceae, and Prymnesiophyceae.

Ultrastructural analysis indicated that the alga in the spinose Globigerinella aequilateralis resembles a prymnesiophyte because the chloroplasts lack a girdle lamella. The algae in the non‐spinose species and the short‐spined Globigerina cristata resemble endocytic chrysophytes or diatoms because of the presence of a girdle lamella. Ultrastructural characteristics of the chrysophycophycean alga present in planktonic Foraminifera are discussed and compared to those of non‐dinoflagellate symbiotic algae associated with other invertebrate hosts.
EFFECTS OF SELENIUM DEFICIENCY ON THE MORPHOLOGY AND ULTRASTRUCTURE OF THE COASTAL MARINE DIATOM THALASSIOSIRA PSEUDONANA (BACILLARIOPHYCEAE)1,2
Authors: Doucette Gregory J. , Price Neil M. , Harrison Paul J.
Published: August 2010

The effects of selenium deficiency on the siliceous and nonsiliceous components of the planktonic marine diatom Thalassiosira pseudonana (Hust.) Hasle and Heimdal (clone 3H) are examined using light and electron microscopy. Selenium deficiency induces elongation along the pervalvar axis initially as a result of chain formation caused by the failure of sibling cells to separate and subsequently by cell elongation via the production of hyaline girdle bands. In Se‐deficient cultures cell elongation involves the blockage of both mitotic and cytokinetic components of cell division. Selenium deficiency results in ultrastructural alterations in the reticular membrane system and in mitochondrial and chloroplast membranes. Various types of inclusions are seen in vacuolar areas and the accumulation of lipid reserves is evident in Se‐deficient cells. These results provide indirect evidence for a metabolic Se requirement in this algal species.
REGULATION OF GAS VESICLE CONTENT AND BUOYANCY IN LIGHT‐OR PHOSPHATE‐LIMITED CULTURES OF APHANIZOMENON FLOS‐AQUAE (CYANOPHYTA)1
Authors: Konopka Allan , Kromkamp Jacco , Mur Luuc R.
Published: August 2010

Measurements of the gas vesicle space in steady‐state light or phosphate‐limited cultures of Aphanizomenon flos‐aquae Ralfs, strain 7905 showed that gas vesicle content decreased as energy‐limited growth rate increased but was the same at several phosphate‐limited growth rates. Upon a decrease in growth irradiance, gas vesicle content did increase in phosphate‐limited cultures, but the cultures remained nonbuoyant as long as P was limiting. Buoyant, energy‐limited cultures lost their buoyancy in less than 2 h when exposed to higher irradiances. The primary mechanism for buoyancy loss was the accumulation of polysaccharide as ballast. Collapse of gas vesicles by turgor pressure played a minor role in the loss of buoyancy. When cultures were exposed to higher irradiances, cells continued to synthesize gas vesicles at the same rate as before the shift for at least 1 generation time. The amount of ballast required to make individual filaments in the population sink varied 4‐fold. This variation appears to be due to differences in gas vesicle content among individual filaments.
THE ROLE OF DIATOMS IN STROMATOLITE GROWTH: TWO EXAMPLES FROM MODERN FRESHWATER SETTINGS1
Authors: Winsborough Barbara M. , Golubić Stjepko
Published: August 2010

Some modern laminated and calcified stromatolitic structures are partially or completely formed by eukaryotes. Diatom populations in freshwater environments with elevated ionic concentrations contribute to calcite precipitation, and the formation of distinctive mineral‐rich stromatolitic laminae. Two types of stromatolite‐forming diatom populations were observed. In the first example, in stromatolies growing on a quarry ledge near Laegerdorf, North Germany, calcite crystals with biogenic imprints form around polysaccharide stalks of the diatom Gomphonema olivaceum var. calcarea (Cleve) Cleve‐Euler. These individually precipitated crystals eventunally become cemented together in layers, forming rigid, laminated stromatolitic deposits which drape over the quarry ledge. In the second example, in stromatolites forming in a shallow stream near Cuatro Ciénegas, Coahuila, Mexico, diatomaceous laminae also form by the accumulation of carbonate particles in a matrix of diatoms and their extracellular polysaccharide products. These laminae become thick enough to drape over individual stromatolite heads. The diatoms responsible for these deposits are Amphora aff. A. Katii Selva, Nitzschia denticula Grun., and six other species. At Cuatro Ciénegas, in addition to the diatomaceous laminae, carbonate‐rich cyanobacterial layers, dominated by two cyanobacterial species with different fabrics and porosities, are also present and contribute substantially to the growth of the stromatolites. In both the Laegerdorf and Cuatro Ciénegas examples, entire stromatolites or thick laminations on stromatolites are built by a small number of diatom species which produce copious amounts of extracellular stalk, gel, and sheath material, a property they share with cyanobacterial stromatolite builders.
SYSTEMATICS AND ECOLOGY OF LYNGBYA SPP. AND ASSOCIATED SPECIES (CYANOPHYTA) IN A NEW ENGLAND SALT MARSH1,2
Authors: Baker Kathleen Kromer
Published: August 2010

Field populations of the most abundant filamentous blue‐green algae (cyanobacteria) from a northern New England salt marsh were examined for the presence of natural morphological clusters. A continuum in the distribution of average cell sizes and shapes for individual trichomes was evident. However, there was a high frequency of certain cell sizes (six cluster, which were also separated by several qualitatives characters (end cell shape, granule location, and cell color). In clonal cultures the trichomes of these culsters maintained the morphology of the original isolated trichome and thus morphology apperated to be stable. The clusters were either named according to Gietler's (1932.) terminology or assigned numbers if no adequate descriptions were availble: (1) Lyngyya and Phormidium spp., (2) Microcoleus chthonoplastes Thur. (3) Lyngbya sp.1, (4)Lyngbya sp. 2 (5) Lyngbya aestruarii (Mert.) Liebmann, and, (6) Lyngbya aestuarii (mert. Liebmann, and, (6) Lyngbya sp. 3. All goups had maximum asbundance in late summer. Microcoleus chthonoplastes occurred throughtout the; year, while Lyngbya aestuarri and Lynobya sp. 3 occurred throughout the summer and fall. It is concluded that both field and culture information are useful in enhancing our knowledge of blue‐green algal systematics.
RAPID AMMONIUM UPTAKE BY FRESHWATER PHYTOPLANKTON1
Authors: Suttle Curtis A. , Harrison Paul J.
Published: August 2010

A natural assemblage of freshwater phytoplankton was removed from an oligotrophic lake and grown at N:P supply ratios of 5:1, 15:1 and 45:1 (by atoms) in semicontinuous culture. After a minimum of 31 days at an average daily growth rate of 0.5 d−1, experiments were conducted examining the time‐course of saturated ammonium uptake rates. Cultures grown under the two lowest N:P supply ratios demonstrated greatly elevated initial, specific uptake rates for ammonium and were able to sequester between 7 and 21% of their daily N requirement in less than 5 min. The initial rates declined rapidly but were followed by a subsequent increase and decrease over a 120 min period.
PRIMARY PRODUCTION OF EDAPHIC ALGAL COMMUNITIES IN A MISSISSIPPI SALT MARSH1
Authors: Sullivan Michael J. , Moncreiff Cynthia A.
Published: August 2010

Primary production rates of edaphic algae associated with the sediments beneath four monospecific canopies of vascular plants were determined over an annual cycle in a Mississippi salt marsh. The edaphic algal flora was dominated by small, motile pennate diatoms. Algal production (as measured by14C uptake) was generally highest in spring‐early summer and lowest in fall. Hourly rates ranged from a low of 1.4 mg C/m2in Juncus roemerianus Scheele to a high of 163 mg C/m2beneath the Scirpus olneyi gray canopy. Stepwise multiple regressions identified a soil moisture index and chlorophyll a as the best environmental predictors of hourly production; light energy reaching the marsh surface and sediment and air temperature proved of little value. Adding the relative abundances of 33 diatom taxa to the set of independent variables only slightly increased R2; however, virtually all variables selected were diatom taxa. R2was only 0.38 for the Spartina alterniflora Loisel. habitat but ranged from 0.70 to 0.87 for the remaining three vascular plant zones. Annual rates of algal production (g C/m2) were estimated as follows: Juncus (28), Spartina (57), Distichlis spicata (L.) Greene (88), and Scirpus (151). The ratio of annual edaphic algal production to vascular plant net aerial production (EAP / VPP) was 10–12% for the first three habitats and 61% for Scirpus. Chlorophyll a concentrations, annual algal production rates, and EAP / VPP values were comparable to those determined in Texas, Delaware, and Massachusetts salt marshes but lower than those reported for Georgia and particularly California marshes.
DIEL CHANGES IN THE COMPOSITION OF PHOTOSYNTHETIC PIGMENTS AND CELLULAR CARBON AND NITROGEN IN CHATTONELLA ANTIQUA (RAPHIDOPHYCEAE)1
Authors: Kohata Kunio , Watanabe Masataka
Published: August 2010

An axenic clonal culture of Chattonella antiqua (Hada) Ono was grown on a 12: 12 h LD cycle in a laboratory culture tank containing 1 m3 of f/2 medium. Diel changes in mean cell volume, cellular carbon (carbon content per cell), C/N ratio, cellular Chl a, Chl a/c ratio and carotenoid composition were observed. Mean cell volume and cellular C, N and pigments increased during the light period as a result of photosynthesis and decreased with increase of cell concentration by phased cell division during the dark period. These changes indicated that carbon assimilation and pigment synthesis occurred together during the light period. However, the patterns of increase were not the same since different diel patterns were also found in the ratios of C/N and chl a/c. Photosynthetic pigments were analyzed by reversed‐phase high‐performance liquid chromatography with ion‐pairing solution. This analysis showed that the dominant carotenoids in C. antiqua were fucoxanthin, violaxanthin and β‐carotene. Diel patterns of Chls a and c were similar to that of fucoxanthin but different from those of violaxanthin and β‐carotene. The cellular contents of Chl a, fucoxanthin and carbon increased in a parallel manner during the light period. On the other hand, the increase of violaxanthin was restricted to only a few hours at the beginning of the light period during cell division cycles.
PHOTOSYNTHETIC PHYSIOLOGY OF PROROCENTRUM MARIAE‐LEBOURIAE (DINOPHYCEAE) DURING ITS SUBPYCNOCLINE TRANSPORT IN CHESAPEAKE BAY1
Authors: Harding Lawrence W. , Coats D. Wayne
Published: August 2010

This paper presents results of field studies on the estuarine dinoflagellate Prorocentrum mariae‐lebouriae (Parke & Ballantine) Faust in Chesapeake Bay. We tested the hypothesis that the photosynthetic physiology of Prorocentrum shows adaptive responses to low‐light during a lengthy subpycnocline transport in estuarine circulation. Prorocentrum underwent a seasonal, northward trnasport between February and June, 1984 and 1985. Low cell densities occurred in the seaward part of the estuary during winter and early‐spring, subpycnocline populations progressed up‐estuary in the ensuring 2–3 months, and dense surface populations developed in the mesohaline portion of the estuary thereafter. We sampled Prorocentrum from surface and subpycnocline waters and measured photosynthesis‐light (P‐I) relations with in situ incubations. The photophysiology of Prorocentrum collected below the pycnoline differed from that of cells in the surface mixed layer in that photosynthetic efficiency, α‐cell−1, was higher, photosynthetic capacity, Pmax‐cell−1 was ·4 times greater for subpycnocline (≦ 10m) samples than for those from the surface mixed layer (≧ 6m). Comparison of in situ photosynthetic properties to those generated in laboratory studies showed that values of α·cell−1 for both surface and subpycnocline samples were in the range found for cultures in low‐light. Concentrations of Chls a, c and peridinin·cell−1 and molar pigment ratios peridinin: Chl a and Chl a: Chl c were not significantly different for the surface and subpycnocline samples, nor were C · cell−1 or C : Chl a. Chloroplast and starch volume fractions and the number of thylakoids were the same for samples collected at different depths, and there was no evidence of cytoplasmic vacuolization in any field samples. These morphometric data for cells from natural populations of Prorocentrum most closely resembled data for laboratory cultures grown at or near 2.6E·m‐−2·4d−1. A lower growth irradiance of 0.3E·m−2·d−1 produced indications of stress in cultures, including starch depletion and vacuolization, that were never observed in natural populations. Based on the combination of these findings, we conclude that Prorocentrum is adapted to low‐light both in the surface mixed layer and beneath the pycnocline, although certain photophysiological characteristics distinguish these two groups of samples.
Modeling of Gas‐Phase Transport and Composition Evolution during the Initial‐Stage Sintering of Boron Carbide with Carbon Additions
Authors: Rossi Mark A. , Matthewson M. John , Kaza Anil , Niesz Dale , Haber Richard L.
Published: August 2010

Densification of B4C during sintering can be aided by removing the native B2O3(condensed) (B2O3(c)) layer present on the starting B4C powder. B2O3 can be removed by adding excess C and holding the powder compact at an intermediate temperature below the normal sintering temperature. This allows time for CO and minor boron gases to diffuse out from the porous compact before the pores close. This process was examined using a computational model based on codiffusion of multiple gas species, which enables prediction of the gas‐ and condensed‐phase composition as a function of time and position in the specimen. The model, described previously elsewhere, was originally applied to the SiC/SiO2 system but has been adapted for the B4C/B2O3 system. The results are used to determine the optimum holding time for complete B2O3(c) removal as a function of key parameters, such as specimen thickness, particle size, temperature, etc. The role of gas‐phase transport in residual C and B4C profiles is also examined.
Improvement of Microwave Dielectric Characteristics in SrLaAlO4Ceramics by Ca Substitution
Authors: Peng Li Qin , Mao Min Min , Chen Xiang Ming
Published: August 2010

The improvement in microwave dielectric characteristics by Ca substitution in SrLaAlO4ceramics together with the stability of K2NiF4structure were investigated. X‐ray diffraction analysis and the scattering electron images combined with EDS analysis indicated that the matrix phase was a solid solution with a composition represented by the chemical formula Sr1−xCaxLaAlO4in the entire range of 0≤x≤0.9, and minor amount of LaAlO3secondary phase was detected only in the composition ofx=0.8 and 0.9. The relative permittivity increased slightly with increasingx, while the temperature coefficient of resonant frequency was tuned from −33.9 to −14.7 ppm/°C. The significant improvement ofQfvalue was achieved in the present ceramics with increasingxand reached the maximum atx=0.4, but it turned to decrease forx>0.4. The best combination of microwave dielectric characteristics was achieved atx=0.4: ɛr=18.1,Qf=150 500 GHz, and τf=−26.2 ppm/°C.
Foetal Erythropoiesis in the Mouse
Authors: Bro‐Rasmussen Frede , Henriksen O.
Published: August 2010

In the foetal erythropoiesis in mouse foetuses, a change from nucleated erythroblasts to anuclear erythrocytes takes place within a period of a little more than 24 hours. This change is due to extrusion of the nuclei. The present findings give rise to the assumption that it would be reasonable to consider the primitive erythroblasts which are characteristic of early foetal erythropoiesis as well as the subsequent definitive erythroblasts to be links in a continued and gradual developmental series, not as two generations of foetal blood cells. The possibility of nuclear extrusion in human foetal erythropoiesis and medullary erythropoiesis is discussed.
Transfusion Therapy in Factor XIII (F. S. F.) Deficiency
Authors: Ikkala Eero , Myllylä Gunnar , Nevanlinna H. R.
Published: August 2010

Human fraction I was transfused into an adult patient with factor XIII deficiency. Tooth extractions were performed on the day of transfusion and three days later without any abnormal bleeding. The disappearance of factor XIII activity was followed for nine days. Six hours after transfusion about 50 per cent of the transfused activity could be recovered in the blood of the patient and the half‐life of factor XIII was estimated to be about four‐five days. The present observations and reports in the literature suggest that factor XIII is haemostatically effective in quite low concentrations.
The Effect of EDTA and ACD on the Recovery and Survival of Cr51‐labelled Blood Platelets
Authors: Abrahamsen Arne Foss
Published: August 2010

Two anticoagulants, EDTA and ACD, were compared as to their influence on recovery and survival time of in vitro Cr51‐labelled blood platelets

With EDTA, pronounced trapping of the platelets occurred during the first 24 hours after infusion, due to an in vitro time‐consuming process. With ACD, the trapping was small, and maximum recovery occurred much earlier than with EDTA. Consequently, higher recoveries of infused platelets were obtained with ACD than with EDTA. The survical time was approximately the same with both anticoagulants

During progressive storage, survival time and maximum recovery both decreased more rapidly with EDTA than with ACD

It is concluded that ACD causes less damage to platelets than EDTA and is superior for platelet transfusion and labelling.
The Effect of Desferrioxamine on Iron Metabolism in Man
Authors: Hallberg Leif , Hedenberg Lars
Published: August 2010

The possible use of desferrioxamine (DF) to measure body iron stores necessitated studies on the source of the iron excreted in the urine with the compound. DF did not take significant amounts of iron from transferrin because:

(1) DF did not affect the plasma iron turnover

(2) The excretion of a transferrin‐bound radioiron tracer was not increased by DF

(3) Induced elevation of the plasma iron level was followed only by a slight increase in the iron excretion

(4) No effect was observed on the incorporation into red cells of a transferrin‐bound radioiron tracer by DF

Other studies indicated that iron, in the stage of being incorporated into red cell precursors, was not a probable source of the iron excreted with DF

A significant delay in the excretion of iron with DF was regularly observed and found to be due to a delayed mobilisation of iron

Further studies are necessary to find the source of iron excreted after administration of DF.
Treatment of Pruritus in Hodgkin's Disease and in Reticulum Cell Sarcoma
Authors: Bichel Jørgen , Brincker Hans
Published: August 2010

10 patients in whom pruritus was a very prominent symptom were treated with levomepromazine in daily doses of 25–50 mg. 7 of these patients suffered from Hodgkin's disease and 3 from reticulum cell sarcoma. In a number of patients levomepromazine controlled pruritus effectively without significant side‐effects. Though all the patients had other simultaneous treatments, e.g. radiation treatment or chemotherapy, the treatment with levomepromazine is considered to be the cause of relief of the pruritus in most of the patients.
Acute Agranulocytosis Following Infectious Mononucleosis Report of a Case
Authors: Wulff Henrik R.
Published: August 2010

A 19‐year‐old girl, whose sister had died from leukaemia, presented as a typical case of infectious mononucleosis, but after an afebrile period of 9 days agranulocytosis developed. Treatment with prednisone was instituted and a complete remission followed. A few previous reports dealing with this rare complication of infectious mononucleosis are reviewed.
Haemorrhagic Thrombocythaemia Due to Defect Platelet Adhesiveness
Authors: Cronberg Stig , Nilsson Inga Marie , Gydell Karl
Published: August 2010

Platelet adhesiveness was studied in 8 patients with thrombocythaemia with and without bleeding symptoms.

Four patients with haemorhagic thrombocythaemia showed prolonged bleeding time and decreased platelet adhesiveness. Four patients with thrombocythaemia but with normal bleeding time, 3 of whom without bleeding symptoms, had normal adhesiveness.
The Molecular Weight of Factor XII (Hageman Factor) Estimated with Ionizing Radiation
Authors: Haanen C. , Morselt G. , Schoenmakers J. , Maters M. , Braams R.
Published: August 2010

The radiation sensitivity of dried functional proteins is roughly proportional to the molecular weight of the particular proteins under investigation. From a comparison of the radiation sensitivity of Factor XII with those of three different enzymes, the molecular weight of Factor XII could be estimated at approx. 80,000.
Glucose Metabolism in Normal Erythrocytes II Factors Influencing the Hexokinase Step
Authors: Verdier Carl‐Henric de , Garby Lars
Published: August 2010

Factors influencing the rate of glucose conversion in red blood cells have been investigated using haemolysates and a purified hexokinase system.

The KM‐values for glucose and ATP indicate that the glucose concentrations usually occurring in red blood cells are optimal, whereas variations around the physiological ATP‐concentration will strongly influence the conversion rate.

Glucose 6‐phosphate is a potent competitive inhibitor of hexokinase with respect to ATP. Other phosphocompounds tested, fructose 6‐phosphate, fructose 1,6‐diphosphate and 2,3‐diphosphoglycerate, have no inhibitory effect. Inorganic phosphate decreases the inhibition caused by glucose 6‐phosphate. The mechanism for this action is not clear; an interpretation of the data obtained is suggested, however.

In intact red blood cells, inosine blocks the phosphorylation of glucosee. The explanation for this effect appears to be the marked increase in glucose 6‐phosphate and the decrease in inorganic phosphate.
Irregular Blood Group Antibodies in 200,000 Individuals
Authors: Kissmeyer‐Nielsen F.
Published: August 2010

A survey is presented of 4168 sera containing irregular blood‐group antibodies. The antibodies were found during 309,335 antibody screenings and 135,402 cross matchings of blood samples from about 200,000 individuals.

About 50 per cent of the antibodies were anti‐D, sometimes together with other antibodies in Rh negatives (D neg), 8 per cent were Rh antibodies in Rh positives (D pos) and many of these antibodies were detectable only by a two‐stage enzyme technique and not by AHG‐technique.

Almost 15 per cent of the antibodies belonged to the Lewis‐system. There was a significantly increased number in females of the fertile age, and there was a significant decrease in the number of group O individuals among the Lewis‐immunized persons. The low number of group O individuals indicate a hitherto unrecognized relationship between the ABO‐ and Lewis‐systems.

Altogether 2.1 per cent of the individuals described possessed one or more irregular antibodies. The importance is discussed of avoiding complications from these antibodies during blood transfusions. It is concluded that a reliable cross‐match should include a two‐stage enzyme technique as well as the usual saline and AHG tests. It is emphasized that the antibody screening is an efficient prophylactic measure, particularly for smaller hospitals, where complicated cross‐matchings are impractical.
Enhancing Blood Fibrinolytic Activity by a Niacin Compound III. Study of the Activation Mechanism
Authors: AMERY A. , VERMYLEN J. , VERSTRAETE M.
Published: August 2010

The mechanism of the endogenous activation of the fibrinolytic system in humans by a niacin compound has been investigated.

No relation was found between this activation process and changes in the blood glucose level or the oxygen saturation in venous blood. Activation was still possible in reserpine pretreated persons.

After a first injection a decrease in leucocytes was noted. After a series of five injections no activation was obtained and no more leucocyte decrease was observed. At this stage normal activation could still be obtained by applying a cuff on the upper arm with a pressure halfway between systolic and diastolic values, suggesting a different activation pathway.
Studies on Hypoxia IV The Differential Haemopoietic Response to Moderate and Severe Hypoxia
Authors: Yoffey J. M. , Smith N. C. W. , Wilson R. S.
Published: August 2010

Two groups of guinea pigs were subjected to hypoxia at altitude equivalents of 10,000 ft. and 20,000 ft. respectively. Changes in the blood and spleen were observed over a period of 5 days.

In the blood there were more and younger reticulocytes at 20,000 ft. than at 10,000 ft. In both groups polycythaemia developed.

There was no change in the weight of the spleen at 10,000 ft. but a highly significant increase at 20,000 ft.
Crude or Refined Intrinsic Factor in Preparations for the Oral Treatment of Pernicious Anaemia
Authors: Berlin H. , Berlin R. , Brante G.
Published: August 2010

A report is given of a comparative study of the absorption of vitamin B12 with the aid of crude or purified intrinsic factor preparations.

A crude hog's pylorus material, contained in Hepaforte®, was shown to have an intrinsic factor activity, in relation to its 12 binding capacity, about 40 per cent of that in a purified material used in Bendogen®. No qualitative difference in intrinsic factor activity could be traced for the two materials studied.

In pernicious anaemia patients, refractory to standard treatment with vitamin B12 + intrinsic factor, the B12 absorption is generally in the normal range, when the amount of intrinsic factor material given is sufficiently high. Long term clinical trials show, however, that some refractory patients show subnormal serum B12 values even after intrinsic factor doses much higher than those generally recommended. Also in these studies no fundamental difference was found between crude and purified intrinsic factor materials.

Oral treatment of pernicious anaemia with vitamin B12 plus intrinsic factor has no place in modern therapy, especially in view of our present knowledge that a daily oral dose of 1 mg vitamin B12 without intrinsic factor gives full protection in all cases of B12 deficiency.
Periodic Thrombocytopenia or Tidal Platelet Dysgenesis in a Man
Authors: ENGSTRÖM K. , LUNDQUIST A. , SÖDERSTRÖM N.
Published: August 2010

The authors describe the haematologic findings in a man aged 61, who for two years has been under observation with a syndrome of thrombocytopenia, regularly alternating with thrombocytosis of a very regular interval of 39 days. This tidal fluctuation of the platelet counts was within the range 10,000–900,000/μl. There was a synchronous fluctuation of the megakaryocyte numbers in the bone marrow, megakaryocytes being virtually absent in periods of thrombocytopenia. The present condition is by this fact distinct from cyclic thrombotytopenia synchronous with the menstrual cycle in women, in which megakaryocytes are usually plentiful.

This case it to all appearences the third one described in the literature of a condition which we would like to labelad interimtidal platelet dysgenesis.
Desferrioxamine‐Induced Urinary Iron Excretion in Normal and Iron‐Deficient Subjects
Authors: Hallberg Leif , Hedenberg Lars
Published: August 2010

The fraction of intravenously administered desferrioxamine (DF) and radioiron‐labelled ferrioxamine excreted with the urine varied within a narrow range in normal and iron‐deficient subjects. The DF‐induced urinary iron excretion is thus well correlated to the amount of iron chelated in the body.

The variation in the amount of iron excreted with the urine after intravenous administration of 10 mg DF/kg body weight was studied in normal and iron‐deficient men and women. The iron excretion was significantly lower in iron‐deficient than in normal subjects, and it was lower in women than in men.

The results showed that the iron excretion reflected the iron status of the body.
The Influence of Acute and Long‐Term Exercise on Adenosine Diphosphate‐Induced Platelet Thrombosis and Plasma Lipids in Rats Fed a 40 Per Cent Butter Diet
Authors: Nordöy Arne , Newland Hillery , Hamlin & James T.
Published: August 2010

The present study was performed in order to determine whether acute or long‐term exercise would influence the tendency to platelet‐thrombosis and the level of the main plasma lipids. Rats given a 40 per cent butter diet for 7 weeks were exposed to acute and long‐term exercise on a treadmill; one group was not exercised. Except for an increase of the free fatty acids in acute exercised rats, no changes were found in total cholesterol, phospholipids, triglycerides and free fatty acids in the plasma. There was no difference in the incidence of ADP‐induced thrombosis among the three groups. Non‐fasting, non‐exercised animals had higher plasma phospholipid and triglyceride levels than fasting, non‐exercised animals. No difference in the incidence of thrombosis was found between fasting and non‐fasting animals.

No relation could be established between the incidence of thrombosis and acute or long‐term exercise in the rat. Increase of triglyceride, phospholipid and free fatty acid levels in plasma with more than 100 per cent did not influence the incidence of ADP‐induced thrombosis.
Gastric Factors Influencing Iron Absorption in Anaemic Patients
Authors: Jacobs A. , Rhodes J. , Eakins J. D.
Published: August 2010

The absorption of a tracer dose of ferric citrate given to normal human subjects together with a meal was not increased when gastric juice from an anaemic patient was given simultaneously. The increase in iron absorption which occurs in achlorhydric anaemic patients when gastric juice from another anaemic patient is given appears to be due to the acid content of the gastric juice. These findings do not support the hypothesis that there is a substance in gastric juice other than acid which influences iron absorption.
The Effect of Demecolcine on the Oxalate‐Induced Formation of Radial‐Segmented Nuclei (Rieder Cells)
Authors: Norberg Bo , Söderström Nils
Published: August 2010

As evidenced by comparison with oxalate‐treated controls, the formation of radialsegmented lymphocyte and monocyte nuclei in oxalated blood is efficiently inhibited by the colchicine derivative demecolcine in a concentration (1.76 times 10‐7M) slightly above the minimum one required to ensure mitotic arrest in metaphase. This finding is discussed in relation to known data about the dynamics and action mechanism of colchicine and colchicine analogs. It is proposed that the influence of demecolcine on the oxalate‐induced radial segmentation might be explained by the hypothesis that radial segmentation is the result of a contraction of fibrous structures radiating from the centrosomal region, presumably interphasic remnants of the mitotic spindle.
Heavy Metals in the Granules of Eosinophilic Granulocytes
Authors: Pihl E. , Gustafson G. T. , Josefsson B. , Paul K.‐G.
Published: August 2010

An ultrastructural modification of the sulfide‐silver method disclosed that rat and cattle eosinophilic granulocytes contain heavy metals in the non‐crystalloid parts of their specific granules and possibly also in the cell membrane. Metal analysis of isolated granules by means of atomic absorption spectrophotometry indicated that the principal metal contained in the granules is zinc. Consequently the metal demonstrated ultrastructurally in eosinophil granules is thought to be zinc.
Photometric Quantitation of Haemagglutination
Authors: Dybkjaer E.
Published: August 2010

A modified technique for photometric quantitation of haemagglutination was employed in experiments with anti‐A test sera and Arcell suspensions. The agglutinates and the free cells were separated by simple sedimentation. As an absolute separation was impossible in this way, no exact estimation of percentage agglutination could be made. But an estimation of the antibody dilution which removes 50 per cent of the erythrocytes by agglutination and accelerated sedimentation was a far more accurate value for the strength of the antibody than the serological titration commonly used.