bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioerosive Structures of sclerozoan foraminifera from the Lower Pliocene of Southern Spain: a contribution to the palaeoecology of marine hard substrate communities
Authors: SANTOS A. , MAYORAL E.
Published: November 2006

Abstract:  A palaeoecological study of sclerozoan foraminifera of the families Saccamminidae (aff. Sagenina), Lituolidae (Placopsilina), Cibicididae (Cibicides, Dyocibicides, Cibicidella) and Planorbulinidae (Planorbulina and Planorbulinella) that colonized epifaunal bivalves (ostreids and pectinids) during the early Pliocene in southern Spain has led to the recognition of two new boring ichnogenera: Camarichnus ichnogen. nov., with two ichnospecies, C. subrectangularis ichnosp. nov. and C. arcuatus ichnosp. nov., and Canalichnus ichnogen. nov., with one ichnospecies, C. tenuis ichnosp. nov. The first two ichnospecies were produced by adnate lituolids and cibicidids, the last by saccamminids. Their recognition is very important when quantifying populations of these organisms. Colonisation took place after death of the host bivalves, when they acted as very stable substrates whose topography probably controlled the initial settlement pattern of the foraminifera. The colonisation sequence started with the foraminifera (lituolids‐saccamminids‐cibicidids‐planorbulinids) and was followed by vermetid gastropods, serpulids, spirorbids, cheilostome bryozoans and/or ostreids. Preferred orientations and overgrowth relationships between cheilostome bryozoans and serpulids have been detected in this material.
The postcranial skeleton of the Hyposaurinae (Dyrosauridae; Crocodyliformes)
Authors: SCHWARZ DANIELA , FREY EBERHARD , MARTIN THOMAS
Published: November 2006

Abstract:  A detailed description of the postcranial skeleton of the Hyposaurinae is presented, based on the hitherto known and new postcranial material. The postcranial skeleton of the hyposaurine Dyrosauridae differs from that of all other crocodilians by the high neural spines, which can reach up to four times the length of the vertebral body, thoracic ribs, which are five times longer than the adjacent vertebral body, dorsal osteoderms lacking an external keel, deep haemal arches, which reach up to 3·4 times the length of the vertebral body, an ilium with a prominent craniodorsal tubercle, and a scapula with an expanded and lateromedially flattened scapular wing, which makes the scapula 1·5 times as large as the coracoid. The similarity of the postcranium of Dyrosaurus, Hyposaurus, Congosaurus and Rhabdognathus allows a uniform skeletal reconstruction for the Hyposaurinae. Only fragmentary material is known from the Phosphatosaurinae. The comparative osteological description of all hyposaurine specimens known to date establishes a basis for future constructional morphological analyses and the reconstruction of their evolutionary history.
A revision of scombrid fishes (Scombroidei, Perciformes) from the Middle Eocene of Monte Bolca, Italy
Authors: MONSCH KENNETH A.
Published: November 2006

Abstract:  A taxonomic revision of mackerel‐like fishes (Scombridae, Scombroidei, Perciformes) from the Monte Bolca localities in Italy is presented as part of continuing research into phylogenetic relationships of fossil and Recent scombroids. Three new genera are proposed: †Godsilia, †Pseudauxides and †Thunnoscomberoides. In addition, species generally known as †Thynnus bolcensis, †Thynnus lanceolatus, †Scombrosarda propterygia, †Scomberomorus speciosus and †Scomberomorus tenuis are renamed †Thunnoscomberoides bolcensis comb. nov., †Godsilia lanceolata comb. nov., †Auxides propterygius comb. nov. and †Pseudauxides speciosus comb. nov., respectively. †S. tenuis, a nomen nudum, is a junior synonym of †P. speciosus. Provisional phylogenetic hypotheses of these Monte Bolca scombrids are as follows. †Auxides and †Pseudauxides are most likely primitive sister taxa of the mackerels Scomber and Rastrelliger with †Pseudauxides as the most primitive. †Godsilia may be placed between Scombrinae and Scomberomorinae. †Thunnoscomberoides seems to fit between Scombrinae and Thunnini.
A new species of Clevosaurus (Lepidosauria: Rhynchocephalia) from the Upper Triassic of Rio Grande do sul, Brazil
Authors: BONAPARTE JOSÉ F. , SUES HANS‐DIETER
Published: November 2006

Abstract:  Well‐preserved cranial remains of a small sphenodontian lepidosaur from the Upper Triassic Caturrita Formation of Rio Grande do Sul, Brazil, are the first record of the genus Clevosaurus Swinton, 1939 from South America. They represent a new species, Clevosaurus brasiliensis, which is distinguished by a very short antorbital region of the skull (corresponding to about 20 per cent of skull length) and the presence of teeth in addition to two longitudinal rows on the pterygoid. C. brasiliensis most closely resembles C. bairdi from the Lower Jurassic of Nova Scotia (Canada) and C. mcgilli from the Lower Jurassic of Yunnan (China). The discovery of Clevosaurus in the Upper Triassic of southern Brazil provides a significant range extension of this widely distributed sphenodontian genus. Along with other recent finds, it also suggests that there may have been less biotic provincialism among terrestrial vertebrates during the Late Triassic than has previously been assumed.
Bromalites from the Soom Shale Lagerstätte (Upper Ordovician) of South Africa: palaeoecological and palaeobiological implications
Authors: ALDRIDGE RICHARD J. , GABBOTT SARAH E. , SIVETER LUCY J. , THERON JOHANNES N.
Published: November 2006

Abstract:  Bromalites from the Soom Shale are allocated to five main categories on the basis of shape, content and internal structure: those containing broken conodont elements; those containing brachiopod fragments; corrugated/spiral forms; coiled coprolites and wrinkled coprolites. It is impossible to allocate specific bromalites to the organisms that formed them, but the occurrence of crushed discinoid valves in several specimens demonstrates that an effective durophagous predator was present in the Soom Shale community. The presence of fragmented elements of conodonts in other specimens provides direct evidence of tiering within the predatory trophic level in the Soom Shale. Conodonts, other agnathan vertebrates, orthoconic cephalopods and eurypterids are all possible contenders for producing most of the bromalites recorded, but there may have been unrecorded large predators in the community.
Bizarre fossil insects: web‐spinning sawflies of the genus Ferganolyda (Vespida, Pamphilioidea) from the Middle Jurassic of Daohugou, Inner Mongolia, China
Authors: RASNITSYN ALEXANDR P. , ZHANG HAICHUN , WANG BO
Published: November 2006

Abstract:  Three new species, attributed to the extinct family Xyelydidae of the Pamphilioidea (Order Vespida = Hymenoptera), are described from the Middle Jurassic of Daohugou, Inner Mongolia, China: Ferganolyda scylla sp. nov., F. charybdis sp. nov. and F. chungkuei sp. nov. The new material demonstrates that the genus Ferganolyda, which was previously considered to be a morphologically ordinary group of web‐spinning sawflies, is in fact a highly unusual insect taxon. It is characterised, particularly in the male sex, by a huge head (about half as wide as the entire body length) and unusual modification of the antennae. Interpretation of the function of the unusual head and antennae is intriguing but unresolved.
Profile of lupus autoantibodies found in Asia
Authors: MOK Mo‐Yin
Published: November 2006

Systemic lupus erythematosus (SLE) is characterized by the presence of serum hypergammaglobulinaemia and a vast variety of autoantibodies. As SLE is a multifactorial disease, different genetic makeup in different ethnic groups is likely to contribute to variations on disease prevalence, clinical features and autoantibody profiles. In this article, the prevalence of autoantibody profiles and their clinical associations in SLE patients in different Asian countries were reviewed. Anti‐extractable nuclear antibodies including anti‐Ro and anti‐Sm antibodies were found to be more frequent in Eastern patients than Caucasians. On the other hand, the prevalence of antiphospholipid antibodies was lower in Asians. The clinical associations of different autoantibodies are in general similar to those reported in Caucasian cohorts but with some variations in different Asian countries. This may be affected by the method of measurement of these serum autoantibodies, standardization of immunoassays, sample size of the studies and the method of statistical analysis. Immunogenetic studies into some autoantibodies including anti‐Ro/SSA and beta2 glycoprotein I‐dependent anticardiolipin antibodies in Asian lupus patients revealed association with HLA Class II alleles.
The genetics of systemic lupus erythematosus: differences across ethnicities
Authors: KOCHI Yuta , SHIMANE Kenichi , YAMAMOTO Kazuhiko
Published: November 2006

With the acceleration in understanding of the human genome over the past decade, genetic studies have revealed several specific genes associated with a predisposition to systemic lupus erythematosus (SLE). These studies have shown that some of the genetic variants are shared with other autoimmune diseases, and the contribution of each variant to disease differs among different ethnic groups. This article summarizes recent findings from genetic analyses of SLE, with particular emphasis on ethnic differences between Asian populations and others.
Mycophenolate mofetil in the treatment of lupus nephritis: an appraisal of recent data
Authors: CHAN Tak Mao
Published: November 2006

After nearly two decades of relative requiescence, a plethora of new drugs or biologic agents are currently being studied for their therapeutic potential in lupus nephritis. While corticosteroid remains an indispensable component in induction treatment for severe proliferative lupus nephritis, the advent of mycophenolate mofetil (MMF) offers an alternative to cyclophosphamide (CTX), thereby reducing the occurrence of treatment‐related adverse effects, especially in patients requiring multiple courses of therapy for flares. Data on the high treatment efficacy and favourable tolerability of MMF were first reported in Chinese patients with diffuse proliferative lupus nephritis. The improved safety profile of MMF was subsequently confirmed in patients of Caucasian, Hispanic, or African origin, in whom comparable or even better treatment efficacy compared with CTX was observed. However, the response rates differed between these studies. This review aims to provide a succinct update on the reported experience that compared MMF with other immunosuppressive agents in the treatment of lupus nephritis. Considering potential ethnic differences in the disease course and/or treatment response, it remains to be examined whether the favourable long‐term clinical outcomes observed in Chinese patients with corticosteroid and MMF as continuous treatment from induction to maintenance could be reproduced in patients of other ethnic origins. In addition, the relative merit and cost‐effectiveness of MMF against alternative maintenance immunosuppressive agents in the prevention of disease flares deserve further investigation.
Clinical problem‐solving: ‘persistent knee arthritis and prolonged fever in a lupus patient’
Authors: PEREZ Emmanuel C. , NAVARRA Sandra V.
Published: November 2006

Salmonella infections occur more frequently among immunocompromised patients such as those with systemic lupus erythematosus (SLE), with high propensity for extra‐intestinal, including osteoarticular, involvement. Hemarthrosis following trauma, typhoid fever and septic arthritis of the knee developed in a 20‐year‐old female lupus patient with pulmonary hypertension, maintained on corticosteroids and warfarin. This article takes the reader through the clinical problem‐solving process with an SLE patient whose illness is confounded by prolonged fever, with manifestations indistinguishable from that of either lupus activity and/or an infection. Early diagnosis, appropriate antibiotics, and if necessary, surgical intervention are essential principles of management to improve prognosis and prevent long‐term disabilities such as destructive arthropathy.
Management of systemic lupus erythematosus: a brief update on recent advances
Authors: WONG Maida , LAU And C. S.
Published: November 2006

Systemic lupus erythematosus (SLE) has remained one of the most baffling autoimmune rheumatic diseases since it was described in the 19th century. It is a multisystemic, chronic condition that affects individuals with life‐threatening irreversible end‐organ damage and debilitating clinical features. The course of SLE varies from periods of quiescence to ones of exacerbation that may involve any organ system in almost any combination. In particular, SLE typically attacks young women at their childbearing years, which makes the therapeutic goals and pharmacological management challenging. The management of patients with SLE in Asia is further complicated by the facts that these patients tend to have a more severe disease, do not have ready access to medical treatment, are not able to afford expensive drugs, especially novel immunosuppressive and biologic agents, and are more susceptible to serious infective complications. In this article, we will provide a brief update on the currently available drug treatment for SLE, and recent advances in this area. The emphases are on early recognition and monitoring of disease complications and the judicious use of immunosuppressive drugs.
GROWTH AND MORPHOLOGY OF YOUNG GAMETOPHYTES OF PORPHYRA ABBOTTAE (RHODOPHYTA): EFFECTS OF ENVIRONMENTAL FACTORS IN CULTURE1
Authors: Hannach Gabriela , Waaland J. Robert
Published: November 2006

Growth, blade shape and blade thickness of young gametophytes of Porphyra abbottae Krishnamurthy cultured from conchospores were determined at various combinations of temperature (8, 10, 12° C), photon flux density (17.5, 70, 140 μmol·m‐−2·S−1), nutrient concentration (5, 25, 50, 100% f medium) and water motion (0, 50, 100, 150 rpm). Growth (as surface area) was light‐saturated at 70 μmol· m−2· S−1, light‐inhabited at 140 μmol·m−2· S−1, and nutrient‐saturated an 25% f medium. Temperature had no significant effect on growth. Water motion and nutrients had an interactive effect on growth, with water motion having the greatest effect at the lowest nutrient concentrations. Water motion enhanced growth even at saturating nutrient concentrations.

Blade length / width ratio was greater in low light (2.5) than in saturating light (1.9); with increasing water motion the ratio increased from 1.2 to 2.4. Blade thickness (53‐88 μm) was greatest at the highest nutrient concentrations and at the lowest water motion levels. Temperature and light did not have a consistent effect on blade thickness.
PHOTOSYNTHESIS OF TWO MORPHOLOGIES OF NOSTOC PARMELIOIDES (CYANOBACTERIA) AS RELATED TO CURRENT VELOCITIES AND DIFFUSION PATTERNS1
Authors: Dodds Walter K.
Published: November 2006

Colonies of the stream‐inhabiting cyanobacterium Nostoc parmelioides Kützing often contain a single endosymbiotic dipteran larva Cricotopus nostocicola (Wirth), which induces a morphological change from small, spherical colonies to larger, ear‐shaped colonies. At a current velocity of 0 cm · s−1, whole colonies containing the midge showed overall rates of 14CO2 uptake and nitrogenase activity that were higher than those when the midge was absent (sphere‐shaped colonies). Spherical colonies incubated at current velocities of 5‐10 cm · s−1did not show higher rates of 14CO2 or 15N2 incorporation than those with the larvae (ear‐shaped colonies). Ear‐shaped colonies extended well into regions of higher current velocity, whereas spherical colonies did not. Photosynthesis of ear‐shaped colonies was stimulated by increased current velocity, increased inorganic C and decreased O2 concentrations. Moreover, levels of O2 at the surface of midge‐inhabited colonies decreased with increased current velocity. The morphological change induced by the larva is detrimental (lowers photosynthesis and N2 fixation) in quiescent water but not at current velocities above 10 cm · s−1. This is probably a result of higher diffusion of O2 and CO2 associated with the midge‐induced morphology.
COMPARATIVE ANALYSES OF THE DINOFLAGELLATE FLAGELLAR APPARATUS. II. CERATIUM HIRUNDINELLA1
Authors: Roberts Keith R.
Published: November 2006

The three‐dimensional structure of the flagellar apparatus in the gonyaulacoid dinoflagellate. Ceratium hirundinella var. furcoïdes (Schröder) Hub.‐Pest. was determined using serial section electron microscopy. The flagellar apparatus is quite large and consists of several components. The two basal bodies nearly abut at their proximal ends and are separated by an angle of approximately 120° The broad longitudinal microtubular root extends from the cell's left edge of the longitudinal basal body and bends around the sulcal/cingular depression into the cell's left antapical horn. A transverse striated fibrous root is associated with the transverse basal body and a narrow electron dense extension is present along the anterior edge of the transverse basal body. This study revealed severa1 hitherto unreported fibrous components of the flagellar apparatus that link the various microtubular and fibrous components to themselves and to the two striated collars. A large striated fibrous connective links the two striated collars to one another. This fibrous connective is linked to another striated fibrous connective that originates from the longitudinal basal body and lies perpendicular to the longitudinal microtubular root. The readily identifiable and numerous components of the Ceratium flagellar apparatus are comparable to those of other dinoflagellates. The combined presence of well dpveloped striated collars, a striated collar connective, and a basal body angle of approximately 120° indicates that this flagellar apparatus is most like that described for Peridinioid dinoflagellates. Important similarities are also noticeable between this flagellar apparatus and that of Oxyrrhis marina.
UPTAKE, METABOLISM, AND RELEASE OF CAMP IN SELENASTRUM CAPRICORNUTUM (CHLOROPHYCEAE)1
Authors: Francko David A.
Published: November 2006

Uptake rate, intracellular metabolism, and extracellular release of cAMP were examined in batch cultures of the unicellular alga Selenastrum capricornutum Printz (Chlorophyceae). cAMP uptake was linearly dependent on external substrate concentration (0.5 nM to 1 mM) over a broad range of culture cell densities (1.7‐5 × 106cells. mL−1) to mid‐to‐late log phase growth. Chromatographic analyses indicated that the majority of assimilated [3H]‐cAMP was converted within 30 min to radiolabelled material which co‐chromatographed with ADP/ATP and adenosine. About 20% of the (3H]‐label originally added to cells as a [3H]‐cAMP was released to the extracellular medium within 10 min, and chromatographic analyses demonstrated that most of the radiolabelled material was released as cAMP. Analyses with cell suspensions preincubated in KCN or DCMU suggested that cAMP release, but not uptake, was repressed by respiratory or photosynthetic electron flow inhibitors. However, the data were consistent with a passive CAMP uptake mechanism only if much of the assimilated CAMP was bound or compartmentalized.
PH‐DEPENDENCE OF CHLORTETRACYCLINE(CTC)‐INDUCED PLUG FORMATION IN NITELLA FLEXILIS (CHARACEAE)1
Authors: Foissner Ilse
Published: November 2006

The formation of chlortetracycline(CTC)‐induced wall appositions (callose plugs) in Nitella flexilis (L.)Ag. was pH‐dependent in the range between 4.3‐8.3. Plug number and plug diameter increased with the pH of the CTC solution. At pH 4.3 plug formation was light‐dependent and occurred below the alkaline regions of the cell surface which form during photo synthetic assimilation of HCO3−. Inhibition of photosynthesis by 3–(3′,4′‐dichlorophenyl)‐1, 1‐dimethylurea prevented plug formation in the light. Dark‐treated cells could be induced to form plugs by raising the pH of the CTC solution. The formation of large but incomplete plugs in the presence of cytochalasin B is explained by the formation of numerous weak alkaline sites. I suggest that CTC enhances locally the Ca2+content at the cytoplasm near the plasmamembrane. The ionophoric character of CTC is probably more pronounced at high pH mainly because of a weaker binding with cations and a closer contact with the membrane.
PHOTOSYNTHESIS OF ALGAL CULTURES AND PHYTOPLANKTON FOLLOWING AN ACID pH SHOCK1
Authors: Nalewajko Czeslawa , O'Mahony Margaret A.
Published: November 2006

In acidifying lakes, pH decreases abruptly in response to acid precipitation events. We tested the hypothesis that, in comparison to a circumneutral lake, phytoplankton photosynthesis in an acidifying lake is less sensitive to a rapid decrease in pH (acid pH shock).

Phytoplankton in Plastic Lake, which is undergoing acidification, was characterized by a predominance of Pyrrophyta, and phytoplankton photosynthesis decreased to a lesser extent in response to an acid pH shock than the photosynthesis of populations from St. Nora Lake, a circumneutral lake located nearby, in which Pyrrophyta were not abundant. Rates of phytoplankton photosynthesis in acid pH shock experiments were significantly correlated with hydrogen ion but not with dissolved inorganic carbon (DIC) concentrations.

Depression of photosynthesis following an acid pH shock occurred in axenic cultures of Chlorella pyrenoidosa Chick but was not observed in axenic cultures of the acidophilic alga Chlorella saccharophila (Krug.) Nadson or in three species isolated from Plastic Lake. However, the three isolates were not acidophilic during growth. We conclude that phytoplankton in acidifying lakes consists predominantly of species which are tolerant to acid pH for short periods (hours) but cannot grow at these pHs.
MORPHOLOGY AND DEVELOPMENT OFAHNFELTIA PLICATA(RHODOPHYTA): PROPOSAL OF AHNFELTIALES ORD. NOV.1
Authors: Maggs Christine A. , Pueschel Curt M.
Published: November 2006

Ahnfeltia plicata (Hudson) Fries, the type species ofAhnfeltiaFries, is currently assigned to the Phyllophoraceae (Gigartinales). Several morphological and biochemical characters distanceA. plicatafrom the Phyllophoraceae but, because sexual reproduction has never been demonstrated, an alternative placement has not been possible.A. plicatanow is shown to have a heteromorphic sexual life history. Erect branched gametophytes are dioecious. In male sori, spermatangia are cut off transversely from spermatangial mother cells. Female sori form numerous terminal sessile carpogonia. Following fertilization, several zygotes in each sorus fuse facultatively with undifferentiated intercalary cells of the female sorus and cut off gonimoblast initials obliquely outwards. These initials give rise to branching gonimoblast filaments that fuse with apical and intercalary female sorus cells and with each other, then grow radially outward in the compound external carposporophyte and terminate in carposporangia. Carpospores develop in culture into crustose tetrasporophytes identical toPorphyrodiscus simulansBatters. Field‐collectedP. simulanstetraspores grew into erectA. plicataaxes. Tetrasporangia are formed by division and enlargement of crust apical cells followed by sequential enlargement and maturation of tetrasporocytes in an erosive process. Monosporangia are formed in sori on male gametophytes. Pit plugs of both gametophyte and tetrasporophyte phases consist of naked plug cores without cap layers of membranes. Gametophytes exhibit both cell fusions and secondary pit connections whereas tetrasporophytes form cell fusions but lack secondary pit connections. On the basis of the unique female and postfertilization reproductive development and in conjunction with the pit plug structure which is unique among florideophytes, the order Ahnfeltiales, containing the family Ahnfeltiaceae, is proposed.
DIEL CHANGES IN THE COMPOSITION OF PHOTOSYNTHETIC PIGMENTS AND CELLULAR CARBON AND NITROGEN IN PYRAMIMONAS PARKEAE (PRASINOPHYCEAE)1
Authors: Kohata Kunio , Watanabe Masataka
Published: November 2006

Diel changes in mean cell volume, cellular carbon (carbon content per cell), cellular Chl a, C/N ratio, Chl a/carbon ratio and pigment composition were determined for an axenic clonal culture of Pyramimonas parkeae Norris et Pearson through three 12:12 h LD cycles in a laboratory culture tank of 1 m3. Mean cell volume and cellular C, N and most pigments increased during the light period as a result of photosynthesis and decreased with an increase in cell density by phased cell division during the dark period. Chi a and Chi b increased in a parallel manner during the light period. Increases in the diel synthesis pattern of carotenoids varied. Violaxanthin and lutein content increased for a few hours at the beginning of the light period and preceeded that of neoxanthin. The diel synthesis pattern of neoxanthin was similar to that of Chi a. Increases of loroxanthin and its ester form were slower than that of Chi a at the beginning of the light period. A net increase of α‐carotene was observed during the dark period. Mass spectroscopy of carotenoid structure showed a new xanthophyll, loroxanthin dodecenoate, in this species.
EVIDENCE THAT THE NUCLEOMORPHS OF CHLORARACHNION REPTANS (CHLORARACHNIOPHYCEAE) ARE VESTIGIAL NUCLEI: MORPHOLOGY, DIVISION AND DNA‐DAPI FLUORESCENCE1
Authors: Ludwig Martha , Gibbs Sarah P.
Published: November 2006

Chlorarachnion reptans Geitler shows affinities to both the Chlorophyceae and the chloroplast endoplasmic reticulum‐containing chromophyte algae in possessing chlorophyll b and chloroplasts which are limited by four membranes, respectively. In the periplastidal compartment surrounding each of the four to eight chloroplasts of a C. reptans cell are putative eukaryotic‐sized ribosomes, scattered tubules and vesicles, and a small double‐membrane‐limited nucleus‐like organelle named the nucleomorph. The nucleomorphs display 4′‐6‐diamidino‐2‐phenylindole (DAPI)fluorescence which is sensitive to DNase digestion, but not to treatment with RNase. The nucleomorphs also contain a fibrillogranular body which resembles a nucleolus. Nucleomorph division occurs by the sequential infolding of the inner and outer envelope membranes and subsequent constriction in two, with no involvement of microtubules. In all these characteristics, the nucleomorphs of C. reptans are similar to the cryptomonad nucleomorph which has been hypothesized to be the vestigial nucleus of an ancestral red alga which gave rise to the chloroplasts of the Cryptophyceae. The presence of chlorophyll b and the contents and morphology of C. reptans chloroplast compartments suggest a green algal origin for the chloroplasts of these cells. The discovery of a second organism with a DNA‐containing, nucleus‐like organelle in its chloroplast compartment lends strong support to the hypothesis that the chloroplasts of many algae have evolved from eukaryotic endosymbionts.
INFLUENCE OF CELL SHAPE AND SIZE ON ALGAL COMPETITIVE ABILITY1
Authors: Grover James P.
Published: November 2006

Allometric relations between physiological processes and cell volume and surface area are combined with the variable‐internal‐stores model of growth to predict the ability of hypothetical phytoplankton to compete for phosphorus at equilibrium. The analysis shows that for spherical cells, smaller cells are better competitors than large ones. For cells that are very elongated in shape, however, large cells are often better competitors than small ones. The cells predicted to be the best competitors compare favorably in size and shape with the species observed to dominate in phosphorus‐limited chemostats at equilibrium.
UNIQUE LOCATION OF THE PHYCOBILIPROTEIN LIGHT‐HARVESTING PIGMENT IN THE CRYPTOPHYCEAE1
Authors: Spear‐Bernstein Laurel , Miller Kenneth R.
Published: November 2006

The cryptophyte algae, or cryptomonads, comprise a small algal group with a unique photosynthetic apparatus. Both a chlorophyll a/c2light‐harvesting complex and a phycobiliprotein antenna (which can be either phycoerythrin or phycocyanin) are present, with the phycobiliprotein playing the major role in harvesting light for photosynthesis. Longstanding circumstantial evidence suggested that, in cryptophytes, the phycobiliprotein is located in the intrathylakoid space (thylakoid lumen) rather than on the outer surface of the thylakoid as part of a phycobilisome as in other algae. We used immunogold labeling to show conclusively that 1) the phycoerythrin (PE) of the cryptophyteRhodomonas lensPascher and Ruttner is located within the intrathylakoid space, 2) the PE is not exclusively bound to the thylakoid membrane but instead is distributed across the thylakoid lumen and 3) a fraction of this PE is tightly associated with the thylakoid membrane. The thylakoids are not everted to compensate for this unusual arrangement. The location of the major light‐harvesting pigment on the “wrong” side of the otherwise very normal photo‐synthetic membrane is unexpected, unique to the cryptophytes, and, remarkably, does not impair the photosynthetic abilities of this organism. A model is presented which incorporates these results ‐with previous information to give a complete structural picture of the cryptophyte light‐harvesting apparatus.
HEAVILY LICHENIZED PHYSOLINUM (CHLOROPHYTA) FROM A DIMLY LIT CAVE IN MISSOURI1
Authors: Davis Joseph S. , Rands David G. , Lachapelle Mario
Published: November 2006

Heavily lichenized Physolinum monile (De Wildem.) Printz from damp limestone walls in a dimly lit cave located in Missouri was studied from fresh collections and specimens fixed in situ, and from cultures. The narrow (7‐13 μm wide thallus), profusely branched plant consisted of filaments of the alga P. monile ensheathed by clear fungal cells (5‐8 in a single layer) that adhered tightly to each other and completely covered the algal cells. Cells of P. monile filaments were uninucleate, each containing a single massive chloroplast with numerous tightly packed thylakoids and lipid droplets and surrounded by a thin layer of cytoplasm. No plasmodesmata occurred in the cellulosic crosswalls between adjacent cells. The ensheathing fungal cells contained concentric bodies, produced haustoria that penetrated the algal cells, and developed hyphae (the tips of which formed clusters of conidia). Ensheathing fungal cells were well situated and constructed to concentrate light on the algal cells. Colonies of blue‐green algae were firmly attached to the surface of the fungal cells. The association was slow growing but frequently produced and released aplanospores from the algal cells. Aplanospores were single (not attached to each other) with smooth walls or united in groups of two or more. Structures resembling lichen soredia, composed of aplanospore‐like cells attached to one or more comdia‐like cells, commonly occurred among the lichenized Physolinum filaments. The single chloroplast that occupies most of the cell's volume, the numerous, tightly packed thylakoids, and light focusing by ensheathing fungus cells may enable the organism to survive in a dimly lit environment. Because the filamentous alga reproduces only by aplanospores, we propose resurrection of the genus Physolinum. The lichenized Physolinum somewhat resembles the lichens Coenogonium moniliforme Tuck. and Cystocoleus Thwaites.
AN ENCYSTMENT STAGE, BEARING A NEW SCALE TYPE, OF THE ANTARCTIC PRASINOPHYTE PYRAMIMONAS GELIDICOLA AND ITS PALEOLIMNOLOGICAL AND TAXONOMIC SIGNIFICANCE1
Authors: van den Hoff John , Burton Harry R. , Vesk Maret
Published: November 2006

Cysts of the Antarctic prasinophyte Pyramimonas gelidicola McFadden were found in water samples from a fjord and a saline lake in the Vestfold Hills, Antarctica Unialgal cultures of P. gelidicola from Ace Lake produced cysts. After ca. five weeks, tile cysts settled and adhered to the bottom of the culture flask. The cyst wall was covered by a scale type not seen on the flagellated cells; however, the base of the cyst scale was similar to the box scales of P. gelidicola motile cells. Cyst scales were also found off the continental shelf in Prydz Bay.

In a 1.7 m sediment core taken from Ace Lake, both cyst scales and box scales of P. gelidicola occurred at most depths. Differences in the ratio of these two scale types at different depths in the core may indicate past ecological changes in the lake. Upper sediments of the core were dated at 5310 ± 90 yrs B.P., indicating that prasinophyte scales may be recognizably preserved for extended periods.

P. gelidicola was widely distributed in saline lakes of the Vestfold Hills with salinities of 3.2–133% and temperatures ranging from – 5.0 to 10.4°C. This is the first report of encystment of P. gelidicola and, to our knowledge, is the first record of a prasinophyte with two distinctly different scale types occurring on cells during different stages of the life history.
NITROGEN LIMITATION IN ISOCHRYSIS GALBANA (HAPTOPHYCEAE). II. RELATIVE ABUNDANCE OF CHLOROPLAST PROTEINS1
Authors: Falkowski Paul G. , Sukenik Assaf , Herzig Ronny
Published: November 2006

Using spectroscopic, biophysical and immunological techniques, we assayed the relative abundance often chloroplast proteins and protein complexes in the marine haptophyte, Isochrysis galbana Green, grown at nine steady‐state dilution rates in nitrogen‐limited chemostats. The proteins included Photosystem I reaction center (RCI) chlorophyll protein, CP1; Photosystem II reaction center (RC II) protein, D1; two chlorophyll a‐binding apoproteins, CP 43 and CP 47; 33 KDa oxygen evolving protein, OEC 33; α subunit of coupling factor, CF1α; large (LSU) and small subunits (SSU) of ribulose 1,5‐bisphosphate carboxylase, RuBisCO; the chlorophyll a/c/fucoxanthin protein complex, LHCP; and cytochrome b6/f. Seven of the ten protein complexes are encoded in the chloroplast, two are encoded in the nucleus and one shares chloroplast and nuclear genomes. Over the range of dilution rates (0.96‐0.18 d−1) cell N decreased 42% and cellular chlorophyll a decreased 50%; however, the stoichiometric proportion of RC II: cytochrome b6/f: RC I remained constant, averaging 1:3.3:0.8. In contrast, RuBisCO / PS II decreased by 58%. The light harvesting chlorophyll a/c/fucoxanthin protein complex increased relative to RC II; however, as cells became more nitrogen limited the fraction of total cell nitrogen contained in RuBisCO decreased from 21.3 to 6.7%, whereas that of the light harvesting complex remained relatively constant, averaging 6.8%. Our results generally support the hypothesis that in nitrogen limited cells, proteins encoded in the nuclear genome are synthesized preferentially over those encoded in the chloroplast.
SURVIVAL OF SCENEDESMUS ACUMINATUS (CHLOROPHYCEAE) IN DARKNESS1
Authors: Dehning Irmtraut , Tilzer Max M.
Published: November 2006

Survival of the green alga Scenedesmus acuminatus Lagerh. in complete darkness was studied in axenic batch cultures at 7°C and 22°C for three months. The decrease in cell numbers was insensitive to temperature and slower than the loss of dry weight. However, the lag phase before cells began to lyse was more than twice as long at 7° C than at 22°C. The decline in cellular carbohydrates and proteins occurred in two phases. During the first 3‐4 days, the decrease in cellular carbohydrate levels was significantly accelerated and temperature‐sensitive. Pyrenoids disappeared within 5 days of darkness. Proteins showed 20‐fold higher degradation rates at 22°C than at 7°C during the first 4 days. Thereafter, the rates of carbohydrate and protein decomposition were slow and temperature‐independent. By contrast, lipids degraded only little at virtually constant and temperature‐insensitive rates over the entire experimental period.

After three months of dark incubation, about 40% of the remaining cells had retained their growth potential. However, the lag phase, after which cell division was resumed when exposed to light, increased with the duration of the previous dark period. The decrease in photo synthetic potential, which was more pronounced at 22° C than at 7° C, was apparent both in declining maximum assimilation numbers and maximum quantum yields. Cellular chlorophyll a concentrations in surviving cells decreased only slightly.

We conclude that the primary means by which S. acuminatus survives extended dark periods is by reduction of catabolic reactions. This was suggested by the slow loss of cell weight. No evidence of significant heterotrophic acetate uptake was found. The initial temperature‐dependence of most observed processes indicates that in natural environments chances for survival of algae are augmented by the prevailing low water temperatures.
TRANSIENT PHOTOSYNTHETIC RESPONSES OF NITROGEN‐DEPRIVED PETALONIA FASCIA AND LAMINARIA SACCHARINA (PHAEOPHYTA) TO AMMONIUM RESUPPLY1
Authors: Williams Susan L. , Herbert Stephen K.
Published: November 2006

Petalonia fascia (Müller) Küntze and Laminaria saccharina (L.) Lamouroux cultured in N‐free medium exhibited transient depressions in light‐limited and light‐saturated gross O2 evolution within 0.3 h following ammonium resupply. Recovery of photosynthesis to pre‐resupply rates required 24 h. After 6‐9 d of ammonium resupply, photo synthetic rates of N‐deprived algae were similar to those of control plants grown with nitrogen. This study demonstrates that N‐deprived macroalgae exhibit suppressed photosynthesis upon nitrogen resupply similar to many microalgal species. The apparent slowness of short‐term recovery from nitrogen‐elicited photo synthetic suppression may have ecological consequences for macroalgae under conditions of patchy nutrient supply.
BIOMINERALIZATION OF THE STALKS OF ANTHOPHYSA VEGETANS (CHRYSOPHYCEAE)1
Authors: Lee Robert Edward , Kugrens Paul
Published: November 2006

Mineralized stalks of the chryophyte Anthophysa ve‐getans (O. F. Müller) Stein were examined by electron microscopy, and the composition of the stalks was determined by energy dispersive x‐ray microanalysis. Colonies grown in water from a local lake (Dowdy Lake) had mineralized stalks that were colorless and composed mainly of spherules of calcium phosphate up to 0.7 μm in diameter. The addition of 0.1 mM MnCl2 to the culture medium resulted in deeply orange‐brown stalks mineralized primarily with minute granules of a manganese compound. The addition of 0.1 mM FeCl3 to the culture media resulted in light yellow stalks mineralized mainly with small granules of an iron compound. The addition of 0.1 mM MgCl2 or KCl resulted in stalks that were similar in appearance and composition to the colonies grown in culture medium alone. These results show that the composition of the mineralized stalks of A. vegetans is dependent on the elements present in the culture medium. This is also the first time that calcium phosphate has been reported as a mineralization product in the chrysophytes.
EVIDENCE FOR SEXUAL REPRODUCTION IN THE PRIMITIVE GREEN ALGA NEPHROSELMIS OLIVACEA (PRASINOPHYCEAE)1
Authors: Suda Shoichiro , Watanabe Makoto M. , Inouye Isao
Published: November 2006

Evidence for a specialized sexual process in Nephroselmis olivacea Stein is presented. This alga is a member of the Prasinophyceae, which is regarded by some as the most primitive Class of green plants. N. olivacea has a heterothallic type of mating system. Plus and minus gametes were morphologically similar but showed different behaviors during the mating process. The minus gamete settled to the substratum, attaching by its ventral side. The plus gamete attached to the dorsal side of the minus gamete by the region near the flagellar bases of the plus gamete. The mature zygotes were spherical and strongly adhered to the substratum. After zygote germination, two biflagellate daughter cells, each with two pyrenoids were liberated. These cells divided, resulting in four vegetative cells, each with a single pyrenoid.
DETECTION OF CHLOROPHYLLS c1, c2 AND c3 IN PIGMENT EXTRACTS OF PRYMNESIUM PARWM (PRYMNESIOPHYCEAE)1
Authors: Fawley Maruin W.
Published: November 2006

Three chlorophyll c‐type pigments were separated by reversed‐phase high Performance liquid chromatography and thin‐layer chromatography from pigment extracts of the prymnesiophyte, Prymnesium parvum Carter. Based on spectral characteristics, retention times, and comparison with reference pigments isolated from the diatom Phaeodactylum tricornutum Bohlin, two of these pigments were identijied as chlorophyll c1 and c2. The other pigment was identified by its absorption spectrum and thin‐layer chromatography retention times as the newly described chlorophyll c3. However, in other prymnesiophytes so far examined, chlorophyll c1 and chlorophyll c3 were present with no chlorophyll cl. The discovery of chlorophyll c3 with chlorophyll c1 and chlorophyll c3 in Prymnesium parvum therefore represents the first report of this combination of pigments in prymnesiophytes.
EFFECT OF POLYCARBONATE CONTAINERS ON THE GROWTH OF TWO SPECIES OF MARINE DIATOMS1
Authors: Metaxas Anna
Published: November 2006

Two species of marine diatoms [Skeletonema costatum (Greville) Cleve and Thalassiosira pseudonana (Hustedt) Hasle and Heimdal] were grown in glass and polyarbonate containers. S. costatum exhibited a signzJicantly lower exponential growth rate and maximal yield and a signajcantly longer lag phase when grown in polycarbonate. Exponential growth rate and maximal yield of T. pseudonana was significantly reduced (P < 0.05 in all cases). This study suggests that a difference in diatom growth between glass and polyarbonate containers might arise in certain cases. However, such a difference may not be detectable with all biomass measurement techniques or with low within‐treatment replication.
PARTIAL PURIFICATION OF FRUCTOSE 1,6‐BISPHOSPHATASE FROM THE MARINE MACR0ALGA BRYOPSIS CORTICULANS (CHLOROPHYCEAE)1
Authors: Yu Shukun
Published: November 2006

Fructose 1,6‐bisphosphntase (FRPase, EC 3.1.3.11) partially purified from the marine green seauleed Bryopsis corticulans Setch exhibited a single active Peak on a Sephadex G‐200 column but two distinct peaks on a DEAE cellulose column. The two fractions shared the same molecular weight of 162,000 as revealed by gel filtration. The FBPase from Bryopsis was unstable in storage elen zlheii an appropriatr amount of 2‐mercaptoethnnol was present unless Mn2+and glycerol uere added in the buffer. Preliminary results indicate that the FBPase is of chloroplastic origin.
CELL DIVISION PATTERNS AND DIURNAL CYCLE OF PORPHYRA ABBOTTAE (RHODOPHYTA, BANGIALES) CARPOGONIAL AND CARPOSPORE DEVELOPMENT1
Authors: Cannon Marilyn I.
Published: November 2006

Post‐fertilization development of carpospores in Porphyra is a well‐documented phenomenon. Development of the pre‐fertilization carpogonial cells from vegetative cells, however, has not been previously described. In Porphyra abbottae Krishn., a rock? intertidal monostromatic species occurring from British Columbia to central California, large cells, designated hue CIS “procarpogonial mother cells” (PMCs), initiated the formation of the carpogonial cells. The PMCs formed during late night mitoses beginning at 0200 h with cytokinesis from 0300‐0500 h during short day periods of 10:14 h LD in northern California (38°20′N, 123°03′W and 36°37′N, 121°55′W). The PMC cut off numerous smaller cells which in turn divided equal. Approximately 12 h Inter, at 1500 h (day 1) the Smaller cells were recognizable as carpogonial cells by the presence of trichogynes growing from the cytoplasm out through the cell wall to the thallus surface. In another 24 h (day 2), the fertilized carpogonia had divided into carpospore packets. Spores were released at 1500 h the following day (day 3), their projection creating escape channels through the cell walls.
Personal Values, Beliefs, and Ecological Risk Perception
Authors: Slimak Michael W. , Dietz Thomas
Published: November 2006

A mail survey on ecological risk perception was administered in the summer of 2002 to a randomized sample of the lay public and to selected risk professionals at the U.S. Environmental Protection Agency (US EPA). The ranking of 24 ecological risk items, from global climate change to commercial fishing, reveals that the lay public is more concerned about low‐probability, high‐consequence risks whereas the risk professionals are more concerned about risks that pose long‐term, ecosystem‐level impacts. To test the explanatory power of the value‐belief‐norm (VBN) theory for risk perception, respondents were questioned about their personal values, spiritual beliefs, and worldviews. The most consistent predictors of the risk rankings are belief in the new ecological paradigm (NEP) and Schwartz's altruism. The NEP and Schwartz's altruism explain from 19% to 46% of the variance in the risk rankings. Religious beliefs account for less than 6% of the variance and do not show a consistent pattern in predicting risk perception although religious fundamentalists are generally less concerned about the risk items. While not exerting as strong an impact, social‐structural variables do have some influence on risk perception. Ethnicities show no effect on the risk scales but the more educated and financially well‐off are less concerned about the risk items. Political leanings have no direct influence on risk rankings, but indirectly affect rankings through the NEP. These results reveal that the VBN theory is a plausible explanation for the differences measured in the respondents' perception of ecological risk.
Improving SVT Discrimination in Single‐Chamber ICDs: A New Electrogram Morphology‐Based Algorithm
Authors: KLEIN GEORGE J. , GILLBERG JEFFREY M. , TANG ANTHONY , INBAR SHMUEL , SHARMA ARJUN , UNTERBERG‐BUCHWALD CHRISTINA , DORIAN PAUL , MOORE HANS , DURU FIRAT , ROONEY ETHAN , BECKER DANIEL , SCHAAF KATIE , BENDITT DAVID ,   FOR THE WORLDWIDE WAVE INVESTIGATORS
Published: November 2006

Introduction: Wide‐spread adoption of ICD therapy has focused efforts on improving the quality of life for patients by reducing “inappropriate” shock therapies. To this end, distinguishing supraventricular tachycardia from ventricular tachycardia remains a major challenge for ICDs. More sophisticated discrimination algorithms based on ventricular electrogram morphology have been made practicable by the increased computational ability of modern ICDs.

Methods and Results: We report results from a large prospective study (1,122 pts) of a new ventricular electrogram morphology tachycardia discrimination algorithm (Wavelet™ Dynamic Discrimination, Medtronic, Minneapolis, MN, USA) operating at minimal algorithm setting (RV coil‐can electrogram, match threshold of 70%). This is a nonrandomized cohort study of ICD patients using the morphology discrimination of the Wavelet algorithm to distinguish SVT and VT/VF. The Wavelet criterion was required ON in all patients and all other supraventricular tachycardia discriminators were required to be OFF. Spontaneous episodes (N = 2,235) eligible for ICD therapy were adjudicated for detection algorithm performance. The generalized estimating equations method was used to remove bias introduced when an individual patient contributes multiple episodes. Inappropriate therapies for supraventricular tachycardia were reduced by 78% (90% CI: 72.8–82.9%) for episodes within the range of rates where Wavelet was programmed to discriminate. Sensitivity for sustained ventricular tachycardia was 98.6% (90% CI: 97–99.3%) without the use of high‐rate time out.

Conclusions: Results from this prospective study of the Wavelet electrogram morphology discrimination algorithm operating as the sole discriminator in the ON mode demonstrate that inappropriate therapy for supraventricular tachycardia in a single‐chamber ICD can be dramatically reduced compared to rate detection alone.