bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure of the spermatozoid ofLycopodiella lateralis(Lycopodiaceae)
Authors: Maden Angel R. , Renzaglia Karen Sue , Whittier Dean P. , Garbary David J.
Published: February 2008

The spermatozoid of Lycopodiella lateralis (R. Br.) B. Øllgaard is ovoid and biflagellated and contains little cytoplasm. A large, rounded, condensed nucleus occupies the central region of the cell. At the rear of the cell is a cluster of starch-containing plastids associated with numerous elongated mitochondria and small pockets of remnant cytoplasm. The multilayered structure coils laterally around the cell anterior for just over one revolution. An anterior mitochondrion underlies the multilayered structure over its entire length and several smaller mitochondria line the inner anterior coil. Some 150 spline microtubules extend from the multilayered structure and coil posteriorly at approximately a 45° angle to the longitudinal axis of the cell. Microtubules progressively increase in length from the margins of the multilayered structure to the center and thus only a central core of approximately 30 microtubules encircles the organelles at the base of the cell. The two basal bodies are parallel and staggered in their position over the multilayered structure and are separated by about 80° around the circumference of the cell anterior. The flagella emerge in parallel and coil for nearly two revolutions. Comparisons among Lycopodiella, Palhinhaea, and Lycopodium provide the basis for evolutionary inferences associated with modifications in spermatozoid structure such as changes in cell size, whole cell coiling, and distance between basal bodies. Phylogenetic analysis of male gametogenesis suggests that Lycopodiella is part of a monophyletic lycopsid assemblage near the base of the vascular plants. Within this clade, Lycopodiella is most closely related to Palhinhaea, with Lycopodium, Phylloglossum, and Selaginella forming a sister clade. Key words: Lycopodiella, Lycopodium, spermatozoid, land plant phylogeny, locomotory apparatus, ultrastructure.
Landscape-scale patterns in plant species richness along an arctic river
Authors: Gould William A. , Walker Marilyn D.
Published: February 2008

We examined relationships of vascular plant species richness with mean July temperature and components of landscape heterogeneity to determine the relative influence of temperature and the physical landscape on plant richness along the north-flowing Hood River in the Northwest Territories of Canada. We also examined variations in the composition of the flora to better understand the relationship between riparian gradients, environmental controls, environmental heterogeneity, and species richness. The vascular flora for the area studied includes 210 species. Richness at 17 sites along the river ranged from 69 to 109 species within 2400-m2sample areas. Sites with the lowest richness were those in the upper reaches of the river, with richness generally increasing downstream. Variation in richness along the river is correlated with increasing environmental heterogeneity (r2 = 0.598, P = 0.0003), calculated as an index summarizing the range of site-level variation in a set of components including substrate type and texture, topographic variation (slope and aspect), relative surface area, substrate moisture, and soil pH. The most significant component of the index is an increase in the range of soil pH. Soil pH tends to increase downstream, and average site soil pH is the single best predictor of species richness (r2 = 0.857, P < 0.0001). The primary cause of higher soil pH is the presence of uplifted marine sediments, and tills derived from nonacidic Precambrian rock common along the lower river. Key words: species richness, arctic, riparian, pH, mean July temperature, environmental heterogeneity.
Seasonal variations of photosynthetic capacities of white spruce (Picea glauca) and jack pine (Pinus banksiana) saplings
Authors: Man Rongzhou , Lieffers Victor J.
Published: February 2008

Seasonal photosynthetic capacity (maximum rate of net photosynthesis at saturating light) was assessed in 30-year-old open-grown Pinus banksiana Lamb, and 20-year-old open-grown and understory Picea glauca (Moench) Voss in central Alberta. Photosynthesis commenced in early April despite cold soils (0 °C) and night frosts. It fluctuated greatly in the summertime during the periods of summer droughts and stopped abruptly in late October when night air temperature dropped below −10 °C. In comparing seasonal maximums, there was proportionally lower photosynthetic capacity in Pinus banksiana than in Picea glauca in the spring and autumn; however, in the summer, photosynthetic capacity in Pinus banksiana was less variable than in Picea glauca. The fluctuation of photosynthetic capacity in understory Picea glauca saplings was greatly reduced in the summertime compared with open-grown saplings. The data suggest that Picea glauca is able to use the periods of high light in the understory when the aspen is leafless by quickly regaining photosynthetic capacity in the spring and maintaining photosynthesis well into the late autumn. Key words: Picea glauca, Pinus banksiana, photosynthesis, season.
La détermination du contenu lipidique et de la capacité de vol chez quelques espèces d'oiseaux de rivage (Charadriidae et Scolopacidae)
Authors: McNeil Raymond
Published: February 2008

The author presents several equations which make possible the estimation of the fat content (fat % lean dry weight) and the flight range (miles) of 12 species of shorebirds (Charadriidae and Scolopacidae), from the fresh weight of the bird and a visual classification of its subcutaneous fat deposits. Such equations allow the bird-banders and the experimental ornithologists to gather a large amount of data concerning the physiological pre- and post-migratory state of these birds and their migration routes.
Observations of the regeneration of a new test by the foraminifer Discorbis sp.
Authors: Walker David A.
Published: February 2008

A specimen of Discorbis sp., while maintained in culture for several weeks, was accidentally crushed, resulting in definite damage to the test, but unrecognizable (although possible) damage to the cytoplasm. Within a week cytoplasm protruded from beneath the test and new test material was being constructed. During the next 2 weeks a new test was completely constructed, but attached to the original test. Chamber arrangement of the regenerated test was extremely irregular for a Discorbis.
Seasonal variations in the mass and composition of brown adipose tissue in the meadow vole, Microtus pennsylvanicus
Authors: Didow L. A. , Hayward J. S.
Published: February 2008

Wild meadow voles were collected each month of the year and analyzed for the mass and composition of their brown adipose tissue. The relative mass of brown adipose tissue decreased with increasing body weight in both summer and winter.Seasonal changes in the relative mass of brown adipose tissue were inversely related to seasonal changes in ambient temperature. In mature voles, the relative mass of brown adipose tissue was lowest during summer (0.5%) and increased rapidly to a level of 1.7% in early winter. Similarly, immature voles had their lowest relative mass in summer (1.0%) and increased this to 2.3% in winter. Both groups showed some decrease in the winter amount of the tissue when the subnivean environment became established. The percentage composition of brown adipose tissue with respect to water, lipid, and protein did not change significantly through the year.The results provide corroboration for laboratory studies which show that the mass and composition of brown adipose tissue are related to the requirement for cold thermogenesis. In voles, this requirement was present throughout the year and varied only in degree.
The effect of winter drainage on reservoir benthic fauna
Authors: Paterson C. G. , Fernando C. H.
Published: February 2008

Winter drainage of Laurel Creek Reservoir in southern Ontario exposed the benthic environment to atmospheric conditions for between 168 and 176 days. During the first 50 days, which had above-freezing temperatures, much of the fauna was destroyed. In the next 100 days the substrate became frozen to depths greater than 20 cm. Freezing of the substrate resulted in the loss of the oligochaetes, nematodes, and oribatoid mites as well as a large percentage of the chironomid fauna. Small numbers of the caddis fly, Agraylea multipunctata; the chironomid Cricotopus trifasciatus; and the molluscs Planorbula jenksii and Lymnaea palustris were found to survive the period of freezing and the subsequent short period of thawing before the refilling of the reservoir. Indirect evidence suggests the survival of small numbers of certain species of chironomids not found in the samples. Glyplotendipes barbipes showed the highest survival under the conditions of exposure, as the population immediately after refilling was between 12.5 and 46.4% of that found before drainage of the reservoir. The fauna did not actively move deeper into the substrate as freezing progressed although the probability of survival was greater at the deeper levels. A. multipunctata, C. trifasciatus, and G. barbipes have been found able to pupate and emerge after survival in the exposed substrate.
Summer activity of Myotis lucifugus (Chiroptera:Vespertilionidae) at hibernacula in Ontario and Quebec
Authors: Fenton M. Brock
Published: February 2008

"Swarming" refers to the summer nocturnal flights through hibernacula by the five species of bats known to hibernate locally. A total of 6400 bats was handled during studies of swarming at 10 hibernacula in Ontario and Quebec from 1966 to 1968. Juveniles comprised over 50% of the swarming population, and the proportion of females in this population was greater than that observed in hibernating populations. Two phases of swarming have been distinguished: the first, occurring in August, lacks both sexual activity and a hibernating population, and the second, which begins in September, involves both sexual activity and the buildup of a hibernating population. Possible functions of swarming are discussed.
Ancyracanthopsis bendelli. sp. (Acuariidae:Schistorophinae) from Pacific Coast grouse, with observations on related nematode genera
Authors: Adams James R. , Gibson George G.
Published: February 2008

A. bendelli n. sp. differs from the others of the genus in that its dentate cephalic quadrants join laterally producing a bipartite rather than quadripartite appearance. It can be recognized also by its combination of large dentiform processes, long vestibule, short glandular oesophagus, and 9–14 pairs of preanal papillae; no other species parasitizes an obligate terrestrial host. The following species composition is proposed for Ancyracanthopsis Diesing, 1861: A. bilabiata (Molin, 1860) A. coronata (Molin, 1860); A. madagascariensis Kung, 1948; A. petrovi Guschanskaya, 1950; (?)A. parvialata (Belopolskaya, 1953); A. gallinulae (Wang, 1966) n. comb.; and A. bendelli n. sp. It is concluded that A. quadripartita (Clapham, 1945) and A. schikhobalovi Guschanskaya, 1950 are synonyms of A. coronata, and that Skrjabinobronema sinica Wang, 1966 is a synonym of A. madagascariensis. Specimens of Sciadiocara umbellifera (Molin, I860) (Syn: S. legendrei Petter, 1967) from British Columbia possess minute serrations along the posterior edges of the cephalic lappets. Viktorocara limosae Mawson, 1968 is considered a synonym of V. limosae Daiya, 1966. Stellocaronema Gilbert, 1930 should contain S. skrjabini Gilbert, 1930 (Syn: S, glareolae Mawson, 1968) and S. fausti (Li, 1934) n. comb, (Syn: Stellocaronema buckleyi Sarwar, 1956); S, charadrii Mawson, 1968 probably represents a new genus. New records are A. coronata from Actitis macularia and Seiurus noveboracensis in British Columbia and from Cassidix mexicanus in Mexico; V. limosae from Erolia alpina; and S. skrjabini from E. alpina, Ereunetes mauri, and Crocethia alba in British Columbia.
Nematode morphogenesis: fine structure of the molting cycles in Panagrellus silusiae (de Man 1913) Goodey 1945
Authors: Samoiloff M. R. , Pasternak J.
Published: February 2008

The mode of formation of a new cuticle in the free-living nematode Panagrellus silusiae is similar at each of the three postpartum molts. Molting begins with the appearance of filaments adjacent to the hypodermis. The new cuticle accumulates material and lacks organization during the early stage of the molt. The edge of the new cuticle adjacent to the old cuticle is composed of an amorphous row of particles and a filamentous region abuts the hypodermis. Eventually, a complete cuticle is produced beneath the preexisting one.The shedding of the old cuticle varies in different molts. In the larval molts (L2 to L3 and L3 to L4) and the molt to the adult female the cuticle is discarded piecemeal. During the molt to the adult male the old cuticle splits and is shed as a single piece.Before completion of ecdysis in the final female molt, the new cuticle folds extensively. This folding does not occur during any other molt.Resorption of the old cuticle is never observed. There is no microscopic evidence of protein synthesis in the interchordal hypodermis during the molting process.
Observations on the functional anatomy of the reproductive organs of Sitophilus (Coleoptera: Curculionidae)
Authors: Khan N. R. , Musgrave A. J.
Published: February 2008

In Sitophilus granarius (L.) and S. zea-mais (Mots.), sperm are stored, apparently in active motion, in the spermatheca of the female for several weeks, and apparently escape in small numbers continuously along the duct of the spermatheca, whose gland may supply them with energy. In laboratory experiments, sperm activity seemed to be associated with dehydration, and the presence of K+, Na+, Zn+, and Cl− ions. Secretion of the so-called prostate gland of the male activated sperm in S. granarius. Sperm itinerary from testis to egg is discussed.
Ecological segregation of systematically related stream insects
Authors: Grant P. R. , Mackay R. J.
Published: February 2008

Insects from a stream at Mont St. Hilaire, Quebec, were sampled monthly for 1 year. The degree of ecological difference between congeneric species in three orders was assessed by using a "coefficient of separation", similar to a modified Jaccard coefficient. It was found that species differed most in their season of occurrence, least in the substrates they occupied. The significance of this result in terms of the avoidance of competition is considered.
Observations on the glochidia of Lampsilis radiata (Gmelin) infesting yellow perch, Perca flavescens (Mitchill) in the Bay of Quinte, Lake Ontario
Authors: Tedla Shibru , Fernando C. H.
Published: February 2008

Analysis of incidence and intensity of infestation of yellow perch, Perca flavescens (Mitchill), by the glochidia of Lampsilis radiata from weekly samples from May to September and single samples in October and November indicate that the two subspecies, Lampsilis radiata radiata and Lampsilis radiata siliquoidea, shed their glochidia in late spring and throughout the summer in the Bay of Quinte, Lake Ontario. Smaller fish are more heavily infested with these glochidia than larger ones. About 50% of the preparasitic glochidia of Lampsilis radiata siliquoidea survived for 12, 70, and 120 h at 20°, 12°, and 10 °C respectively. The parasitic period of the glochidia of L. r. siliquoidea on yellow perch under experimental conditions was 50 days at 15 °C from the May infestation. Yellow perch carried the glochidia for a longer period from an August infestation. All the glochidia recovered 50 days after infestation, both from May and August infestations, had undergone metamorphosis. There was no difference in the degrees of infestation of the different species of fish used in our experiments. Pumpkinseed, Lepomis gibbosus (Linnaeus); rock bass, Ambloplites rupestris (Rafinesque); and white perch, Roccus americanus (Gmelin) lost their infestations in a week. Presumably no metamorphosis took place under these conditions. Black crappie, Pomoxis nigromaculatus (LeSueur); largemouth bass, Micropterus salmoides (Lacepede), smallmouth bass, M. dolomieui Lacepede: and yellow perch carried the infestation till they were killed 20 days later. There was no relationship between the numbers of glochidia (Lampsilis radiata) and copepods, (Ergasilus confusus Bere) on naturally infested yellow perch, nor on rock bass, smallmouth bass, and pumpkinseed which harbored Ergasilus spp. naturally and which were infested with the glochidia of L. r. siliquoidea experimentally.
Observations on the labium of Corixidae (Hemiptera)
Authors: Jarial M. S. , Scudder G. G. E. , Teraguchi S.
Published: February 2008

The structure of the dorsal wall of the labium in the corixid Cenocorixa bifida is described. This area has an extremely thin cuticle, bears numerous sense organs, and has an enlarged and elaborate epidermis beneath the cuticle. The area becomes impregnated with silver when insects are placed in a 0.2% solution of silver nitrate, and this silver is shown to be located in the layers of the cuticle and in the underlying epidermis. It is shown, by autoradiographic techniques, that the area will take up 22Na when the insects are placed in labelled media. An association with ionic regulation is suggested.
Gross and microscopic anatomy of the orbital glands of Malaclemys and other emydine turtles
Authors: Cowan F. B. M.
Published: February 2008

A gross anatomical and light microscopic study of the orbital regions of several stenohaline and one euryhaline emydine turtles has shown that each has two orbital glands, the Harderian and the lachrymal. The Harderian is apparently serous and is identical in all species. The lachrymal gland of all the stenohaline species is a mixed seromucous gland. In the euryhaline Malaclemys, the lachrymal gland differs in being much larger and possessing a structure which resembles to a degree other known salt glands. The lachrymal glands from Malaclemys housed in salt and in fresh water differ in size and histochemistry. Whether these differences are related to salt secretion, corneal lubrication, or some other function is not known.
Larval Echinococcus multilocularis Leuckart, 1863 in the southern Interlake area in Manitoba
Authors: Lee Chiu-Fan
Published: February 2008

Larval Echinococcus multilocularis was found in one of 25 Peromyscus maniculatus collected in a dolomite quarry near Gunton, about 30 miles north of Winnipeg. This finding shows that E. multilocularis is present in Manitoban rodents at least in an area of 60 sq. mi.
Cardioinhibitor nerves in Limulus
Authors: Burg R. Von , Corning W. C.
Published: February 2008

When dorsal nerves 7 or 8 arising from the Limulus accessory brain are sectioned, cardioacceleration results; direct stimulation of these nerves produces cardioinhibition. These findings demonstrate a cardioinhibitory function. The results of forebrain lesions suggest that these inhibitors may be activated by higher brain centers.
Laboratory hybridization in green lacewings (Neuroptera: Chrysopidae: Chrysoperla): evidence for genetic incompatibility
Authors: Wells Marta Martínez
Published: February 2008

Courtship songs are an important reproductive barrier in lacewings of the genus Chrysoperla, so heterotypic matings should occur less readily than homotypic matings. In addition, if song morphs have become separate species, there may be some postzygotic isolation between song morphs. Two generations of crosses using sympatric P1 and P3 morphs of Chrysoperla plorabunda provide evidence for both hypotheses. In the first stage of the experiment, egg laying (an indication of mating success) was delayed by a week in heterotypic crosses compared with homotypic crosses, and hatching success of eggs from hybrid crosses was 16% lower than that from control crosses. In the second stage of the experiment, backcrosses involving P3 morph males or females were the least successful in mating. When pairs did mate, they did so a week later than in the other crosses. Thus, behavioral isolation delays heterotypic matings when females are not given a choice of mates. These results provide some genetic evidence that the song morphs of the C. plorabunda complex are biological species.
Proximate determination of clutch size in lesser black-backed gulls: the roles of food supply and body condition
Authors: Bolton Mark , Monaghan Pat , Houston David C.
Published: February 2008

Though many authors have demonstrated an adaptive relationship between food supply or territory quality and clutch size, the proximate mechanism by which clutch size is determined remains largely unknown. A series of supplementary feeding experiments on lesser black-backed gulls (Larus fuscus) is used in conjunction with a new technique to measure pectoral muscle protein levels in live birds to investigate the relationships between food supply, body condition, and clutch size. Comparisons across treatments revealed a positive relationship between the level of flight muscle protein at the start of laying and clutch size, but not egg size. In a year when the clutch sizes of unfed birds were reduced, suggesting low food availability, gulls provided with a protein supplement had higher levels of flight muscle protein at the start of laying and laid larger clutches than birds that received no food supplement. In contrast, gulls provided with an additional energy source (fat) did not attain higher protein levels or lay larger clutches than unfed gulls. In a second year, when unfed gulls laid larger clutches, which were typical for the species, supplements of two different protein types (fish and egg) had no effect on clutch size, though egg-fed females laid considerably (10%) larger eggs. However, there were no detectable differences in condition between treatments at the start of laying, suggesting that though flight muscle protein levels may be of importance in determining clutch size, they may be of lesser significance for egg size, which may be largely influenced by dietary intake.
Role of spawning condition in the determination of the reproductive traits of spring- and autumn-spawning Atlantic herring from the southern Gulf of St. Lawrence
Authors: Bradford Rodney G.
Published: February 2008

Mature spring-spawning (May–June) and autumn-spawning (August–September) herring differ in total weight. Autumn herring have both heavier gonads and higher somatic weights at length. Both the residual levels of storage lipids and somatic weight at length, corrected for storage lipid, are higher in autumn than in spring. Within spawning seasons, males and females deplete the same amount of storage energy. Percent somatic lipid content is positively correlated with body size during spring but shows no relationship to body size in autumn. These patterns indicate that the relative allocation of storage energy to reproduction differs with spawning season. Spring spawners (lengthy gonad maturation period) allocate proportionally more storage energy to routine and active metabolism than autumn spawners (brief gonad maturation period). The low intercept and steep slope of the gonad weight – length relationship for spring spawners reflect the interaction between decreasing metabolic rate with body size and increasing storage energy capacity with body size. Egg weight is unrelated to the parent's somatic lipid content for either spawning group. Spawning history (recruit versus repeat spawning) has only a minor influence on egg weight.
Aggregations of newly metamorphosed Bufo americanus: tests of two hypotheses
Authors: Heinen Joel T.
Published: February 2008

Newly metamorphosed anuran amphibians of several species have been observed to form very dense aggregations around the peripheries of breeding ponds; in some cases, the animals will literally pile on conspecifics. Two hypotheses used to explain the behavior were tested in several experimental situations: that juvenile anurans aggregate as a response to (i) predation risk or (ii) desiccation. Two experimental setups were used to test the first hypothesis. There was no tendency for nonphysiologically stressed juvenile Bufo americanus to group on a relatively high-risk substrate or in the presence of a preformed group, with or without a predator present. The results of two additional experiments showed that these animals aggregated as a response to desiccation and that animals desiccated alone suffered greater weight loss and mortality than those desiccated in groups. Thus, the results strongly support the hypothesis that these young anurans aggregate in response to the risk of desiccation, not to the risk of predation.
Larval and pupal microhabitat selection by Simulium truncatum Lundström, S. rostratum Lundström, and S. verecundum AA (Diptera: Simuliidae)
Authors: McCreadie John W. , Colbo Murray H.
Published: February 2008

Larval and pupal microhabitat selection by the cytospecies Simulium truncatum Lundström, S. rostratum Lundström, and S. verecundum AA was investigated. Last-instar larvae of S. truncatum and S. rostratum selected different microhabitats as shown by their response to velocity, depth, and outlets. Optimal stream velocity for larval S. truncatum and S. rostratum was estimated as 0.36 and 0.69–0.73 m/s, respectively. The microdistribution of S. truncatum showed a parabolic response to outflows with peak abundance occurring between 10.5 and 16.0 m from outlets. The distance-preference curve for S. rostratum was the complete inverse of that for S. truncatum, with maximum abundance of S. rostratum occurring immediately below and 20 m removed from the outlet. Abundance of larval S. truncatum decreased exponentially with depth (0.03–0.34 m), whereas the microdistribution of S. rostratum and a mixed 5. rostratum/S. verecundum AA population was not influenced by water depth (0.03–0.19 m). The microdistribution of pupae was similar to that of last-instar larvae for both S. truncatum and S. rostratum. Although larval microdistribution was influenced by velocity (S. truncatum, S. rostratum) and depth (S. truncatum), it was not possible to explain these patterns in relation to larval size.
Survie oeufs–juvéniles et force des classes d'âge des grands brochets (Esox lucius) de la rivière aux Pins, près de Montréal, Québec
Authors: Massé Gérard , Dumont Pierre , Fortin Réjean
Published: February 2008

Exhaustive counts of northern pike that use the Rivière aux Pins and of 0+ juvenile pike produced in this river, based on trap net and seine catches, coupled with potential fecundity estimates, allowed survival rates of pike eggs to migrant 0+ juveniles to be evaluated in a natural situation, in 1975, and in a controlled water level situation, in 1976. In 1975, 3393 juveniles aged 0+ were produced from 9 210 900 eggs potentially deposited by 404 females, yielding a 0.037% survival rate. In 1976, 34 062 juveniles aged 0+ were produced from 8 536 800 eggs potentially deposited by 310 females, yielding a 0.399% survival rate. The higher survival rate in 1976 could have resulted from the water level control and (or) from the higher spring waters in 1976. However, 1975 and 1976 both produced strong year classes, suggesting that potential fecundity and 0+ juvenile production on the spawning grounds are not the only factors influencing recruitment in this species.
A chromatic action spectrum for planktonic predation by juvenile yellow perch, Perca flavescens
Authors: Loew E. R. , McFarland W. N. , Mills E. L. , Hunter D.
Published: February 2008

The intensity of light required for juvenile yellow perch, Perca flavescens, to strike at planktonic prey was determined at 14 wavelengths, particular attention being paid to the near-ultraviolet region of the spectrum. Juvenile yellow perch are known to possess near-ultraviolet-sensitive photoreceptors, which are absent in adults. The action spectrum obtained shows three peaks: one between 640 and 700 nm, one between 490 and 525 nm, and one in the near-ultraviolet range, between 360 and 400 nm. The relative amplitude of the near-ultraviolet peak is greater than the amplitudes of the other two peaks. These results reveal that juvenile yellow perch can detect and recognize prey using only near-ultraviolet visual cues. This finding is discussed in terms of the visual ecology of juvenile and adult yellow perch.
The impact of prey behaviour and prey density on the foraging ecology of Ranatra montezuma (Heteroptera): a serological examination
Authors: Blinn Dean W. , Runck Clay , Davies Ronald W.
Published: February 2008

Serological techniques were used to examine the seasonal and diel diets of Ranatra montezuma (Heteroptera) in the fishless, thermally constant environment of Montezuma Well, Arizona. Although alternative invertebrate prey were diverse and abundant, copepods were the primary food of first-instar R. montezuma, while the endemic amphipod Hyalella montezuma was the preferred food of adults. Laboratory predation experiments and serological diet analyses from field collections suggest that R. montezuma feeds more actively at night when prey densities in Montezuma Well are elevated in the littoral vegetation. Prey behaviour is very important in the foraging ecology of R. montezuma. Hyalella montezuma, which swim in the littoral vegetation, were captured more frequently than more sedentary damselfly larvae (Telebasis salva). Prey-choice experiments and in situ serological diet analyses suggest that the high standing crop of R. montezuma is dependent upon the presence of high densities of actively swimming H. montezuma.
Rhysia fletcheri (Cnidaria, Hydrozoa, Rhysiidae), a new species of colonial hydroid from Vancouver Island (British Columbia, Canada) and the San Juan Archipelago (Washington, U.S.A.)
Authors: Brinckmann-Voss A. , Lickey D. M. , Mills C. E.
Published: February 2008

A new species of colonial athecate hydroid, Rhysia fletcheri, is described from Vancouver Island, British Columbia, Canada, and from Friday Harbor, Washington, U.S.A. Its relationship to Rhysia autumnalis Brinckmann from the Mediterranean and Rhysia halecii (Hickson and Gravely) from the Antarctic and Japan is discussed. Rhysia fletcheri differs from Rhysia autumnalis and Rhysia halecii in the gastrozooid having distinctive cnidocyst clusters on its hypostome and few, thick tentacles. Most of its female gonozooids have no tentacles. Colonies of R. fletcheri are without dactylozooids. The majority of R. fletcheri colonies are found growing on large barnacles or among the hydrorhiza of large thecate hydrozoans. Rhysia fletcheri occurs in relatively sheltered waters of the San Juan Islands and on the exposed rocky coast of southern Vancouver Island.
Effets de la ration alimentaire, de la densité intraspécifique et des relations entre individus sur la croissance des juvéniles de l'espèce Nereis diversicolor (Annelida: Polychaeta)
Authors: Scaps Patrick , Retière Christian , Desrosiers Gaston , Miron Gilles
Published: February 2008

We studied the effects of food intake, intraspecific density, and interactions between individuals on the growth of laboratory-raised juveniles of Nereis diversicolor fed different quantities of Tetramin. A daily intake of 3.33 mg of Tetramin per individual resulted in an optimal mean mass gain. At densities above 3000 individuals/m2, not only was the growth rate reduced, but biomass and survival rates were also diminished. Frequent handling and the thermodifferential shock that ensured created a stress that had the same negative effects. Variations in responses to aggregation or isolation were high, as revealed by groups of juveniles captured in winter or in spring reacting differently: growth was not affected by the breeding conditions in the winter-caught worms but was faster in spring-caught individuals kept in isolation.
Survival of Petasiger nitidus (Digenea: Echinostomatidae) cercariae in relation to temperature, pH, and salinity
Authors: Shostak Allen W.
Published: February 2008

Cercariae of Petasiger nitidus, shed from naturally infected Helisoma trivolvis, were maintained at various temperatures (4–35 °C), pH levels (5–9), and salinities (5 mg – 29 g NaCl/L). The optimal temperature for survival was 8 °C. Survival at 8 and 23 °C exhibited significant but low-magnitude variation with pH. The optimal salinity at 23 °C was 2.9 g NaCl/L; concentrations of 17.5 g/L or greater were lethal within 1 h. Cercariae tolerated a range of environmental conditions similar to that tolerated by their molluscan host, suggesting that survival of cercariae does not limit the geographical distribution of P. nitidus.
Aggression of guarding male smallmouth bass (Micropterus dolomieui) towards potential brood predators near the nest
Authors: Ongarato R. J. , Snucins E. J.
Published: February 2008

Models of potential brood predators placed near the nest were used to elicit defence behaviour in male smallmouth bass (Micropterus dolomieui) in the field. The three predator models represented a conspecific, a species found in the lake (yellow perch, Perca flavescens), and a species not present in the lake (brown bullhead, Ictalurus nebulosus). Aggressive behaviour increased with brood age and with decreasing distance between model and nest. Brood-guarding smallmouth bass exhibited a generalized response to the three predator models and did not discriminate between them by altering levels of aggression.
STATEFINDER PARAMETERS FOR FIVE-DIMENSIONAL COSMOLOGY
Authors: CHANG BAORONG , LIU HONGYA , XU LIXIN , ZHANG CHENGWU
Published: February 2008

We study the statefinder parameter in the five-dimensional big bounce model, and apply it to differentiate the attractor solutions of quintessence and phantom field. It is found that the evolving trajectories of these two attractor solutions in the statefinder parameters plane are quite different, and that are different from the statefinder trajectories of other dark energy models.
EXPLORING THE ULTRA-HIGH ENERGY SKY: STATUS AND FIRST RESULTS OF THE PIERRE AUGER OBSERVATORY
Authors: VAN ELEWYCK VERONIQUE
Published: February 2008

The Pierre Auger Southern Observatory, a hybrid detector for the study of ultra-high energy cosmic rays (UHECRs), is now operating for more than three years and approaching completion. This paper describes the present status and the performance of the Observatory, with an emphasis on the advantages provided by the combined use of two different detection techniques. A panorama of the most recent results related to the spectrum, composition and arrival directions of the UHECR is then presented, along with a brief discussion of their impact on our knowledge of the UHECRs' origin and composition.
Analyzing Protein Interaction Networks Using Structural Information
Authors: Kiel Christina , Beltrao Pedro , Serrano Luis
Published: February 2008

Determining protein interaction networks and predicting network changes in time and space are crucial to understanding and modeling a biological system. In the past few years, the combination of experimental and computational tools has allowed great progress toward reaching this goal. Experimental methods include the large-scale determination of protein interactions using two-hybrid or pull-down analysis as well as proteomics. The latter one is especially valuable when changes in protein concentrations over time are recorded. Computational tools include methods to predict and validate protein interactions on the basis of structural information and bioinformatics tools that analyze and integrate data for the same purpose. In this review, we focus on the use of structural information in combination with computational tools to predict new protein interactions, to determine which interactions are compatible with each other, to obtain some functional insight into single and multiple mutations, and to estimate equilibrium and kinetic parameters. Finally, we discuss the importance of establishing criteria to biologically validate protein interactions.
Should Binge Eating Disorder Be Included in the DSM-V? A Critical Review of the State of the Evidence
Authors: Striegel-Moore Ruth H. , Franko Debra L.
Published: February 2008

Binge eating disorder (BED) was introduced in 1994 as a provisional eating disorder diagnosis. The core symptom is recurrent binge eating in the absence of inappropriate compensatory behaviors and/or extreme dietary restraint. This review examines the status of the literature on BED according to five criteria that have been proposed to determine whether BED warrants inclusion in the psychiatric nosology as a distinct eating disorder. We conclude that each of these criteria was met. There is a commonly accepted definition of and assessment approach to BED. The clinical utility and validity of BED have been established, and BED is distinguishable from both bulimia nervosa and obesity. BED should be included in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders.
The Behavioral Genetics of Personality Disorder
Authors: Livesley W. John , Jang Kerry L.
Published: February 2008

Behavioral genetics research has opened a new window on understanding personality disorder. The earliest studies were focused on establishing the relative contributions of genes and the environment in these disorders. Although these studies provided solid evidence of the importance of genetic and environmental influences on personality disorder and showed that all aspects of personality disorder are subject to genetic influence, heritability studies are limited because they are not helpful in explicating causal mechanisms. More recent research has focused on the relative contributions of the covariation of personality disorder diagnoses and traits, which allows one to examine etiological relationships. These developments are leading to major changes in ideas about what constitutes the environment and nature of the interplay between genes and environment. The present review examines major themes in this growing body of research in the context of current issues in the personality disorders.
Death by a Thousand Cuts: Granzyme Pathways of Programmed Cell Death
Authors: Chowdhury Dipanjan , Lieberman Judy
Published: February 2008

The granzymes are cell death–inducing enzymes, stored in the cytotoxic granules of cytotoxic T lymphocytes and natural killer cells, that are released during granule exocytosis when a specific virus-infected or transformed target cell is marked for elimination. Recent work suggests that this homologous family of serine esterases can activate at least three distinct pathways of cell death. This redundancy likely evolved to provide protection against pathogens and tumors with diverse strategies for evading cell death. This review discusses what is known about granzyme-mediated pathways of cell death as well as recent studies that implicate granzymes in immune regulation and extracellular proteolytic functions in inflammation.
Protein Tyrosine Phosphatases in Autoimmunity
Authors: Vang Torkel , Miletic Ana V. , Arimura Yutaka , Tautz Lutz , Rickert Robert C. , Mustelin Tomas
Published: February 2008

Protein tyrosine phosphatases (PTPs) are important regulators of many cellular functions and a growing number of PTPs have been implicated in human disease conditions, such as developmental defects, neoplastic disorders, and immunodeficiency. Here, we review the involvement of PTPs in human autoimmunity. The leading examples include the allelic variant of the lymphoid tyrosine phosphatase (PTPN22), which is associated with multiple autoimmune diseases, and mutations that affect the exon-intron splicing of CD45 (PTPRC). We also find it likely that additional PTPs are involved in susceptibility to autoimmune and inflammatory diseases. Finally, we discuss the possibility that PTPs regulating the immune system may serve as therapeutic targets.
JNK- and IκB-dependent pathways regulate MCP-1 but not adiponectin release from artificially hypertrophied 3T3-L1 adipocytes preloaded with palmitate in vitro
Authors: Takahashi Kazuto , Yamaguchi Shinya , Shimoyama Tatsuhiro , Seki Hiroyuki , Miyokawa Kaoru , Katsuta Hidenori , Tanaka Toshiaki , Yoshimoto Katsuhiko , Ohno Hideki , Nagamatsu Shinya , Ishida Hitoshi
Published: February 2008

Obese conditions increase the expression of adipocytokine monocyte chemoattractant protein-1 (MCP-1) in adipose tissue as well as MCP-1 plasma levels. To investigate the mechanism behind increased MCP-1, we used a model in which 3T3-L1 adipocytes were artificially hypertrophied by preloading with palmitate in vitro. As observed in obesity, under our model conditions, palmitate-preloaded cells showed significantly increased oxidative stress and increased MCP-1 expression relative to control cells. This increased MCP-1 expression was enhanced by adding exogenous tumor necrosis factor-α (TNF-α; 17.8-fold vs. control cells, P < 0.01) rather than interleukin-1β (IL-1β; 2.6-fold vs. control cells, P < 0.01). However, endogenous TNF-α and IL-1β release was not affected in hypertrophied cells, suggesting that these endogenous cytokines do not mediate hypertrophy-induced increase in MCP-1. MCP-1 secretion from hypertrophied cells was significantly decreased by treatment with antioxidant N-acetyl-cysteine, JNK inhibitors SP600125 and JIP-1 peptide, and IκB phosphorylation inhibitors BAY 11-7085 and BMS-345541 ( P < 0.01). MCP-1 secretion was not affected by peroxisome proliferator-activated receptor-γ (PPARγ) antagonists assayed. Adiponectin, another adipocytokine studied in parallel, also showed increased release in hypertrophy relative to control cells. But in contrast to MCP-1, adiponectin release was significantly suppressed by both exogenous TNF-α and IL-1β as well as by PPARγ antagonists bisphenol A diglycidyl ether and T0070907 ( P < 0.01). JNK inhibitors and IκB phosphorylation inhibitors showed no significant effect on adiponectin. We conclude that adipocyte hypertrophy through palmitate loading causes oxidative stress, which in turn increases MCP-1 expression and secretion through JNK and IκB signaling. In contrast, the parallel increase in adiponectin expression appears to be related to the PPARγ ligand properties of palmitate.
Oxidative stress stimulates skeletal muscle glucose uptake through a phosphatidylinositol 3-kinase-dependent pathway
Authors: Higaki Yasuki , Mikami Toshio , Fujii Nobuharu , Hirshman Michael F. , Koyama Katsuhiro , Seino Tetsuya , Tanaka Keitaro , Goodyear Laurie J.
Published: February 2008

We determined the acute effects of oxidative stress on glucose uptake and intracellular signaling in skeletal muscle by incubating muscles with reactive oxygen species (ROS). Xanthine oxidase (XO) is a superoxide-generating enzyme that increases ROS. Exposure of isolated rat extensor digitorum longus (EDL) muscles to Hx/XO (Hx/XO) for 20 min resulted in a dose-dependent increase in glucose uptake. To determine whether the mechanism leading to Hx/XO-stimulated glucose uptake is associated with the production of H2O2, EDL muscles from rats were preincubated with the H2O2scavenger catalase or the superoxide scavenger superoxide dismutase (SOD) prior to incubation with Hx/XO. Catalase treatment, but not SOD, completely inhibited the increase in Hx/XO-stimulated 2-deoxyglucose (2-DG) uptake, suggesting that H2O2is an intermediary leading to Hx/XO-stimulated glucose uptake with incubation. Direct H2O2also resulted in a dose-dependent increase in 2-DG uptake in isolated EDL muscles, and the maximal increase was threefold over basal levels at a concentration of 600 μmol/l H2O2. H2O2-stimulated 2-DG uptake was completely inhibited by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin, but not the nitric oxide inhibitor NG-monomethyl-l-arginine. H2O2stimulated the phosphorylation of Akt Ser473(7-fold) and Thr308(2-fold) in isolated EDL muscles. H2O2at 600 μmol/l had no effect on ATP concentrations and did not increase the activities of either the α1 or α2 catalytic isoforms of AMP-activated protein kinase. These results demonstrate that acute exposure of muscle to ROS is a potent stimulator of skeletal muscle glucose uptake and that this occurs through a PI3K-dependent mechanism.
Altered heart rate control in transgenic mice carrying the KCNJ6 gene of the human chromosome 21
Authors: Lignon Jacques M. , Bichler Zoë , Hivert Bruno , Gannier François E. , Cosnay Pierre , del Rio José A. , Migliore-Samour Danièle , Malécot Claire O.
Published: February 2008

Congenital heart defects (CHD) are common in Down syndrome (DS, trisomy 21). Recently, cardiac sympathetic-parasympathetic imbalance has also been documented in DS adults free of any CHD. The KCNJ6 gene located on human chromosome 21 encodes for the Kir3.2/GIRK2 protein subunits of G protein-regulated K+(KG) channels and could contribute to this altered cardiac regulation. To elucidate the role of its overexpression, we used homozygous transgenic (Tg+/+) mice carrying copies of human KCNJ6. These mice showed human Kir3.2 mRNA expression in the heart and a 2.5-fold increased translation in the atria. Phenotypic alterations were assessed by recording electrocardiogram of urethane anesthetized mice. Chronotropic responses to direct (carbachol) and indirect (methoxamine) muscarinic stimulation were enhanced in Tg+/+mice with respect to wild-type (WT) mice. Alternating periods of slow and fast rhythm induced by CCPA (2-chloro- N-cyclopentyl-adenosine) were amplified in Tg+/+mice, resulting in a reduced negative chronotropic effect. These drugs reduced the atrial P wave amplitude and area. P wave variations induced by methoxamine and CCPA were respectively increased and reduced in the Tg+/+mice, while PR interval and ventricular wave showed no difference between Tg+/+and WT. These results indicate that Tg+/+mice incorporating the human KCNJ6 exhibit altered Kir3.2 expression and responses to drugs that would activate KGchannels. Moreover, these altered expression and responses are limited to sino-atrial node and atria that normally express large amounts of KGchannels. These data suggest that KCNJ6 could play an important role in altered cardiac regulation in DS patients.
Synthesis and Rietveld refinement of skutterudite-related phase CoSn1.5Te1.5
Authors: Laufek F. , Návrátil J. , Goliáš V.
Published: February 2008

Crystal structure of the skutterudite-related phase has been refined by the Rietveld method from X-ray powder diffraction data. Refined crystallographic data for CoSn1.5Te1.5area=12.9063(2) Å,c=15.7837(3) Å,V=2276.89(4) Å3, space groupR3(No. 148),Z=24, andDx=7.50 g/cm3. The crystal structure of the title compound can be viewed as a modification of the skutterudite structure (CoAs3)—it is isostructural with CoGe1.5Te1.5and IrSn1.5Te1.5. In the structure of CoSn1.5Te1.5, the Sn and Te atoms exhibit long-range ordering, which results in lowering of the original cubic symmetry of the skutterudite structure to the trigonal one.
Diffraction data of Zn3Cu4Sb2O12
Authors: Harrington Richard , Miles Gabrielle C. , West Anthony R.
Published: February 2008

A new phase Zn3Cu4Sb2O12 was analyzed by X-ray powder diffraction. Its monoclinic unit cell parameters are a=21.0378(19) Å, b=8.7825(7) Å, c=5.5860(4) Å, and β=112.578(7)°, and the space group is either Cc (9) or C2/c (15). From comparison with density measurements, Z=4.