bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Factors Controlling the Distribution of Two Pond‐Dwelling Ciliates with Algal Symbionts (Frontonia vernalis and Euplotes daidaleos)1
Authors: Finlay B. J. , Berninger U.‐G. , Stewart L. J. , Hindle R. M. , Davison W. 
Published: May 2007

ABSTRACTThe vertical distributions of two pond‐dwelling zoochlorellae‐bearing ciliates (Euplotes daidaleos Diller & Kounaris, 1966 and Frontonia vernalis Ehrenberg, 1838) were monitored over a 24‐h period. Both species maintained peak abundance at a low O2 level (usually < 1 mg/liter). They did not migrate in response to the changing light level. Experiments with laboratory cultures indicated that the characteristic distribution in an O2 gradient in the dark was largely controlled by the oxygen tension. The increased motility in anoxia and high pO2 was independent of large changes in pCO2 and pH. Ciliates living in anoxia or a very low pO2 would migrate out of the dark and into the dimly lit (10 μE m‐2 sec‐1) part of a glass cell because there they could photosynthesize, produce O2, and create a suitable oxygenated microenvironment; a further increase in the light level caused a slow migration out of the light. Similar migrations were observed when the light level remained low but the pO2 was artificially raised. Ciliates suspended in 1 μM DCMU (an inhibitor of photosynthetic O2 evolution) took longer to migrate into the light and they did not avoid high light levels (> 100, μE m‐2 sec‐1)‐ Frontonia suspended in water with a pO2 of 1% aggregated at a low light level (1 μE m‐2 sec‐1); peak daytime abundance in the pond occurred at about this light level. Frontonia vernalis tends to swim vertically upwards (anterior end up) when suspended in anoxic water. This apparent negative geotaxis compensates for the high sedimentation velocity (0.36 mm sec‐1) of this large ciliate and facilitates its aggregation at the metalimnion. The O2 tension appears to be the principal factor controlling the vertical distributions of both species. Occasional, enhanced convection within the metalimnion has a secondary influence. Light influences the vertical profile only if it promotes photosynthesis and increases the intracellular pO2.
Transmission and Ecology of Trypanosomatid Flagellates of Water Striders (Hemiptera: Gerridae)
Authors: TIESZEN KENNETH L. , MOLYNEUX DAVID H. 
Published: May 2007

ABSTRACTAn investigation of transmission and ecology of the monogenetic trypanosomatids, Blastocrithidia gerridis and Crithidia flexonema, in Gerris is described. Motile free‐living flagellates of both species were found in the faeces of Gerris and in the water on which the bugs inhabited. Transmission of both trypanosomatid species occurred from naturally infected wild‐caught bugs to flagellate‐free laboratory‐bred bugs via water. Crithidia flexonema was also transmitted to laboratory‐bred bugs after being isolated in culture. Observations of experimentally infected bugs indicate that C. flexonema flagellates are imbibed and pass through the fore‐ and midgut to the hindgut where they become attached and multiply. There was no evidence to suggest transovarial transmission. In a 3‐yr investigation into the prevalence of trypanosomatids in a natural population of adult Gerris odontogaster, it was found that the infection rate varied between 19% and 100%. There was no significant difference in infection rates between females and males. The infection rate peaked for each year in late spring or early summer. The significance of these results is discussed in relation to the ecology and behaviour of Gerris. The results indicate that the infections are maintained in hibernating bugs over winter.
Flagellar Membrane and Paraxial Rod Proteins of Leishmania: Characterization Employing Monoclonal Antibodies
Authors: ISMACH RICHARD , CIANCI CATHERINE M. L. , CAULFIELD JOHN P. , LANGER PAMELA J. , HEIN ANN , McMAHON‐PRATT DIANE 
Published: May 2007

ABSTRACTFlagella‐specific proteins of Leishmania have been identified employing the monoclonal antibody technique. Six monoclonal antibodies recognized 3 different proteins. A doublet of protein of Mr 69,000 and 74,000 Da identified by monoclonal antibodies F‐3, F‐4 and F‐6 is continuously distributed along the flagellum by immunofluorescence. Immunocytochemical electron microscopic studies localize these molecules to the paraxial rod of the flagellum. A single protein of Mr 13,200 Da is recognized by monoclonal antibodies F‐1, F‐2 and F‐5. The distribution of the Mr 13,200 protein appears irregular, occurring in localized patches along the length of the flagellum, especially at the flagellar tip. Immunocytochemical electron microscopic experiments show that the Mr 13,200 molecule is associated with the membrane of the flagellum. Indirect immunofluorescence experiments demonstrated these monoclonal antibodies cross‐reacted with members of the Kinetoplastida family (Endotrypanum, Trypanosoma, Leishmania) suggesting that these molecules may be evolutionarily conserved.
Scanning Electron Microscopic Observation of Differentiation from the Reproductive Short Form to the Infectious Long Form of Holospora obtusa
Authors: FUJISHIMA MASAHIRO , SAWABE HISAHIRO , IWATSUKI KENJI 
Published: May 2007

ABSTRACTTo identify the surface features of Holospora obtusa during its differentiation from the reproductive short form to the infectious long form, bacteria of four different buoyant densities were isolated by Percoll density gradient centrifugation of homogenates of host cells or isolated macronuclei, and examined with a scanning electron microscope. Bacteria of buoyant density 1.09 g/ml were reproductive short forms as well as cells at various stages in the elongation process including fully elongated ones. Bacteria of buoyant densities 1.11 g/ml and 1.13 g/ml were premature long forms and those of 1.16 g/ml were mature infectious long forms. Bacteria of buoyant density 1.09 g/ml had an entirely rough surface while those of buoyant densities 1.11 g/ml and 1.13 g/ml were smooth and had wale‐like stripes on their surface. A small tapered tip was observed at one end of the bacteria of buoyant density 1.13 g/ml. Bacteria of buoyant density 1.16 g/ml had an entirely smooth surface, but one end always showed a rough surface; this locally differentiated surface of the special tip of the infectious long form may be responsible for both the nuclear and species specificities of the infectivity of H. obtusa. These observations indicate that the surface of H. obtusa changes during differentiation and the special tip develops in bacteria of buoyant density 1.13 g/ml.
The Large, Free‐living Amoebae: Wonderful Cells for Biological Studies
Authors: JEON KWANG W. 
Published: May 2007

ABSTRACTThe large, free‐living amoebae have been widely used as model cells for studying a variety of biological phenomena, including cell motility, nucleocytoplasmic interactions, membrane function, and symbiosis. Results of studies by our group on amoebae as moving cells, as material for micrurgical manipulations, and as hosts for intracellular symbionts are summarized here. In particular, our recent studies of the amoeba as a microcosm, in which spontaneously infecting foreign microbes have become integrated as necessary cell components, are described in some detail. These processes have involved an initial microbial infection, mutual adaptation by the host and symbionts, and development of obligatory symbiosis. Evidence is presented to show that symbiont‐derived macromolecules are involved in the protection of symbionts from digestion, the symbionts have acquired regulatory elements on their chromosomal genes to enhance production of beneficial gene products, and symbionts apparently utilize host‐derived macromolecules to their benefit. These studies involved morphological observations both at light and electron microscopic levels, physiological and genetic studies, production and use of poly‐ and monoclonal antibodies, and molecular‐biological approaches including gene cloning and sequencing. It is shown that amoebae are uniquely suited as model cells with which to study these phenomena.
Chemosensory Responses of Acanthamoeba castellanii: Visual Analysis of Random Movement and Responses to Chemical Signals
Authors: SCHUSTER F. L. , LEVANDOWSKY M. 
Published: May 2007

ABSTRACTA visual assay slide chamber was used in conjunction with time‐lapse videomicroscopy to analyze chemotactic behavior of axenically grown Acanthamoeba castellanii. Data were collected and analyzed as vector scatter diagrams and cell tracks. Amebas responded to a variety of bacterial products or potential bacterial products by moving actively toward the attractant. Responses to the chemotactic peptide formyl‐methionyl‐leucyl‐phenylalanine (fMLP), lipopolysaccharide, and lipid A were statistically significant (P≤ 0.03), as was the response to fMLP benzylamide (P≤ 0.05). Significant responses to cyclic AMP, lipoteichoic acid, and N‐acetyl glucosamine were also found.Chemotactic peptide antagonists, mannose, mannosylated bovine serum albumin, and N‐acetyl muramic acid all yielded nonsignificant responses (P > 0.05). There was no single optimal concentration for response to any of the attractants tested, and amebas responded equally over the range of concentrations tested. Pretreatment of amebas with chemotactic peptides, bacterial products, and bacteria reduced the directional response to attractants. Amebas that had been grown in the presence of bacteria appeared more responsive to chemotactic peptides. Treatment of amebas with trypsin reduced the response of cells to chemotactic peptides, though sensitivity was restored within a couple of hours. This suggests the ameba membrane may have receptors, sensitive to these bacterial substances, which are different from the mannose receptors involved in binding bacteria to the membrane during phagocytosis. The rate of movement was relatively constant (ca. 0.40 μm/s), indicating that the locomotor response to these signals is a taxis, or possibly a klinokinesis, but not an orthokinesis. Studies of the population diffusion rate in the absence of signals indicate that the basic population motility follows the pattern of a Levy walk, rather than the more familiar Gaussian diffusion. This suggests that the usual mathematical models of ameboid dispersion may need to be modified.
Cell Invasion by the Microsporidium Encephalitozoon intestinalis
Authors: MAGAUD ANNE , ACHBAROU ABDERRAHIM , DESPORTES‐LIVAGE ISABELLE 
Published: May 2007

SUMMARYThe ultrastructural study of the invasion of cells (THP1 AND RK13) by E. intestinalis shown that infective stages enter host cells via a phagocytic process intitiated at the contact of the apical part of spores with host cell membrane. The polar tube is extruded within an invagination of the host cell membrane that extends inside a pseudopod containing microfilaments. These observations suggest that microsporidia as well as other intracellular pathogens can induce host cell alterations facilitating the invasio.
Population genetics of Scirtothrips perseae: tracing the origin of a recently introduced exotic pest of Californian avocado orchards, using mitochondrial and microsatellite DNA markers
Authors: Rugman‐Jones P.F. , Hoddle M.S. , Stouthamer R. 
Published: May 2007

AbstractThe Californian avocado industry has recently been impacted by the establishment of three exotic arthropod pests that are native to Mexico and Central America. Establishment of all three pests is thought to have resulted from illegal movement of host plants (avocado) into California. To identify likely sources and routes of entry of such pest invasions, we examined the population genetics of the most recent invader, avocado thrips [Scirtothrips perseae Nakahara (Thysanoptera: Thripidae)], using mitochondrial DNA (mtDNA) and microsatellite markers. The mtDNA sequences revealed three geographically distinct and divergent lineages, of which the mtDNA haplotypes of Californian individuals were most closely related to populations in the center of the pest's native range. Analysis of allele frequencies at four microsatellite loci added resolution, indicating Coatepec Harinas, Mexico, as the most likely source of the Californian population. Statistically, we did not detect any bottleneck in population size associated with the invasion of California. However, estimates of the effective population size of the invading population suggest that a severe bottleneck occurred, indicating that the quantity of host‐plant material entering California was small. Our findings implicate Coatepec Harinas, a large avocado germplasm and breeding center, as the most likely source of the introduced Californian population of S. perseae and as a likely source of previous and future avocado pest introductions. Efforts to identify natural enemies of S. perseae for biological control should focus on Coatepec Harinas and immediate surrounds. Moreover, identification of the source of invasive pests enables the establishment and enforcement of plant quarantine and free‐trade protocols.
Clinical models that objectively evaluate interproximal plaque based on total protein concentration
Authors: Milanovich N. , Souza S. M. , De Jager M. , Hefti A. F. 
Published: May 2007

AbstractAim: To establish clinical models that accurately and objectively assess the levels of interproximal plaque (IPP) by measuring the total protein concentration.Material and Methods: The multiple treatment (MTM) and single‐treatment models (STM) were designed as randomized, double‐blinded, crossover studies whereby IPP was collected using floss. The total protein concentration in the plaque was then measured using a fluorescence microplate assay. To demonstrate sensitivity, the levels of residual IPP were compared for two distinctly different plaque removal routines: brushing versus brushing+flossing.Results: Eighteen subjects completed the study for the MTM, while 16 participants completed the study for the STM. The results showed that both models were able to distinguish between treatments. Moreover, fundamental profiles were established that describe the mean changes in the IPP concentration over time and by treatment. Finally, a comparison between our results and a direct measure of IPP, i.e., plaque weight, demonstrated the potential of using protein as a quantitative means to assess IPP levels.Conclusion: The MTM and STM provide an objective, quantitative assessment of IPP based on the total protein concentration in plaque.
Women and English Renaissance Drama: Making and Unmaking ‘The All‐Male Stage’
Authors: McManus Clare 
Published: May 2007

AbstractWe can no longer refer to ‘the all‐male stage’ of Renaissance drama without a qualifying remark about the many performing women of early modern England. Over the past decade or so the combined efforts of feminism, gender studies and historicised archival work have shown that Shakespearean theatre was by no means an all‐male pursuit in which women were represented only by transvestite boy actors. Recent research has uncovered a diverse and energetic range of female performers beyond the single‐sex playhouse stages of Shakespearean London and has shown women to have a crucial role in early modern theatre. This article considers how the emergence of the woman player as a subject of study has changed the way that we think and write about Shakespearean drama. In particular, women's performance challenges the central critical paradigms of ‘the all‐male’ and ‘the English stage’, while the plays of Shakespeare, Jonson and other canonical authors are changed by our new understanding of women's theatricality.
The Silver‐Fork Novel across Romantic and Victorian Views: Class, Gender and Commodity Culture, 1820–1841
Authors: O’Cinneide Muireann 
Published: May 2007

AbstractThis article considers changing critical perceptions of the literature of the period between the 1820s and the 1840s, in particular the popular ‘silver‐fork’ or fashionable novel. Greater awareness of the class dynamics of the era has significant implications for our understanding, both of the genre itself, and of the wider relationships between literature, class, gender and politics in the decades before and after Reform. I discuss scholarship on the central tensions of the genre between upper‐class status and middle‐class readerships; the models of authorship this produces; the lines of literary descent revealed through the genre; and finally the construction of the genre as commodity and the relation of this to the figure of the dandy. Finally, I suggest directions in which further research is likely to tend. These questions are part and parcel of a more general overall re‐evaluation taking place in nineteenth‐century studies of the border lines between Romanticism and Victorianism. Re‐considering the silver‐fork novel, therefore, is not simply a matter of discussing an obscure genre, but a way into the central literary concerns of a crucial period for our understanding of the nineteenth century.
Determining priorities for research in ageing: A community survey
Authors: Byles Julie , Parkinson Lynne , Nair Balakrishnan (Kichu) , Watson Jane , Valentine Megan 
Published: May 2007

Objectives:  This paper reports the culmination of a local process of priority setting for ageing research. Methods:  A cross‐sectional random community mailout was conducted across 1500 Hunter region, Australia, households during 2001, using the modified Dillman procedures. The survey included 38 research topics and priority items. Research priorities were grouped according to factors identified by factor analysis. Results:  There were 694 respondents. Four research priority factors were identified: age‐related diseases, symptoms and problems of ageing, lifestyle factors, and mental and social issues of ageing. Top‐rating priorities were stroke, dementia, heart disease and cancer. Overall, more women and older people (65+ years) ranked items as very important. Lifestyle factors were mentioned most often as the most important health and social issues facing older people. Conclusions:  Community views should be considered where evidence and researcher interest can support this.
Validating an Australian version of the Time and Change Test: A screening test for cognitive impairment
Authors: Nair Balakrishnan R , Browne William Lee , Chua Ling‐Ern , D’Este Catherine , O'Dea Ian , Agho Kingsley 
Published: May 2007

Objectives:  The ‘Time and Change Test’– a brief cognitive screening test has been validated in several countries to assess cognitive impairment. We attempted to validate an Australian version of the test among hospital inpatients. Methods:  One hundred and thirty patients consented to participate in the study. They underwent an assessment for a Diagnostic and Statistical Manual of Mental Disorders (DSM IV) diagnosis for dementia or delirium, the Mini‐Mental State Examination and the Time and Change Test. Results:  The Time and Change Test had a sensitivity of 44% (95% CI; 23%, 66%) and a specificity of 90% (**80%, 96%) for a DSM IV diagnosis of dementia or delirium. Conclusions:  This version of the Time and Change was less sensitive than other versions. The sensitivity of the test came from the change component, and reduced complexity of this task may account for this finding. We recommend study of a more complex change‐making test as a screening tool for cognitive impairment.
Visual impairment in an aged care ward
Authors: Rush Katherine , Dillon Louise , Scharf Simon 
Published: May 2007

Introduction:  Visual impairment is common in older people, and is a risk factor for falls and hip fractures, reduced independence and quality of life. Objectives:  To assess the prevalence and causes of visual impairment in an aged care ward, and to evaluate whether routine eye assessment, and referral to an eye specialist was worthwhile to detect patients with low vision that could be correctable. Method:  Clinical eye examination of 100 consecutive inpatients and review of medical records. Patients with a new diagnosis of visual impairment were referred for ophthalmology or optometry assessment. Results:  The prevalence of low vision was 36% and the prevalence of blindness was 9%. There were 18 patients referred for specialist review, three patients were recommended a new treatment but only two received treatment. Conclusion:  Visual impairment was prevalent. Although refractive error and cataracts were common, in only a few cases did detection and specialist referral lead to improved visual outcomes.
Social capital among older residents of a coastal resort: A survey of social resources and vulnerabilities
Authors: Barr Felicity , Russell Cherry 
Published: May 2007

Objective:  To document the characteristics and social networks of older residents of a coastal resort, as part of a qualitative study of their social capital. Methods:  A 15‐item questionnaire was mailed to a sample of 200 Seniors’ Card holders, stratified by age and gender, resident in three postcodes in coastal New South Wales. While the purpose of the survey was to recruit volunteers for interviews, analysis of the 103 responses provided useful data about broad characteristics of the sample group. This paper presents results of this analysis. Results:  The most common form of household was the couple without children and most respondents were optimistic about the availability of help from family and friends. Gender and age differences were identified in rates of living alone, having relatives nearby, going out, belonging to clubs and associations, volunteering and use of transport. Conclusion:  Variations in social patterns both reflect and foreshadow the vulnerability of individuals to changes in life circumstances.
Contrasting copper evolution in ω Centauri and the Milky Way
Authors: Romano Donatella , Matteucci Francesca 
Published: May 2007

Abstract
Despite the many studies on stellar nucleosynthesis published so far, the scenario for the production of copper in stars remains elusive. In particular, it is still debated whether copper originates mostly in massive stars or in Type Ia supernovae. To answer this question, we compute self-consistent chemical evolution models taking into account the results of updated stellar nucleosynthesis. By contrasting copper evolution in ω Cen and the Milky Way, we end up with a picture where massive stars are the major factor responsible for the production of copper in ω Cen as well as the Galactic disc.
POSITIONAL DISTRIBUTION OF FATTY ACIDS IN TRIACYLGLYCEROLS OF SEAL BLUBBER OIL
Authors: WANASUNDARA UDAYA N. , SHAHIDI FEREIDOON 
Published: May 2007

ABSTRACTThe positional distribution of long‐chain ω3 polyunsaturated fatty acids namely eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) in the triacylglycerol (TAG) molecules of seal blubber oil was determined and compared with that of commercially available menhaden oil via stereospecific analysis. In seal blubber oil, EPA, DPA and DHA occurred mainly in the sn‐1 and sn‐3 positions of the TAG molecules. The amounts were EPA, 8.36 and 11.2; DPA, 3.99 and 8.21; and DHA, 10.5 and 17.9%, respectively. In menhaden oil, DPA and DHA occurred mainly in the sn‐2 position of the TAG at 3.11 and 17.2%, respectively. However, EPA was equally distributed in the sn‐2 and sn‐3 positions and was present only in minute amounts in the sn‐1 position.