bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forecasting with a Bayesian DSGE Model: An Application to the Euro Area
Authors: Smets Frank , Wouters Raf 
Published: October 2004

AbstractIn monetary policy strategies geared towards maintaining price stability, conditional and unconditional forecasts of inflation and output play an important role. In this article we illustrate how modern sticky‐price dynamic stochastic general equilibrium (DSGE) models, estimated using Bayesian techniques, can become an additional useful tool in the forecasting kit of central banks. First, we show that the forecasting performance of such models compares well with a‐theoretical vector autoregressions. Moreover, we illustrate how the posterior distribution of the model can be used to calculate the complete distribution of the forecast, as well as various inflation risk measures that have been proposed in the literature. Finally, the structural nature of the model allows computing forecasts conditional on a policy path. It also allows examination of the structural sources of the forecast errors and their implications for monetary policy. Using those tools, we analyse macroeconomic developments in the euro area since the start of EMU.
EFFECT OF CULTURE AND BLOOM DEVELOPMENT AND OF SAMPLE STORAGE ON PARALYTIC SHELLFISH POISONS IN THE CYANOBACTERIUM ANABAENA CIRCINALIS
Authors: Negri Andrew P. , Jones Gary J. , Blackburn Susan I. , Oshima Yasukatsu , Onodera Hideyuki 
Published: October 2004

ABSTRACT Paralytic shellfish poisons (PSPs) were detected in 24 of 31 bloom samples dominated by the cyanobacterium Anabaena circinalis Rabenhorst, collected from across Austraia. The ability to produce PSPs has been maintained in everal non‐axenic strains of A. circinalis kept in culture, whereas strains that were non‐toxin‐producing when isolated have remained as such. PSPs were detected and quantified by high‐performance liquid chromatography (HPLC), and the structures were confirmed by electrospray mass spectroscopy. The concentration of toxins in PSP positive samples ranged from 50 to 3400 μg.g‐1 dry weight. Toxin profiles were always dominated by the N‐sulfocarbamoyl‐11‐hydroxysulfate C toxins, C1 and C2 (44–85 mol%), with the remainder consisting of gonyautoxins‐2, −3, and −5, decarbamoylgonyautoxins‐2 and −3, saxitoxin, and decarbamoylraxitoxin. N1‐‐hydroxy PSPs, commonly found in marine dinoflagellates, were absent, suggesting that A. circinalis lacks the enzyme responsible for N1‐‐hydroxylation. On a dry weight basis, the amount of toxin in cultured Anabaena circinalis (strain ACMB06)rose significantly (P < 0.05)over time from 570 to 3400 μg.g.‐1 cells in late stationary phase. However, there was no significant trend in cellular toxin quota (toxin per cell) over the life of the culture; this may be explained by variation in cell mass. On average, batch cultures of Anabaena circinalis contained 19% extracellular toxin, which increased slightly over the growth cycle and had a composition similar to that of the intracellular toxins. As cultures aged, the formation of decarbamoyl toxins and increases in theα‐/β‐epimer ratios of C toxins and gonyautoxins were observed. The variation in these components during stationary phase in culture was sufficient to explain the variation in relative PSP composition observed among natural bloom samples. Because decarbamoylgonyautoxins are much more toxic than C toxins on a molar basis, these transformations also lead to an increase in toxicity of the sample or bloom over time. The transformations of PSPs, which occur during aging and sample storage, render the comparison of PSPs by HPLC unreliable for phenotyping Anabaena circinalis, unless strains are cultured, harvested, and analyzed under standard conditions.
DIFFERENCES IN THE PROTEIN PROFILES OF CULTURED AND ENDOSYMBIOTIC SYMBIODINIUM SP. (PYRROPHYTA) FROM THE ANEMONE AIPTASIA PALLIDA (ANTHOZOA)
Authors: Stochaj Wayne R. , Grossman Arthur R. 
Published: October 2004

ABSTRACT One‐ and two‐dimensional sodium dodecylsulfate‐polyacrylamide gel electrophoresis and immunological analyses were used to visualize differences in polypeptides synthesized by Symbiodinium sp. from the anemone Aiptasia pallida when grown in the cultured and endosymbiotic states (freshly isolated zooxanthellae). Surprisingly, a comparison of proteins in cultured and endosymbiotic Symbiodinium sp. revealed only four major polypeptides with similar isoelectric and molecular mass characteristics. Using monospecific antibodies, we demonstrated differences in specific proteins synthesized by the dinoflagellate in the two different growth states. The dimeric, 14 kDa form of the peripheral membrane peridinin‐chlorophyll a binding protein predominates under endosymbiotic conditions, whereas the monomeric, 35 kDa form predominates under the culture conditions used in this study. Antibodies to form II ribulose‐1,5–bisphosphate carboxylase revealed 62 and 60 kDa, forms of this protein in the alga grown as an endosymbiont and in, culture, respectively. Differences in the integral membrane peridinin‐chlorophyll a‐c‐binding proteins were also observed. These results demonstrate that there are major changes in the populations of proteins synthesized by Symbiodinium sp. in response to the conditions in hospite. Such changes may reflect a developmental switch that tailors the physiology of the alga to the conditions encountered in the endosymbiotic state.
INVESTIGATION OF 4‐METHYL STEROLS FROM CULTURED DINOFLAGELLATE ALGAL STRAINS
Authors: Piretti Marco Vincenzo , Pagliuca Giampiero , Boni Laurita , Pistocchi Rossella , Diamante Maurizio , Gazzotti Teresa 
Published: October 2004

ABSTRACT The marine dinoflagellates Prorocentrum micans, Gonyaulax polyedra, Gymnodinium sp., and Alexandrium tamarense, collected from the Adriatic Sea during red‐tide blooms, were cultured to investigate the 4‐methyl sterol constituents. To ascertain a possible influence of cell age on the 4‐methyl sterol content, for one strain (Gymnodinium sp.)we investigated the composition of these constituents at exponential and stationary growing phases. The lipid material extracted with acetone from the lyophilized algal samples was fractionated by thin‐layer chromatography. The 4‐methyl sterols recovered from the layer were converted into the corresponding OTMS derivatives. Nine of 11 constituents were identified by gas chromatography and gas chromatography‐mass spectrometry; only two minor constituents were characterized by their gas chromatographic parameters. All free methyl sterols identified in the algal samples had been detected previously in various dinoflagellates. The 4‐methyl sterol fractions generally contained very few constituents. Except for the Gymnodinium sp. sample, collected at the exponential growing phase (GyD2 exp), which contains 4,24‐dimethylcholestan‐3‐ol as a unique constituent, dinosterol was the major component. Moreover, 4,24‐ethylcholestan‐3‐ol was also an important constituent of both Prorocentrum and Gonyaulax strains, whereas considerable amounts of dinostanol characterized all the Gymnodinium sp. strains. In addition, the latter contained several minor constituents such as 4‐methylcholestan‐3‐ol, 4,24‐dimethylcholesta‐22‐en‐3‐ol, and 4‐methyl‐24‐ethylcholestan‐3‐ol. 4‐Methyl‐24‐methylene‐cholestan‐3‐ol was a constituent of the Gymnodinium sp. sample, collected at the stationary growing phase (GyD2 stat)only, whereas 4‐methylgorgostanol was identified only in the Alexandrium tamarense Gt4 strain. Except for 4‐methyl‐24‐ethylcholesta‐8(14)‐en‐3‐ol, all the methyl sterol constituents from our algae show a saturated polynuclear system. The pathways by which side‐chain modifications occur in dinoflagellate 4‐methyl sterols are considered, and a map of the fragmentation pattern of the trimethylsilyl‐4‐methyl sterols under electronic impact is also reported.
HIGH LOCALIZATION OF RIBULOSE‐1,5‐BISPHOSPHATE CARBOXULASE/OXYGENASE IN THE PYRENOIDS OF CHLAMYDOMONAS REINHARDTII (CHLOROPHYTA), AS REVEALED BY CRYOFIXATION AND IMMUNOGOLD ELECTRON MICROSCOPY
Authors: Morita Eiko , Kuroiwa Haruko , Kuroiwa Tsuneyoshi , Nozaki Hisayoshi 
Published: October 2004

ABSTRACT The distribution of ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) in the chloroplasts of the unicellular green alga Chlamydomonas reinhardtii Dangeard was examined using cryotechnique and conventional fixation for immunogold electron microscopy. Both methods provided essentially identical results, although somewhat higher densities of gold particles indicating Rubisco molecules were recognized in the pyrenoids of cryofixed cells. The gold particles were highly concentrated in the pyrenoid matrix within the chloroplasts. Even when considering the vast difference in volume between the pyrenoid and the rest of the Chloroplast, more than 99% of the total Rubisco labeling in the chloroplast was calculated to be present in the pyrenoid matrix. High localization of Rubisco in the pyrenoid matrix was also recognized regardless of cell age, based on immunofluorescence microscopy of the same en bloc samples. These results are inconsistent with a recent immunocytochemical study employing cryotechnique in which more than 90% of the total Rubisco was recognized in the thylakoid region (thylakoid membranes and stroma) of C. reinhardtii cells. Rubisco highly localized in the pyrenoid matrix may take part in active photosynthetic CO2 fixation and/or the CO2 concentrating mechanism.
VEGETATIVE AND SEXUAL ASPECTS OFDINOPHYSIS PAVILLARDI(DINOPHYCEAE)
Authors: Giacobbe Maria Grazia , Gangemi Ester 
Published: October 2004

ABSTRACTPhases in the life history of the dinoflagellateDinophysis pavillardiSchroeder from cultured phytoplankton assemblages are described. Under stressful conditions, induced in the laboratory through substantial thermic and nutritive changes, vegetative cells divided repeatedly. Scanning electron and light microscopy of dividing specimens showed that thecal fission began with the separation of the sulcal and ventral epithecal plates and the simultaneous dislocation of the pore plates from the right cell half. The posterior progression of the division led to pairs of cells attached antapically, which produced a new wall of reduced size. This phase of the life cycle coincided with the appearance and development of small forms ofD. pavillardi,which displayed cytological features and behavior typical of male gametes, suggesting a process of gametogenesis through depauperating mitotic divisions. Anisogamy occurred at the time of the maximum production of small cells and involved the shedding of thecal components by the smaller gamete and subsequent cytoplasmic fusion and formation of planozygotes. Although the dormancy aspects of this species remain unknown, these observations provide the first evidence of sexuality.
COMPARATIVE MORPHOLOGY, CROSSABILITY, AND TAXONOMY WITHIN THE CALOGLOSSA CONTINUA (DELESSERIACEAE, RHODOPHYTA) COMPLEX FROM THE WESTERN PACIFIC
Authors: Kamiya Mitsunobu , Tanaka Jiro , Hara Yoshiaki 
Published: October 2004

ABSTRACT Systematic studies were undertaken on the Caloglossa continua (Okamura) King et Puttock complex from Japan, Singapore, and Australia, based on morphology and reproductive compatibility. Specimens from Japan had two to six cell rows derived from a nodal axial cell, at the margin opposite the branch, whereas those from Australia possessed only a single cell row. Specimens from Singapore formed one to four cell rows per nodal axial cell and always contained at least one single cell row on any one thallus. These differences were maintained in cultured materials over a range of temperatures or salinities. Type material of C. continua had the same morphology as the Japanese specimens in this study. Carpospores discharged from the Japanese isolate germinated at 10°C, whereas those from Singapore and Australia died at this temperature. In hybridization experiments, the Japanese entity was completely nonfertile with both the Singaporean and Australian isolates. Many pseudocystocarps were produced in the crossing between the male from Australia and the female from Singapore, although the reciprocal combination did not produce any such structures. On the basis of the discontinuous morphology coupled with the complete reproductive isolation, the entities from Singapore and Australia are described here as C. monosticha sp. nov. The entities with multiple cell rows likely expanded their geographic range from tropical regions, where the majority of Caloglossa species are now distributed, to high‐latitude regions, and such an expansion would be associated with acquiring low‐temperature tolerance.
THE CYST‐THECA RELATIONSHIP IN CALCIODINELLUM OPEROSUM EMEND. (PERIDINIALES, DINOPHYCEAE) AND A NEW APPROACH FOR THE STUDY OF CALCAREOUS CYSTS
Authors: Montresor Marina , Janofske Dorothea , Wallems Helmut 
Published: October 2004

ABSTRACT The paratabulate calcareous cyst of Calciodinellum operosum Deflandre was recorded in a sediment trap sample collected in the Bay of Naples (Tyrrhenian Sea, Italy). The germination of this resting stage produced a phototrophic vegetative cell that had the typical plate pattern of a Scrippsiella species. The cyst morphotypes, observed in a clonal culture of this species, ranged from cysts with well‐developed paratabulation to cysts in which the paratabulation was barely visible, to cysts covered by irregularly shaped crystals. The analysis of thin sections of the calcareous cysts using the polarized light microscope equipped with crossed nicols and a gypsum plate showed that the optical orientation of the calcite crystals was tangential in all the morphotypes examined. We suggest that the crystallographic method we describe might provide insights for calcareous cyst taxonomy and phylogeny.
PHYLOGENETIC AFFINITIES OF CRYSONEPHELE PALUSTRIS (CHRYSOPHYCEAE) BASED ON INFERRED NUCLEAR SMALL‐SUBUNIT RIBOSOMAL RNA SEQUENCE
Authors: Saunders Gary W. , A. Hill David R. , Tyler Peter A. 
Published: October 2004

ABSTRACT The nuclear small‐subunit ribosomal DNA sequence was determined from the colonial chromophytic alga Chrysonephele palustris Pipes, Tyler, et Leedale using polymerase chain reaction methods. The inferred ribosomal RNA sequence was included in a multiple alignment, containing heterokont chromophytes, and subjected to molecular systematic analyses in order to determine the phylogenetic relationships of this alga. Chrysonephele palustris grouped within the Chrysophyceae and not in an intermediate position between the Chrysophyceae and Eustigmatophyceae, suggesting that Chrysonephele is not a phylogenetic link between these algal classes.
A PHYLOGENETIC ANALYSIS OF THE SYNUROPHYCEAE USING MOLECULAR DATA AND SCALE CASE MORPHOLOGY
Authors: Lavau Stephanie , Saunders Gary W. , Wetherbee Richard 
Published: October 2004

ABSTRACT The phylogeny of the Synurophyceae was investigated by parsimony analysis of scale case characters and small‐sub unit (18S) ribosomal RNA (rRNA) sequence data. Analysis of 1 eustigmatophycean (outgroup), 3 chrysophycean, and 10 synurophycean 18S rRNA sequences corroborated the inference from ultrastructural information that the Synurophyceae is a monophyletic assemblage. Tessellaria vol‐vocina, which had been tentatively proposed as a member of the Synurophyceae, was confirmed as the earliest lineage within the Synurophyceae by both the molecular analysis and an evaluation of published ultrastructural data. A second set of analyses investigated the relationships among Tessellaria volvocina, 6 Synura species, and 10 Mallomonas species/varieties, with particular reference to the validity of current classifications of the Synurophyceae and the characters upon which they are based. The molecular and scale case phylogenies were not totally resolved but were largely congruent. The data sets were combined to produce another phylogeny, which showed greater resolution. The combined phylogeny weakly supported our representatives of Synura and Mallomonas as monophyletic groupings and also upheld several of the sections within these genera that are recognized by current classifications. However, some changes to the classification and delineation of these genera are recommended and predicted. Both our 18S rRNA sequence and scale case data sets were more appropriate for examining the branching order among the more closely related text rather than resolving the deeper branching points of the synurophycean phylogeny.
MOLECULAR SYSTEMATICS OF ECTOCARPUS AND KUCKUCKIA (ECTOCARPALES, PHAEOPHYCEAE) INFERRED FROM PHYLOGENETIC ANALYSIS OF NUCLEAR‐ AND PIASTTD‐ENCODED DNA SEQUENCES
Authors: Stache‐Crain Birgit , Müller Dieter G. , Goff Lynda J. 
Published: October 2004

ABSTRACT The phylogeny of Ectocarpus and Kuckuckia strains representing widely separated populations from both hemispheres was inferred from sequence analysis of the internal transcribed spacers of the nuclear ribosomal DNA (ITS 1—5.8S‐ITS 2) and the spacer region in the plastid‐encoded ribulose‐bis‐phosphate‐carboxylase (RUBISCO) cistron (partial rbc L‐spacer‐partial rbc S). Both sequences resulted in matching phylogenies, with the RUBISCO spacer region being most informative at the level of genera and species and the internal transcribed spacer sequences at the level of species and populations. Three major clades were formed by strains previously described by morphology and physiology as Kuckuckia, E. fasciculatus, and E. siliculosus, confirming the validity of these taxa. Ectocarpus and Kuckuckia are regarded as sibling taxa with respect to the outgroup species Feldmannia simplex, Hincksia mitchelliae, and Pilayella littoralis. The clade formed by sexual E. siliculosus strains and most asexual Ectocarpus strains was subdivided into several clades that are consistent with geographical races within E. siliculosus. The inferred phylogeny of Ectocarpus corresponds generally with results from cross‐fertilization experiments, morphology, and lipid analysis. A hypothesis on the origin and dispersal of E. siliculosus suggests several natural dispersal events during periods of global cooling as well as recent and possibly anthropogenic dispersal events.
ELEMENTAL COMPOSITION, CORRELATIONS, AND RATIOS WITHIN A POPULATION OF STAURASTRUM PLANCTONICUM (ZYGNEMATALES): AN X‐RAY MICROANALYTICAL STUDY1
Authors: Sagee David C. , Holland Ruth 
Published: October 2004

ABSTRACTIndividual cells of Staurastrum planctonicum (Teil.) within a mixed freshwater phytoplankton sample were analyzed by scanning electron microscope X‐ray microanalysis to determine their elemental composition. X‐ray emission spectra routinely showed clear peaks of P, S, and Cl, plus monovalent (Na, K, and divalent (Mg, Ca) cations. Si and Cu were also present in lower quantities. Concentrations of individual elements (expressed as mmol.kg−1 dry weight) varied widely among cells, with values over the sample population approximating to a normal distribution. Although intracellular anion and cation levels varied considerably, significant correlations occurred between concentrations of monovalent and divalent cations (mean ratio 1.4), major diffusible anions and cations (mean ratio 1,2), and total levels of electropositive and electronegative elements (mean ratio 1.2). The monovalent cations of K and Na occurred at a mean ratio of 1.2 and were not significantly correlated.Concentrations of individual elements (except Si) showed clear positive correlations within the analyses, with 12 highly significant (99% probability) correlations out of 36 possible combinations. Principal factor analysis showed that elemental correlations were determined by two major factors, with two resulting groups of elements—(Na, S, Cl, Ca, Cu) and (Mg, P, K). Statistical relationships between elements followed a clear correlation pattern, which retained its characteristics even when elemental concentrations were expressed per unit P rather than per unit dry weight. Elemental concentrations were closely similar in matching, but not nonmatching, smicells.The statistical pattern of elemental associations noted in Staurastrum parallels that seen in X‐ray micro‐analytical studies of other algae but differs in detail. This pattern of statistical associations has biological implications in terms of cell compartmentation, characterization of different cell types, and cell interactions with their environment.
RECENT APPEARANCE OF CYLINDROSPEMOPSIS (CYANOBACTEIUA) IN FIVE HYPEREUTROPHIC FLORIDA LAKES1
Authors: Chapman Andrew D. , Schelske Claire L. 
Published: October 2004

ABSTRACTObservations of historical and recent phytoplankton samples from five hypereutrophic Florida lakes indicate that nitrogen‐fixing cyanobacteria in the genus Cylindrospermopsis Seenayya et Subba Raju have entered these water‐bodies sometime in the last 30 years. Cylindrospermopsis forms a year‐round bloom in one of the five lakes, dominates seasonally in another, and is at least at times an important component of the phytoplankton community in the remaining three. The increase in abundance of Cylindrospermopsis in Florida lakes could have implications for water management.
DIVERSITY OF HALOGENATED SECONDARY METABOLITES IN THE RED ALGA LAURENCIA NIPPONICA (RHODOMELACEAE, CERAMIALES)1,2
Authors: Masuda Michio , Abe Tsuyoshi , Sato Shinji , Suzuki Teruaki , Suzuki Minoru 
Published: October 2004

ABSTRACTMany morphologically similar, but chemically distinct, populations have been found in the marine red alga Laurencia nipponica Yamada (Rhodomelaceae, Ceramiales) growing in Japan. Each chemical type is characterized by a specific end‐product of halogenated secondaly metabolite synthesis: chamigrane‐type sesquiterpenoids such as prepacifenol and halochamigrene epoxide and C15 bromoethers such as laurencin, laureatin, isoprelaurefucin, epilaurallene, and kumausallene. These seven types of secondary metabolite syntheses remained the same in the wild and under various culture conditions. Because bromoethers and terpenoids are probably synthesized by different metabolic pathways, it is virtually certain that different sets of enzymes participate in their synthesis. Prepacifenol‐ and laureatin‐producing populations were selected as representatives of terpenoid and bromoether groups, respectively. F1 tetrasporophytes derived from crosses between reciprocal, female and male gametophytes of prepacifenol‐ and laureatin‐producing strains bore both types of metabolites, suggesting that the genes Producing these enzyme systems are encoded by nuclear genomes. The F1 gametophytes resulting from the reciprocal crosses produced either prepacifenol or laureatin, and the four individuals derived from spore tetrads (a set of tetraspores derived from a single tetrasporangium) produced either prepacifenol or laureatin in a 1:1 ratio, indicating that genes participating in terpenoid synthsis and those participating in bromoether synthesis are on different loci of homologous chromosomes and are segregated at meiosis (tetrasporogenesis). One individual of this interpopulational F1 gamtophyte produced both parental types of metabolite, perhaps indicating the occurrence of a recombination type. Natural hybrid individuals, including such recombination‐type gametophytes, were found in a sympatric locality at which these two chemical types occur. F1 tetrasporophytes derived from crosses between respective prepacifenol‐ and laureatin‐producing strains and their F1 gametohytes produced only parental‐type metabolite‐producing plants. These results indicate that the diverse chemical types can be referred to as races (chemical races).