bluuebunny/crossref_metadata_2025 huggingface dataset:
INFLUENCE OF NATURAL ULTRAVIOLET RADIATION ON LOTIC PERIPHYTIC DIATOM COMMUNITY GROWTH, BIOMASS ACCRUAL, AND SPECIES COMPOSITION: SHORT‐TERM VERSUS LONG‐TERM EFFECTS1, 2
Authors: Bothwell Max L. , Sherbot Darren , Roberge Andre C. , Daley Ralph J.
Published: August 2006

Growth rates, accumulation dynamics, and species succession of periphytic diatom communities were examined in the presence and absence of natural ultraviolet (UV) radiation using a series of outdoor, continuous‐flow experimental flumes located on the South Thompson River, British Columbia. In a short‐term experiment (2–3 wk), log‐phase growth rates of naturally seeded diatom communities comprised of Tabellaria fenestrata (Lyngb.) Kütz., T. flocculosa (Roth) Kütz., Fragilaria crotonesis Kitton, and F. vaucheriae (Ehr.) Peter. exposed to 90% ambient photosynthetically active radiation (PAR) + UV were 30–40% lower than growth rates under 90% PAR alone. UV inhibition of growth rate was independent of the degree of P limitation within the range of relative specific growth rates (μ:μmax‐P) of 0.5–1.0. In a long‐term trial, inhibition of attached diatom accumulation under 90% PAR + UV during the first 2–3 wk was corroborated. Reduction of full sunlight to 50% PAR + UV prevented the initial inhibition phase. The initial inihibitory effect of 90% PAR + UV on algal accumulation was reversed after 3–4 wk, and by 5 wk total diatom abundance (chlorophyll a, cell numbers and cell biovolumes) in communities exposed to PAR + UV were 2–4‐old greater than in communities protected from UV. Under 90% PAR + UV and 50% PAR + UV, a succession to stalked diatom genera (Cymbella and Gomphoneis) occurred. Species succession under UV radiation doubled the mean cell size of the diatom communities. The shift from inhibition to a long‐term increase in the autotrophic community under PAR + UV compared to PAR alone provides further evidence against the use of short‐term incubation experiments to define the long‐term implications of increases in UVB. These results suggest that the ecological effects of present‐day levels of UVB and UVB:UVA ratios on autotrophic communities are not well understood and might be mediated through complex trophic level interactions.
COMPARATIVE EFFECTS OF pH AND ALUMINUM ON SILICA‐LIMITED GROWTH AND NUTRIENT UPTAKE IN ASTERIONELLA RALFSII VAR. AMERICANA (BACILLARIOPHYCEAE)1
Authors: Gensemer Robert W. , Smith Ralph E. H. , Duthie Hamish C.
Published: August 2006

The acidophilic diatom Asterionella ralfsii cf. var. americana Körn. was grown in continuous culture to examine the influences of both pH and Al on Si‐limited growth and uptake kinetics. In contrast to nutrient‐replete cultures of A. ralfsii, lowering pH from approximately 6 to 5 reduced algal cell density, chlorophyll a concentration, and intensity of in vivo fluorescence (IVF) at steady state. The lower pH treatments were also characterized by lower Si cell quotas and higher residual dissolved Si concentrations in chemostats with similar nutrient supply rates. Physiological responses to Al stress differed from those to pH reduction when cultures were Si‐limited. Nominal Al additions of 20 μmol·L−1 reduced chlorophyll a concentration and IVF values at higher pH, but all other biomass and chemical parameters remained constant at steady state. The combined efects of Al and reduced pH were more severe than either stress alone, inducing culture washout at pH 4.8. Short‐term Si uptake experiments performed at pH 6 showed that Al influenced Michaelis‐Menten parameter estimates. Half‐saturation (Ks and maximum uptake rate (Vm) constants increased approximately 8‐ and 2‐fold in the presence of Al, respectively, but this difference was only significant for Vm. Similar to previously observed effects of Al on cell morphology in A. ralfsii, Si uptake kinetics were more sensitive to Al additions than to Silimited growth per se.
THE BIOCHEMICAL COMPOSITION OF MARINE MICROALGAE FROM THE CLASS EUSTIGMATOPHYCEAE1
Authors: Volkman John K. , Brown Malcolm R. , Dunstan Graeme A. , Jeffrey S. W.
Published: August 2006

The biochemical composition of four strains of microalgae from the class Eustigmatophyceae was determined to assess their usefulness as live feeds for mariculture and to establish characteristic features for use in chemotaxonomic studies. We studied Nannochloropsis salina (strain CS‐190) from Scotland, two strains of Nannochloropsis oculata (CS‐179 and CS‐216) from Japan, and an unnamed eustigmatophyte (CS‐246) isolated from Queensland waters that appears to be closely related to N. oculata. Gross compositional features were similar: total carbohydrate ranged from 5.2% (N. oculata CS‐179) to 8.9% (N. salina) of cell dry weight. Polysaccharide comprised 74% (N. oculata CS‐179) to 88% (CS‐246) of this total. Glucose was the principal polysaccharide sugar (45.2–66.2% of total sugars). Other sugars included fucose, galactose, mannose, rhamnose, ribose, and xylose (2.0–14.0%). Arabinose was a minor constituent in all species (0.6–1.7%). Protein varied from 17.8% (N. salina) to 22.1% (N. oculata CS‐216) of the cell dry weight. The major amino acids were arginine, glutamate, and asparatate (7.2–10.4% of total amino acids), with methionine, cystine, histidine, tryptophan, hydroxy‐proline, ornithine, and γ‐aminobutyric acid much less abundant (0.03–2.6%). Lipid content ranged from 8.2% (N. oculata CS‐216) to 16.9% (N. salina) of cell dry weight, the latter value reflecting enhanced concentrations of triacylglycerols in N. salina. The major fatty acids were palmitic acid (16:0), palmitoleic acid [16:1(n‐7)], and eicosapentaenoic acid [20:5(n‐3)] with lesser amounts of lauric acid (14:0), linoleic acid [18:2(n‐6)], and others. The sterols consisted almost entirely of cholesterol, which is an essential constituent of crustacean diets. Chlorophyll a ranged from 0.6% (N. oculata CS‐216) to 1.7% (N. oculata CS‐179 and N. salina) of cell dry weight. Chlorophylls b and c were not detected. All strains contained a characteristic pattern of carotenoid pigments, which included violaxanthin, β‐carotene, zeaxanthin, and a pigment tentatively identified as vaucheriaxanthin‐ester. The distinctive pigment and lipid compositional data can be used as chemotaxonomic markers for Nannochloropsis and for assigning microalgae to the class Eustigmatophyceae. Nannochloropsis oculata is widely used as an algal feed in mariculture, and based on the similarity of the biochemical data, both N. salina and the unnamed tropical species should also prove to be nutritionally valuable live algal feedstocks. Feeding trials will be needed to confirm this.
VARIATIONS IN FLORIDOSIDE CONTENT AND FLORIDOSIDE PHOSPHATE SYNTHASE ACTIVITY IN PORPHYRA PERFORATA (RHODOPHYTA)1
Authors: Meng Jianxin , Srivastava Lalit M.
Published: August 2006

The diurnal and seasonal variations in floridoside content and floridoside phosphate synthase (FPS) activity were measured in samples of Porphyra perforata J. Ag. growing in the field. Floridoside content generally increased about fourfold from early morning to the middle of the day and then dropped gradually in the afternoon and the evening. On a monthly basis, there was a steady increase in floridoside content from February to May. A similar trend in monthly increase in FPS activity was also observed from February to April. The level of FPS activity varied with the time of day. The highest activity was observed early in the morning shortly after dawn; subsequently, it decreased, reaching about 50% of the peak value late in the afternoon/evening. On a daily as well as seasonal basis, a change in FPS activity correlated with a change in floridoside content. Among environmental factors, floridoside content and FPS activity showed a positive correlation with daylength and temperature on a seasonal basis. However, on a daily basis, salinity and water temperature did not seem to affect the floridoside content or the FPS activity.
A SIGNAL GLYCOPROTEIN WITH α‐d‐MANNOSYL RESIDUES IS INVOLVED IN THE WOUND‐HEALING RESPONSE OF ANTITHAMNION SPARSUM (CERAMIALES, RHODOPHYTA)1
Authors: Kim Gwang Hoon , Fritz Lawrence
Published: August 2006

A variety of fluorescein isothiocyanate‐labeled lectins specific for different sugar moieties were examined as probes for the wound‐healing response in the filamentous red alga Antithamnion sparsum Tokida. Among them, only concanavalin A (ConA) and Lens culrinaris agglutinin (LCA), which have specificity to α‐D‐mannosyl residues, bound specifically to repair cells during the wound‐healing process. When ConA or LCA was added at various time intervals after wounding, it first bound (3 h post‐wounding) as a thin layer at the tips of the adjacent cells. Later (4–5 h post‐wounding) labeling also appeared at the tips of the repair cells. Intense labeling at these sites continued throughout the healing process until repair cell fusion, at which time the lectin labeling was reduced to a narrow ring around the area of fusion. When added to plants prior to wounding and continually monitored, these same lectins acted as inhibitors to the wound‐healing response. Other control lectins showed no inhibitory effects. A crude extract solution obtained from decapitated filaments stimulated the wound‐healing response, and a lectin‐binding component bound strongly to a protein‐binding transfer membrane. These results suggest that the labeled compound is a glycoprotein that has α‐D‐mannosyl residues and is similar to the repair hormone rhodomorphin found in Griffithsia pacifica Kylin.
PARTIAL CHARACTERIZATION OF THE CHLOROPLAST GENOME FROM THE CHROMOPHYTIC ALGA SYNURA PETERSENII (SYNUROPHYCEAE)1
Authors: Wee James L. , Chesnick Joby , Cattolico Rose Ann
Published: August 2006

Hoechst dye 33258‐CsCl density gradients were used to isolate two satellite DNA species from Synura petersenii Korsh. sensu lato, a member of the Synurophyceae. One satellite DNA was identified as the chloroplast genome. The chloroplast genome is the smallest (91.5 kb) published for any chromophyte and approximates the size of the smallest functional chlorophyte chloroplast genome (Codium fragile, 89 kb). The second satellite DNA was small (34.5 kb), and its origin is undetermined. The potential of using the S. petersenii chloroplast genome in comparative studies for evaluating organellar evolution and algal systematics is discussed.
PROROCENTRUM BELIZEANUM, PROROCENTRUM ELEGANS, AND PROROCENTRUM CARIBBAEUM, THREE NEW BENTHIC SPECIES (DINOPHYCEAE) FROM A MANGROVE ISLAND, TWIN CAYS, BELIZE1
Authors: Faust Maria A.
Published: August 2006

Three new benthic dinoflagellate species, Prorocentrum belizeanum, Prorocentrum elegans, and Prorocentrum caribbaeum, from mangrove floating detritus are described from scanning electron micrographs. Species were identified based on shape, size, surface micromorphology, ornamentation of thecal plates, and architecture of the periflagellar area and intercalary band.

Cells of P. belizeanum are round to slightly oval with a cell size of 55–60 μm long and 50–55 μm wide. Areolae are round and numerous (853–1024 per valve) and range from 0.66 to 0.83 μm in size. The periflagellar area of P. belizeanum is a broad V‐shaped depression; it accommodates a flagellar and an auxiliary pore and a flared, curved apical collar. The intercalary band of P. belizeanum is horizontally striated.

Prorocentrum elegans is a small species 15–20 μm long and 10–14 μm wide, with an ovate cell shape. The thecal surface is smooth. Two sizes of valve pores were recognized: large, round pores (20–22 per valve) arranged in a distinct pattern and smaller pores situated in an array along the intercalary band. The periflagellar area is V‐shaped; it accommodates an uneven sized flagellar pore, an auxiliary pore, and an angled protuberant flagellar plate. The intercalary band is transversely striated. It is a bloom‐forming species.

Prorocentrum caribbaeum cells are heart‐shaped with a rounded anterior end and a pointed posterior end. Cells range from 40 to 45 μm long and 30 to 35 μm wide. Thecal surface has two different‐sized pores: large, round pores (145–203 per valve) arranged perpendicularly from the posterior margins, and small, round pores unevenly distributed on the thecal surface. The periflagellar area is ornate. It is V‐shaped with a curved apical collar located next to the auxiliary pore; a smaller protuberant apical plate is adjacent to the flagellar pore. The intercalary band is transversely striated and sinuous. Cells are active swimmers.
ANTIVIRAL ACTIVITY OF CULTURED BLUE‐GREEN ALGAE (CYANOPHYTA)1
Authors: Patterson Gregory M. L. , Baker Kathleen K. , Baldwin Cynthia L. , Bolis Christine M. , Caplan Faith R. , Larsen Linda K. , Levine Ira A. , Moore Richard E. , Moore E. , Nelson Carrie S. , Tschappat Kathryn D. , Tuang Grace D. , Boyd Michael R. , Cardellina John H. , Collins Ralph P. , Gustafson Kirk R. , Snader Kenneth M. , Weislow Owen S. , Lewin Ralph A.
Published: August 2006

Lipophilic and hydrophilic extracts from approximately 600 strains of cultured cyanophytes, representing some 300 species, were examined for antiviral activity against three pathogenic viruses. Approximately 10% of the cultures produced substances that caused significant reduction in cytopathic effect normally associated with viral infection. The screening program identified the order Chroococcales as commonly producing antiviral agents.
A COMPARATIVE STUDY OF TEMPERATURE RESPONSES OF CARIBBEAN SEAWEEDS FROM DIFFERENT BIOGEOGRAPHIC GROUPS1
Authors: Pakker Hans , Breeman Anneke M. , Prud'homme van Reine Willem F. , van den Hock Chris
Published: August 2006

Temperature tolerances were determined for Caribbean isolates (total 31) of seaureds belonging to three distributional groups: 1) species confined to the tropical western Atlantic (Botryocladia spinulifera, Chamaedoris peniculum, Cladophoropsis sundanensis, Dictyopteris justii, Dictyurus occidentalis, Haloplegma duperreyi, and Heterosiphonia gibbesii); 2) amphi‐Atlantic species with a (sub)tropical distribution that have their northern boundary in the eastern Atlantic at the tropical Cape Verde Islands (Bryothamnion triquetrum and Ceramium nitens) or the subtropical Canary Islands (Ceratodictyon intricatum, Coelothrix irregularis, Dictyopteris delicatula, Ernodesmis verticillata, and Lophocladia trichoclados; and 3) species with an am‐phi‐Atlantic tropical to warm‐temperate distribution also occurring in the Mediterranean (Cladophoropsis membranacea, Digenea simplex, Microdictyon boergesenii, and Wurdemannia miniata). For some isolates, growth response curves and temperature requirements for reproduction were also determined. Growth occurred in the range (18)20–30° C with optimum growth rates at 25°–30°C, irrespective of distribution group. Reproduction generally occurred at (20)25°–30° C although there were some exceptions. Species were extremely stenothermal, with those restricted to the western Atlantic surviving a total range of only 10/13° C (between 18/20° and 30/33° C). Tolerance to high temperatures was correlated with vertical position in the iniertidal/subtidal zone rather than biogeography grouping. Species restricted to the subtidal were the least tolerant, with permanent survival at 30° C but not at 33°C. Tolerance to low temperatures was not different in subtidal and intertidal species but was significantly better in am phi‐Atlantic than in western Atlantic species. In the former group, damage occurred at 15°–18° C but in the latter group at 18°‐20° C. We propose that these differences in low‐temperature tolerances in Caribbean populations of species from different distribution groups reflect adaptations to glacial cold‐stress in the tropical eastern Atlantic and subsequent trans‐Atlantic dispersal.
DIURNAL RECRUITMENT PATTERNS IN ALGAE: EFFECTS OF LIGHT CYCLES AND STRATIFIED CONDITIONS1
Authors: Hansson Lars‐Anders
Published: August 2006

The diel pattern in algal habitat shift between sediment and water was recorded above (shallow site) and below (deep site) the thermocline in a stratified, unproductive forest lake. Migrating algae were caught in funnel traps, and the net transport was calculated. Diel recruitment patterns varied temporally within site and spatially between sites. For most species, recruitment and sinking was low at the deep site during stratification. When stratification began to break down in August, the migratory activity increased at the deep site, suggesting that the stratified conditions affected algal migratory behavior. Although light obviously affected algal migration, recruitment often deviated from consistent diel patterns, indicating that simple light‐dark cycles are not sufficient to explain algal migratory patterns. Instead, the study suggests that some algal species have receptors able to detect several environmental variables, including light and variables associated with stratified conditions. Hence, some algal species, but not others, may be able to optimize resource needs by properly adjusting the timing for recruitment from the sediment surface in relation to the risk of being trapped below the euphotic zone by a thermocline not possible to penetrate.
DEGRADATION OF ADENINE BY PROTOTHECA ZOPFII (CHLOROPHYTA)1
Authors: Sarcina Mary , Casselton Peter J.
Published: August 2006

The purines 6‐amino‐2‐hydroxypurine and 6‐amino‐8‐hydroxypurine, not normally associated with purine degradation in algae, were isolated by high‐pressure liquid chromatography from cell extracts of Prototheca zopfii Krüger grown with adenine as the sole nitrogen source.
PHYLOGENETIC RELATIONSHIPS OF SPECIES OF UNCERTAIN TAXONOMIC POSITION WITHIN THE ACROCHAETIALES‐PALMARIALES COMPLEX (RHODOPHYTA): INFERENCES FROM PHENOTYPIC AND 18S rDNA SEQUENCE DATA1
Authors: Saunders Gary W. , Bird Carolyn J. , Ragan Mark A. , Rice Ellen L.
Published: August 2006

Nucleotide sequences of the small‐subunit ribosomal RNA gene(18S rDNA)were newly determined for four members of the related rhodophyte orders Palmariales and Acrochaetiales and were compared by neighbor‐joining and parsimony analyses with four previously published sequences from these orders. A published rDNA sequence fromNemalion helminthoides (VelleyinWithering)Batters(Nemaliales)and a gene sequence determined herein forNothocladus nodosusSkuja(Batrachospermales)were used as outgroups. Sequences were very similar within the Palmariales with a maximum difference of 13 nucleotides out of 1772 between members of the families Palmariaceae and Rhodophysemataceae. Despite similarities in life history, the acrochaetioid algaeRhodo‐chorton purpureum (Lightfoot) Rosenvinge and Rhodothamniella floridula (Dillwyn)J. FeldmanninChristensen were phylogenetically separated withR. purpureum affiliated weakly with Acrochaetiales, and R. floridulaforming a sister branch unequivocally to palmarialean algae of the families Rhodophysemataceae and Palmariaceae. Rhodothamniella floridulais postulated on both molecular and phenotypic grounds(encompassing biochemical and anatomical characters, and life history features)to represent an early lineage, Rhodothamniellaceae fam. nov., in the Palmariales. The family Rhodophysemataceae appeared paraphyletic in the sequence analyses, but a monophyletic Rhodophysemataceae could not be rejected by Templeton‐Felsenstein or Kishino‐Husegawa tests, and the family was clearly monophyletic in analysis of the phenotypic data. The earlier tentative placement of Rhodophysemataceae in the Palmariales rather than Acrochaetiales was confirmed.
BIOCHEMICAL, PHYSIOLOGICAL, AND MOLECULAR ANALYSIS OF SEXUAL ISOLATION IN THE SPECIES COMPLEX CLOSTERIUM PERACEROSUM‐STRIGOSUM‐LITTORALE (CHLOROPHYTA)1
Authors: Sekimoto Hiroyuki , Sone Yutaka , Fujii Tadashi
Published: August 2006

Closterium strains obtained from Japan (NIES‐64 and ‐65)and Nepal (NIES‐67 and ‐68)have been classified as the same taxonomic species; however, they are sexually isolated from each other. When NIES‐64 and ‐65 cells were separately incubated in a medium in which both strains had previously been cultured together, release of protoplasts from both strains was observed. We suggest that factors responsible for the release of protoplasts from cells of both NIES‐64 and ‐65 are produced in a mixed culture of these cells and function during conjugation. These factors, however, had no effect on the release of protoplasts from cells of strains NIFS‐67 or ‐68. Alternatively, a protein that is responsible for the release of protoplasts from cells of NIES‐68, called the protoplast‐release‐inducing protein (PR‐IP),had no effect on the release of protoplasts from cells of strains NIES‐64 or ‐65. When the media obtained from the culture of NIES‐64 and ‐65 cells at various mixing ratios were analyzed by western blotting with antiserum to a 42‐kDa subunit of PR‐IP, no cross reaction was detected. In Southern hybridization analysis, no hybridizing band was observed when genomic DNAs of NIES‐64 and ‐65 cells were probed with cDNAs encoding the two subunits of PR‐IP. We suggest from these results that the factors responsible for the release of protoplasts from NIES‐64 and ‐65 cells are not structurally similar to PR‐IP. It is known that the release of PR‐IP from NIES‐67 cells can be induced by the action of another sex pheromone (PR‐IP inducer)which is released by NIES‐68 cells. In contrast, no protoplast‐release‐inducing activity was observed from either NIES‐64 or ‐65 in a culture medium conditioned by opposite strains. We suggest that the conjugation systems employed by strains NIES‐64/ NIES‐65 and strains NIES‐67 /NIES‐68 differ, and we propose a possible mechanism of sexual isolation between these biological species.
A MOLECULAR PHYLOGENY OF THE GELIDIALES (RHODOPHYTA) BASED ON ANALYSIS OF PLASTID rbcL NUCLEOTIDE SEQUENCES1
Authors: Freshwater D. Wilson , Fredericq Suzanne , Hommersand Max H.
Published: August 2006

Parsimony analyses of rbcL nucleotide. sequences were used to develop hypotheses of relationships among taxa in the taxonomically difficult order Celidiales including species from seven currently recognized genera: Capreolia, Gelidiella, Gelidium, Onikusa, Pterocladia, Ptilophora, and Suhria. Nucleotide. sequences of rbcL from red algae are variable and provide a large number of informative characters for phylogenetic analysis, yet the absence of insertion/deletion mutations allows for the unambiguous alignment of sequences. Species were resolved into 10 well‐.supported major clades representing genera and species complexes. The topological positions of these 10 clades within trees are also well supported and indicate that Gelidium and Pterocladia as currently circumscribed are not monophyletic. These results call for a revision of the classification of the Gelidiales.
INFERRING TAXONOMIC POSITIONS AND TESTING GENUS LEVEL ASSIGNMENTS IN COCCOID GREEN LICHEN ALGAE: A PHYLOGENETIC ANALYSIS OF 18S RIBOSOMAL RNA SEQUENCES FROM DICTYOCHLOROPSIS RETICULATA AND FROM MEMBERS OF THE GENUS MYRMECIA (CHLOROPHYTA, TREBOUXIOPHYCEAE CL. NOV.)1
Authors: Friedl Thomas
Published: August 2006

Complete nuclear‐encoded small‐subunit ribosomal RNA (18S rRNA) coding sequences were determined for the coccoid green algae Dictyochloropsis reticulata (Tschermak‐Woess) Tschermak‐Woess, Myrmecia astigmatica Vinatzer, and M. bisecta Reisigl, to investigate the taxonomic position of Dictyochloropsis Geitler and of the genus Myrmecia Printz. Phylogenies inferred from these data revealed a sister‐group relationship between D. reticulata and certain coccoid green algae that lack motile stages (autosporic coccoids) within the order Microthamniales. The monophyletic origin of the Microthamniales, including autosporic coccoids previously classified in the Chlorophyceae, is clearly resolved by the rRNA sequence data. This finding. shows the considerable taxonomic breadth of that order, whose taxonomic position has been unclear so far. A new class, Trebouxiophyceae, is proposed for this group of green algae. Phylogenetic inferences from the rRNA sequences show paraphyly of the genus Myrmecia. The 18S rRNA sequence data suggest that, among taxa that share similar vegetative cell morphologies, the zoospore characters resolve better the actual genus and species boundaries. Within identical zoospore types, the rRNA data allow further resolution of taxonomic relationships. On the basis of the.se findings, I propose that the genus Friedmannia Chantanachat ± Bold be merged into Myrmecia and that only those species be left in the genus Myrmecia that are identical in particular zoospore characters (i.e. those described in detail for M. israeliensis (Chantanachat ± Bold) comb, nov.), namely M. astigmatica, M. biatorellae (Tschermak‐Woess ± Ptesst) Petersen, and M. israeliensis. Myrmecia bisecta has to be excluded from Myrmecia; its taxonomic position within the Trebouxiophyceae is unclear.
A CLADISTIC ANALYSIS OF THE EVOLUTION AND BIOGEOGRAPHY OF DURVILLAEA (PHAEOPHYTA)1
Authors: Cheshire Anthony C. , Conran John G. , Hallam Neil D.
Published: August 2006

The genus Durvillaea currently has four recognized species found along many exposed, rocky coastlines of the temperate to sub‐Antarctic regions in the Southern Hemisphere. We propose that the current species distributions are related primarily to vicariance events and subsequent speciation associated with the breakup of Gondwana between 40 and 100 Ma. From an ancestral species, a stipitate species developed in the Tasman basin, with separation and speciation resulting in the D. potatorum/ D. willana complex in southeastern Australia and New Zealand. A second line of evolution led to D. chathamensis and D. antarctica characterized by a honeycombed medulla. The extensive distribution of D. antarctica throughout the Southern Hemisphere is related to both vicariance and dispersal events. The status of D. chathamensis as a species distinct from D. antarctica is questioned. The affinities of an as yet undescribed taxon from the Antipodes Islands are thought to be with the D. potatorum complex but require further study before they can be defined more precisely.
Nontraditional Students, Accelerated Programs, Grade Expectations, and Instructor Evaluations
Authors: Gershuny Pamela , Rainey Carolyn
Published: August 2006

This article is intended as both a cautionary tale and an encouraging guide for instructors who are beginning to teach in accelerated programs designed to attract nontraditional students. This article is based, in part, on classroom action research conducted through surveys, observations, exams, and assessments, in an introductory business law course taught in two different universities. Initially, this article seeks to define and examine the particular issues of the nontraditional student using demographic and anecdotal data gathered on nontraditional students at the University of Cincinnati and traditional students at Southeast Missouri State University. Special attention is given to the role of gender and role strain in nontraditional students. Role strain has three dimensions: (1) role conflict from simultaneous, incompatible demands; (2) role overload (insufficient time to meet all demands); and (3) role contagion or preoccupation with one role while performing another. The article also examines the relationship between grade expectations/grade inflation and instructor evaluations.
Impact of heat shock on heat shock proteins expression, biological and commercial traits of Bombyx mori
Authors: CHAVADI VASUDHA B. , SOSALEGOWDA APARNA H. , BOREGOWDA MANJUNATHA H.
Published: August 2006

We report the thermotolerance of new bivoltine silkworm, Bombyx mori strains NB4D2, KSO1, NP2, CSR2 and CSR4and differential expression of heat shock proteins at different instars. Different instars of silkworm larva were subjected to heat shock at 35°C, 40°C and 45°C for 2 hours followed by 2 hours recovery. Heat shock proteins were analyzed by SDS‐PAGE. The impact of heat shock on commercial traits of cocoons was analyzed by following different strategies in terms of acquired thermotolerance over control. Comparatively NP2 exhibited better survivability than other strains. Resistance to heat shock was increased as larval development proceeds in the order of first instar > second instar > third instar > fourth instar > fifth instar in all silkworm strains. Expression of heat shock proteins varies in different instars. 90 kDa in the first, second and third instars, 84 kDa in the fourth instar and 84, 62, 60, 47 and 33 kDa heat shock proteins in fifth instar was observed in response to heat shock. Relative influence of heat shock on commercial traits that correspond to different stages was significant in all strains. In NB4D2, cocoon and shell weight significantly increased to 17.52% and 19.44% over control respectively. Heat shock proteins as molecular markers for evaluation and evolution of thermotolerant silkworm strains for tropics was discussed.
Inducing and isolation of antibacterial peptides from oriental fruit fly, Bactrocera dorsalis Hendel
Authors: DANG XIANG‐LI , TIAN JIN‐HUAN , YI HUI‐YU , WANG WEN‐XIAN , ZHENG MIN , LI YI‐FENG , CAO YANG , WEN SHUO‐YANG
Published: August 2006

One antibacterial activity fraction from an immunized dipteran insect, Bactrocera dorsalis, was isolated and purified by prepurification, ion‐exchange chromatography, gel filtration chromatography and reverse‐phase high performance liquid chromatography (HPLC). The final purified fraction was checked on the Smart system HPLC and was judged as a pure fraction. The results of physical and biological analysis revealed that this fraction is heat stable and showed strong activities against Gram‐positive bacterial growth. It possesses antibicrobial peptide properties and is worth further investigation.
Storage of osmotically treated entomopathogenic nematode Steinernema carpocapsae
Authors: FENG SHI‐PENG , HAN RI‐CHOU , QIU XUE‐HONG , CAO LI , CHEN JING‐HUA , WANG GUO‐HONG
Published: August 2006

The infective juveniles (IJs) of Steinernema carpocapsae‘All’ were osmotically stressed by a mixture of ionic (fortified artificial seawater) and non‐ionic (3.2 mol/L glycerol) solutions to establish a method for osmotic storage of entomopathogenic nematodes. Seven combinations (termed solution A to G) with different proportions of these two solutions were tested, with sterile extra pure water (sepH2O, termed solution H) as a control. The mortality of the IJs at a concentration of 5 × 105 IJ/mL in the solutions A to G, and H were 13.2%, 16.2%, 16.7%, 13.5%, 25.2%, 31.6%, 44.6%, and 1.0%, respectively, after 21 days storage at 25°C. Most of the IJs shrunk and stopped motility after 6–9 hours incubation at 25°C in solutions A to D. Based on the results, solutions A to D and H were chosen to further test the osmotic survival of the IJs at different IJ concentrations (5 × 105, 2.5 × 105, 2 000 IJ/mL) and incubation temperature (30°C, 25°C, 10°C). The resulting IJs were exposed to a high temperature assay (45°C for 4 h, HTA). Osmotically stressed IJs showed improved heat tolerance. The mortality of the IJs increased with the increasing concentrations of the test IJs and the storage temperatures after exposing to the HTA. More than 88.4%, 62.3% or 2.4% of the treated IJs died at the above three IJ concentrations, respectively. At the three IJ concentrations (2 000 IJs/mL, 2.5 × 105 IJs/mL or 5 × 105 IJs/mL), the highest mortality was recorded in solution D (11.6%, 85.9% or 98.0%, respectively), and the lowest mortality in solution B (2. 4%, 62.3% or 86.6%, respectively). No untreated IJs survived after the heat treatment. During 42 days storage at 10°C, the IJs mortality in the solutions A to D and H were 7.19%, 5.97%, 4.41%, 4.34%, and 4.34% respectively, and showed no significant differences. In conclusion, osmotic treatment of the IJs of S. carpocapsae‘All’ in a mixture of ionic and non‐ionic solutions enhances the heat tolerance. The mortality of the IJs after HTA increased with the increasing concentrations of the test IJs and the storage temperatures after exposure to the HTA. The result is promising for the osmotic storage of the entomopathogenic nematodes.
Sublethal effects of malathion on boll weevil (Coleoptera: Curculionidae) fecundity when maintained on cotton squares or artificial diet
Authors: ARMSTRONG JOHN SCOTT , SHOWLER ALLAN T. , SÉTAMOU MAMOUDOU , GREENBERG SHOIL
Published: August 2006

Mated 3‐day‐old female boll weevils, Anthonomus grandis grandis Boheman, reared from field‐infested cotton (Gossypium hirsutum L.) squares were topically treated with an estimated LD50 of malathion (2 μg) to assess its effects on fecundity, oviposition, and body fat condition. Two different food sources, cotton squares and artificial diet, were assessed in malathion‐treated and nontreated (control) weevils. The LD50 caused ∼50% mortality in the square‐fed malathion treatment, but the artificial diet‐fed malathion‐treated weevils were less susceptible. LD50 survivors fed on the squares produced ≥ 9 times more chorionated eggs in the ovaries and oviposited ≥ 19‐fold more than survivors fed artificial diet, regardless of the malathion treatment. Boll weevils that survived a 2 μg LD50 malathion and also fed squares were ∼4.5‐fold leaner than diet‐fed weevils. Our findings demonstrate that non‐resistant boll weevils surviving a sublethal dose of malathion will reproduce without any delay or significant loss in fecundity, and the food source for which boll weevils are maintained when conducting these assays will directly affect the results. The significance of these findings and how they are related to the final stages of eradicating the boll weevil from the US are discussed.
Effect of age on reproductive attributes of an aphidophagous ladybird, Cheilomenes sexmaculata
Authors: OMKAR  , SINGH SATYENDRA K. , SINGH KALPANA
Published: August 2006

The effect of both male and female age was investigated on certain reproductive attributes, viz. mating incidence, mating duration, fecundity, percent egg viability, ratio of reproductive and non‐reproductive periods and reproductive rate, of an aphidophagous ladybird, Cheilomenes sexmaculata (Fabricius). Females started mating at the age of 8 hours post‐emergence (PE) and males at the age of 2 days PE. Mating in the laboratory was a male‐dominated phenomenon. The mating duration and reproductive rate of 10‐day‐old females when mated with males of varying ages increased up to the male age of 60 days, and thereafter decreased, whereas, fecundity, egg viability and ratio of reproductive and non‐reproductive periods increased up to the male age of 50 days, and thereafter declined. However, when females of varying ages were mated with 10‐day‐old males, fecundity and reproductive rate increased up to 40 days of female age, respectively, then decreased. The ratio of reproductive and non‐reproductive periods increased with increasing age of females. Mating age for optimal reproductive output was 10J50‐day‐old males and NE to 40‐day‐old females. Reproductive cessation in males was recorded after 50 days PE, whereas in females at the age of 40 days PE. Higher mating durations lead to elevated reproductive rates. Delay in the reproductive phase was positively correlated with longevity. The results of this study may aid mass multiplication of this ladybird by identifying and promoting usage of adults of optimal age. Our results also enhance our understanding of the effect of age on reproductive attributes in ladybirds.
On the qualification of anechoic chambers; Issues related to signals and bandwidth
Authors: Cunefare Kenneth A. , Badertscher Jeff , Wittstock Volker
Published: August 2006

The qualification of anechoic and hemianechoic chambers requires selection of signal type and acquisition bandwidth to be used. This work demonstrates that, while a broadband random source may be used, the signal at points removed from the source are not composed of random combinations of direct and reflected waves, except in the limit of infinite bandwidth. It is shown that chamber qualification may be represented as finding the ratio of two transfer functions, where one includes the reflected waves, and the other is the free-field transfer function between the source and receiver. Consideration of this approach leads to a generic representation for the deviation from free-field performance where bandwidth is demonstrated to suppress the dominant modulation contributions of reflections. It is demonstrated that pure-tone qualifications will always exhibit a higher deviation from free-field performance than a broadband qualification. Finally, it is shown that the use of an incoherent source model in method-of-images simulations for the broadband performance of anechoic chambers is fundamentally flawed.
Artificial neural network discrimination of black-capped chickadee (Poecile atricapillus) call notes
Authors: Nickerson Carly M. , Bloomfield Laurie L. , Dawson Michael R. W. , Sturdy Christopher B.
Published: August 2006

Artificial neural networks were trained to discriminate between two different notes from the “chick-a-dee” call of the black-capped chickadee (Poecile atricapillus). An individual note was represented as a vector of nine summary features taken from note spectrograms. A network was trained to respond to exemplar notes of one type (e.g., A notes) and to fail to respond to exemplar notes of another type (e.g., B notes). After this training, the network was presented novel notes of the two different types, as well as notes of the same two types that had been shifted upwards or downwards in frequency. The strength of the response of the network to each novel and shifted note was recorded. When network responses were plotted as a function of the degree of frequency shift, the results were very similar to those observed in birds that were trained in an analogous task [Charrier et al., J. Comp. Psychol. 119(4), 371–380 (2005)]. The implications of these results to simulating behavioral studies of animal communication are discussed.
An amplitude quotient based method to analyze changes in the shape of the glottal pulse in the regulation of vocal intensity
Authors: Alku Paavo , Airas Matti , Björkner Eva , Sundberg Johan
Published: August 2006

This study presents an approach to visualizing intensity regulation in speech. The method expresses a voice sample in a two-dimensional space using amplitude-domain values extracted from the glottal flow estimated by inverse filtering. The two-dimensional presentation is obtained by expressing a time-domain measure of the glottal pulse, the amplitude quotient (AQ), as a function of the negative peak amplitude of the flow derivative (dpeak). The regulation of vocal intensity was analyzed with the proposed method from voices varying from extremely soft to very loud with a SPL range of approximately 55dB. When vocal intensity was increased, the speech samples first showed a rapidly decreasing trend as expressed on the proposed AQ-dpeak graph. When intensity was further raised, the location of the samples converged toward a horizontal line, the asymptote of a hypothetical hyperbola. This behavior of the AQ-dpeak graph indicates that the intensity regulation strategy changes from laryngeal to respiratory mechanisms and the method chosen makes it possible to quantify how control mechanisms underlying the regulation of vocal intensity change gradually between the two means. The proposed presentation constitutes an easy-to-implement method to visualize the function of voice production in intensity regulation because the only information needed is the glottal flow wave form estimated by inverse filtering the acoustic speech pressure signal.
The occurrence of the Coanda effect in pulsatile flow through static models of the human vocal folds
Authors: Erath Byron D. , Plesniak Michael W.
Published: August 2006

Pulsatile flow through a one-sided diffuser and static divergent vocal-fold models is investigated to ascertain the relevance of viscous-driven flow asymmetries in the larynx. The models were 7.5 times real size, and the flow was scaled to match Reynolds and Strouhal numbers, as well as the translaryngeal pressure drop. The Reynolds number varied from 0–2000, for flow oscillation frequencies corresponding to 100 and 150Hz life-size. Of particular interest was the development of glottal flow skewing by attachment to the bounding walls, or Coanda effect, in a pulsatile flow field, and its impact on speech. The vocal folds form a divergent passage during phases of the phonation cycle when viscous effects such as flow separation are important. It was found that for divergence angles of less than 20degrees, the attachment of the flow to the vocal-fold walls occurred when the acceleration of the forcing function was zero, and the flow had reached maximum velocity. For a divergence angle of 40degrees, the fully separated central jet never attached to the vocal-fold walls. Inferences are made regarding the impact of the Coanda effect on the sound source contribution in speech.
Repetition Pitch glide from the step pyramid at Chichen Itza
Authors: Bilsen Frans A.
Published: August 2006

Standing at the foot of the Mayan step pyramid at Chichen Itza in Mexico, one can produce a pitchy “chirp” echo by handclapping. As exposed by Declercq et al. [J. Acoust. Soc. Am. 116, 3328–3335 (2004)], an acoustic model based on optical Bragg diffraction at a periodic structure cannot explain satisfactorily the chirp-echo sonogram. Alternatively, considering the echo as a sequence of reflections, and given the dimensions of the pyramid and source-receiver position, the chirp is predicted correctly as a Repetition Pitch glide of which the pitch height is continuously decreasing within 177ms from 796 to 471Hz-equivalent.
On tuning a reactive silencer by varying the position of an internal membrane
Authors: Lawrie Jane B. , Guled Idil M. M.
Published: August 2006

A mode-matching method is used to investigate the performance of a two-dimensional, modified reactive silencer. The modification takes the form of a membrane which is attached to the internal walls of the expansion chamber parallel to the axis of the inlet/outlet ducts. The height of the membrane above the level of the inlet/outlet ducts can be varied and, by this means, the device is tuned. It is shown that the stopband produced by the silencer can be broadened and/or shifted depending upon the height to which the membrane is raised. Attention is focused on the efficiency of the device at low-frequencies—the regime where dissipative silencers are usually least effective. The potential use of the device as a component in a hybrid silencer for heating ventilation and air-conditioning (HVAC) ducting systems is discussed.
Cues for masked amplitude-modulation detection
Authors: Nelson Paul C. , Carney Laurel H.
Published: August 2006

The ability of psychoacoustic models to predict listeners’ performance depends on two key stages: preprocessing and the generation of a decision variable. The goal of the current study was to determine the perceptually relevant decision variables in masked amplitude-modulation detection tasks in which the modulation depth of the masker was systematically varied. Potential cues were made unreliable by roving the overall modulation depth from trial to trial or were reduced in salience by equalizing the envelope energy of the standard and target after the signal was added. Listeners’ performance was significantly degraded in both paradigms compared to the baseline (fixed-level modulation masker) condition, which was similar to those used in previous studies of masking in the envelope-frequency domain. Although this observation was broadly consistent with a simple long-term envelope power-spectrum model, there were several aspects of the data that were not. For example, the steep rate of change in threshold with masker depth and the fact that an optimal amount of envelope noise could enhance performance were not predicted by decision variables calculated directly from the stimulus envelope. A physiologically based processing model suggested a realistic nonlinear mechanism that could give rise to these second-order features of the data.
Translation of bubbles subject to weak acoustic forcing and error in decoupling from volume oscillations
Authors: Krefting Dagmar , Toilliez Jean O. , Szeri Andrew J. , Mettin Robert , Lauterborn Werner
Published: August 2006

A microbubble in a sound wave oscillates in volume and translates unsteadily. The two motions are coupled. In large-scale simulations of the structure of bubble clouds driven by acoustic fields, it has been of significant convenience to decouple volume oscillations and translation, as an approximation. The errors of this decoupling approximation were considered in an earlier presentation [A. J. Reddy and A. J. Szeri, J. Acoust. Soc. Am. 112, 1346–1352 (2002)], in the parameter range of interest in medical ultrasound. In this work, the approximation is reexamined for a much broader range of driving frequencies and bubble sizes. Solving the equation of motion for linearly oscillating bubbles, it is found that even for weak acoustic forcing, the translation speed obtained with the decoupling approximation can be in error as much as 30% relative to the translation speed in the full equations. The error depends on the bubble size, the driving frequency, and the liquid properties. The results are presented in a form convenient for applications. The principal utility of the analysis is for bubbles in microgravity, or in normal gravity driven by a soundfield with a horizontal wave-number vector.
A note on the calibration of pressure-velocity sound intensity probes
Authors: Jacobsen Finn , Jaud Virginie
Published: August 2006

A pressure-velocity sound intensity probe is a device that combines a pressure microphone with a particle velocity transducer. Various methods of calibrating such sound intensity probes are examined: a far field method that requires an anechoic room, a near field method that involves sound emitted from a small hole in a plane baffle, a near field method where the sound is emitted from a hole in a spherical baffle, and a method that involves an impedance tube. The performance of the two near field methods is examined both in an anechoic room and in various ordinary rooms. It is shown that whereas reflections from the edges from a plane baffle disturb the calibration, the method based on a spherical baffle gives acceptable results in a wide frequency range even when the calibration is carried out in a small office, provided that the distance between the hole and the device under test is about 5cm.
Spatial sampling for night levels estimation in urban environments
Authors: Romeu J. , Jiménez S. , Genescà M. , Pàmies T. , Capdevila R.
Published: August 2006

The procedure for spatial sampling in order to find out the relation between Lday and Lnight for urban noise is presented. From that data, other parameters like Ldn or Lden can be easily obtained from Lday values. To this end, a long-term measuring campaign was carried out in eight cities of different types and sizes in northeastern Spain. The statistical treatment of the measures was based on a characterization of the streets in view of their type, including factors such as traffic and land use, which enabled a final classification of six types of streets. The results show that streets of the same type located in different cities do not have the same value for Lday-Lnight, due to socioeconomic factors, but analyzed city by city have a close to normal (or t-Student) distribution. Under this behavior, it is demonstrated that a sample of between 14 and 25 points, depending on the city characteristics, is needed in order to calculate Lday-Lnight, with a confidence level of 95% and a margin of error of ±1dB(A).