bluuebunny/crossref_metadata_2025 huggingface dataset:
The Periplasmic Disulfide Oxidoreductase DsbA Contributes to
Haemophilus influenzae
Pathogenesis
Authors: Rosadini Charles V. , Wong Sandy M. S. , Akerley Brian J.
Published: January 2008

Haemophilus influenzae
is an obligate human pathogen that persistently colonizes the nasopharynx and causes disease when it invades the bloodstream, lungs, or middle ear. Proteins that mediate critical interactions with the host during invasive disease are likely to be secreted. Many secreted proteins require addition of disulfide bonds by the DsbA disulfide oxidoreductase for activity or stability. In this study, we evaluated the role in
H. influenzae
pathogenesis of DsbA, as well as HbpA, a substrate of DsbA. Mutants of
H. influenzae
Rd and type b strain Eagan having nonpolar deletions of
dsbA
were attenuated for bacteremia in animal models, and complemented strains exhibited virulence equivalent to that of the parental strains. Comparison of predicted secreted proteins in
H. influenzae
to known DsbA substrates in other species revealed several proteins that could contribute to the role of
dsbA
in virulence. One candidate, the heme transport protein, HbpA, was examined because of the importance of exogenous heme for aerobic growth of
H. influenzae
. The presence of a
dsbA
-dependent disulfide bond in HbpA was verified by an alkylation protection assay, and HbpA was less abundant in a
dsbA
mutant. The
hbpA
mutant exhibited reduced bacteremia in the mouse model, and complementation restored its in vivo phenotype to that of the parental strain. These results indicate that
dsbA
is required in vivo and that HbpA and additional DsbA-dependent factors are likely to participate in
H. influenzae
pathogenesis.
Impact of Recombinant Adenovirus Serotype 35 Priming versus Boosting of aPlasmodium falciparumProtein: Characterization of T- and B-Cell Responses to Liver-Stage Antigen 1
Authors: Rodríguez Ariane , Goudsmit Jaap , Companjen Arjen , Mintardjo Ratna , Gillissen Gert , Tax Dennis , Sijtsma Jeroen , Weverling Gerrit Jan , Holterman Lennart , Lanar David E. , Havenga Menzo J. E. , Radošević Katarina
Published: January 2008

Prime-boost vaccination regimens with heterologous antigen delivery systems have indicated that redirection of the immune response is feasible. We showed earlier that T-cell responses to circumsporozoite (CS) protein improved significantly when the protein is primed with recombinant adenovirus serotype 35 coding for CS (rAd35.CS). The current study was designed to answer the question whether such an effect can be extended to liver-stage antigens (LSA) ofPlasmodium falciparumsuch as LSA-1. Studies with mice have demonstrated that the LSA-1 protein induces strong antibody response but a weak T-cell immunity. We first identified T-cell epitopes in LSA-1 by use of intracellular gamma interferon (IFN-γ) staining and confirmed these epitopes by means of enzyme-linked immunospot assay and pentamer staining. We show that a single immunization with rAd35.LSA-1 induced a strong antigen-specific IFN-γ CD8+T-cell response but no measurable antibody response. In contrast, vaccinations with the adjuvanted recombinant LSA-1 protein induced remarkably low cellular responses but strong antibody responses. Finally, both priming and boosting of the adjuvanted protein by rAd35 resulted in enhanced T-cell responses without impairing the level of antibody responses induced by the protein immunizations alone. Furthermore, the incorporation of rAd35 in the vaccination schedule led to a skewing of LSA-1-specific antibody responses toward a Th1-type immune response. Our results show the ability of rAd35 to induce potent T-cell immunity in combination with protein in a prime-boost schedule without impairing the B-cell response.
Genomic Analysis Reveals
Mycoplasma pneumoniae
Repetitive Element 1-Mediated Recombination in a Clinical Isolate
Authors: Musatovova Oxana , Kannan T. R. , Baseman Joel B.
Published: January 2008

Mycoplasmas are cell wall-less bacteria that evolved by drastic reduction of the genome size. Complete genome analysis of
Mycoplasma pneumoniae
revealed the presence of numerous copies of four distinct large
M. pneumoniae
repetitive elements (RepMPs). One copy each of RepMP2/3, RepMP4, and RepMP5 are localized within the P1 operon (MPN140 to MPN142 loci), and their involvement in sequence variation in adhesin P1 and adherence-related protein B/C has been documented. Here we analyzed a clinical strain of
M. pneumoniae
designated S1 isolated from a 1993 outbreak of respiratory infections in San Antonio, TX. Based on the type of RepMPs within the P1 operon, we classified clinical isolate S1 as type 2 with unique minor sequence variations. Hybridization with oligonucleotide arrays revealed sequence divergence in two previously unsuspected hypothetical genes (MPN137 and MPN138 loci). Closer inspection of this region revealed that the MPN137 and MPN138 loci harbored previously unrecognized unique RepMP1 sequences found only in
M. pneumoniae
. PCR and sequence analyses revealed a recombination event involving three RepMP1-containing genes that resulted in fusion of MPN137 and MPN138 reading frames and loss of all but a short fragment of another RepMP1-containing locus, MPN130. The multiple copies of unique RepMP1 elements spread throughout the chromosome could allow vast numbers of sequence variations in clinical strains. Comparisons of amino acid sequences showed the presence of leucine zipper motifs in MPN130 and MPN138 proteins in reference strain M129 and the absence of these motifs in the fused protein of S1. The presence of tandem leucine and other repeats points to possible regulatory functions of proteins encoded by RepMP1-containing genes.
Molecular Evidence of Nosocomial
Pneumocystis jirovecii
Transmission among 16 Patients after Kidney Transplantation
Authors: Schmoldt Sabine , Schuhegger Regina , Wendler Thorsten , Huber Ingrid , Söllner Heidelore , Hogardt Michael , Arbogast Helmut , Heesemann Jürgen , Bader Lutz , Sing Andreas
Published: January 2008

In recent years, clusters of
Pneumocystis jirovecii
(formerly
Pneumocystis carinii
) pneumonia (PCP) among immunocompromised individuals have been reported. Mostly, the source of infections was suspected to be within the clinical settings when transplant recipients and PCP patients shared hospital facilities. We report on a cluster of 16 renal transplant recipients positive for
P. jirovecii
. None of them received anti-
Pneumocystis
prophylaxis prior to
P. jirovecii
detection. Epidemiological studies revealed that 15 of them had received kidney transplants at a German university hospital and attended the same inpatient and outpatient clinic from January through September 2006. Multilocus sequence typing (MLST) was performed on the following genes:
ITS1
, β-
tub, 26S
, and
mt26S. P. jirovecii
DNA was available from 14 patients and showed identical MLST types among these renal transplant recipients. Surprisingly, one patient who was treated at a different nephrological center and reported no personal contact with patients from the renal transplantation cluster harbored an identical
P. jirovecii
MLST type. Three HIV-positive patients and one bone-marrow-transplanted hematologic malignancy patient—treated at different medical centers—were used as controls, and different MLST types were revealed. Interestingly, in three of the four previously described regions, new alleles were detected, and one new polymorphism was observed in the
mt26S
region. The epidemiological data and the genotyping results strongly suggest a nosocomial patient-to-patient transmission of
P. jirovecii
as the predominant transmission route. Therefore, strict segregation and isolation of
P. jirovecii
-positive/suspected patients in clinical settings seems warranted.
E4Orf6-E1B-55k-Dependent Degradation of De Novo-Generated Adeno-Associated Virus Type 5 Rep52 and Capsid Proteins Employs a Cullin 5-Containing E3 Ligase Complex
Authors: Nayak Ramnath , Farris K. David , Pintel David J.
Published: January 2008

Degradation of de novo-generated adeno-associated virus type 5 (AAV5) Rep52 and capsid proteins is part of the limited target specificity displayed by adenovirus type 5 E4Orf6-E1B-55k as part of a cullin 5-containing E3 ligase complex. Both Rep and capsid proteins can be found in the ligase complex, and their presence is dependent on interaction between E4Orf6 and elongins B and C. Degradation of AAV5 proteins can be inhibited by a dominant-negative ubiquitin that prevents chain elongation or by small interfering RNA directed against cullin 5.
Levels and correlates of awareness of tobacco promotional activities among adult smokers in Malaysia and Thailand: findings from the International Tobacco Control Southeast Asia (ITC-SEA) Survey
Authors: Yong H-H , Borland R , Hammond D , Sirirassamee B , Ritthiphakdee B , Awang R , Omar M , Kin F , Zain Z bt M , Lee W B , Siahpush M , Fong G T
Published: January 2008

Aim:

To examine the impact of tobacco advertising policy on adult smokers’ awareness of tobacco promotion in two developing countries—Malaysia and Thailand.

Methods:

Data from 2004 Malaysian and 2000 Thai adult smokers who participated in the baseline wave of the International Tobacco Control Southeast Asia survey (ITC-SEA). Respondents were asked in a face-to-face interview conducted between January and March 2005 to indicate their levels of awareness of tobacco advertising and promotional activities in the last six months.

Results:

Unprompted awareness of any tobacco marketing activities was very low in Thailand (20%) but significantly higher in Malaysia (53%; OR = 5.6, 95% CI: 3.5 to 8.9, p<0.001). When prompted about specific locations, Thai adult smokers reported very low recall of tobacco advertising where it was banned, being highest around point of sale, particularly street vendors (7.5%). In contrast, Malaysian adult smokers reported significantly higher levels of awareness of tobacco advertising in all locations (range = 17.7% noticing in disco lounges to 59.3% on posters) including where they are notionally banned (for example, billboards).

Conclusions:

These findings demonstrate that comprehensive tobacco advertising legislation when well implemented can lead to dramatic decline in awareness of tobacco promotion, thus supporting strong implementation of Article 13 of the Framework Convention on Tobacco Control.
The role of tobacco control policies in reducing smoking and deaths in a middle income nation: results from the Thailand SimSmoke simulation model
Authors: Levy D T , Benjakul S , Ross H , Ritthiphakdee B
Published: January 2008

Objectives:

With the male smoking prevalence near 60% in 1991, Thailand was one of the first Asian nations to implement strict tobacco control policies. However, the success of their efforts has not been well documented.

Methods:

The role of tobacco control policies are examined using the “SimSmoke” tobacco control model. We first validated the model against survey data on smoking prevalence. We then distinguished the effect of policies implemented between 1991 and 2006 from long-term trends in smoking rates. We also estimated smoking attributable deaths and lives saved as a result of the policies.

Results:

The model validates well against survey data. The model shows that by the year 2006, policies implemented between 1991 and 2006 had already decreased smoking prevalence by 25% compared to what it would have been in the absence of the policies. Tax increases on cigarettes and advertising bans had the largest impact, followed by media anti-smoking campaigns, clean air laws and health warnings. The model estimates that the policies saved 31 867 lives by 2006 and will have saved 319 456 lives by 2026.

Conclusions:

The results document the success of Thailand in reducing smoking prevalence and reducing the number of lives lost to smoking, thereby showing the potential of tobacco control policies specifically in a middle-income country. Additional improvements can be realised through higher taxes, stronger clean air policies, comprehensive cessation treatment policies, and targeted media campaigns.
Cell wall and plasmalemma modifications in diseased and injured plant tissues
Authors: Wheeler Harry
Published: January 2008

Pathological modifications in structure at the cell wall – plasmalemma interface are common in diseased plant tissues. These modifications vary from small, localized structures which invaginate the protoplast to large, irregularly contoured elaborations which envelop haustoria. Some published electron micrographs suggest that the plasmalemma may be discontinuous in areas adjacent to modified cell walls. Structural changes in cell walls, similar to those in diseased plants, are common in plant roots exposed to uranyl acetate. In such roots, the plasmalemma appeared distinctly discontinuous in cells with highly modified walls, whereas it was continuous in adjacent cells with little or no wall modification. In both types of cells, internal membranes and organelles appeared normal. This suggests that the breaks seen in the plasmalemma were not fixation artifacts. In untreated roots, apparent discontinuities in the plasmalemma were observed only in secretory outer root cap cells which contained masses of mucilaginous material between the wall and protoplast. Since uranyl treatment does not increase the rate of electrolyte loss from tissue, these observations suggest that modified cell walls may assume some of the permeability functions usually attributed to the plasmalemma.
Structure and function of wall appositions. 1. General histochemistry of papillae in barley coleoptiles attacked by Erysiphe graminis f. sp. hordei
Authors: Smart Michael G. , Aist James R. , Israel Herbert W.
Published: January 2008

Penetration pegs of Erysiphe graminis D.C. f. sp. hordei Em. Marchal are usually not impeded by normal papillae of barley coleoptiles, whereas oversize papillae are impenetrable to appressoria of the pathogen. We investigated the chemical composition of these papillae and the cell walls by classical histochemistry, in part to extend the fragmented knowledge of these structures and in part to find out if there are differences between normal and oversize papillae which would account for their different efficacies in resisting penetration. These papillae were indistinguishable from one another histochemically and contained protein, carbohydrate other than pectin, and a phenolic which was not lignin. We report also a definitive proof of callose in papillae. They do not contain cutin or suberin. The cell wall did not contain callose or cutin–suberin but did contain protein, pectin, and a phenolic (also not lignin). The results imply that different linkages between molecules in oversize papillae, or some other differences not revealed in this study, are responsible for their ability to prevent fungal penetration.
Resistance of Lycopersicon species to Bemisia tabaci, a tomato leaf curl virus vector
Authors: Channarayappa Channarayappa , Shivashankar G. , Muniyappa V. , Frist R. H.
Published: January 2008

More than 1200 cultivars, breeding lines, and wild species of Lycopersicon were screened for resistance to the tomato leaf curl virus under field conditions. All accessions of Lycopersicon esculentum were found susceptible to tomato leaf curl virus. Three lines of Lycopersicon hirsutum and one of Lycopersicon peruvianum accessions showed apparent resistance to the tomato leaf curl virus owing to the failure of virus transmission by whiteflies. Morphological analysis by light and scanning electron microscopy revealed distributions of different types of trichomes on leaf surfaces. Lycopersicon hirsutum proved to be the least affected by the leaf curl virus because it did not support whitefly infestation to any extent. Lycopersicon hirsutum differed from other species by the presence of glandular trichomes designated type VIc. Whiteflies became entrapped in the exudate of type VIc trichome glands before they could transmit the virus. Thus, it may be possible to control tomato leaf curl virus transmission by breeding plants with certain types of trichomes, especially trichome type VIc. Key words: leaf curl virus, nonpreference, physical resistance, glandular exudate, trichomes, whitefly.
Pathogenicity of Pythium torulosum to roots of Agrostis palustris in black-layered sand produced by the interaction of the cyanobacteria species Lyngbya, Phormidium, and Nostoc with Desulfovibrio desulfuricans
Authors: Hodges Clinton F.
Published: January 2008

Studies were initiated to determine the pathogenicity of Pythium torulosum to Agrostis palustris roots growing in sand with subsurface black layer produced by the interaction of cyanobacteria and the sulfate-reducing bacterium Desulfovibrio desulfuricans. The interaction of P. torulosum with cyanobacteria and D. desulfuricans was also evaluated. Pythium torulosum decreased the dry weight of roots and shoots of A. palustris to 41 and 35%, respectively, of the control plants in the absence of black layer and the organisms responsible for its formation. The combination of P. torulosum and D. desulfuricans, in the absence of black layer, induced the most severe decrease in root (20% of controls) and shoot (25% of controls) dry weights. Damage to roots induced by P. torulosum in combination with various isolates of cyanobacteria, in the absence of black layer, was equal to that of P. torulosum alone; shoot dry weight loss was less than that caused by P. torulosum alone. Pathogenicity of P. torulosum to roots when combined with cyanobacteria and D. desulfuricans in the presence of black layer was the same as that with P. torulosum alone and in combination with cyanobacteria; shoot dry weight did not differ from that of P. torulosum combined with cyanobacteria. The presence of cyanobacteria with P. torulosum and D. desulfuricans in black-layered sand decreased root and shoot dry weight loss induced by the two latter organisms. Key words: anaerobic, black plug layer, golf greens, sulfate reduction.
Mechanical properties of the parenchyma of potato (Solanum tuberosum cv. Russet Burbank)
Authors: Pang C. H. , Scanlon M. G.
Published: January 2008

The mechanical properties of plant materials and plant structures influence the form, function, distribution, and utilization of plants. The shear and compressive stiffnesses of different regions of potato parenchyma were measured to more fully characterize the mechanical properties of this important storage organ. Measurements were performed on tubers that had been stored for 1 and 10 months. Slices and cylinders of parenchyma were excised from the centre of the tubers in three directions (and slices from the outer portion in two directions). Slices were subjected to small-strain oscillatory shear at frequencies of 0.02, 0.2, and 2 Hz. Cylinders were subjected to three cycles of uniaxial compression at 2 and 20 cm∙min−1. The coefficient of variation of measured parameters ranged on average from 16 to 44% for both crops and both tests. At small strains, potato parenchyma behaved essentially as an elastic material. The results from both small-strain oscillatory shear and uniaxial compression suggested that potato parenchyma is anisotropic in nature. Slices from the outer and inner regions of the tuber had different shear stiffness values. The shear stiffness of tubers stored for 1 month was approximately 70% greater than those stored for 10 months. Repeated compressive loading of potato parenchyma cylinders ameliorated the differences in stiffness and energy absorption between short- and long-term stored tubers, attributable to movement of fluids from the cells during compression. The observations emphasize the complexity of potato tissue and how its mechanical properties change during storage. Keywords: shear, compression, energy absorption, stiffness, turgor, storage, anisotropicity.
Biomass and production of two vascular plants in a boreal mesotrophic fen
Authors: Saarinen Timo
Published: January 2008

The vertical distribution of biomass and production was measured using indirect 14C isotope techniques in a boreal mesotrophic fen dominated by Carex rostrata and Potentilla palustris. The biomass of C. rostrata was high (2290 g∙m−2), 78% of which was fine-root biomass. Even with a low turnover rate (0.59 yr−1), fine roots also accounted for 74% of the total production of 1424 g∙m−2∙yr−1. The majority of the belowground biomass was found in the uppermost 30 cm. However, living roots of C. rostrata were found down to a depth of 230 cm. In fen ecosystems, the direct input of carbon through deep-penetrating roots to slowly decomposing layers may considerably affect the accumulation of peat. Keywords: biomass, Carex rostrata, fen, peat, production, roots.
Comparative study of 7 fluorescent pseudomonad clinical isolates
Authors: Chapalain A. , Rossignol G. , Lesouhaitier O. , Merieau A. , Gruffaz C. , Guerillon J. , Meyer J.-M. , Orange N. , Feuilloley M.G.J.
Published: January 2008

There is some debate about the potential survival of Pseudomonas fluorescens at temperatures above 37 °C and its consequences for infectious potential, owing to the heterogeneity of clinical strains. Seven clinical strains growing at 37 °C or more were submitted for polyphasic identification; 2 were identified as Pseudomonas mosselii and 4 were precisely characterized as P. fluorescens bv. I or II. The binding indexes on glial cells of the strains identified as P. fluorescens bv. I and P. mosselii were compared with that of a reference psychrotrophic strain, P. fluorescens MF37 (bv. V). Clinical P. fluorescens had a similar adherence potential range than strain MF37. Conversely, the binding indexes for P. mosselii strains were 3 times greater than that for strain MF37. These data, and those obtained by comparing the cytotoxic activities of P. fluorescens clinical strains, suggest the existence of different virulence mechanisms, leading either to a low infectious form or to a microorganism with cytotoxic activity in the same range as that of P. mosselii or even Pseudomonas aeruginosa .
Cytogenetic studies in relation to taxonomy within the family Gryllidae (Orthoptera). I. Subfamily Gryllinae
Authors: Lim H.-C. , Vickery V. R. , Kevan D. K. McE.
Published: January 2008

Twelve species of Gryllinae were studied to determine the number, morphology and behavior of their chromosomes. The male diploid numbers ranged from 19 to 31. Gryllus campestris and a population of "G. bimaculatus" from Singapore showed anomalies in chromosome behavior and structure, including breaks, stickiness, C-mitosis, polyploidy, lagging, unequal segregation and non-disjunction in the former and many aberrations and loss of fertility in the latter. One or two B-chromosomes occurred in some individuals of G. veletis, the chromosome number of this species thus varying from 2n ♀ = 29 to 31. In the Gryllinae, karyotypic differences are shown to be more useful than chromosome number at the species level; differences in chromosome number are useful taxonomically at the generic level, when combined with differences in karyotypes.
Ultrastructure of the frozen-etched polar filament in a microsporidan Thelohania bracteata (Strickland, 1913)
Authors: Liu T. P. , Davies D. M.
Published: January 2008

The polar filament of Thelohania bracteata has eight coils and possesses a double membrane. Fractured faces of each layer of this membrane bear many particles arranged in net-like pattern. This pattern distinguishes the polar filament membrane from the spore membrane and other cytomembranes. The polar filament possesses a central tubular structure which is ringed by 12 microcylinders arranged symmetrically. The significance of these observations is discussed.
Effect of dietary carbohydrate intake on the growth of Hymenolepis diminuta (Cestoda) in the laboratory rat
Authors: Dunkley Lorna C. , Mettrick D. F.
Published: January 2008

Using isocaloric balanced diets, the effect of increasing host dietary carbohydrate intake on the growth of 14-day-old Hymenolepis diminuta has been determined. The carbohydrate component of the diet varied between 0.5 and 7.2 g per rat per day out of a total dietary intake of 9 g per rat per day. Increasing host dietary glucose resulted in a linear increase in growth by H. diminuta, and no asymptote was observed. Increasing host dietary corn (maize) starch resulted initially in a more rapid rate of growth of the worms than on the glucose diet, but further starch intake above the level of 5.2 g per rat per day inhibited worm growth. Increasing H+ ion concentration after feeding may have inhibited mucosal hydrolysis of the starch, so that undigested carbohydrate entered the colon, accounting for the greater loss of body weight of the starch-fed rats as compared with the glucose-fed animals. As the rate of growth of H. diminuta is directly related to amount of available glucose, it is concluded that intestinal luminal glucose on the cornstarch diet was not proportional to the amount of dietary starch fed.
The effect of mebendazole on the development of Hymenolepis diminuta in Tribolium confusum
Authors: Evans W. S. , Novak Marie
Published: January 2008

Tribolium confusum parasitized by Hymenolepis diminuta were allowed to feed on mixtures composed of 0.005 to 20 g of mebendazole (Telmin: methyl-5-benzoyl benzimidazole-2-carbamate) in 10 g of flour from day 1 (24 h) to day 9 post infection. Retarded cysticercoid development, lowered incidence of infection, and reductions in the number of cysticercoids recovered per beetle were produced by drug levels of 0.1, 1.0, and 10 g respectively. None of the drug concentrations tested produced 100% mortality, and developing cysticercoids varied considerably in their tolerance of mebendazole.
Hematopoiesis of the kissing gourami (Helostoma temmincki). Effects of starvation, bleeding, and plasma-stimulating factors on its erythropoiesis
Authors: Weinberg Sheila R. , LoBue Joseph , Siegel Charles D. , Gordon Albert S.
Published: January 2008

Starvation and bleeding of the kissing gourami were found to induce a pronounced anemia. After 9 days of starvation there was a 45% decrease in the numbers of circulating erythrocytes, and within 24 h of bleeding a fish (1% of the body weight) there was a 39% decrease in the red cell count, which elicited a reticulocytosis and leukocytosis. The blood volumes remained unchanged in the starved or bled fish. When the 9-day-starved fish was used to evaluate the hematopoietic-stimulating capacity of different substances, plasma from normal fish decreased erythropoietic activity, while plasma from fish made anemic by bleeding or 1 International Reference Preparation unit of human urinary erythropoietin evoked erythropoietic and leukocytopoietic activities.The estimated minimal red cell life-span in this fish was found to be about 13 days. However, there was some evidence for the existence of a population of long-lived erythrocytes. The 59Fe incorporation value per milligram of organ was highest in the spleen, with kidney and liver showing less activity.These studies not only provide information for the understanding of the regulatory mechanism(s) involved in blood cell production in the fish, but also present evidence of the existence in fish of intrinsic hemopoietic regulatory factors, possibly hormonal in nature.
A model of foregut activity in the blowfly Phormia regina Meigen. III. Analysis of crop-valve function during the crop-emptying process
Authors: Thomson A. J. , Holling C. S.
Published: January 2008

The crop valve (valve V4) in the blowfly foregut consists of circular muscles surrounding the opening of the crop duct within the crop. Although these muscles are anatomically part of the crop, which acts as a muscular pump, they act in a manner that imparts a valvular function to the structure. This variation in function is shown to be the result of differences between crop and valve in size and spacing of muscle fibres.
A Nosema (Microsporida) epizootic in fairy shrimp (Crustacea: Anostraca)
Authors: Daborn Graham R.
Published: January 2008

A new species of Nosema (Microsporida) is recorded in two species of Branchinecta. In the first year of occurrence (1970) 100% of B. gigas and 91% of B. mackini were infected at the beginning of June. Mortality of infected animals was much higher than of uninfected ones. Infections recurred in 1971 with maximum values of 47% and 57% in B. gigas and B. mackini, respectively, and in 1972 with values of <10% in each, but they were not evident in 1973. No effect on host egg production was detected.
Artificial insemination vs. natural mating in captive American kestrels
Authors: Bird D. M. , Laguë P. C. , Buckland R. B.
Published: January 2008

Methods for semen collection and intra vaginal insemination of birds of prey are described in detail. To study the practicability of these techniques in breeding birds of prey, a comparison was made between artificial insemination (AI) and natural mating (NM) in captive American kestrels (Falco sparverius). Sixteen pairs were used in 1974, 8 of which were naturally mated, and 30 pairs were used in 1975, 12 of which were naturally mated.The overall fertilities from either mating type were comparable (AI = 57%, NM = 61%), although one could calculate a 15% higher fertility in AI compared with NM birds if one excludes those eggs too far developed before the first insemination. The hatchability of eggs produced by either mating type under artificial and natural incubation did not differ significantly.
The dynamics of two aquatic plant–snail associations
Authors: Pip Eva , Stewart John M.
Published: January 2008

Submerged macrophyte communities in the Delta Marsh on the southern shore of Lake Manitoba were sampled quantitatively using a modified macrophyte sampler. Two major plant–snail associations, expressed in terms of numbers of snails per unit dry plant weight and per unit plant surface area, and in terms of snail biomass per unit dry plant weight, were found: Physa gyrina and Potamogeton pectinatus, and Lymnaea stagnalis and P. richardsonii. The associations were not constant but showed well-defined peaks correlated with growth of the respective host plants. The peaks were composed of newly hatched snails and some adults. Peaks for Physa gyrina coincided with carbohydrate maxima, especially of fructose and glucose, in the tissues of Potamogeton pectinatus. Peaks for Lymnaea stagnalis coincided with sucrose maxima in P. richardsonii. The hypothesis is presented that plant exudates may attract specific snail species. Such mechanisms reduce interspecific competition for food.
Unusual songs with comments on song learning among vireos
Authors: James Ross D.
Published: January 2008

Sonographic comparisons are made between the songs of an olive-sided flycatcher and a red-eyed vireo singing flycatcherlike phrases, plus the songs of a red-eyed vireo and a warbling vireo singing phrases like those of red-eyed vireo. These unusual songs seem to be the result of mistakes in learning made during song development rather than the result of hybridization.
The anatomy and histology of the internal reproductive organs of the sunflower beetle, Zygogramma exclamationis (Coleoptera: Chrysomelidae)
Authors: Gerber G. H. , Neill G. B. , Westdal P. H.
Published: January 2008

The anatomy and histology of the female and male internal reproductive organs of the sunflower beetle, Zygogramma exclamationis (F.), are described. The female system consists of a vagina, bursa copulatrix, common oviduct, lateral oviducts, spermatheca, spermathecal accessory gland, and ovaries. Twelve ovaries examined contained from 23 to 32 telotrophic ovarioles, the average being 27.3. The male system consists of a pair of bilobed testes, a pair of accessory glands, vasa deferentia, and an ejaculatory duct which is bifurcated at its anterior end. Three testes examined contained 34, 36, and 37 sperm tubes, respectively. The basic features of the reproductive systems of Z. exclamationis are similar to those of other Chrysomelidae.
Predatory responses of a raptor guild to changes in prey density
Authors: Phelan Frank J. S. , Robertson Raleigh J.
Published: January 2008

The responses of a guild of open-country birds of prey to changes in prey density were studied on a simple island habitat in southern Ontario. Numerical responses were conspicuous in all species, while functional responses were weak. Individual raptor species displayed characteristic responses, differing from others in intensity and aspects of seasonality related to breeding versus wintering. Yet a basic similarity in the form of response for all species present at any one season, and a complementarity of responses of species present through the changing seasons, resulted in an overall guild level pattern of numerical and functional response of predators to changes in prey density. The synchronous fluctuations of predator and prey densities observed are similar to those of arctic areas and unusual for the temperate regions where the study was conducted. Characteristics of the predator and prey assemblages and features of the study site were important in determining the type, the intensity, and the level (species or guild) at which the responses were exhibited.
Effect of age and parity on weight gain and entry into hibernation in Richardson's ground squirrels
Authors: Michener Gail R.
Published: January 2008

Weight gain and time of entry into hibernation were recorded for nonparous yearling, parous yearling, and parous 3-year-old Spermophilus richardsonii in southern Alberta in 1977. Nonparous squirrels steadily gained weight over the 12-week period between emergence from hibernation and immergence into hibernation. The weight pattern of parous squirrels exhibited a sub-cycle of weight gain, weight loss, and weight maintenance associated with pregnancy, parturition, and lactation resulting in delayed attainment of prehibernation peak weights and delayed entry into hibernation. There was no difference in time of emergence of parous and nonparous females in the subsequent spring. Age affected rates of post lactation weight gain such that the oldest mothers remained active longest but attained the lowest prehibernation weights. Oldest mothers had the lowest over-winter survival rate.
Effects of a spring snowstorm on behavior, reproduction, and survival of Belding's ground squirrels
Authors: Morton Martin L. , Sherman Paul W.
Published: January 2008

From 30 April to 26 May 1977 a snowstorm occurred in the Sierra Nevada where we were studying Spermophilus beldingi. The storm began 8 days after ground squirrels began emerging from hibernation. During the storm, emergence nearly ceased and mating was suspended, body weights decreased sharply, locomotor abilities became impaired, and nocturnal burrow sharing increased. The animals became more susceptible to predation, and one case of intraspecific killing and cannibalism was observed. At least four animals starved; they were totally depleted of fat and had atrophied livers. During the storm, more adult females than males perished; 60% of females disappeared in 1977 vs. 32 and 26% in 1975 and 1976, respectively. Furthermore, when compared with 1975 and 1976, fewer 1977 females mated, conceived, or weaned young.During 1969–1977 at Tioga Pass, first emergence of S. beldingi varied up to 6 weeks with the animals emerging earliest in years of lightest snowpacks. At high altitudes where summers are brief, early emergence may increase the likelihood that young will reach appropriate body size before winter. On the other hand, avoidance of the effects of unpredictable spring storms favors later emergence. In 1977, because of the snowstorm, late emergers were favored.
Helminths in coyotes (Canis latrans Say), wolves (Canis lupus L.), and red foxes (Vulpes vulpes L.) of southwestern Manitoba
Authors: Samuel W. M. , Ramalingam S. , Carbyn L. N.
Published: January 2008

Forty-three coyotes, 12 wolves, and 6 red foxes from an area around Riding Mountain National Park in southwestern Manitoba were examined for parasitic helminths. Eleven, 8, and 5 species were found in coyotes, wolves, and red foxes, respectively. Alaria marcianae, Alaria arisaemoides, and Toxascaris leonina were found in all three host species; Echinococcus granulosus, Taenia hydatigena, Uncinaria stenocephala, and Oslerus (Oslerus) osleri in wolves and coyotes; and Echinococcus multilocularis in coyotes and red foxes. Taenia pisiformis and T. leonina were the most prevalent species in coyotes; E. multilocularis and E. granulosus, the most numerous. Echinococcus granulosus was the most prevalent and numerous species in wolves. Alaria marcianae and T. leonina were found in all red foxes. The significance of the coyote as a major definitive host of E. multilocularis in southwestern Manitoba is discussed.
Maturité sexuelle et âge à la première reproduction dans une population de plaine de Lacerta vivipara
Authors: Heulin Benoît
Published: January 2008

A lowland population of Lacerta vivipara was studied near Paimpont, France. Under favorable climatic conditions, the young grow rapidly and approximately 50% of them can breed when they are 1 year old. This particular characteristic has not been found in previously studied populations from more northerly areas or mountain habitats; these individuals never reproduce before 2 years of age. Intraspecific, altitudinal, and latitudinal variations in the age of reproduction are discussed in relation to the direct influence of climatic conditions and the possible involvement of selective pressures.[Journal translation]
Histology of reproduction in harp and grey seals during pregnancy, postparturition, and estrus
Authors: Ouellette J. , Ronald K.
Published: January 2008

Reproductive tracts were collected on the eastern coast of Canada from adult female grey seals (Halichoerus grypus) during gestation and postparturition, and from adult female harp seals (Phoca groenlandica) during delayed implantation and postparturition. Reproductive tracts were fixed in 10% buffered formalin for light microscopy. The placental site and adjacent tissue were preserved in 2% glutaraldehyde – 1% paraformaldehyde for scanning electron microscopy. During the delay of blastocyst implantation, the endometria of the gravid and nongravid uterine horns were similar in microscopic appearance. During gestation, maternal septa were often surrounded by maternal epithelium deep into the placental labyrinth except distally, where the maternal cells were replaced by syncytium. Marginal hematomas increased in size and complexity throughout placentation. Following parturition, uterine regression occurred earlier in harp seals (10 days postpartum) than in grey seals (21–25 days postpartum). Postpartum changes were most pronounced in the placental site where the blood vessels underwent extensive reorganization. In some specimens, the extensively vascularized placental site of the previous pregnancy was still apparent 12 months later. Epithelial replacement in the uterus was complete in grey seals 21–25 days postpartum and sooner in harp seals. Cervical and vaginal stratification occurred in both phocids following parturition and increased towards estrus. A recently ovulated grey seal was obtained between 21 and 25 days postpartum. The vaginal stratification and the presence of sperm in their uterine horns indicated that grey seals began estrus about 12–17 days postpartum. In harp seals, estrus appeared to occur towards the end of the lactational period, about 10–12 days postpartum.
Breeding site characteristics and breeding success in Thick-billed Murres
Authors: Birkhead T. R. , Greene E. , Biggins J. D. , Nettleship D. N.
Published: January 2008

Breeding site characteristics of Thick-billed Murres, Uria lomvia, differed significantly between Cape Hay, Bylot Island, and Coburg Island, N.W.T., Canada. Logistic regression analysis showed that at both colonies site characteristics had significant effects on breeding success. At Coburg Island the slope and width of the ledge were the most important factors, whereas at Cape Hay the number of walls and neighbours, and to a lesser extent the width of the ledge, best explained the variation observed in breeding success. Egg and chick mortality factors differed at each colony. At Coburg Island most eggs were lost through accidentally rolling off ledges, and at this colony birds on level sites on broad ledges were most successful. At Cape Hay most mortality of eggs and chicks occurred as a result of rock- and ice-falls; sites offering some protection were the most productive. Comparisons are made with other studies, and the role of breeding site quality in population regulation is discussed.
Transport characteristics of the isolated rectal complex of the mealworm Tenebrio molitor
Authors: Tupy J. H. , Machin J.
Published: January 2008

The coupling between water and ion transport in the rectal complex of mealworms can be studied further using an in vitro preparation under oil. Preliminary investigations into the properties of such a preparation are described. The preparation remains viable over several hours when sustained with transportable cations, primarily potassium but not sodium, which appears to be the limiting factor in generating long-term water absorption. Potassium is selectively transported by the Malpighian tubules surrounding the rectum, thus generating osmotic forces necessary for water absorption from within the lumen. Reabsorption was studied using sucrose solutions of different concentrations in the rectal lumen. The preparation absorbed water from extremely low water activities down to the same threshold value (aw = 0.88) observed in intact animals. Absorption rates were less than half those observed in vivo, probably because of the viscosity of the sucrose solutions. Transported water emerging from the common duct of the preparation included a significant contribution from the haemolymph.
Electrophysiology of oocytes during meiotic maturation and after ovulation in brook trout (Salvelinus fontinalis)
Authors: Marshall William S. , Habibi Hamid R. , Lessman Charles A.
Published: January 2008

Brook trout oocytes were stripped of their follicular layers and were impaled with both voltage-measuring and current-passing microelectrodes. The membrane resting potential (Vm) was −46 ± 1.2 mV (mean ± SE, n = 50, bath grounded) in control denuded oocytes with an intact germinal vesicle. Vm was reduced to −38 ± 1.8 mV (n = 16) in eggs that had ovulated in vivo. Accompanying the potential drop was a marked increase in membrane resistance (Rm) from 26 ± 1.7 in denuded oocytes to 1640 ± 150 kΩ∙cm2 in ovulated eggs and a reduction in membrane current (Im) from 2380 ± 260 to 25 ± 2.6 nA∙cm2. The increased resistance in ovulated eggs was in part the result of reduced Na+ and K+ membrane conductances; there was no significant change in Cl− conductance. Treatment of denuded oocytes with 17α-20β-dihydroxyprogesterone produced germinal vesicle dissolution; in denuded oocytes that had undergone germinal vesicle dissolution in vitro, Rm increased and Im decreased, comparable at least qualitatively to the changes seen after ovulation in vivo. The results indicate that major electrophysiological changes accompany germinal vesicle dissolution and ovulation in brook trout oocytes.
The New World genus Lathrapanteles n. gen.: Phylogeny and placement in the Microgastrinae (Hymenoptera: Braconidae: Cotesiini)
Authors: Williams D. J. M.
Published: January 2008

The new genus Lathrapanteles is erected for Sathon papaipemae (Muesebeck) and three new species, L. ampyx (type locality, Cali, Colombia), L. fuscus (type locality, Notre Dame du Portage, Québec), and L. heleios (type locality, Mer Bleue, Ottawa, Ontario). The genus and species are described from cocoons, adult and larval structure, and distribution. Host-dependent variability in the first tergum of the metasoma of L. papaipemae n. comb. is discussed. A key to species and reconstructed phylogeny are given for Lathrapanteles. Placement of the genus in the Cotesiini and its effect on microgastrine classification is discussed.
The role of infant isolation calls in mother–infant reunions in the little brown bat, Myotis lucifugus (Chiroptera: Vespertilionidae)
Authors: Thomson C. E. , Fenton M. B. , Barclay R. M. R.
Published: January 2008

The role of infant isolation calls (i-calls) in mother–infant communication in Myotis lucifugus, the little brown bat, was investigated in a natural nursery colony near Westport, Ontario. Analysis of isolation calls showed considerable individual variation, compatible with the hypothesis that the calls contain individual signatures. Presentations of isolated infants or recordings of their i-calls elicited specific rather than general responses, and females were selective about the young they would retrieve and nurse. Infants, however, were less selective, attempting to nurse from any convenient female. Retrievals of isolated infants by females was usually preceeded by careful inspection, which included olfactory cues. Our results suggest that female M. lucifugus selectively nurse their own young, having recognized them by a combination of olfactory and acoustic cues. We also describe a short i-call (<10 ms long) that elicits a high level of flight response from newly volant young and appears to be a "distress" call.
Histological and ultrastructural observations on the secondary scolex and strobila of Haplobothrium globuliforme (Cestoda: Haplobothrioidea)
Authors: MacKinnon Barbara M. , Burt Michael D. B.
Published: January 2008

The strobila attached to the primary scolex of Haplobothrium globuliforme fragments to produce numerous secondary scolices. These secondary scolices develop mature and gravid proglottides. The secondary scolex consists of four shallow disclike bothria which surround a raised apical area. The tegument bears small microtriches, 0.6 μm long, and the tegumental cytoplasm is filled with electron-dense discs and mitochondria. Ducts filled with electron-dense secretory bodies were seen in the scolex and occasionally were seen to fuse with the tegument. The tegument of the neck region is similar to that of the scolex. More posteriorly, the strobilar tegument bears elongated, uniform microtriches, 1.2–1.5 μm long with pronounced electron-dense tips. The anterior-most proglottides, attached to the secondary scolex, each terminate in four skirtlike appendages. The inner, posterior surfaces of these appendages bear robust, clublike microtriches or spines. Adjacent to these microtriches secretory ducts release electron-dense secretory bodies to the surface of the tegument. It is suggested that these appendages may function as accessory adhesive organs.
Developmental stability, heterozygosity, and genetic analysis of morphological variation in pink salmon (Oncorhynchus gorbuscha)
Authors: Beacham Terry D.
Published: January 2008

Heterozygosity of 26 pink salmon (Oncorhynchus gorbuscha) families was compared with family survival rates up to 410 d after fry emergence and also with asymmetry of pectoral and pelvic fin ray numbers. There was no significant association between heterozygosity calculated at six electrophoretic loci and either survival rate or asymmetry in fin ray number at any time during the 410-d rearing period. More heterozygous families did not have higher survival rates than less heterozygous families, and they did not have less asymmetry in the fin ray characters. Heritabilities of 11 morphometric characters were, on average, lower than the heritabilities of the 2 meristic characters examined. There is no evidence yet to indicate that increased heterozygosity results in increased canalization of morphology in pink salmon.