bluuebunny/crossref_metadata_2025 huggingface dataset:
Hematological and clinicochemical values for free-ranging pronghorn fawns
Authors: Barrett Morley W. , Chalmers Gordon A.
Published: August 2008

From 1973 to 1975, inclusive, blood from 253 free-ranging pronghorn (Antilocapra americana) neonates in southeastern Alberta was obtained for hematological and clinicochemical determinations. Mean erythrocyte, hematocrit, hemoglobin, and erythrocyte sedimentation rate values were 9.68 × 106/mm3, 39.7%, 14.6 g/dL, and 21.5 mm/24 h, respectively. Mean leukocyte number in fawns was 3.97 × 103/mm3 of which 62.9% were neutrophils. The high erythrocyte, hematocrit, and hemoglobin values may be a significant adaptive characteristic of pronghorn fawns. Mean clinicochemical values for pronghorn neonates included the following: calcium 12.4 mg/dL, magnesium 2.2 mg/dL, phosphorus 10.0 mg/dL, sodium 145.2 mequiv./L, potassium 6.23 mequiv./L, cholesterol 67.4 mg/dL, glucose 203.5 mg/dL, and creatinine 2.37 mg/dL. With respect to serum enzymes, mean values for glutamic-oxaloacetic transaminase (EC 2.6.1.1), glutamic-pyruvic transaminase (EC 2.6.1.2). creatine phosphokinase (EC 2.7.3.2), and alkaline phosphatase (EC 3.1.3.1) were 106.48 Reitman–Frankel units (R.F.u.)/mL, 2.0 R.F.u./mL, 40.08 International Units (IU)/dL, and 29.64 King–Armstrong units (K.A.u.)/mL, respectively. The mean blood urea nitrogen value was 21.32 mg/dL and total protein value was 4.78 g/dL; the mean albumin:globulin ratio was 1.01. Significant variation of blood values was associated with year of sampling, number of fawns per doe, and sex of fawns. Many blood values were correlated significantly with physical and physiological characteristics of fawns and with environmental temperature and wind speed.
Henneguya doori Guilford, 1963 (Myxosporida) of Perca flavescens in New Brunswick
Authors: Cone D. K.
Published: August 2008

Of the Perca flavescens collected during winter from Little Magaguadavic Lake, New Brunswick, 34% were infected with Henneguya doori Guilford, 1963. Cysts were on the primary gill lamellae and formed white nodules (0.5 to 0.9 mm in size) that contained dense masses of mature spores. Most cysts were in septal tissue near the afferent artery (inflowing blood) and a few were in secondary lamellae. Cysts were absent from septal tissue that surrounded the efferent artery (outflowing blood). This distribution suggests that infective trophozoites enter the primary gill lamellae via the afferent artery and then migrate through the endothelium and develop in the septal tissue. Some infective trophozoites appear to enter secondary lamellae but possibly because of the small diameter of the capillaries do not reach the efferent artery and thus develop in the capillary bed.Mature spores found in the present study are morphologically similar to spores of H. doori described from Lake Michigan. Henneguya doori occupies the same tissue in the same host species as Henneguya percae Fantham, Porter, and Richardson, 1939, and spores of the two species have some morphological similarities. It is concluded that H. doori may be a synonym of H. percae.
Thick-billed murres and black guillemots in the Barrow Strait area, N.W.T., during spring: distribution and habitat use
Authors: Bradstreet Michael S. W.
Published: August 2008

During the "spring" periods of 1974–1976, Uria lomvia and Cepphus grylle in the central Canadian Arctic were concentrated in the Barrow Strait area. Aerial surveys indicated that densities of both species were higher in interface habitats (i.e. along boundaries of land or ice and marine water) than in areas of open water distant from coasts or landfast ice. Murres occurred in higher densities along offshore than along coastal landfast ice edges; guillemots showed no preference between these two habitats. Guillemots, but not murres, occurred in small cracks in landfast ice. The overall preference of murres and guillemots for interface habitats was compared with the results of two other studies of the distribution of these alcids in high arctic areas.
The effect of temperature on developmental rates in the nudibranch Cadlina luteomarginata
Authors: Dehnel Paul A. , Kong David C.
Published: August 2008

Egg masses of the nudibranch Cadlina luteomarginata, which were spawned in the laboratory from adults held at 10 °C, were reared at four experimental temperatures, 5, 10, 15, and 20 °C. To determine the effect of temperature on developmental rates, the time required to develop the following stages or structures at these four temperatures was determined: polar body formation, first cleavage, second cleavage, third cleavage, fourth cleavage, gastrulation, closure of the blastopore, cilia formation, oral invagination, rudiment of the foot, shell formation, ciliation of the foot, statocyst formation, collapse of the egg capsule, and hatching as a veliger. The data show that as the temperature decreases the time required for a particular stage to develop increases. Embryos reared at 20 °C degenerated after the fourth cleavage stage. Total time required to reach the hatching stage (veliger) at the control temperature (10 °C) was 35 days, whereas the time required at 15 °C was 25 days and at 5 °C was 86 days. These data show that development is temperature dependent.
Assessment of variability among diets of individual deer with the aid of canonical analysis
Authors: Willms W. , Hudson R. J. , McLean A.
Published: August 2008

Canonical analysis was compared with dissimilarity indices for evaluating the food niche of mule deer. Significant differences were found among individual deer primarily in their predilection for shrubs and secondarily in their selection of forbs or grasses. Patterns of selection changed with plant communities, reflecting changing availabilities and possibly associative affects of individual food items. Diets also changed from winter to spring particularly in the relative contribution of forbs. Canonical analysis proved useful for identifying changes in the food niche since, as a multivariate technique, it evaluated complete diets and obviated univariate analysis of each dietary component.
Foraging by bumble bees on patches of artificial flowers: a laboratory study
Authors: Hartling L. K. , Plowright R. C.
Published: August 2008

A remotely controlled artificial flower system for investigation of bumble bee foraging behaviour in the laboratory is described. The behaviour of Bombus atratus Fkln. workers from captive colonies trained to forage on patches of artificial flowers in a flight room conformed well to the predictions of optimal foraging theory. Within-patch movement was systematic, tending to minimize repeat visits to flowers sampled previously. Between-patch movement was influenced both by frequency of encounters with empty flowers in the first patch and by inter-patch distance.
Sequence organization in the genomic DNA of the chum salmon, Oncorhynchus keta
Authors: Hanham Ann , Smith Michael J.
Published: August 2008

The reassociation kinetics and sequence organization of the DNA of chum salmon, Oncorhynchus keta, were measured. Reassociation kinetic studies were carried out by hydroxyapatite chromatography with DNA sheared to lengths of 0.3 and 3.2 kilobases (kb). Kinetic analysis, using a least squares fitting procedure, demonstrated the presence of repeated sequences. Approximately 70% of the DNA sheared to a fragment length of 0.3 kb was found to contain repeated sequences that were reiterated over a range of 30 to 3000 times. A highly repeated or fold-back component comprised 10% of the DNA at this fragment length. The interspersion of repeated sequences with single copy DNA was indicated by the accelerated rate of reaction of 3.2 kb fragments and the reduced hyperchromicity of such fragments reacted to low values of product of concentration and time of incubation (C0t). Digestion with a single strand-specific nuclease demonstrated the presence of two fragment lengths of repeated sequences; the first, 0.35 kb in length, was shown to have a 13 °C depression in melting temperature whereas the longer repeat sequences (≥ 2.0 kb) had a near native melting temperature.
Distribution and systematic relationship of Tadarida bivittata and Tadarida ansorgei (Chiroptera: Molossidae)
Authors: Eger Judith L. , Peterson Randolph L.
Published: August 2008

Morphologically similar Tadarida bivittata and T. ansorgei inhabit dry, woodland savannah areas of central Africa, where they are partially sympatric. Specimens of these species were divided into population samples based on geographic proximity. Multivariate analysis of variance indicated that both species are sexually dimorphic. Results of principle components analysis illustrated interspecific differences. In areas of sympatry, specimens were subjected to discriminant analysis to confirm their identity. Based on this analysis, classification functions are provided as a useful aid for identifying the two species.
Development of the haptor of Urocleidus adspectus Mueller, 1936 (Monogenea: Ancyrocephalinae)
Authors: Cone D. K.
Published: August 2008

Urocleidus adspectus Mueller, 1936 (Ancyrocephalinae) was transmitted experimentally to Perca flavescens and development of its haptor studied at 20 °C.The oncomiracidial haptor unfolds into a ventrally directed disc with 14 marginal hooks. Hamulus rudiments appear in multinuclear oncoblasts lying immediately anterior to the larval disc. The four oncoblasts move into the disc in synchrony and rudiments develop into blades. Five days postinfection, when most larvae were found on the gills, the disc is differentiating into the haptor of adult worms. The tissue enclosing the partially developed blades of the hamuli initially projects from the posteroventral surface of the haptor; tips of the ventral blades point anteriorly or anteroventrally and tips of the dorsal blades point dorsally or anterodorsally. With further growth the tissue enclosing the blades comes to project posteriorly from the haptor; tips of the ventral blades point anteroventrally and tips of the dorsal blades point anterodorsally. During differentiation, the tips of the blades of marginal hooks II come to point ventrally. The posterolateral margins of the larval disc fold dorsally and carry marginal hooks III and IV onto the dorsal surface of the haptoral lobes. Marginal hooks V come to lie laterally on the lobes while I, VI, and VII are ventral. Seven days postinfection, the haptoral sclerites of many worms are fully developed and some worms produce eggs.
The distribution of putative neurosecretory cells in the central nervous system of the North American medicinal leech Macrobdella decora
Authors: Webb Rodney A. , Orchard I.
Published: August 2008

Nerve cells that displayed a distinct Tyndall blue–white effect were observed in the supra- and sub-oesophageal ganglia, the ventral nerve cord ganglia, and the posterior ganglion of the Gnathobdellid leech Macrobdella decora. These cells formed four anatomically distinct groups in the supraoesophageal ganglion and occupied characteristic and analogous positions in the other ganglia. Light microscopy of these blue–white cells revealed histochemical properties not seen in other nerve cells. The perikarya of the four groups of blue–white cells in the supraoesophageal ganglion were examined with the electron microscope and found to contain large membrane-bounded electron-dense granules similar to those observed in proven neurosecretory cells. Tracts from two of these cell groups possibly form primitive neurohemal organs. A neurosecretory role for the blue–white cells is suggested.
Rhythms of activity and oxygen consumption in the common pond clam, Ligumia subrostrata (Say)
Authors: McCorkle Susan , Shirley Thomas C. , Dietz Thomas H.
Published: August 2008

Diurnal rhythms were found in the unionid clam Ligumia subrostrata for valve activity and oxygen consumption. Valve closures and valve gape were measured as indices of valve activity. Recordings were made after the animals were entrained to each of three photoperiods: 12 h light (L): 12 h dark (D), 16 L: 8 D, and 24 L. Statistically significant (P < 0.01) rhythms of activity were found in 12 L: 12 D and 16 L: 8 D photoperiods with high activity occurring during the dark phase. The onset of darkness was indicated as the entraining factor. No rhythm of valve activity was found in 24 L. Flow-through respirometry of individual clams was used to determine if oxygen consumption paralleled activity rhythms. Rhythms of oxygen consumption were present in all three photoperiods with a change in light rather than the onset of darkness as the entraining factor. The activity rhythm was exogneous, whereas the oxygen consumption rhythm was an endogenous rhythm. Overall levels of activity and oxygen consumption were highest in the 16 L: 8 D regimen and depressed in constant light.
The ectoparasites of some marine birds from Bamfield Marine Station, British Columbia, with particular reference to the common murre, Uria aalge (Pont.)
Authors: Ballard John T. , Ring Richard A.
Published: August 2008

Six species of birds from the region of the Bamfield Marine Station, British Columbia, were examined for ectoparasites. A total of seven species of Mallophaga belonging lo five genera (Saemundssonia, Austromenopon, Cummingsielli, Anatoecus, and Anaticola) were recovered. One flea (Mioctenopsylla traubi, Siphonaptera), leather mites of the genus Zachvatkinia, other mites of the genera Ameronothrus. Cymbaeremaeus, and Rhinonyssus, and ticks of the genus Ixodes were also identified. Each host species and its ectoparasites are discussed separately. Differences in the ectoparasite burdens of juveniles and adults of both sexes of the common murre, Uria aalge (Pont.), are compared and contrasted.
Haul-out behaviour and densities of ringed seals (Phoca hispida) in the Barrow Strait area, N.W.T.
Authors: Finley Kerwin J.
Published: August 2008

Numbers of ringed seals hauled out on the ice began to increase in early June. Numbers on the ice were highest from 0900 to 1500 hours Central Standard Time and lowest (average 40–50% of peak) in early morning. Seals commonly remained on the ice for several hours, and occasionally (during calm weather) for > 48 h. Numbers on the ice were reduced on windy days and possibly also on unusually warm, bright and calm days. Seals tended to face away from the wind (particularly with high wind speed) and oriented broadside to the sun. Seals usually occurred singly (60–70% of all groups) at their holes.Numbers of seals hauled out at Freemans Cove remained relatively constant during June (maximum density 4.86/km2), whereas at Aston Bay numbers increased dramatically to a maximum density of 10.44/km2 in late June. The increase was thought to be due to an influx of seals abandoning unstable ice. The density of seal holes at Freemans Cove (5.92/km2) was much higher than at Aston Bay (2.73/km2). The ratio of holes to the maximum numbers of seals (1.12:1) at Freemans Cove represents a first estimate of this relationship in an apparently stable population.
Observations on the life history of the water mite, Unionicola formosa (Acari: Hydrachnellae)
Authors: Paterson C. G. , MacLeod R. K.
Published: August 2008

Under laboratory conditions larvae of the water mite, Unionicola formosa, can transform to the nymphal stage in the absence of an aquatic insect host.
"Stretch-receptive" neurons with central somata are associated with the uropods in megalopa of Emerita analoga (Crustacea, Anomura)
Authors: Paul Dorothy Hayman , Paul Miles
Published: August 2008

Large neuronal processes have been traced from the sixth (terminal) abdominal ganglion to the basal region of the uropod in megalopa of the sand crab. Emerita analoga. In location and appearance these neurons are similar to the monopolar, nonspiking sensory neurons which form a stretch receptor in the adult. The structural development of this sense organ, therefore, is completed by the time the adult tail fan structure is first present and before the appearance of the behavior to which it contributes.
Coexistence and resource partitioning in two species of darters (Percidae), Etheostoma nigrum and Percina maculata
Authors: Smart Heather J. , Gee John H.
Published: August 2008

This study investigated partitioning of resources along the dimensions of space, food, and time by johnny darters (Etheostoma nigrum) and blackside darters (Percina maculata). Although both species were abundant in the midcourse of the Whitemouth River and occurred together in all habitats, space was partitioned on a vertical basis. Johnny darters were exclusively benthic whereas blackside darters were much less restricted to the bottom. The latter retained a well developed swim bladder permitting use of the vertical component of the environment. Partitioning of food resources occurred and although similar taxa were consumed by both species (aquatic insects and Crustacea) the proportions were not similar. Johnny darters fed mainly on benthic items whereas blackside darters ate pelagic items. Differences in protrusibility of premaxilla, position of the mouth and eyes, retinal acuity, and number and morphology of gill rakers reflected different modes of life. There was no evidence of partitioning by time.
Morphology and morphometry of the appendicular skeleton of the red fox (Vulpes vulpes)
Authors: Bisaillon André , DeRoth Laszlo
Published: August 2008

The morphological and morphometrical characteristics of the limb bones are studied in 8 adult male and 17 adult female red foxes (Vulpes vulpes). Although the appendicular skeleton is similar in structure in both sexes, it is possible to distinguish between male and female animals using some measurements of the pelvic limb bones.
An analysis of respiratory surface area as a limit to activity metabolism in anurans
Authors: Hillman Stanley S. , Withers Philip C.
Published: August 2008

Maximal [Formula: see text] and resting [Formula: see text] oxygen consumption rates of a variety of anuran amphibians were measured to evaluate the proportionality between [Formula: see text], [Formula: see text], and mass. Interspecific differences in the slope of the function relating [Formula: see text] and body mass were not correlated with differences in respiratory capillary length. Interspecific differences in absolute [Formula: see text] were not matched by any interspecific difference in respiratory capillary length. Unilaterally pneumonectomized Xenopus laevis did not show a decline in [Formula: see text] proportional to the amount of respiratory surface area removed. The data indicate that respiratory surface area does not impose a maximum limit on gas exchange in anuran amphibians.
Typhlocoelum cucumerinum (Digenea: Cyclocoelidae): detailed analysis of distribution in wild ducks of southern Manitoba
Authors: Scott Marilyn E. , McLaughlin J. Daniel , Rau Manfred E.
Published: August 2008

A survey of 3319 wild ducks shot on the Delta Marsh, Manitoba, in 1977 and 1978 revealed that 10.0% of Anas spp. harboured Typhlocoelum cucumerinum cymbium and 9.9% of Aythya spp. harboured Typhlocoelum cucumerinum cucumerinum. The American wigeon, Anas americana Gmelin, and the ring-necked duck, Aythya collaris (Donovan), are recorded as new hosts for T. cucumerinum. Data were analysed for differences in prevalence, abundance, and intensity of infection among host species, and for seasonal, age, and sex differences within host species. Prevalence ranged from 0.0% in gadwall to 31.4% in canvasbacks; mean intensity ranged from 1.0 in wigeon to 3.8 in canvasbacks. Theoretical frequency distributions for abundance of T. cucumerinum were constructed and compared with the data for each host species. Eight of 10 had a negative binomial distribution and 2 had a Poisson distribution. Two potential explanations for the variation in distribution of T. cucumerinum among host species were investigated: susceptibility and feeding ecology. Firstly, it was shown experimentally that gadwall, mallard, blue-winged teal, and canvasback ducklings are equally susceptible to the initial stages of infection. Secondly, there was a positive correlation between T. cucumerinum infections and occurrence of snails in the diet of the various host species.
Studies of morphological parameters affecting ungulate locomotion in snow
Authors: Telfer Edmund S. , Kelsall John P.
Published: August 2008

We deal with possible morphological adaption to varied snow conditions by four North American ungulate species. Chest heights and weight loads on track are key parameters in estimating capabilities of species, and of age and sex classes within species, to cope with snow. Methods believed suitable for measuring those parameters in replicable fashion are discussed. Comparative studies of bison (Bison bison), moose (Alces alces), wapiti (Cervus elaphus), and white-tailed deer (Odocoileus virginianus) are described. There are pronounced differences in both parameters between species and between some age and sex classes within species. Chest heights of the three cervids differed by a fixed interval suggesting that differential ability to use varied snow depths may play a role in resource partitioning. Differential winter mortality may be related to sex and age class differences in ability to cope with snow. Morphological differences relate to regional distributions by determining species suitability for survival in varying snow regimes.
Action des substances soufrées volatiles du poireau (Allium porrum) sur la ponte d'Acrolepiopsis assectella (Lepidoptera: Hyponomeutoïdea): prépondérance des thiosulfinates
Authors: Auger J. , Thibout E.
Published: August 2008

When the leaves of Allium species are broken, it is usually considered that diffusion of alkyl disulfides occurs. These stable compounds are supposedly formed by intracellular reduction of the unstable thiosulfinates. As thiosulfinates are also converted into disulfides by spontaneous disproportionation, the authors suppose that thiosulfinates would be emitted from the vegetal cell and next would be slowly disproportionated into disulfides. This hypothesis is much more consistent with the assumption that volatile substances yield spatial–temporal information and facilitate the location of the plant by the leek moth. Therefore, the effect of dimethyl or dipropyl thiosulfinates on oviposition behaviour of the leek moth is tested. Daily and total oviposition and number of laying females are compared in four groups of mated females: without volatile components of leek (Allium porrum), with disulfides, with thiosulfinates, and with leek volatile substances. In all cases, insects are more sensitive to the labile thiosulfinates than to the stable disulfides or even sometimes to leek volatile substances. These results strengthen our hypothesis that the thiosulfinates diffuse into the air and seem to indicate that labile chemical substances are significant in inter- or intra-specific communication in insects.
Behavioral thermoregulation and locomotor activity of Perca flavescens
Authors: Reynolds William Wallace , Casterlin Martha Elizabeth
Published: August 2008

Ten yearling yellow perch (Perca flavescens) were tested individually for 3-day periods in electronic shuttleboxes to determine their diel patterns of behavioral thermoregulation and of locomotor activity relative to a natural April photoperiod, and to determine the relationship between preferred temperatures and activity. The perch exhibited a diel rhythm of preferred temperature, with a predawn minimum of 16.7 °C and a dusk maximum of 23.8 °C. The 24-h mean was 20.2 °C; the diurnal mean was 21.5 °C and the nocturnal mean was 18.5 °C. Locomotor activity (quantified as mean photocell-monitored light-beam interruptions per hour) was crepuscular, with a major peak (25 units/h) at dusk, and a smaller peak (14.4 units/h) at dawn. Nocturnal activity was slightly greater (5.3 units/h) than diurnal activity (4.4 units/h). Locomotor activity relative to temperature exhibited a local minimum (0.4–6.2 units/h) at 22.2 °C.
Temperature regulation in freely diving harp seals (Phoca groenlandica)
Authors: Gallivan G. J. , Ronald K.
Published: August 2008

Measurements were made of the relation between body temperature, respiration, diving pattern, and water temperature using three adult harp seals (Phoca groenlandica). Core temperature, ventilation, gas exchange, and diving pattern were not affected by water temperature ranging from 1.8 to 28.2 °C. The basal metabolic rate of the seals in this study was not significantly different than that predicted for terrestrial mammals of equivalent size. Expired heat loss and convective heat loss from the body accounted for 16% of the heat loss and were independent of water temperature. The remaining 84% of the heat was lost from the flippers which accounted for less than 14% of the surface area. Calculations of the ratio of convective heat transfer coefficients of the blubber layer indicate that internal conduction rather than external convection governed heat loss.
Population regulation in spruce grouse: a working hypothesis
Authors: Boag D. A. , McCourt K. H. , Herzog P. W. , Alway J. H.
Published: August 2008

We studied a population of spruce grouse in southwestern Alberta over a period of 10 years. During this time the density of birds in the spring population varied between 10.5 and 19.3 per 100 ha. Changes in density appeared to reflect changes in rates of recruitment to the spring population more than changes in rates of mortality among the members of the established population. Recruitment of yearlings was influenced by the density of adults at the onset of the breeding season as was the number of young surviving to independence. We postulate that these two relationships prevent spring densities varying greatly from year to year: spacing behaviour of adults appears to regulate the spring density of grouse locally by forcing yearlings, in excess of those required to fill vacancies, to disperse; the density of grouse during the breeding season appears to influence inversely the number of juveniles surviving to September and consequently the number of yearlings locally available the following spring.
Crossonema capitospinosum new species and description of C. menzeli and C. fimbriatum juveniles (Nematoda: Criconematidae)
Authors: Ebsary B. A.
Published: August 2008

Crossonema capitospinosum new species from northern Ontario is described and illustrated. It is differentiated from C. menzeli and C. fimbriatum by more body annules, more anterior vulva and anus, 30 thin head spines, and thin, irregularly aligned body spines. From C. abies it differs by more posterior excretory pore, shorter stylet, and two head annules with prominent thin spines. The juveniles of C. menzeli and C. fimbriatum are described for the first time and are characterized by 10–13 longitudinal rows of scales.
Octopine metabolism in Sepia officinalis: effect of hypoxia and metabolite loads on the blood levels of octopine and related compounds
Authors: Storey Kenneth B. , Storey Janet M. , Johansen Kjell , Hochachka Peter W.
Published: August 2008

Male Sepia officinalis were subjected to hypoxia and the concentrations of blood metabolites were measured during stress and recovery. Blood octopine levels were elevated during hypoxia, whereas blood glucose concentration declined. During recovery, octopine was rapidly cleared from the blood while blood glucose concentration increased, initially overshooting the control level, before returning to prehypoxia levels.The clearance of an octopine bolus (300 μmol given intravenously) from the blood was followed. Octopine uptake from the blood was correlated with a transient rise in blood glucose concentration. Injection of an arginine bolus resulted in an increase in blood octopine levels, whereas a lactate bolus led to elevated blood glucose and octopine levels.The data show that octopine concentration in cephalopod blood is modulated in response to physiological stress and that octopine metabolism is closely integrated with the metabolism of glucose, arginine, and lactate. It is suggested that the octopine produced during glycolytic muscular work is transported via the bloodstream for use as an aerobic substrate in other tissues. The inverse relationship between blood octopine and glucose levels suggests the presence of a modified "Cori cycle" in which octopine released from muscle can be taken up by tissues capable of utilizing the compound as a gluconeogenic substrate.
Nymphal development of Baetis vagans McDunnough (Ephemeroptera: Baetidae) and drift habits of large nymphs
Authors: Corkum Lynda D. , Pointing P. J.
Published: August 2008

Nymphal development of Baetis vagans McDunnough was studied at the Forks of the Credit River, Peel County, Ontario. Here, B. vagans is a bivoltine species inhabiting fast water; one generation occurs in the stream from November until late May and a second generation of smaller nymphs from July until mid-October. Nymphs continued to grow over winter although growth was slower than in the summer generation.In laboratory drift studies, the presence of a stonefly predator, Paragnetina media (Walker), significantly increased the drift of large Baetis vagans nymphs during dark periods. By drifting at night, mayfly nymphs may be less susceptible to predation by both invertebrates and fish.
Survival in fluctuating populations of the vole Microtus townsendii
Authors: Beacham Terry D.
Published: August 2008

Four populations of the vole Microtus townsendii were trapped concurrently with live traps and pitfalls from May 1976 until June 1978. The capture of a large number of young in pitfalls indicated that mortality was higher among postweanlings than among any other age group. Juvenile survival was highest in increasing populations and lowest in declining ones, but pre-weanling survival was lowest in peak populations. Larger voles survived better than smaller ones, and females survived better than did males. Minimum survival rates of different size and sex classes of voles were dependent upon the trapping technique used.
Description of a free-living Polychaete without gut: Astomus taenioides n.gen., n.sp. (Protodrilidae, Archiannelida)
Authors: Jouin Claude
Published: August 2008

This study describes a new Protodrilidae that lives in the coral sands of the Island of Moorea (French Polynesia). Astomus taenioides n.gen., n.sp. has no gut, mouth, anus, pharyngeal bulb, nor salivary glands. However, a thin median cord of cells rich in refringent granules takes the place of a gut and probably represents an endodermal vestige and a stocking location for reserve substances. The surface of the epidermis is increased due to an enlargement of the segments into lateral lobes; cilia are abundant and the cuticle well developed. These characteristics might favor considerable exchanges between the organism and its surroundings. The absorption of dissolved organic substances, well known in other marine invertebrates, seems to be developed in this case to the point that this annelid, like the pogonophores, can survive without any gut. If, compared with Annelida, the principal trait of the Pogonophora is regarded to be the absence of a gut and the absorption of nutritive elements solely through the epidermis, the consequence of the discovery of this Protodrilidae is to eliminate the last barrier separating Pogonophora from Annelida.
Effects of a rabbit on nesting common terns
Authors: Courtney Peter A.
Published: August 2008

Reproductive biology of common terns (Sterna hirundo) was studied at an insular breakwater site at Port Colborne, Ontario in 1976 and 1977. The unusual occurrence of an eastern cottontail rabbit (Sylvilagus floridanus) in the ternery in 1977 disrupted nesting activity and nocturnal incubation attentiveness. Effects resulting from disruption of nocturnal incubation, including prolongation of incubation periods and retardation of evaporative water loss from eggs, are examined.
Behavioural variability in a sample of young domestic chickens
Authors: Gebotys Robert J. , White Nicholas R. , Macdonald Glenn E.
Published: August 2008

Using following-time data from an imprinting study involving heat and tactile reinforcement, a multivariate discriminant analysis detected the existence of at least two subpopulations differing in following time. Further analyses showed that the subpopulations were not a result of the experimental manipulations used in the study. The existence of separate subpopulations may help explain the high variability in following times, especially if the subpopulations are differentially affected by imprinting and other developmental processes.
Naturally occurring diblastodermic eggs in the zebrafish, Brachydanio rerio
Authors: Laale Hans Willer
Published: August 2008

Naturally occurring monoblastodermic and diblastodermic eggs were obtained from one pair of mature zebrafish, Brachydanio rerio (Cyprinidae). The diblastodermic condition reported is unique for teleosts in that it is the first occurrence to be adequately documented in the literature. The formation of two blastoderms is due to a primary fission of the first two blastomeres involving an underlying aberrant egg organization. The subsequent formation of conjoined twins is attributed to secondary fusion of the two adjacent blastoderms during epiboly. Of 21 diblastodermic eggs laid in four separate spawnings, 9 died during epibolic overgrowth, 7 exhibited regulation and developed into normal or near-normal embryos, and 5 gave rise to duplicate embryos of the anadidymus type. The report describes and discusses this extremely rare mode of pregastrula twinning in bony fishes.
Responses of vertebral numbers in rainbow trout to temperature changes during development
Authors: Lindsey C. C. , Brett A. M. , Swain D. P. , Arnason A. N.
Published: August 2008

Eggs from one pair of an inbred hatchery strain of Salmo gairdneri were divided into 16 lots, each of which was subjected either to a sustained temperature of 4 or 12 °C, or to a temperature break (one-way transfer between these two temperatures in either direction), or to a temperature pulse (two-way transfer) at various developmental stages. Breaks in either direction produced overcompensation (vertebral counts beyond that produced by sustained rearing at the temperature to which the embryos were transferred) if applied early, or paradoxical reaction (in the unexpected direction) if applied late. Results from the temperature breaks and from the one successful pulse were satisfactorily fitted by one set of parameters computed for a previously described "atroposic" model. This is the first test for any species which combines results both of breaks in two directions and a pulse, all using the same two temperatures and offspring from a single cross; the model therefore gains credence. Contrary to a previous report, rainbow trout do not differ qualitatively in vertebral response from other teleosts; difficulties in fitting of previously published data on the species probably arose from genetic diversity in the experimental material. Evidence is also presented that fin-ray counts are unreliable in fish preserved at fork lengths of under 29 mm, which may account for failure to fit the atroposic model to our or to most other published responses of salmonid fin rays to temperature changes.
The relationships between winter climate and selection on body size of house sparrows
Authors: Fleischer Robert C. , Johnston Richard F.
Published: August 2008

Overwinter modification of the morphology of house sparrows was examined in relation to the intensity of proximate wintertime climatic conditions. Samples were a posteriori for four of six comparisons for males and three of five for females. Two comparisons were collected specifically (one recently) to examine overwinter changes. Comparisons were of multivariate assessments of skeletal measurements for subadult fall (males only) and total fall versus total spring samples. There were significant differences in PC1 (overall body size) between fall and spring groups for 3 of 11 comparisons. For males, the overwinter change in size was significantly correlated (p < 0.01) with the proximate level of precipitation. For females, overwinter change in size correlated best with the deviation of a winter's temperature from the all-time mean winter temperature (p < 0.05). Only for females did changes in variance correlate with climate (temperature deviation, p < 0.05). This suggests that increasing severity of winter climate results in larger males, but smaller (and less variable) females. A combination of physiological (energetic), behavioral (dominance relations), and ecological pressures may cause the observed size changes.
Profitable stream positions for salmonids: relating specific growth rate to net energy gain
Authors: Fausch Kurt D.
Published: August 2008

A model is developed to predict potential net energy gain for salmonids in streams from characteristics of water velocity and invertebrate drift. Potential net energy gain, or potential profit, is calculated for individuals of three species of juvenile salmonids in a laboratory stream aquarium, based on the energy available from drift minus the cost of swimming to maintain position. The Michaelis–Menten or Monod model is used to describe the relationship between potential profit and specific growth rate. Potential profit was a better predictor of specific growth rate for coho salmon (Oncorhynchus kisutch) than for brook trout (Salvelinus fontinalis) or brown trout (Salmo trutta). Coho salmon always achieved higher specific growth rates than either brook trout or brown trout in concurrent experiments, and maintained growth to lower resource thresholds. In each experiment, fish established intraspecific hierarchies and dominant fish held positions affording maximum potential profit. The use of potential profit as an optimal foraging model was tested by predicting the potential for net energy gain at coho salmon positions from the overall pattern of flow and invertebrate drift in the stream aquarium, and ranking these positions from highest to lowest potential profit. This predicted ranking was nearly identical to the rank observed in the linear dominance hierarchy. The results of experiments confirm ideas of other investigators about mechanisms of microhabitat selection by stream salmonids.
Range extension and fossil occurrences of Holoboreaphilus nordenskioeldi (Mäklin) (Coleoptera: Staphylinidae) in North America
Authors: Morgan Alan V. , Morgan Anne , Miller Randall F.
Published: August 2008

The staphylinid beetle Holoboreaphilus nordenskioeldi (Mäklin) has been recorded from both northeastern and northwestern North America. Two new collecting localities on the western shore of Hudson Bay are reported. The distribution of this species is discussed with reference to fossil occurrences in Late Pleistocene deposits in North America, and two possible postglacial recolonisation routes are postulated.
A revision of the Tubificidae and Lycodrilidae (Annelida, Oligochaeta) known from Lake Baikal
Authors: Brinkhurst R. O.
Published: August 2008

Twenty-five species in 10 genera are reported from Lake Baikal, though the number of each is uncertain because of remaining taxonomic problems. Twenty of the species are endemic, the remaining five being the previously reported Spirosperma (as Peloscolex) velutinus and Rhyacodrilus coccineus, and the newly reported Tubifex superiorensis. T. kessleri and T. acapillatus. The last two consist of a complex of subspecies, some of which may be endemic; R. coccineus inaequalis is also reported as an endemic subspecies in the literature. Five of the genera are endemic: Baikalodrilus (formerly part of Peloscolex) with three or four species. Lycodrilides (two species). Lycodrilus (one species), and the monotypic abyssal Svetlovia and Rhyacodrilides. Other presently described abyssal forms (Tubifex taediosus. T. minutes, Peloscolex malevici) are of doubtful generic attribution and could increase the list of endemic genera. These species were not available for this study, nor were Rhyacodrilus korotneffi and R. multispinus from the north of the lake, and Lycodrilus phreodriloides, a species listed as incertae sedis in Lycodrilus until it is redeseribed. The Tubifex species described here support the contention that the genus is polyphyletic, and two groups (Tubifex sensu stricto and sensu lato) are recognized. The description of the type species of Isochaetides may precipitate further revision of that taxon also. The Family Lycodrilidae consists of two tubificine tubificid genera plus a lumbriculid, and is, therefore, dissolved. Most common holarctic and palaearctic genera are absent. The names Tubifex excavatus (Hr.) and Lycodrilides grubei (Mich.) are new combinations.
Helminths of fishes from the St. Marys River, Michigan
Authors: Muzzall Patrick M.
Published: August 2008

Three hundred fifty-four fishes of 30 species collected from the St. Marys River, Michigan, were examined for helminths. Thirty-two species (8 Digenea, 11 Cestoda, 8 Nematoda, 5 Acanthocephala) were recovered from the digestive tracts of 233 fishes. The prevalence and host distribution of these helminths and information on larval helminths are presented.
SIMULATION OF MAJORITY RULE DISTURBED BY POWER-LAW NOISE ON DIRECTED AND UNDIRECTED BARABÁSI–ALBERT NETWORKS
Authors: LIMA F. W. S.
Published: August 2008

On directed and undirected Barabási–Albert networks the Ising model with spin S = 1/2 in the presence of a kind of noise is now studied through Monte Carlo simulations. The noise spectrum P(n) follows a power law, where P(n) is the probability of flipping randomly select n spins at each time step. The noise spectrum P(n) is introduced to mimic the self-organized criticality as a model influence of a complex environment. In this model, different from the square lattice, the order-disorder phase transition of the order parameter is not observed. For directed Barabási–Albert networks the magnetisation tends to zero exponentially and undirected Barabási–Albert networks remain constant.
MODELLING THE DYNAMICS OF AN ADJUSTMENT OF A SEARCH SPACE SIZE IN A GENETIC ALGORITHM
Authors: AMIRJANOV ADIL
Published: August 2008

One way to improve a search strategy in a Genetic Algorithm (GA) is to reduce the search space towards the feasible region where the global optimum is located. The paper describes the effect of an adjustment of a search space size of GA on the macroscopic statistical properties of population such as the average fitness and the variance fitness of population. The set of equations of motion was derived for the one-max problem that expressed the macroscopic statistical properties of population after an adjustment of a search space size in terms of those prior to the operation.
A (ECONOPHYSICS) NOTE ON VOLATILITY IN EXCHANGE RATE TIME SERIES
Authors: MATESANZ DAVID , ORTEGA GUILLERMO J.
Published: August 2008

We propose a volatility and uncertainty country ranking based on the entropic analysis of the real exchange rate dynamics. We show that this ranking is highly correlated with the volatility in the gross domestic product after events of currency crises. By comparing entropy with variance ranking we demonstrate that entropy measures better volatility effects of crises.
Skeletal muscle type comparison of pyruvate dehydrogenase phosphatase activity and isoform expression: effects of obesity and endurance training
Authors: LeBlanc Paul J. , Mulligan Matthew , Antolić AnaMaria , MacPherson Laura , Inglis J. Greig , Martin Dale , Roy Brian D. , Peters Sandra J.
Published: August 2008

Pyruvate dehydrogenase (PDH) plays an important role in regulating carbohydrate metabolism in skeletal muscle. PDH is activated by PDH phosphatase (PDP) and deactivated by PDH kinase (PDK). Obesity has a large negative impact on skeletal muscle carbohydrate metabolism, whereas endurance training has been shown to improve regulatory control of skeletal muscle carbohydrate metabolism, more so when coupled with obesity. A majority of this literature has focused on PDK, with little information available on PDP. To determine the relative role of PDP in regulating skeletal muscle PDH activity with obesity and endurance training, obese and lean Zucker rats remained sedentary or were endurance trained (1 h/day, 5 days/wk) for a period of 8 wk. Soleus, red gastrocnemius, (RG), and white gastrocnemius (WG) muscles were sampled after the training period. The main findings were 1) obesity resulted in a 46% decrease in PDP activity expressed per milligram extracted mitochondrial protein only in RG, while PDP isoform content was unchanged; 2) 8 wk of endurance training led to a significant 1.4–2.2-fold increase in PDP activity of all muscle examined from obese rats, and the concomitant increase in PDP1 protein was only seen in soleus and RG; 3) 8 wk of endurance training led to a trending 1.4–2.2-fold increase in PDP activity of all muscle examined from obese rats, and the concomitant increase in PDP1 protein was only seen in soleus and RG; and 4) PDP2 protein content was not affected by obesity or training. These results suggest that decreased PDP activity in oxidative skeletal muscles may play a role in the impairment of carbohydrate metabolism in obese rats, which is reversible with endurance training.
Local circuit input to the medullary reticular formation from the rostral nucleus of the solitary tract
Authors: Nasse J. , Terman D. , Venugopal S. , Hermann G. , Rogers R. , Travers J. B.
Published: August 2008

The intermediate reticular formation (IRt) subjacent to the rostral (gustatory) nucleus of the solitary tract (rNST) receives projections from the rNST and appears essential to the expression of taste-elicited ingestion and rejection responses. We used whole cell patch-clamp recording and calcium imaging to characterize responses from an identified population of prehypoglossal neurons in the IRt to electrical stimulation of the rNST in a neonatal rat pup slice preparation. The calcium imaging studies indicated that IRt neurons could be activated by rNST stimulation and that many neurons were under tonic inhibition. Whole cell patch-clamp recording revealed mono- and polysynaptic projections from the rNST to identified prehypoglossal neurons. The projection was primarily excitatory and glutamatergic; however, there were some inhibitory GABAergic projections, and many neurons received excitatory and inhibitory inputs. There was also evidence of disinhibition. Overall, bath application of GABAA antagonists increased the amplitude of excitatory currents, and, in several neurons, stimulation of the rNST systematically decreased inhibitory currents. We have hypothesized that the transition from licks to gapes by natural stimuli, such as quinine monohydrochloride, could occur via such disinhibition. We present an updated dynamic model that summarizes the complex synaptic interface between the rNST and the IRt and demonstrates how inhibition could contribute to the transition from ingestion to rejection.