bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Characterization of Emerging Non-Levofloxacin-Susceptible Pneumococci Isolated from Children in South Africa
Authors: Wolter Nicole , du Plessis Mignon , von Gottberg Anne , de Gouveia Linda , Klugman Keith P.
Published: March 2009

Fluoroquinolones are not indicated for use for the treatment of pneumonia in children; however, non-levofloxacin-susceptible
Streptococcus pneumoniae
(NLSSP) has emerged in South Africa among children receiving treatment for multidrug-resistant tuberculosis. This study aimed to genotypically characterize NLSSP isolates. Invasive isolates were collected through active national laboratory-based surveillance for invasive pneumococcal disease (IPD) from 2000 through 2006 (
n
= 19,404). Carriage studies were conducted at two hospitals for patients with tuberculosis in two provinces. Phenotypic characterization was performed by determination of MICs and serotyping. Fluoroquinolone resistance mutations were identified, and clonality was investigated by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Twelve non-levofloxacin-susceptible cases of IPD were identified, and all were in children <15 years of age. Ten isolates were serotype 19F and formed two clusters according to their PFGE profiles, antibiogram types, and fluoroquinolone resistance-conferring mutations. All nine carriage isolates from children in hospital A were NLSSP, serotype 19F, were indistinguishable by PFGE, and were related to invasive isolates in cluster 2. Of 26 child carriers in hospital B, 22 (85%) were colonized with NLSSP. The isolates were indistinguishable by PFGE, although they displayed two serotypes, serotypes 19F and 23F. The isolates were related to invasive isolates in cluster 1; however, higher levofloxacin MICs and different fluoroquinolone resistance mutations were suggestive of horizontal gene transfer. A serotype 23F carriage isolate displayed increased fitness compared with the fitness of an otherwise indistinguishable serotype 19F carriage isolate. These data suggest that a low-level non-levofloxacin-susceptible strain transformed into a highly resistant strain under antibiotic pressure and underwent capsular switching in order to have increased fitness.
First Case Report of Sepsis Due to
Rothia aeria
in a Neonate
Authors: Monju Ayaka , Shimizu Naomasa , Yamamoto Masahiro , Oda Keiko , Kawamoto Yutaka , Ohkusu Kiyofumi
Published: March 2009

Rothia aeria
, a gram-positive coccoid- to rod-shaped bacterium with irregular morphology, is an extremely rare causative organism of infections in humans. We report the first case of
R. aeria
sepsis clinically manifested in a female neonate soon after birth.
Mycobacterium tuberculosis
Transmission Is Not Related to Household Genotype in a Setting of High Endemicity
Authors: Marais B. J. , Hesseling A. C. , Schaaf H. S. , Gie R. P. , van Helden P. D. , Warren R. M.
Published: March 2009

Among the different strains of
Mycobacterium tuberculosis
, Beijing has been identified as an emerging genotype. Enhanced transmissibility provides a potential mechanism for genotype selection. This study evaluated whether the Beijing genotype is more readily transmitted than other prevalent genotypes to children in contact with an adult tuberculosis (TB) index case in the child's household. We conducted a prospective, community-based study at two primary health care clinics in Cape Town, South Africa, from January 2003 through December 2004. Bacteriologically confirmed new adult pulmonary TB cases were genotyped by IS
6110
DNA fingerprinting; household contacts less than 5 years were traced and screened for
M. tuberculosis
infection and/or disease. A total of 187 adult index cases were identified from 174 households with children aged less than 5 years. Of 261 child contacts aged 0 to 5 years, 219 (83.9%) were completely evaluated and the isolate from the index case was successfully genotyped.
M. tuberculosis
infection (induration of ≥10 mm by Mantoux tuberculin skin test) was documented in 118/219 (53.9%) children; 34 (15.5%) had radiographic signs suggestive of active TB. There was no significant difference in the ratio of infected children among those exposed to the Beijing genotype (51/89; 57.3%) and those exposed to non-Beijing genotypes (55/115; 47.8%) (odds ratio, 1.5; 95% confidence interval, 0.8 to 2.7). Genotyping was successful for six children diagnosed with active TB; the isolates from only two children had IS
6110
fingerprints that were identical to the IS
6110
fingerprint of the isolate from the presumed index case. We found no significant association between the
M. tuberculosis
genotype and transmissibility within the household. However, undocumented
M. tuberculosis
exposure may have been a major confounding factor in this setting with a high burden of TB.
Cues for orientation in hummingbird foraging: color and position
Authors: Miliar Richard S. , Tamm Staffan , Sutherland Glenn D. , Gass Clifton Le
Published: March 2009

In this study we examined the relative influence of the color and position of food sources on the feeding patterns of hummingbirds. We studied ruby-throated hummingbirds (Archilochus colubns) in the field and rufous hummingbirds (Selasphorous rufus) in the laboratory. The field experiments demonstrated that the use of equally profitable feeders in arrays is more strongly influenced by position than by color. This suggests that hummingbirds learn and remember the locations of profitable food sources and return to them preferentially if the reward continues to be adequate. The laboratory experiments demonstrated that although hummingbirds learn quickly to return to a single profitable feeder in a linear array of unprofitable ones if it is marked by a consistent color cue, their learning is strongly influenced by position in the absence of color cues. This suggests that hummingbirds' spatial memory may be limited in resolution and that they may use visible landmarks to improve their performance. These results are consistent with the hypothesis that landmarks facilitate foragers' limited ability to learn and remember profitable locations in their environments.
Adaptations of metabolism for freeze tolerance in the gray tree frog, Hyla versicolor
Authors: Storey Janet M. , Storey Kenneth B.
Published: March 2009

Biochemical adaptations allowing the natural survival of extracellular freezing were examined in the gray tree frog, Hyla versicolor. Laboratory-reared immature adults froze between −1 and −1.5 °C and survived 5 days of freezing at −2 °C as well as repeated rapid bouts of freeze–thaw. Measurements of ice content showed 41.5% of total body water frozen. Glycerol accumulated as the cryoprotectant in sexually mature adult H. versicolor (423 μmol/mL in blood) while both glycerol and glucose accumulated in immature adults (16.3 ± 6.8 and 25.9 ± 11.6 μmol/mL in blood, respectively). Cryoprotectant synthesis was freezing stimulated only and did not occur over long-term cold acclimation at 0 to 1 °C. Cryoprotectant synthesis was correlated with a 203% increase in liver total phosphorylase activity and an increase in phosphorylase a content from 40 to 60%. Activities of 15 other enzymes of intermediary metabolism were determined in liver and leg muscle; activities of most enzymes increased with freezing exposure as did soluble protein content. Survival of freezing depends upon anaerobic mechanisms of energy production in tissues. Frogs frozen at −2 °C accumulated lactate in liver and muscle. Energy charge dropped in both tissues and the creatine phosphate reserves of muscle were depleted.
Life history of anadromous arctic charr, Salvelinus alpinus, in the Fraser River, northern Labrador
Authors: Dempson J. B. , Green J. M.
Published: March 2009

Upstream migrations of anadromous Arctic charr, Salvelinus alpinus, were monitored in the Fraser River, Labrador. Samples of charr were randomly obtained from 1975 to 1979 for biological analysis of age, growth, reproductive, and migratory characteristics. The run begins in mid-July and extends until late September. Larger charr tend to enter the river first with a progressive decrease in mean length throughout the run. Size and age composition of migrant charr range from 13 to 82 cm ([Formula: see text], 45.1 ± 7.3) and from 3 to 18 years (8.3 ± 1.7), respectively. Spawning activity peaks during the last 2 weeks in October. Fecundity of fish 41–61 cm in fork length ranged from 2316 to 9245 eggs (4665 ± 434) with approximately 75% of females mature by 8 years of age. There was no evidence from tag recaptures over an 8-year period (1976–1983; N = 241) that Fraser River charr undergo extensive marine migrations. Approximately 84% of the recaptures were from fish which either returned to the Fraser River or were caught in commercial and domestic fisheries in adjacent Nain and Tikkoatokak bays. In comparison with other North American Arctic charr populations, Fraser River charr are similar with respect to the large variability observed in age at length, variable maturation cycle, and preponderance of females at sea during the summer. Differences, however, occur among individual life history characteristics such as growth rate, size and age at first seaward migration, size and age at maturity, fecundity, and movements at sea.
Population characteristics of the Burwash caribou herd in the southwestern Yukon estimated by capture–recapture analysis
Authors: Gauthier D. A. , Theberge J. B.
Published: March 2009

Seasonal censuses (calving, rut, and winter periods) and other surveys were undertaken to apportion changes in mountain caribou (Rangifer tarandus caribou) numbers to changes in mortality, recruitment or ingress–egress, and to assess seasonal distribution. Data were collected from September 1978 to June 1982 in the St. Elias Mountains of the southwestern Yukon. Thirty-nine caribou were radiocollared and used in capture–recapture analysis. Estimates varied from a minimum herd size of 330 to a maximum of 560. Bulls comprised 33% of animals older than calves. Calving occurred between 15 May and 13 June from 1979 to 1982. Pregnancy rates varied from 78 to 82% during 1980 to 1982 while calves comprised 20% of the herd in calving periods, 19% during ruts, and 18% during midwinters. Recruitment (% yearlings) varied from 9% in 1980 to 13% in 1981 and 14% in 1982. Neonate mortality (birth to 3.5 weeks) varied from 13 to 49% between 1980 and 1982. An average of 56% of calves died within 5 months of birth. Natural mortality rates of adult–subadults varied between 6 and 9%. All evidence indicated stable or slowly increasing numbers until winter 1982 when movement from the study area was documented. The total range size was 1978 km2 with the herd occupying two distinct seasonal ranges in upland tundra plateaux separated by lowland boreal forest. Herd densities (based on seasonal range size) averaged 1.66 caribou/km2. The proportion of the herd in each upland area varied consistently between seasons and years such that variations in numbers could be accounted for by mortality, recruitment, and movement from the study area in the winter of 1982.
The life history and systematics of deep-sea lizard fishes, genus Bathysaurus (Synodontidae)
Authors: Sulak Kenneth J. , Wenner Charles A. , Sedberry George R. , Guelpen Louis Van
Published: March 2009

Bathysaurus agassizii was found to be a junior synonym of Bathysaurus ferox. The two valid species of the genus Bathysaurus, B. ferox and B. mollis, are circumglobal except beneath polar waters. Bathysaurus ferox is known mostly from depths of 1000 to 2500 m and temperatures of 4 to 3 °C; B. mollis is known mostly from 2500 to 4500 m and from 3.0 to 2.0 °C. In the Middle Atlantic Bight, the numerical density of B. ferox from trawl samples was 0–8 fish/25 × 103 m2; biomass was 0–8000 g for the same unit area. No clear "bigger–deeper" trend was evident for either species. Both species have been shown to be synchronous hermaphrodites. Mature gonads in B. ferox have been found in samples off Virginia from November through January; the mean fecundity found was 32 000 ova. Both species are predominantly piscivorous. A large, lipid-rich liver, probably an energy store, constituted up to 20% of the total weight in B. ferox and up to 5% in B. mollis. New records of pelagic postlarvae of both species have been reported. Postlarval development is probably gradual and prolonged, prior to a rapid transformation to the benthic juvenile stage. Postlarval development may occur in midwater within a few hundred metres of the surface.
Salsuginus Beverley-Burton, 1984 (Monogenea: Ancyrocephalidae) from Cyprinodontoidei (Atheriniformes) in North America with descriptions of Salsuginus angularis (Mueller, 1934) Beverley-Burton, 1984 from Fundulus diaphanus and Salsuginus heterocliti n. sp. from F. heteroclitus
Authors: Murith D. , Beverley-Burton M.
Published: March 2009

Salsuginus Beverley-Burton, 1984 has been proposed for ancyrocephalid monogeneans found on North American Cyprinodontoidei (Atheriniformes). The genus is distinguished by the following characteristics: penis sclerotized, tubular, spiralling to form single coil; accessory piece with median groove to accommodate shaft of penis, distal point heavily sclerotized; dorsal and ventral hamuli similar in shape with distinct superficial and deep roots and curved blade; dorsal and ventral transverse bars bandlike, bowed posteriorly with posterior notch at extremities of each: larval hooks of similar shape and size with well-developed sickle bearing thumblike projection. Salsuginus angularis (Mueller, 1934) Beverley-Burton, 1984, the type species, is redescribed from the present material found on Fundulus diaphanus (Lesueur) in Ontario. Salsuginus umbraensis (Mizelle, 1938) n. comb., S. funudulus (Mizelle, 1940) Beverley-Burton. 1984. S. seculus (Mizelle and Arcadi, 1945) n. comb. and S. bahamianus (Hanek and Fernando, 1972) n. comb. are transferred from Urocleidus Mueller, 1934; S. spirae (Williams, 1980) n. comb. is transferred from Ancyrocephalus Creplin, 1839. Material found on F. heteroclitus taken in New Brunswick is described as S. heterocliti n. sp. Evolutionary aspects of Salsuginus spp. are briefly discussed and notes on the identification of species parasitizing Fundulus spp. are presented. Previous records of Salsuginus spp. are listed.
Parsimony and testability: a reply to Dunbar
Authors: Wikander Richard
Published: March 2009

Dunbar (M. J. Dunbar. 1980. Can. J. Zool. 58: 123–128) argues that both the principle of parsimony and testability of scientific hypotheses are unnecessary and even on occasion undesirable features of scientific investigation. These conclusions are based on examination of selected events in the history of science, major innovations, or discoveries which Dunbar argues might never have happened had the investigators responsible for them been constrained by considerations of parsimony and testability. It is argued here that (1) Dunbar has confused the initial conception of an idea or a hypothesis with the problem of choosing between available competing hypotheses: the latter is a problem proper to the logical analysis of scientific procedure, and presupposes hypotheses to begin with, whereas the former is a problem for the psychology of science; and (2) Dunbar has misunderstood the meaning of the term "testability," and has confused it with the meaning of the phrase "testable at time tn."
Intersexual song answering in Red-winged Blackbirds
Authors: Beletsky L. David
Published: March 2009

Female Red-winged Blackbirds (Agelaius phoeniceus) answer their mates' songs with their own songs. Field observations were conducted to determine the extent of song-answering behavior during the Red-winged Blackbird breeding season and to test the hypothesis that song answering in this species is primarily a sexual communication. Females answered significant percentages of their mates' songs during the prenesting and incubation phases of the breeding season, but answering rates declined during the latter phases. Females tended to answer mates when the males were engaged in sexual activities, providing support for the idea that song answering in this species functions in intrapair communication.
Transience of social affiliations among humpback whales (Megaptera novaeangliae) on the Hawaiian wintering grounds
Authors: Mobley Jr. Joseph R. , Herman Louis M.
Published: March 2009

Observations were made from an elevated shore station and from small boats of membership and of changes in membership in pods of humpback whales, Megaptera novaeangliae, assembling in Hawaiian waters during the winter–spring season of 1980. Pod sizes were small, with many singletons, pairs, and triplets, and a few larger sized pods. For pods having a calf present, the modal size was three: the mother, her calf, and an adult "escort" animal. When the calf was absent the modal size was two animals. On the average, 14% of the pods per hour changed membership, either losing or gaining members; for both pods with and without calf, the modal sizes showed the lowest rate of change. The rate of change was seasonally dependent and was at its maximum between mid-February and mid-March, when the relative abundance of whales was also at its maximum. Pods with calf were much more likely to attract new members than to lose members; pods without calf were equally likely to attract or lose members. Twelve cases of photographic resightings of individuals documented changes in affiliations with intervals as short as 1 h. The driving force for the transient nature of pod membership was hypothesized to be the prospecting behavior of mature males searching for sexually mature, receptive females. The overall pattern and duration of social affiliations was consistent with characteristics of polygynous or promiscuous mating systems.
Effect of egg size on incubation time and alevin and fry size in chum salmon (Oncorhynchus keta) and coho salmon (Oncorhynchus kisutch)
Authors: Beacham T. D. , Withler F. C. , Morley R. B.
Published: March 2009

Variability in hatching time, time of exogenous yolk absorption ("button up") of alevins, alevin size, and fry size was investigated with respect to initial egg size for chum salmon (Oncorhynchus keta) and coho salmon (Oncorhynchus kisutch). There was no significant difference with respect to egg size in hatching time of the alevins (stage between hatching and emergence from the redd) or time of exogenous yolk absorption for either species. For both species, alevins hatching from large eggs were longer and had greater amounts of yolk than those hatching from small eggs. Tissue weights of the alevins were not different. The differences in size between these two groups of alevins were maintained throughout the alevin stage and were greater at exogenous yolk absorption than at hatching. Fry (newly emerged, free-swimming young) derived from large eggs had greater tissue weight at exogenous yolk absorption than those derived from small eggs.
Effects of adults on the demography of fox squirrels (Sciurus niger)
Authors: Hansen Lonnie P. , Nixon Charles M.
Published: March 2009

As a test of the hypothesis that adult fox squirrels (Sciurus niger) regulate the number of immature and adult squirrels entering a population, each fall from 1979 to 1981 adult males were removed from two grids (male-removal grids, MRGs), adult females from two grids (female-removal grids, FRGs), all adults from one grid (adult-removal grid, ARG), and one grid was maintained as a control (control grid, CG). The number of previously uncaptured juveniles and subadults (both sexes) and yearling–adult females was greater on FRGs than on the CG and MRGs, especially during the fall. The number of new adult males captured during the fall was higher where adult males had been removed. During spring, reproductive rates (percent lactating) were higher on grids from which females had been removed (FRGs and the ARG), but this was not so during fall. Length of residency was shorter for juvenile–subadult and adult fox squirrels and longer for yearling females where adult females had been removed. Movement patterns in response to removal of adults suggested resident adult females influenced home range size of all sex classes and age-classes. We conclude that the presence of adult females is important in limiting recruitment in local populations of fox squirrels and that this strategy likely evolved in response to resource-limited environments.
Early mother–young interactions in California bighorn sheep, Ovis Canadensis californiana
Authors: Shackleton D. M. , Haywood J.
Published: March 2009

All except 2 of 22 pregnant females isolated themselves from conspecifics to give birth. Isolation is probably an antipredator strategy, although isolation in the 1st day after birth may also help the development of the mother–young bond. Even after they rejoined the herd, the mother and her lamb stayed close together until the lamb was 4 days old when mother–young distances increased sharply, only to decrease again when the lamb began to graze for short periods next to its mother. Neonates were very active, particularly playing, during the 1st day of life. It is suggested that this high level of activity may help develop the motor skills necessary for "follower" young born in steep terrain. Synchrony of activities between a female and her lamb was high when she rested, but when she grazed, her lamb could be engaged in one of many different activities. Suckling behaviour during active and bedding periods differed significantly, with the longest mean suckle durations occurring during or immediately after rest periods. These long suckles were thought to be primarily nutritional, whereas the short, lamb-terminated suckles during active periods were believed to strengthen the mother–young bond rather than to provide milk.
The systematics and zoogeography of Gyrodactylus species (Monogenea) parasitizing gasterosteid fishes in North America
Authors: Cone D. K. , Wiles M.
Published: March 2009

The systematics and zoogeography of Gyrodactylus from gasterosteid fishes (Apeltes quadracus, Culaea inconstans, Pungitius pungitius, Gasterosteus aculeatus, and G. wheatlandi) in North America were examined through a study of museum-held specimens and fresh material collected from localities across Canada. Six species are considered specific to these fishes, namely: G. alexanderi Mizelle and Kritsky, 1967, G. avalonia Hanek and Threlfall, 1969 (syn. G. lairdi Hanek and Threlfall, 1969, G. memorialis Hanek and Threlfall, 1969, G. terranovae Hanek and Threlfall, 1969), G. canadensis Hanek and Threlfall, 1969, G. cameroni Hanek and Threlfall, 1970, G. eucaliae lkezaki and Hoffman, 1957, and an unidentified species resembling G. pungitii Malmberg, 1964. The fauna has striking morphological similarities to that parasitizing the same host fishes in Eurasia. In fact, G. avalonia, G. canadensis, and the unconfirmed species are considered sister species to G. arcuatus Bychowsky, 1933, G. branchicus Malmberg, 1964, and G. pungitii, respectively. The match-ups are considered to have evolved from three lineages that parasitized G. aculeatus and P. pungitius prior to Pleistocene dispersal that resulted in these fishes and their parasites extending over much of the northern hemisphere. Gyrodactylus cameroni from A. quadracus is probably of North American origin and a sister species of G. avalonia. Gyrodactylus alexanderi from Pacific coast G. aculeatus and G. eucaliae from C. inconstans in the continent's central region have ties with a Pacific lineage. The parasites' geographical distributions and possible evolutionary histories since Pleistocene glaciation are discussed.
Feeding ecology of migrating Red-necked Phalaropes (Phalaropus lobatus) in the Quoddy region, New Brunswick, Canada
Authors: Mercier F. M. , Gaskin D. E.
Published: March 2009

During the summers of 1981 and 1982, feeding ecology was studied in migrating populations of Red-necked Phalaropes (Phalaropus lobatus) at their late summer – early fall staging ground in the Quoddy region of the Bay of Fundy (44°55′ – 45°00′ N, 66°54′–66°59′ W). This species was particularly abundant during August 1982 when 5 000 to 20 000/km2 were present in the study area at the peak of occupation. Calanus finmarchicus was both the major prey item and the most plentiful zooplankton species in the area in which the phalaropes fed (mean density, 117 individuals/m2). The birds were consistently found in sectors of the study area corresponding to maximum C. finmarchicus concentrations, made readily available at the surface by upwelling activity. The phalaropes fed almost exclusively on this species, which made up 88.6% of the total number of prey items found in the stomachs; smaller copepods, seeds, and insects made up the rest, with a size limit for ingested prey of 6 mm. The birds fed by pecking constantly at the surface of the water while swimming in a sinusoidal pattern; this differs markedly from the spinning behavior observed near the breeding grounds.
Wolves and coyotes in Ontario: morphological relationships and origins
Authors: Schmitz O. J. , Kolenosky G. B.
Published: March 2009

Morphologically distinct groups of Canis in Ontario were identified using multivariate analyses on 6 body and 21 cranial characters. Three groups of wolves and three groups of coyotes were identified. Wolves in Ontario appeared to exhibit clinal variation. Large wolves were found in the boreal forest region of northern Ontario, intermediate-sized wolves were found in central Ontario, and a small form existed in southern Ontario. Coyotes in Ontario also varied geographically in size. Coyotes in southeastern and central Ontario resembled coyote–wolf hybrids.
The diet of Thick-billed Murres (Uria lomvia) in west Hudson Strait and northeast Hudson Bay
Authors: Gaston A. J. , Noble D. G.
Published: March 2009

We collected feeding adult Thick-billed Murres at several different localities within the foraging range of the colonies at Digges Sound through the breeding seasons in 1980, 1981, and 1982. Examination of prey remains from the stomach and foregut showed that the majority of birds contained prey covering a range of sizes from 0.01 to 47 g wet weight at ingestion. The total energy equivalent of prey found in the majority of stomachs was less than 10% of the birds' probable daily requirements. Comparison of species diversity of prey with that recorded for Thick-billed Murres in the high Arctic suggested that a greater range of prey is available in the low Arctic waters of Hudson Strait. We found little indication of consistent variation in pery occurrence among different feeding areas or within seasons. However, significant variation in diet occurred among years. Problems inherent in the method and the extent of variation among individual birds from the same sample make it difficult to make valid generalizations about the importance of different prey taxa in the diet of the murres.
Diet selection in Arctic lemmings (Lemmus sibericus and Dicrostonyx groenlandicus): food preferences
Authors: Rodgers Arthur R. , Lewis Martin C.
Published: March 2009

Testing of hypotheses relating lemming population dynamics to their food supply requires a detailed understanding of several major components of the diet selection process such as requirements, availability, preference, and selectivity. In this study, food preferences of Arctic lemmings were determined in cafeteria trials: Lemmus preferred graminoids and moss, while Dicrostonyx preferred shrubs and herbs. The stability of these preference patterns in each species was tested in further experimental cafeteria trials. Individuals of both species were pretreated on one of several diets, and two main types of trial were conducted involving limited and unlimited availability of test foods. Naive animals of both species, born and raised in captivity on artificial diets, were also used in the trials. In all cases, preference patterns in each species were maintained, suggesting that they are strongly heritable. Comparison of preference indices to the physical and chemical characteristics of tundra plants indicates that preference patterns in both species are related primarily to macronutrients and caloric content. Differences between Lemmus and Dicrostonyx are determined by secondary compounds and the physical characteristics of the plant species preferred by each. Comparison of ingestion rates and digestibility coefficients indicate that Dicrostonyx has a greater capacity than Lemmus in dealing with the negative characteristics of plants, such as secondary compounds or the presence of plant "hairs."
Free-water clearance by the nasal salt glands of adrenalectomized Pekin ducks (Anas platyrhynchos)
Authors: Butler David Gordon
Published: March 2009

Nasal salt glands in Pekin ducks secreted NaCl and conserved osmotically free water. Neither this process nor the functional adaptation to 0.9% NaCl are regulated directly by adrenocortical steroids.
Effect of exercise and starvation on the activity of glycogen phosphorylase and hexokinase in flight muscle of the American cockroach, Periplaneta americana L.
Authors: Jahagirdar A. P. , Downer R. G. H. , Viswanatha T.
Published: March 2009

Glycogen phosphorylase and hexokinase activities were measured in flight muscle of the American cockroach (Periplaneta americana L.) during running, flight, and starvation. The percentage of total phosphorylase present in the active form increased during the initial stages of exercise (up to 9 min following the initiation of flight) and starvation (up to 2 days starvation), but thereafter returned to normal levels. Mild exercise (running) failed to elicit changes in hexokinase activity during the first 5 min of exercise; however, the activities of the enzyme were elevated at 6, 9, and 12 min following the initiation of flight and throughout a 7-day period of starvation.
Life cycle characteristics of Peromyscus maniculatus nebrascensis
Authors: Millar John S.
Published: March 2009

Life cycle characteristics of Peromyscus maniculatus nebrascensis (Coues) were examined in the laboratory. Females and males bred as early as 35 and 60 days of age, respectively. The minimum time between pairing and parturition was 25.5 days; postpartum gestation averaged 29.5 days. Both litter size [Formula: see text] and neonate weight [Formula: see text] were positively correlated with prebreeding weight of the female. Nestlings attained physiological independence at 19.2 days of age; the weight of young was negatively related to litter size at that time. Females maintained an above-average weight ([Formula: see text] 20.1 g prebreeding) and increased their cumulative food intake by 145% during lactation. The cumulative food intake during lactation was positively related to the number of offspring. A comparison of these traits among populations of P. maniculatus indicates that a relatively early age at physiological independence is common to grassland mice. However, selection for early independence does not appear to have had significant effects on other reproductive and developmental traits.
Cathepsin B and aminopeptidase in the posterior midgut of Phymata wolffii Stål (Hemiptera: Phymatidae)
Authors: Houseman Jon G. , Morrison P. E. , Downe A. E. R.
Published: March 2009

The posterior midgut of the phymatid Phymata wolffii Stål contains cathepsin B and aminopeptidase activity. Identification of cathepsin B was based on maximal hydrolysis of benzoyl-DL-arginine-2-naphthylamide and benzoyl-DL-arginine-p-nitroanilide at pH 5.8 and 5.5, respectively. Cathepsin B hydrolysis of the tested substrates was activated by thiol chemicals and ethylenediaminetetraacetic acid (EDTA) and inhibited by tosyl-L-lysine chloromethyl ketone, iodoacetamide, and soybean trypsin inhibitor. Aminopeptidase hydrolyzed leucine-p-nitroanilide maximally at pH 7.8 and hydrolysis of the substrate was activated by magnesium and inhibited by EDTA, dithiothreitol, glutathione, and cysteine. The molecular weight of cathepsin B was 40 000 and was greater than 150 000 for aminopeptidase.
Bioenergetics of the western spruce budworm (Lepidoptera: Tortricidae) with comments on endotherm and ectotherm population energetics
Authors: Reichenbach Norman G. , Stairs Gordon R.
Published: March 2009

Energetic components (respiration, consumption, frass production, and growth) for larvae of the western spruce budworm (WSB), Choristoneura occidentalis, were modeled using multiple regression techniques for a range of temperatures (10–31 °C) and body weights (5–200 mg). These functions were used in a simulation of the bioenergetics of the WSB under different variable temperature regimes (average temperatures ranging from 10 to 22 °C). Simulation results showed that production increased as temperature increased. Net production efficiencies remained high (maximum ca. 32%) for all temperature regimes save the lowest, in which the maximum net production efficiency (production/assimilation) was 16%. Final assimilation efficiencies ranged from 50 to 52%. Early instar larvae had low total respiration costs, high assimilation efficiencies, low consumption rates, and rapid rates of tissue production. As the larvae increased in size, consumption rates increased, assimilation efficiencies declined, yet the total amount of energy assimilated increased so that production continued. Population energetics of the larvae showed that WSB were similar to other herbivorous ectotherms. Relative to endotherms, ectotherm populations consume similar quantities of energy and exist at higher biomasses per unit area.
Heterologous radioimmunoassay of LH in two seasonally breeding animals: hare (Lepus europaeus) and mink (Mustela vison)
Authors: Mondain-Monval Michelle , Caillol Monique , Meunier Monique
Published: March 2009

A heterologous radioimmunoassay using ovine LH as the labelled hormone, canine LH as the standard, and a rabbit antiovine LH serum (GDN 15) was developed and validated for LH measurement in the plasma of two seasonally breeding animals (induced ovulators). Physiological validation of the assay was evidenced by the increase in LH levels after LHRH injections and castration. In the hare, the longer the time after castration, the higher the cumulative response of LH after LHRH stimulation.
Electron microscopic study of cuticular and cellular structures of the body surface of the winter stonefly nymph, Taeniopteryx burksi Ricker and Ross (Plecoptera: Taeniopterygidae)
Authors: Kapoor N. N.
Published: March 2009

Scanning electron microscopy of the body surface of the stonefly nymph, Taeniopteryx burksi, shows a characteristic pattern of folds bearing microtrichia. Interspersed among the microtrichia are trichoid sensilla, and bulbiform and hemispheroidal structures. The ultrastructure of the bulbous structure is similar to that of the chloride cell complexes of perlid and nemourid larvae. Three specialized epidermal cells were observed when the hemispheroidal structure was examined by transmission electron microscopy. The central gland cell encloses an apical cavity which leads into a curved epicuticular appendage with a terminal pore. The gland cell is surrounded by two specialized epidermal cells.
Long-term divergence in body size produced by food size in laboratory populations of Acheta domesticus (Orthoptera: Gryllidae)
Authors: Tennis Patricia
Published: March 2009

Experiments were performed to test the hypothesis that food size can act as a selection pressure on body size. For 19–22 generations, two strains of house crickets were reared on small-sized food, large-sized food, or a mixture. Within both strains, small food consistently and significantly produced smaller individuals than did large food or mixed food. In the hybrid strain, rearing of all food-size lines on the same food size revealed that differences observed among the food-size lines had a genetic component. Within the commercial strain, all food-size lines were reared on the same food size during generations 16 and 19 in order to test for genetic divergence among the lines. No differences in body size were observed among the lines for generation 16. However, during generation 19, when populations from each line were reared on all three food-size treatments, the small-food line contained the smallest crickets only when reared on mixed food or large food. Although one cannot rule out alternative hypotheses of maternal effects or genetic drift, the hypothesis of genetic selection on body size by food size cannot be rejected with these data.
The relationship of structure to mechanical function in the third metacarpal bone of the horse, Equus caballus
Authors: Thomason J. J.
Published: March 2009

The relationship of structure to mechanical function is investigated for the third metacarpal of the domestic horse, Equus caballus, as a basis for extrapolating to the functional interpretation of bone structure in fossil equids. The orientation and density of trabeculae in the proximal and distal cancellous regions of the bone are assessed from sections and radiographs, and are quantified stereologically. The principal forces transmitted to the cancellous regions are reconstructed from in vivo strain gauge data in the literature. The major trabecular systems in the bone are oriented and positioned to resist and transmit the forces acting on them, and correlations between structure and function are described. These correlations indicate the potential utility of the results as a basis for interpreting the structure of the homologous bone in extinct equids.
Light microscopical observations on sporogony of Sarcocystis rauschorum (Protozoa: Sarcocystidae) in snowy owls (Nyctea scandiaca)
Authors: Cawthorn Richard J. , Brooks Ronald J.
Published: March 2009

The purpose of the study was to describe, by light microscopy, sporogony of Sarcocystis rauschorum (Protozoa: Sarcocystidae). Two coccidia-free snowy owls (Nyctea scandiaca) were fed bradyzoites of S. rauschorum from varying lemmings (Dicrostonyx richardsoni). At necropsy, 7 days postfeeding, numerous owl tissues were fixed in 10% neutral buffered Formalin and processed for histological examination. Zygotes, oocysts in various stages of sporulation, and fully sporulated oocysts were observed only in the lamina propria of the small intestine. Sporogony of S. rauschorum is similar to that of some other species of Sarcocystis: first nuclear division to two polar nuclei in the oocyst, then cytokinesis with a second nuclear division resulting in two sporoblasts each with two polar nuclei, and finally a third nuclear division and cytoplasmic development producing two sporocysts each with four sporozoites.
Hepatic metallothionein in the winter flounder (Pseudopleuronectes americanus)
Authors: Shears M. A. , Fletcher G. L.
Published: March 2009

A low molecular weight, metal-binding protein, characterized as metallothionein, was isolated from the liver cytosols of winter flounder injected with zinc or cadmium. This identity was confirmed by its amino acid composition, which was similar to that of metallothioneins isolated from the intestinal mucosal cytosol of zinc-injected flounder and from liver cytosols of other species of fish and mammals.
Croissance de la plie rouge (Pseudopleuronectes americanus) de l'estuaire maritime du Saint-Laurent
Authors: Vaillancourt Robert , Brêthes Jean-Claude F. , Desrosiers Gaston
Published: March 2009

A study on the growth in size and weight of the Winter Flounder, Pseudopleuronectes americanus (Walbaum), was conducted from samples collected during the summers of 1979 and 1980, in the bay of Saint-Fabien-sur-Mer (Québec) on the south shore of the Lower St. Lawrence Estuary. Age was determined by otolith readings and length–weight relationships were calculated. Linear growth equations were not statistically different for males and females. On the other hand, weight was found to be higher for females than for males of equal sizes. This relationship also varies with the sampling period, and a substantial weight increase follows the spawning period. The growth of P. americanus is slower in the estuary than in more southern areas, while the weights at equal sizes are higher. These results reflect the severe environmental conditions, which necessitate a large accumulation of food energy by the fish as reserves, to the detriment of growth.
Acuarioids (Nematoda: Acuarioidea) from waders and terns (Aves) in Sabah, East Malaysia: evidence for transmission on the wintering ground
Authors: Wong P. L. , Anderson R. C.
Published: March 2009

Acuarioids of the subfamily Schistorophinae occur primarily in gulls (Laridae) and waders (Scolopacidae, Charadriidae) although they are not highly specific. In the present study, six of these acuarioids were recovered from five species of waders and one species of tern collected in Sabah, East Malaysia (5°10′ N, 118°3′ E). Two of the hosts were residents and the rest were northern breeders on their wintering ground. The recovery of Viktorocara capillaris (Molin, 1860a) and Sciadiocara legendrei Petter, 1967 from the resident birds (Charadrius peronii Schlegel and Gelochelidon nilotica affinis (Horsfield)) confirmed that these nematodes are transmitted in Sabah. This is the first indication that transmission of schistorophines occurs on the wintering ground of their hosts. Since the hosts inhabit the marine environment, marine invertebrates are the most likely intermediate hosts. Several factors are suggested that may facilitate transmission in the wintering area. They include the high ambient temperature promoting rapid development in the intermediate host, the high density of the birds, and the long period (8 months of each year) they spend in the area. Sciadiocara legendrei is redescribed.
Isoelectric focusing of soluble proteins in the characterization of three species of Hymenolepis (Cestoda)
Authors: Dixon Brent R. , Arai Hisao P.
Published: March 2009

A technique involving protein separation was used as an alternative to a morphological approach in the differentiation of the tapeworms Hymenolepis diminuta, H. citelli, and H. microstoma. Isoelectric focusing of soluble proteins was performed on Polyacrylamide gels using extracts from whole, adult worms. Each species of Hymenolepis was found to have a unique protein banding pattern, although some bands appeared to be common to two or all three species. Very little difference was found in the protein banding patterns of worms of a given species, whether they were from a single host individual or two different host individuals of the same species. There was also little difference between gels in the banding patterns of a given species. This technique of soluble protein isoelectric focusing is simple and reproducible, has very good resolution, and seems well suited to taxonomic studies involving tapeworms.
The early development of the northern redbelly dace, Phoxinus eos (Cope)
Authors: Faber Daniel J.
Published: March 2009

Free-swimming larvae of the northern redbelly dace, Phoxinus eos (Cope, 1862), were collected from a shallow pond with a light trap. Preserved specimens are described and illustrated during their ontogenetic period (5.6–15 mm). Morphological, meristic, and pigmentary characteristics provide identification and systematics data for Phoxinus (Chrosomus).
Blissia glabra gen.n., sp.n. (Collembola: Isotomidae) from northwestern Canada
Authors: Rusek J.
Published: March 2009

Blissia glabra, a new genus and species from the Mackenzie River Delta south of Inuvik, N.W.T., is described. The new genus is related to Tetracanthella Schött, 1891 (Isotomidae). Morphological characters as seen with light and scanning electron microscopes are described and figured.
The influence of food resources on life history in Columbian ground squirrels
Authors: Dobson F. Stephen , Kjelgaard Julia D.
Published: March 2009

Life history characteristics were studied experimentally in Columbian ground squirrels (Spermophilus columbianus) at two elevations in the Rocky Mountains of southwestern Alberta, Canada, from 1981 to 1984. In two populations with supplemented food resources, survival of young increased, age at maturity of females decreased, litter size increased, and spring body weight increased in comparison with an initial unmanipulated period and with two populations monitored for reference. For individual ground squirrels, litter size and spring body weight increased under supplementation. Thus, life history characteristics exhibited phenotypically plastic responses to experimental manipulation of food resources. Life history patterns changed among natural ground squirrel populations at different elevations and these changes were likely due to changes in food resources. A general prediction of life history theory that reproductive effort should be highest in years favorable for juvenile survivorship was supported by the experimental results. The results did not support predictions from interspecific studies of changes in life history characteristics that scale to body weight.
The effect of a larval diet supplement on development in the mosquito Wyeomyia smithii (Coq.) under field conditions
Authors: Farkas Martha J. , Brust Reinhart A.
Published: March 2009

The effect of a larval diet supplement on Wyeomyia smithii (Coq.) development was studied within the water-filled leaves of Sarracenia purpurea L. (the purple pitcher plant) in bogs near The Pas and Patricia Beach, Manitoba, and near Kenora, Ontario. The larval diet supplement added to overwintered pitcher plant leaves in the spring was found to significantly accelerate the development of larvae and to produce larger and more fecund adults. Food-limited development of larvae probably plays an important role in the percentage of W. smithii that are bivoltine in northern latitudes.
The life histories of north-temperate populations of the crayfish Cambarus robustus and Cambarus bartoni
Authors: Hamr Premysl , Berrill Michael
Published: March 2009

The life histories of the crayfish Cambarus robustus and Cambarus bartoni were studied in the Kawartha Lakes region of southern Ontario. There were marked differences in their breeding and molting cycles compared with the familiar pattern of the Orconectes species of this region. Egg extrusion occurred later (July in C. robustus, June in C. bartoni), and juveniles therefore did not become free living until late summer or early fall. With little growing time in their first summer, they measured only 5–10 mm in carapace length (CPL) before growth ceased for the winter. At the end of their second summer the still immature crayfish measured 17–26 mm CPL in C. robustus and 13–20 mm CPL in C. bartoni. Maturity was therefore not attained until the end of the third summer, when most C. robustus matured at 34–45 mm CPL and C. bartoni at 25–30 mm CPL. The majority of individuals apparently reproduced for the first time during their fourth summer; a few apparently survived into another summer, reaching carapace lengths greater than 50 mm in C. robustus and 30 mm in C. bartoni. In males of both species, form 1 and form 2 occur throughout the summer. Although lacking the synchrony of Orconectes species, breeding and molting activities are still confined to the period between April and October. The timing of the life-history events observed in these two Cambarus species may be adaptations to seasonal stresses of the swift water environments that these species inhabit as well as to the relative harshness of the northern temperate climate.
Revision of the genus Stellocaronema Gilbert, 1930 (Nematoda: Habronematoidea)
Authors: Wong P. L.
Published: March 2009

Stellocaronema skrjabini is redescribed and the genus is revised. Stellocaronema indica Sharma, 1968 and S. aurangabadensis Ilyas, 1981 are regarded as synonyms of S. fausti (Li, 1934), and S. spinulosus (Molin, 1860) is considered a species inquirenda. The remaining two species regarded as valid are S. charadrii Mawson, 1968 and S. alii Naidu, 1978. In the present study, 7 of 24 species of waders (Charadriidae, Scolopacidae, and Recurvirostridae) examined were infected with S. skrjabini. Prevalences and intensities were unusually high in the marbled godwit (Limosa fedoa (L.)) suggesting that this wader plays an important role in the transmission of S. skrjabini.