bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship between metallothionein and intestinal zinc absorption in the winter flounder
Authors: Shears M. A. , Fletcher G. L.
Published: December 2009

Chromatographic techniques were used to investigate the presence of zinc-binding proteins in the intestinal mucosal cytosols of a marine teleost, the winter flounder (Pseudopleuronectes americanus). A low molecular weight, zinc-binding protein, characterized as metallothionein, was isolated from the intestinal cytosols of zinc-injected flounder. Metallothionein synthesis was induced in the intestine of the flounder by parenteral injections of zinc. However, studies conducted to assess the involvement of metallothionein in gastrointestinal zinc uptake indicated that its presence in the intestinal cytosol was not associated with any enhancement or depression of zinc uptake. These findings contrast with current hypotheses concerning metallothionein function in mammalian intestines.
Productivity of coyotes (Canis latrans) from southern Québec
Authors: Jean Yves , Bergeron Jean-Marie
Published: December 2009

A sample of coyotes harvested in the Eastern Townships of southern Québec indicate that 84% of the sample comprised females under 3 years old. The examination of mature follicles, corpora lutea and corpora albicantia, indicated that the ovulation rates ranged from 6.6 to 8.0, and the mean ovulation frequency was of 57%. The mean litter size was estimated at 7.1 with 46% of the females producing pups. The mean population productivity was of 316 pups per 100 females annually, concurring with rates found in other North American populations. Results suggest that a strong harvesting pressure could be at the origin of the large litter size, of the age structure that favors young animals, as well as the high turnover rate in the population.
Correlations between body temperature and environmental factors and their variations with activity in garter snakes (Thamnophis)
Authors: Gregory Patrick T.
Published: December 2009

The aim of this study was to determine the extent to which several environmental variables were associated with body temperatures of three species of garter snakes (Thamnophis) on Vancouver Island, and whether or not these associations changed with different activities of snakes. Perhaps because the data set was quite heterogeneous, no differences were observed between body temperatures of different species or sexes. In all activity groups, environmental temperatures were the variables most highly correlated with body temperatures; factors such as visible light intensity and cloud cover also were correlated with body temperature in some cases, but added little to the "explained" variation of body temperature. There was little evidence of seasonal or diel fluctuation in body temperature, but more careful data collection may be required to detect these. The correlation between body and environmental temperatures was highest for snakes under cover and lowest for moving snakes. Basking snakes in general were intermediate between these two groups, but snakes basking in the sun under sunny skies showed low correlation between body and environmental temperatures. Snakes, therefore, had body temperatures relatively independent of environmental temperatures under certain circumstances, but conclusions about thermoregulation could not be drawn from these data.
Production in spruce grouse and its relationship to environmental factors and population parameters
Authors: Smyth K. E. , Boag D. A.
Published: December 2009

The extent to which a relationship existed between selected environmental and population parameters and annual production in a population of spruce grouse (Dendragapus canadensis franklinii) was investigated through correlation analysis of data spanning 16 years. Production of young grouse varied between 0.0 and 1.4 young, aged 4 or more weeks, per resident female over the period of this study. There was no evidence that differences in annual productivity were related to variation (maximum of 17 days) in the onset of reproduction, a function of spring temperatures. Nevertheless, weather conditions during incubation and the immediate posthatch period did exhibit a significant correlation with productivity: cold, wet conditions during incubation were associated with years of poor productivity, whereas the same conditions during the immediate posthatch period were associated with years of good survival of young (at least to 19 days of age). Clutch and brood sizes of yearlings were smaller than those of adults; hence, production could be influenced by the proportion of the population in each age category. An inverse relationship between the density of resident females in spring and their annual production, believed to be important in this population, was reexamined with data from an additional 6 years. The relationship, although still inverse, was no longer significant.
Winter diet and intestinal proportions of rock and willow ptarmigan and sharp-tailed grouse in Ontario
Authors: Thomas V. G.
Published: December 2009

Dwarf birch (Betula glandulosa) and willow (Salix spp.) were the principal winter foods of sympatric willow ptarmigan (Lagopus lagopus), rock ptarmigan (Lagopus mutus), and sharp-tailed grouse (Tympanuchus phasianellus) in northern Ontario. Birch catkins and leaf buds made up 90 and 69% of the diet of sharp-tailed grouse and rock ptarmigan, respectively, whereas willow stems and buds formed 68% of the willow ptarmigan diet. Digestive organ weights differed significantly (P < 0.05) among the species of grouse during winter. Within each species, weights of gizzard, caeca, and small intestine were weakly correlated with individual body weight. Total variance in the weight of each digestive organ among species was partitioned into significant effects of species body weight and also species. Seasonal changes to lighter caeca and small intestines were apparent in prebreeding willow ptarmigan and rock ptarmigan coincident with a change in diet to green, growing willow and birch parts. A precise effect of type of diet upon the digestive organ weight of different grouse species was not perceived and was confounded by influences of species body weight.
Demographic parameters at evolutionary equilibrium
Authors: Taylor Peter D. , Williams George C.
Published: December 2009

We reason that natural selection acting under conditions imposed by physical factors (e.g., geometric constraints on growth rate) and community organization (e.g., persistent finite population sizes, equal total biomass of organisms in proportionately equal size ranges) should lead to certain life history features. The initial size of resource-capturing young should be the smallest that permits growth rate to exceed mortality rate so that the age cohort will start to increase in biomass. Production of such young must be an inefficient use of biomass because of metabolism, predation of embryos, the cost of males, and other losses. Mortality rate during juvenile growth should be a power function like growth rate, but always a bit lower so that the age cohort continues to increase and ultimately to compensate for the inefficiency of reproduction. In a constant environment, the individual should stop growing at the size of greatest expected excess of future reproductive resources over size, and thereafter devote all expendable resources to reproduction. Any given size range of animals, such as 1–2 mg or 1–2 kg, should consist of both mature and immature individuals in any community and should be devoting about a third of its investable resources to reproduction and the rest to growth. We use our equations to generate sample life histories. The simple form of our equations organizes these life tables into families of similar schedules with variable generation time.
Relative abilities of three tests to detect variance heterogeneity among mammalian litter sizes
Authors: Zammuto Richard M.
Published: December 2009

An experiment was conducted on mammalian litter size data from six natural populations to test the relative abilities of Bartlett's, Cochran's, and Hartley's tests to ascertain variance heterogeneity among populations. Bartlett's and Cochran's heterogeneity tests detected (P < 0.05) variance heterogeneity among litter sizes for 69 and 77%, respectively, of 1000 random samples of natural data, whereas Hartley's test detected it for only 12% of the same samples. This study suggests that Hartley's test, as conventionally used by biologists, is overly conservative (undesirable for heterogeneity tests) for use with litter size data. It is recommended that the use of Hartley's Fmax test by mammalian researchers for determining differences in variation among litter sizes be restricted to much higher α levels than are conventionally used to protect Fmax users from committing type II errors.
Ecdysis in a parasitic nematode: direct evidence for an ecdysial factor from the head
Authors: Davey K. G. , Goh S. L.
Published: December 2009

Incubating intact Phocanema decipiens in 0.9% NaCl containing insect juvenile hormone 1 (JH) leads to an increase in water volume of the excretory cell as determined by exchange with 3H2O, while incubation in 0.9% NaCl without JH does not. Ligaturing the head end of the worm prevents this increase and injection of extracts of heads into worms stimulates an increase in water content. Application of extract of heads to excretory cells in vitro also leads to an increase in water content of the cells.
Alcataenia campylacantha (Krabbe, 1869) from pigeon guillemots, Cepphus columba Pallas, and black guillemots, Cepphus grylle (Linnaeus), and Alcataenia sp. indet. (Cestoda: Dilepididae) from Kittlitz's murrelets, Brachyramphus brevirostris (Vigors) in Alaska
Authors: Hoberg Eric P.
Published: December 2009

Alcataenia campylacantha (Krabbe, 1869) is redescribed and reported for the first time from pigeon guillemots, Cepphus columba Pallas, in Alaska. Specimens of this cestode were also found in black guillemots, Cepphus grylle (Linnaeus) at Point Barrow, Alaska. There were no substantial differences in morphological characters between populations of this cestode from the North Atlantic and North Pacific basins. Additionally, Alcataenia sp. indet. is reported, with a partial description, from Kittlitz's murrelets, Brachyramphus brevirostris (Vigors), in Alaska. This constitutes the first record of dilepidid cestodes from birds of the genus Brachyramphus Brandt.
Holboell's redpolls: Do they exist?
Authors: Troy Declan M.
Published: December 2009

Holboell's redpoll (Carduelis flammea holboellii) is purported to differ from the common redpoll (C. f. flammea) by being larger, especially in having a larger bill. The distinctiveness of these two taxa was investigated by comparing skeletal dimensions of five samples collected during the breeding season; two from the range of holboellii, three from the range of nominate flammea. Scores along the first principal component, generated from the analysis of 19 skeletal measurements, were used as a measure of overall size. No difference in size of redpolls was found among the samples. Gonys length was used as a measure of bill size. This measure exhibited more interlocality variability than did overall size but could not be used to support the distinctiveness of the two taxa. Male redpolls from the holboellii sample had the largest bills; however, bills from the other location were intermediate in length. Females from both holboellii locations had intermediate length bills. An attempt to identify any measurements that could be used to segregate the two taxa was made using discriminant function analysis. No useful function could be generated. I conclude that recognition of holboellii as a taxon distinct from flammea is unwarranted.
Hysterothylacium analarum n. sp. (Nematoda: Anisakidae) from pumpkinseed, Lepomis gibbosus (Linnaeus), in southern Ontario
Authors: Rye Leslie A. , Baker Michael R.
Published: December 2009

Hysterothylacium analarum n. sp. is described from Lepomis gibbosus (Linnaeus) in Lake St. Nora and Dawson Pond, Ontario (45°09′ N, 78°50′ W). It is distinguished from Hysterothylacium brachyurum Ward &Magath, 1917, the species it most closely resembles by the absence of lateral alae, more numerous spines on the distal extremity of the tail, and relatively more prominent cephalic interlabia. A review of reports of Hysterothylacium spp. from North American freshwater fishes indicates that species have been confused in the literature.
An electrophoretic study of the phylogenetic relationships among four species of sticklebacks (Pisces: Gasterosteidae)
Authors: Hudon Jocelyn , Guderley Helga
Published: December 2009

The genetic relationships between four species of sticklebacks, Gasterosteus aculeatus Linneaus form trachurus, Gasterosteus wheatlandi Putnam, Pungitius pungitius (Linneaus), and Apeltes quadracus (Mitchill) were estimated by a locus-by-locus analysis of interspecific allozyme variation as well as by a band-counting analysis of soluble proteins in muscle. The locus-by-locus data was analysed both by a qualitative cladistic analysis and by a quantitative phenetic analysis. Both the locus-by-locus analysis and the band-counting analysis generated phylogenies which concord with the previously established relationships among these species. Our analyses indicate that these species have diverged considerably with a genetic identity of only 0.37 between the two congeneric species.
Kin selection and adult female Richardson's ground squirrels: a test
Authors: Davis Lloyd S.
Published: December 2009

A population of adult female Richardson's ground squirrels (Spermophilus richardsonii) was experimentally manipulated so that on one half of the study area each of the 9 females had 2 or 3 closely related females (mother, daughter, or littermate sister) as neighbours (the "kin cluster group," KC), while the 10 females on the other half of the area did not have closely related females as contiguous neighbours (the "no kin cluster group," NKC). In the previous year, breeding success and behaviour of females on both halves of the study area were similar. Following the manipulation, KC females spent a greater proportion of their aboveground time feeding, were less vigilant, shared a greater proportion of their core area with their nearest neighbour, were less likely to be involved in interactions that led to chasing and fleeing, and had a much better breeding success compared with females in the NKC group. These results provide a preliminary demonstration that the association of adult female kin to Richardson's ground squirrels can be advantageous, and as such, the observed behavioural asymmetries based upon kinship could be maintained by kin selection.
Phototaxis of adult brine shrimp, Artemia salina
Authors: Bradley David J. , Forward Jr. Richard B.
Published: December 2009

Using phototaxis as a behavioral measure of light perception, spectral and intensity sensitivity were determined for adult brine shrimp, Artemia salina. Spectral sensitivity was characterized by a well-defined maximum at 520 nm light, with perhaps a smaller maximum at 400 nm light. Dark-adapted animals showed a strong negative phototaxis at high intensities between 5.0 × 1012 quanta∙m−2∙s−1 and 3.6 × 1016 quanta∙m−2∙s−1 at 520 nm light. Positive phototaxis was greatest at the low intensity of 2.8 × 1012 quanta∙m−2∙s−1. Threshold sensitivity for both positive and negative phototaxis was approximately 2 × 1012 quanta∙m−2∙s−1.
Cycle de developpement, croissance et production de Sphaerium striatinum (Bivalvia : Pisidiidae) dans le Saint-Laurent (Québec)
Authors: Vincent B. , Lafontaine N.
Published: December 2009

The life cycle of a population of Sphaerium striatinum in the St. Lawrence River (Québec) was studied over a 13-month period. This species has a life-span of 2–3 years and is iteroparous; individuals start producing young at the age of 1 year. Growth in length reached a maximum of 0.010 mm/day between the ages of 0 and 8 months, while the maximum increase in weight occurred during the 2nd year, representing 46% of the total growth. The mean population density was 737 individuals/m2 for the months of May to November 1979; the mean biomass values were 20.6 and 2.1 g/m2, respectively, for total dry weight and dry weight minus shells. Young of the year and yearlings combined represent 96% of the total production, which was calculated to be 14.9 g (total dry weight)/m2. The production to biomass ratio (P/B) decreased with the age of a generation and was 0.72 for the entire population. A comparison of our results with those in the literature indicates that individual growth rates are slower in the St. Lawrence population and that larvae, adults, and reproductive individuals are smaller in size; however, the population's life expectancy is greater. This longer life-span and smaller individual size, along with a delayed sexual maturity, can be explained by the environmental temperature regime.[Journal translation]
Growth curve analysis of birds: the Richards model and procedural problems
Authors: Zach Reto , Liner Yakov , Rigby Gerald L. , Mayoh Keith R.
Published: December 2009

Four sigmoid growth curve models for birds were compared using the daily body masses and primary-feather lengths of 35 nestling tree swallows (Tachycineta bicolor). The Richards model was superior to the von Bertalanffy, Gompertz, and logistic models for body mass, but not for primary-feather length. The latter models have fixed growth forms and are special cases of the flexible Richards model. Owing to parameter correlations, the Richards model was very sensitive to the starting parameter values for the numerical computer fitting routines. The lack of data leading up to the asymptote made it difficult to calculate good starting values for primary-feather length. None of the models tested was completely satisfactory for primary-feather length, as indicated by nonrandomly distributed residuals over time. The log transformation was appropriate for body mass. It homogenized the residual variances and increased the explained percentage of variation. The explained percentage of variation was a useful selection criterion for the best-fitting model, especially since it was directly related to randomness in the distribution of the residuals and homogeneity of residual variances. However, even percentages of variation exceeding 99.5%, did not necessarily indicate an excellent fit. The Richards model did not yield more model parameters for growth curve analysis, because the shape parameter and the growth rate constant were almost perfectly correlated.
Données nouvelles sur la structure et la minéralisation des écailles d'Anguilla anguilla (Osteichthyes, Anguillidae)
Authors: Zylberberg Louise , Meunier François J. , Escaig Françoise , Halpern Sylvain
Published: December 2009

The structure of the scales in Anguilla anguilla was studied by light and electron microscopy and the mineral phase was analyzed by histophysical techniques. Although the scales of the eel are small in size and have a peculiar superficial ornamentation, which consists of a web of mineralized plates, they are composed of the three characteristic layers of the typical elasmoid scale. The discontinuous, superficial outer limiting layer is highly mineralized; in this layer, acid mucosubstances are abundant but collagen fibres are absent. Mineralization in the external layer is not oriented by the network of the thin collagen fibrils. In the basal plate, mineralization is oriented by the thick collagen fibres packed in bundles. The bundles are oriented from the basal part to the surface of the scale but they are not organized in the laminated structure characteristic of most other teleost scales. The mineral phase of the eel is typical of a teleost fish. The peculiar features of the scale in the eel are interpreted here as a discrete example of the phyletical reduction of the dermal skeleton among Actinopterygii.
Female demands: some fitness implications in chickadee flocks
Authors: Orr Craig D. , Verbeek Nicolaas A. M.
Published: December 2009

Female black-capped chickadees (Parus atricapillus), besides searching for their own food, "demand" food from their mates in the spring for extra energy needed to produce and incubate eggs. This behaviour signals their readiness to copulate and it is followed by increased levels of male – male aggression, probably to prevent cuckoldry. Increased aggression owing to limited nest site availability may also be locally important. Subordinate pairs disperse and many presumably die. The extra food allows females with nest sites to breed earlier than if they fed themselves exclusively, and producing early broods appears to be a better fitness strategy than having larger clutches or additional broods. Juveniles from early broods survive better and attain higher social ranks in flock hierarchies, and dominant pairs have the highest overwinter survival rates as well as a better chance than subordinate pairs of obtaining a territory in the spring.
The reproductive cycle in winter flounder, Pseudopleuronectes americanus (Walbaum)
Authors: Burton M. P. , Idler D. R.
Published: December 2009

The reproductive status of winter flounder was analyzed in individuals collected at regular intervals throughout the year. Although spawning occurred in May–June, sperm could be activated in January, and male gonadosomatic indices in November were approximately twice those recorded immediately before spawning. Oocyte recruitment occurs close to spawning, and oocyte changes are compatible with a 3-year cycle. Vitellogenesis of the oldest year class of oocytes is initiated during the summer feeding season and maintained over the nonfeeding winter season. Some females after spawning do not enter the vitellogenic stage but overwinter with two year classes of immature oocytes. This nonreproductive phase in females in related to condition rather than age. Nonreproductive males also occur in the population sampled and in the fall there was a trend towards an increased number with advancing age. The protracted gametogenesis in winter flounder demonstrates the need for caution when assessing spawning condition and reproductive capacity of some fish stocks.
Life cycles, microdistribution, and food of two species of caddisflies (Trichoptera) in a wooded stream in Southern Ontario
Authors: Singh M. P. , Smith S. M. , Harrison A. D.
Published: December 2009

Accounts of life histories, microdistributions, and food of Rhyacophila minor and Wormaldia moesta (Trichoptera) inhabiting a headwater stream in Ontario are presented. Rhyacophila minor is a caseless predator and W. moesta is a net-spinning filter feeder. First-instar larvae of W. moesta inhabited the stream longer than those of R. minor. The other instars of W. moesta grew rapidly and those of R. minor grew slowly. Pupae of both species showed a tendency to aggregate on bare stones. Both species were univoltine and water temperature is hypothesized to be an important factor regulating growth and voltinism. Wormaldia moesta was patchily and R. minor more uniformaly distributed in the stream. Rhyacophila minor preferred moss-covered stones whereas W. moesta preferred bare stones; however, these preferences changed with season and larval instar and are attributed partially to changing physical conditions in the stream. Although R. minor is primarily carnivorous, the early instars fed extensively on plant material; this behavior is attributed partly to their inability to prey and partly to the abundance of plant-food resources. Wormaldia moesta fed primarily on detritus; it may supplement the diet by grazing on diatoms when the seston is in low supply.
Benthoxynus spiculifer n. gen., n. sp. (Copepoda: Siphonostomatoida) associated with Vestimentifera (Pogonophora) at a deep-water geothermal vent off the coast of Washington
Authors: Humes Arthur G.
Published: December 2009

Benthoxynus spiculifer n. gen., n. sp., associated with Vestimentifera, is distinguished from Dirivultus and Ceuthoecetes, the other two genera of the Dirivultidae, as follows: in the female by the 18-segmented first antenna with an aesthete on segment 17, by 3 terminal setae on the second antenna, and by the absence of an inner seta on the first segment of the endopod of leg 3; in the male by the 11-segmented first antenna with an aesthete on segment 10 and a large process with serrate tip on segment 6, and leg 5 reduced to 2 setae, without a free segment.
Pharyngodonids (Oxyuroidea; Nematoda) of Agama adramitana in Saudi Arabia with notes on Parapharyngodon
Authors: Adamson Martin L. , Nasher Abdul Karim
Published: December 2009

Two species of pharyngodonid (Oxyuroidea; Nematoda) parasites were collected from Agama adramitana in Saudi Arabia: Thelandros popovi Markov and Bogdanov, 1963 is redescribed and Parapharyngodon adramitana n. sp. is described for the first time. The new species resembles P. almoriensis and P. kasauli from Agama tuberculata and Uromastix hardwickii, respectively; the genital cone is relatively well-developed, broad lateral alae terminate abruptly 50 to 90 μm anterior to the anus in males, and the caudal extremity of females is abruptly truncate and bears a short spinelike caudal appendage. In P. adramitana the genital cone is less developed and the caudal appendage of the female is more robust than in P. almoriensis and P. kasauli. Parapharyngodon echinatus and P. micipsae are briefly redescribed and differentiated on the basis of material from Tarentola mauritanica (Gekkonidae) from France. Parapharyngodon acanthura (Linstow, 1904) is considered a valid name; it is not a synonym of P. micipsae as Seurat (1917) suggested. In addition, phylogenetic implications of larval morphology and the systematic position of Parapharyngodon are discussed.
A world review of the pomi species group in the genus Typhlodromus Scheuten (Acari: Phytoseiidae)
Authors: Chant D. A. , Yoshida-Shaul E.
Published: December 2009

A revised pomi species group is proposed, with Typhlodromus pomi (Parrott, Hodgkiss &Shoene) as the exemplar. The group is characterized by the presence of seta R1 on the opisthoscutum of adult females and it is composed of 16 species, including 2 new species: Typhlodromus bromus (Denmark) comb, nov., T. eiko E1 Banhawy, T. flumenis Chant, T. herbertae Nesbitt, T. juniperi De Leon, T. juniperoides (De Leon) comb. nov., T. lindquisti n. sp., T. mexicanus (Muma) comb. nov., T. negundinis (Denmark) comb, nov., T. nelsoni Chant, T. pomi (Parrott, Hodgkiss &Shoene), T. pomoides Schuster and Pritchard, T. tuttlei (Denmark) comb, nov., T. validus Chant, T. paraflumenis n. sp., and T. pedoni Zaher and Shehata. Typhlodromus pomoides is reinstated as separate from T. herbertae, and Galendromus deleoni Tuttle and Muma is designated as a junior synonym of T. juniperi. Various generic concepts relating to the species in the pomi group are reviewed, the group is described, and a key to adult females and descriptions of each species are provided.
A world review of four species groups in the genus Typhlodromus Scheuten (Acari: Phytoseiidae): brevicollis, luculentis, carinulatus, and pinnatus
Authors: Chant D. A. , Yoshida-Shaul E.
Published: December 2009

Four new species groups in the genus Typhlodromus Scheuten are proposed. Two of the groups, brevicollis and luculentis, are characterized by the presence of seta R1 on the opisthoscutum and the other two, carinulatus and pinnatus, by the presence of seta S2 and the absence of R1. The brevicollis and carinulatus groups are monotypic. The luculentis group consists of T. serratus (Tuttle and Muma) comb, nov., T. luculentis De Leon, and T. denmarki nom. nov. (formerly Galendromus (Leonodromus) bakeri Denmark). The pinnatus group includes T. pinnatus (Schuster and Pritchard) comb. nov. and T. reticulus (Tuttle and Muma) comb. nov. The male of T. brevicollis (Gonzalez &Schuster) comb. nov. is described for the first time. The generic concepts of previous authors related to the four species groups are outlined briefly. The groups and species are described and keys to the adult females are provided.
A world review of the australicus species group in the genus Typhlodromus Scheuten (Acari: Phytoseiidae)
Authors: Chant D. A. , Yoshida-Shaul E.
Published: December 2009

The revised australicus species group contains two species: Typhlodromus australicus (Womersley), the exemplar of the group, and T. angophorae Schicha. Both species have been recorded only from Australia. Generic concepts relating to the group are reviewed. The group is described and a key to the adult females and descriptions of each species are provided.
Helminth community in the belted kingfisher, Ceryle alcyon (L.), in southern Québec
Authors: Scott Marilyn E.
Published: December 2009

A survey of helminth parasites of 40 belted kingfishers obtained from southern Québec during 1982 and 1983 yielded 11 species of which Uvulifer ambloplitis and Crassiphiala bulboglossa were the most common. The birds had an average of 2.8 species each and 6 parasite species were found to be aggregated in the host population. Three parasites recovered were previously unrecorded from this host: Clinostomum complanatum, Capillaria sp., and Strongyloides sp. Comparison of parasite burdens between male and female hosts and between years revealed no significant differences.
STABILITY ANALYSIS OF THIN SHELL WORMHOLES SUPPORTED BY THE MODIFIED CHAPLYGIN GAS
Authors: BANDYOPADHYAY TANWI , BAVEJA ANUSUA , CHAKRABORTY SUBENOY
Published: December 2009

In this work, the stability of static solutions of spherical thin shell wormholes is analyzed when a slight perturbation (which preserves the basic symmetry) is applied to them. The modified Chaplygin gas (with α = 1 in the equation of state) has been chosen as a candidate for exotic matter needed around the throat. Different cases for such thin shell wormhole construction have been studied, viz. wormholes constructed from Schwarzschild, Schwarzschild–de Sitter, Schwarzschild–anti-de Sitter and Reissner–Nordström metrics. Depending upon the values of the parameters and some restrictions obeyed by them, static stable solutions are seen to exist in some cases.
1E 1207.4–5209-LIKE RADIO-QUIET NEUTRON STARS
Authors: ANKAY ARZU M. , HUDAVERDI MURAT , ERCAN E. NIHAL , ANKAY ASKIN
Published: December 2009

In this work, the results of X-ray spectral analysis of radio-quiet X-ray pulsar 1E 1207.4–5209 and RX J0002+6246, RX J0822–4300, CXOU J185238.6+00402, which have the same observational characteristics as 1E 1207.4–5209, are represented based on XMM-Newton satellite observations. These four neutron stars with common physical properties may have similar physical evolution. It is shown that all of them have Pure blackbody spectra (two-blackbody fits in three cases) without a power law component. No pulsar wind nebula has been observed around any one of them, which strongly shows that they have low rotational energy loss despite their small ages. All of these neutron stars are physically connected to shell-type supernova remnants which are younger than (1–2) × 104 yr . None of these sources has been detected to emit at radiofrequencies. These common spectral properties (and possibly common timing characteristics) of these neutron stars are examined. Their possible evolution is discussed based on a model represented in Ref. 1. As a result, it is quite possible that these objects form a new class of neutron stars quite different than the other types.
AGEGRAPHIC CHAPLYGIN GAS MODEL OF DARK ENERGY
Authors: SHEYKHI A.
Published: December 2009

We establish a connection between the agegraphic models of dark energy and Chaplygin gas energy density in a nonflat universe. We reconstruct the potential of the agegraphic scalar field as well as the dynamics of the scalar field according to the evolution of the agegraphic dark energy. We also extend our study to the interacting agegraphic generalized Chaplygin gas dark energy model.
Timing of dextral strike-slip processes and basement exhumation in the Elbe Zone (Saxo-Thuringian Zone): the final pulse of the Variscan Orogeny in the Bohemian Massif constrained by LA-SF-ICP-MS U-Pb zircon data
Authors: Hofmann M. , Linnemann U. , Gerdes A. , Ullrich B. , Schauer M.
Published: December 2009

The final pulse of the Variscan Orogeny in the northern Bohemian Massif (Saxo-Thuringian Zone) is related to the closure of the Rheic Ocean, which resulted in subduction-related D
1
-deformation followed by dextral strike-slip activity (D
2
-deformation, the Elbe Zone). Taken together, these deformation events reflect the amalgamation of Pangaea in central Europe. Lateral extrusion of high-grade metamorphosed rocks from an allochthonous domain (Saxonian Granulitgebirge) and the top–NW-directed transport of these domains (Erzgebirge nappe complex, Saxonian Granulitgebirge) are responsible for these dextral strike-slip movements. Geochronological data presented herein, together with published data, allow the timing of the final pulse of the Variscan Orogeny and related plutonic, volcano-sedimentary and tectonic processes. Marine sedimentation lasted at least until the Tournaisian (357 Ma). Onset of Variscan strike-slip along the Elbe Zone is assumed to be coeval with the beginning of the top–NW-directed lateral extrusion of the Saxonian Granulitgebirge at 342 Ma (D
2
-deformation). The sigmoidal shape of the Meissen Massif indicates that strike-slip activity was coexistent with intrusion of the pluton at
c
. 334 Ma into the schist belt of the Elbe Zone. In contrast, the intrusion of the Markersbach Granite provides a minimum age of
c
. 327 Ma for the termination of D
2
strike-slip activity, because this undeformed pluton cross-cuts all strike-slip related tectonic structures. Geochronological data of an ash bed from the Permo-Carboniferous Döhlen Basin show clearly that post-orogenic sedimentation of Variscan molasse in that area was already active at 305 Ma. This pull-apart basin is a local example of regional Permo-Carboniferous extension within Pangaea. The uplift and denudation of the Variscan basement in the Saxo-Thuringian Zone occurred between
c
. 327–305 Ma.
Extrusion of high-pressure Cache Creek rocks into the Triassic Stikinia–Quesnellia arc of the Canadian Cordillera: implications for terrane analysis of ancient orogens and palaeogeography
Authors: Dostal Jaroslav , Keppie J. Duncan , Ferri Filippo
Published: December 2009

The volcanic Triassic Takla Group constitutes a significant part of Stikinia and Quesnellia, two major terranes of the Canadian Cordillera that are separated by high-pressure rocks of the Cache Creek terrane containing Asian fauna. The geochemical and isotopic characteristics of the Takla Group in Quesnellia and Stikinia are similar, that is, tholeiitic basalts characterized by low abundances of strongly incompatible trace elements, negative Nb anomalies, +6 to +8 ε
Nd
values, the low initial Sr isotopic ratios, and relatively horizontal chondrite-normalized heavy REE patterns, all features typical of relatively primitive arcs with little or no continental crust involvement. These similarities have led to several geometric models: post-Middle Jurassic duplication by strike-slip faulting, and oroclinal or synformal folding. However, they are all inconsistent with either palaeomagnetic or faunal data, and the presence of a Triassic overstep sequence, which indicates amalgamation
c
. 50 ma before emplacement of the youngest oceanic rocks of the Cache Creek terrane. An alternative model is proposed: oblique eastward subduction of the Cache Creek accretionary prism and fore-arc producing high-pressure metamorphism, followed by extrusion into the arc and exhumation by the Middle Jurassic. This model implies that these high-pressure rocks, rather than marking an oceanic suture between disparate arc terranes, support a para-autochthonous origin.
The evolution of the Uralian orogen
Authors: Puchkov Victor N.
Published: December 2009

The Uralian orogen is located along the western flank of a huge (>4000 km long) intracontinental Uralo-Mongolian mobile belt. The orogen developed mainly between the Late Devonian and the Late Permian, with a brief resumption of orogenic activity in the Lower Jurassic and Pliocene–Quaternary time. Although its evolution is commonly related to the Variscides of Western Europe, its very distinctive features argue against a simple geodynamic connection. To a first order, the evolution of Uralian orogen shows similarities with the ‘Wilson cycle’, beginning with epi-continental rifting (Late Cambrian–Lower Ordovician) followed by passive margin (since Middle Ordovician) development, onset of subduction and arc-related magmatism (Late Ordovician) followed by arc–continent collision (Late Devonian in the south and Early Carboniferous in the north) and continent–continent collision (beginning in the mid-Carboniferous). In detail, however, the Uralides preserve a number of rare features. Oceanic (Ordovician to Lower Devonian) and island–arc (Ordovician to Lower Carboniferous) complexes are particularly well preserved as is the foreland belt in the Southern Urals, which exhibits very limited shortening of deformed Mesoproterozoic to Permian sediments. Geophysical studies indicate the presence of ‘cold’, isostatically equilibrated root. Other characteristic features include a Silurian platinum-rich belt of subduction-related layered plutons, a simultaneous development of orogenic and rift-related magmatism, a succession of collisions that are both diachronous and oblique, and a single dominant stage of transpressive deformation after the Early Carboniferous. The end result is a pronounced bi-vergent structure. The Uralides are also characterized by Meso-Cenozoic post-orogenic stage and plume-related tectonics in Ordovician, Devonian and especially Triassic time. The evolution of the Uralides is consistent with the development and destruction of a Palaeouralian ocean to form part of a giant Uralo-Mongolian orogen, which involved an interaction of cratonic Baltica and Siberia with a young and rheologically weak Kazakhstanian continent. The Uralides are characterized by protracted and recurrent orogenesis, interrupted in the Triassic by tectonothermal activity associated with the Uralo-Siberian superplume.
In the Virtual Extension
Authors: CACM Staff
Published: December 2009

Communications'
Virtual Extension brings more quality articles to ACM members. These articles are now available in the ACM Digital Library
.
Software engineering, smartphones and health systems, and security warnings
Authors: Linden Greg , Ortega Ruben , Hong Jason
Published: December 2009

The
Communications
Web site, http://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish excerpts from selected posts.

twitter

Follow us on Twitter at http://twitter.com/blogCACM

Greg Linden writes about frequent software deployments, Ruben Ortega reports on smartphones and health systems research, and Jason Hong discusses designing effective security warnings.
New search challenges and opportunities
Authors: Savage Neil
Published: December 2009

If search engines can extract more meaning from text and better understand what people are looking for, the Web's resources could be accessed more effectively.
Amir Pnueli
Authors: Hoffmann Leah
Published: December 2009

Remembering a legacy of practical and theoretical innovation.
Triple-parity RAID and beyond
Authors: Leventhal Adam
Published: December 2009

As hard-drive capacities continue to outpace their throughput, the time has come for a new level of RAID.
MapReduce and parallel DBMSs
Authors: Stonebraker Michael , Abadi Daniel , DeWitt David J. , Madden Sam , Paulson Erik , Pavlo Andrew , Rasin Alexander
Published: December 2009

MapReduce complements DBMSs since databases are not designed for extract-transform-load tasks, a MapReduce specialty.
The future of digital imaging
Authors: Hur Wonchang , Kim Dongsoo
Published: December 2009

Introduction

Traditionally, radiology is a support department that provides imaging services to other hospital departments. In this conventional framework, the primary concerns of a radiology department were how to enhance the productivity of imaging workflows. Most efforts have been made principally to remove unnecessary communications and thereby reduce report turnaround time. The introduction of information systems such as PACS (Picture Archiving and Communication System) and RIS (Radiology Information System) are typical examples of such efforts.

Over the past decades, imaging technologies have advanced remarkably, and have led to the proliferation of digital imaging services. Many imaging solution providers are offering various off-the-shelf software programs at more affordable prices. Those programs are equipped with sophisticated imaging functions, and can easily manipulate the large amounts of image data generated from high-performance imaging modalities. As a result, the number of imaging centers providing diagnostic imaging services has grown considerably, and competition between them has intensified.

In this evolving environment, enhanced productivity of imaging workflow is not sufficient to guarantee a competitive and successful imaging business. Rather, more diversified perspectives of customer satisfaction must be considered, and technological advancements must be leveraged for the quality and the competitiveness as well as the productivity of imaging services.

In this article, we envision digital imaging services in radiology, with emphasis on the recent advancements in digital imaging technology and its future direction. Specifically, we focus on the four major issues prevailing in current imaging business practices: specialization, flexibility, reliability, and usability. We investigate the kinds of technologies pertaining to each issue, as well as the ways in which such technologies have enabled the invention of innovative services in diagnostic imaging practice.
Mobile Web 2.0 with multi-display buttons
Authors: Kim Seongwoon , Lee Inseong , Lee Kiho , Jung Seungki , Park Joonah , Kim Yeun Bae , Kim Sang Ryong , Kim Jinwoo
Published: December 2009

Introduction

User-Generated Content (UGC) IS A BURGEONING social phenomenon being watched in today's world with keen interest. UGC is an online new-media content created by users rather than by conventional media such as broadcasters. A typical example would be Flickr, an online photo-sharing site with 37 million images, to which its 1.2 million members add up to 200,000 images daily. UGC is shifting the paradigm of Internet use away from the one-way propagation of media content by companies towards the creation and sharing of media content by and among ordinary users.

The mobile phone is an especially important means of promoting user generation and exchange of media content. Many mobile phones now have built-in digital cameras and inherent network connectivity. These features have greatly facilitated the creation and sharing of media content. For instance, users can immediately upload photos on Flickr with their mobile phones as well as access Flickr and browse other people's media content.

However, the constraints of a typical mobile phone---its small display and limited number of buttons---make use of mobile UGC services challenging. Only a few studies have investigated hardware or software alternatives to address these problems. This article presents a new user interface (UI) for mobile phones, one that makes use of UGC services easier and more efficient.

The new interface has two key characteristics: one pertaining to content structure, and another to content visualization. More specifically, the new UI employs two major mobile Web 2.0 technologies, the tag and the tag cloud, and multi-display buttons increase the display size and flexibility of individual buttons. The interface is dedicated specifically towards supporting exploratory browsing within mobile UGC services, because users of such services are likely to focus on exploratory browsing and serendipitous discovery and be more inclined toward entertainment rather than utility. Here, we describe the new interface and investigate whether it aids in enhancing exploratory browsing within mobile UGC services.
Think big for reuse
Authors: Witman Paul D. , Ryan Terry
Published: December 2009

Introduction

Many organizations are successful with software reuse at fine to medium granularities -- ranging from objects, subroutines, and components through software product lines. However, relatively little has been published on very large-grained reuse. One example of this type of large-grained reuse might be that of an entire Internet banking system (applications and infrastructure) reused in business units all over the world. In contrast, "large scale" software reuse in current research generally refers to systems that reuse a large number of smaller components, or that perhaps reuse subsystems. In this article, we explore a case of an organization with an internal development group that has been very successful with large-grained software reuse.

BigFinancial, and the BigFinancial Technology Center (BTC) in particular, have created a number of software systems that have been reused in multiple businesses and in multiple countries. BigFinancial and BTC thus provided a rich source of data for case studies to look at the characteristics of those projects and why they have been successful, as well as to look at projects that have been less successful and to understand what has caused those results and what might be done differently to prevent issues in the future. The research is focused on technology, process, and organizational elements of the development process, rather than on specific product features and functions.

Supporting reuse at a large-grained level may help to alleviate some of the issues that occur in more traditional reuse programs, which tend to be finer-grained. In particular, because BigFinancial was trying to gain commonality in business processes and operating models, reuse of large-grained components was more closely aligned with its business goals. This same effect may well not have happened with finer-grained reuse, due to the continued ability of business units to more readily pick and choose components for reuse.

BTC is a technology development unit of BigFinancial, with operations in both the eastern and western US. Approximately 500 people are employed by BTC, reporting ultimately through a single line manager responsible to the Global Retail Business unit head of BigFinancial. BTC is organized to deliver both products and infrastructure components to BigFinancial, and its product line has through the years included consumer Internet banking services, teller systems, ATM software, and network management tools. BigFinancial has its U.S. operations headquartered in the eastern U.S., and employs more than 8,000 technologists worldwide.

In cooperation with BTC, we selected three cases for further study from a pool of about 25. These cases were the Java Banking Toolkit (JBT) and its related application systems, the Worldwide Single Signon (WSSO) subsystem, and the BigFinancial Message Switch (BMS).
ACM and India
Authors: Greengard Samuel
Published: December 2009

ACM India aims to become a key information exchange and networking organization for the nation's professional and student communities.
Information access in a multilingual world
Authors: Gey Fredric , Karlgren Jussi , Kando Noriko
Published: December 2009

Multilingual Information Access (MLIA) is at a turning point wherein substantial real-world applications are being introduced after fifteen years of research into cross-language information retrieval, question answering, statistical machine translation and named entity recognition. Previous workshops on this topic have focused on research and smallscale applications. The focus of this workshop was on technology transfer from research to applications and on what future research needs to be done which facilitates MLIA in an increasingly connected multilingual world.