bluuebunny/crossref_metadata_2025 huggingface dataset:
Age, growth, and reproductive patterns of the Pacific white-sided dolphin (Lagenorhynchus obliquidens) taken in high seas drift nets in the central North Pacific Ocean
Authors: Ferrero Richard C. , Walker William A.
Published: May 2008

Biological data were collected from 341 Pacific white-sided dolphins (Lagenorhynchus obliquidens; 171 males and 170 females) taken in high seas drift nets in the central North Pacific Ocean in June–September of 1990 and 1991. Age was determined for 149 dolphins (73 males and 76 females) by counting dentinal growth layer groups and measuring postnatal dentine thickness. Reproductive status was determined for 76 females and 71 males. Ten females were sexually mature (3 pregnant and 7 lactating), as were 11 males. The estimated average length at birth was 91.8 cm (SE = 0.4787 cm; n = 4). The estimated gestation period was 11 – 12 months. The sex ratio was not significantly different from 1:1. The youngest sexually mature male was 10 years of age and the oldest sexually immature male 11 years. The youngest sexually mature female was 8.3 years of age and the oldest sexually immature female 11 years. The average length at sexual maturation was 173.7 cm (SE = 0.8953 cm) for males and 177.5 cm (SE = 1.5 cm) for females. Males and females reached an estimated asymptotic length of 184 and 177 cm, respectively. Estimates of early postnatal growth rates were complicated by poor growth model fit; however, both sexes appeared to grow about 4.5 cm/month during the first half year. A calving period preceded sampling during late winter and spring.
Dive durations in pinnipeds and seabirds
Authors: Boyd I. L. , Croxall J. P.
Published: May 2008

Many endothermic divers regularly exceed the theoretical limit to the duration of aerobic dives, suggesting that assumptions about either the oxygen storage capacity of tissues or the metabolic rate of divers are wrong. This study examined the frequency distributions of dive durations in five species of endothermic divers from the island of South Georgia, South Atlantic. The theoretical aerobic dive time (TADT), calculated from average field metabolic rates, was exceeded regularly by all species except the Antarctic fur seal (<6% of dives). In contrast, the gentoo penguin exceeded its TADT in 69% of dives and the elephant seal in 91%. The frequency distributions of dive durations were bimodal, most especially in the penguins, with one mode below the TADT and another above the TADT, suggesting two different physiological strategies for diving. Interspecific allometric comparisons of dive durations in endothermic divers showed that, in general, relative dive durations in seabirds were greater than in pinnipeds. Dive durations in pinnipeds scaled approximately to field metabolic rate, whereas in seabirds they scaled most closely to flipper surface area, suggesting that they may be partly limited by the rate and degree of conduction of heat to the water.
Oribatida (Acari) associated with three species ofSphagnumat Spruce Hole Bog, New Hampshire, U.S.A.
Authors: Donaldson Gay M.
Published: May 2008

In a topogenous, pond-border, moat bog in New Hampshire, 19 220 adult oribatid mites from 47 species were collected from 3 species of Sphagnum in the early spring, early summer, and late summer. The Sphagnum species were distributed along a gradient of increasing height above the water surface and decreasing shade in the order S. cuspidatum, S. recurvum, and S. magellanicum. Oribatid mite species diversity increased along this gradient in the same order. Four species of the genus Limnozetes were associated with Sphagnum spp. in this bog; they differed in habitat preference among the Sphagnum species. New records for New Hampshire were established for 19 oribatid mite species.
The influence of age on the acquirement of a perch in the black-headed gull (Larus ridibundus L.): new data and a review of the literature
Authors: Nuyts Erik , Bult Abel , Zee Eddy A. Van der
Published: May 2008

In captive black-headed gulls (Larus ridibundus L.), immature birds often win encounters with adults. Under natural conditions, immatures win more fights as challenger, but lose more as challengee if no food is involved. Immatures win more fights for food, both as challenger and as challengee. From the results presented here, and after reviewing the literature on aggressive interactions in the black-headed gull, it is concluded that immatures start and win more fights than adults. They are also more daring in interactions with other species. Some of these differences are probably a result of different foraging strategies of immatures and adults. However, fighting itself may have a higher value for immatures than for adults, perhaps as part of a learning strategy.
Jet-propelled swimming in scallops: swimming mechanics and ontogenic scaling
Authors: Cheng J. Y. , DeMont M. E.
Published: May 2008

Scallop locomotion was investigated on the basis of an analysis of fluid forces acting on the body and the balance of the forces during swimming. A hydrodynamic model for unsteady jet propulsion was developed in which propulsion performance is characterized by three nondimensional parameters: the storage/discharge volume ratio, reduced clapping frequency, and reduced discharge frequency. Pulsed jet propulsion is designed to achieve high thrust, although not necessarily with low hydrodynamic propulsive efficiency, as was previously widely considered. Swimming in scallops is realized by orientating the body at a certain angle of attack and maintaining a minimum swimming speed to prevent sinking. The working frequency of the locomotor system is determined and adjusted by the swimming strategy (angle of attack, swimming speed, and trajectory angle). For Placopecten magellanicus, the optimum angle of attack is about 6° – 12°, at which swimming requires the lowest energy input (lowest frequency) and hydrodynamic behaviour is ideal (without severe separation and stall). To maintain level swimming, P. magellanicus, during almost all their life, must swim at 5 – 7 body lengths per second if postured at a 6° – 12° angle of attack. The estimated Froude efficiency decreases during growth from about 0.5 to 0.3 for level swimming and from about 0.4 to 0.2 for climbing at an angle of 25°. It is suggested that the heavy body and inferior hydrodynamic characteristics (low aspect ratio and imperfect planform shape) have prevented scallops from becoming good swimmers. These problems are enhanced as the animals grow.
Preweaning mortality of Weddell seal pups
Authors: Schreer Jason F. , Hastings Kelly K. , Testa J. Ward
Published: May 2008

We examined mortality prior to weaning of Weddell seal pups (Leptonychotes weddellii), using resighting data collected from 1984 to 1993 on the annual ice of McMurdo Sound, Antarctica. Mortality rates were estimated using counts of dead pups found on the surface and mark–recapture techniques. The standard Jolly–Seber model for open populations fit the recapture data best and corresponded well to the known biology of these animals. Yearly mortality rates estimated by mark–recapture techniques ranged from 6 to 22%, with a mean across years of 13%. These values are twice as high as those previously reported for Weddell seals and those calculated from counts of dead pups in this study. This suggests that there is significant unseen mortality due either to undiscovered fatalities on the ice surface or to significant mortality occurring in the water.
Use of woody plants in construction of beaver dams in northern Ontario
Authors: Barnes D. M. , Mallik A. U.
Published: May 2008

Newly formed beaver dams were studied in the Chapleau Crown Game Preserve of northern Ontario to determine if beavers (Castor canadensis Kuhl) showed any preference in their choice of woody plants in building the dams. Application of Neu's utilization–availability technique showed that beavers exhibited a high preference for alder (Alnus spp., plant species not commonly used as food) stems with diameters of 1.5–3.5 cm and a lesser preference for food-tree stems with diameters of >4.5 cm. We maintain that beavers used large food-tree stems only because they became more accessible after dam construction. Since the alder stems available close to the water's edge accounted for most of the stems of the preferred size, 1.5–3.5 cm, we postulated that selection of woody stems by beavers for construction purposes was based on size rather than on species.
Geographic distribution of mitochondrial DNA haplotypes in grey seals (Halichoerus grypus)
Authors: Boskovic Radmila , Kovacs Kit M. , Hammill M. O. , White B. N.
Published: May 2008

Mitochondrial DNA (mtDNA) variation in grey seals (Halichoerus grypus) was estimated by restriction fragment length polymorphism (RFLP) analysis of samples collected from four geographic locations: the Gulf of St. Lawrencn(n = 24), Sable Island, Nova Scotia (n = 20), Norway (n = 16), and the Baltic Sea (n = 20). In total, 18 haplotypes were identified. Nucleotide diversity was estimated to be 0.0039 for the Gulf of St. Lawrence, 0.0035 for Sable Island, 0.0079 for Norway, and 0.0059 for the Baltic Sea. There were no shared haplotypes between the western North Atlantic and eastern North Atlantic groups, and genetic distances between these populations (2.0–2.4%) suggest that they diverged approximately 1.0–1.2 million years ago. Nucleotide divergence between the Baltic Sea and the Norwegian populations was estimated to be 0.7%, suggesting that separation of these two groups took place much more recently, about 0.35 million years ago. The distribution of mtDNA haplotypes among Canadian grey seals suggests little or no geographic separation between animals breeding in the Gulf of St. Lawrence and those breeding on Sable Island. In addition to providing basic information on stock analysis the grey seal mtDNA RFLP analysis should be of value for further studies including polymerase chain reaction and direct sequence analyses.
The effect of weather conditions on harbour seal (Phoca vitulina) haulout behaviour in the Moray Firth, northeast Scotland
Authors: Grellier Kate , Thompson Paul M. , Corpe Heather M.
Published: May 2008

Abundance data from a 6-year study (1988–1993) of harbour seals (Phoca vitulina) were used to control for seasonal changes in haulout behaviour and assess the effect of temperature and other weather conditions on haulout numbers at a site in Scotland. A significant relationship between Julian day and haulout numbers was consistent between years. In some years, there was also a significant relationship between ambient temperature and haulout numbers, but examination of the residuals around the relationship between haulout numbers and Julian day revealed no evidence for a consistent effect of temperature, wind speed, or wind-chill adjusted temperatures. A weak negative relationship between haulout numbers and both precipitation and cloud cover did exist, but these variables explained little of the variation in seal numbers.
Relationship between a mutualist and a parasite of the laurel fig, Ficus microcarpa L.
Authors: Kobbi May , Edelin Claude , Michaloud Georges , Chaieb Mohamed
Published: May 2008

Since 1986, the sterile populations of the laurel fig, Ficus microcarpa L., in Tunisia have become fertile with the arrival of the species-specific pollinating wasp Parapristina verticillata. However, the invasion in 1992 by one of several species-specific parasitic wasps, Odontofroggatia galili, has changed the parameters of this mutualistic relationship. A fig sample collected at Sfax, Tunisia, was analysed, and randomization of the results showed a highly significant negative correlation between the numbers of wasps and parasites. Moreover, the presence of parasites decreases the fecundity of the figs. The consequences of the competition between O. galili and P. verticillata on this fig – fig pollinator mutualism are discussed.
Life cycles, morphological characteristics, and host specificity of Hepatozoon species infecting eastern garter snakes from Ontario
Authors: Smith Todd G. , Kopko Susan H. , Desser Sherwin S.
Published: May 2008

The life cycles of species of Hepatozoon that occur naturally in eastern garter snakes, Thamnophis sirtalis sirtalis, were studied in the mosquito Culex pipiens in various amphibians, including northern leopard frogs, bullfrogs, gray treefrogs, American toads, and blue-spotted salamanders, and in natricine snakes, including northern water snakes and northern brown snakes. Morphological features of the oocysts of two forms of Hepatozoon from various widely separated regions of Ontario differed with respect to the number of sporozoites per sporocyst and the diameter and shape of the oocyst. However, morphological and morphometric differences were not apparent in the cystic or merogonic stages in the vertebrate hosts. Cystic stages of these haemogregarines were found in the liver of all four species of anurans, but not in salamanders. These forms were transmitted experimentally to garter, water, and brown snakes, with gamonts appearing in erythrocytes 45 days after the snakes were fed infected anurans. A comparison of these forms of Hepatozoon with previously named species of ophidian haemogregarines from North America indicates that there are at least two, and likely more, species of Hepatozoon in Ontario.
Differential absorption of biochemical components in the diet of the cockleCerastoderma edule: enzymatic responses to variations in seston composition
Authors: Ibarrola I. , Iglesias J. I. P. , Navarro E.
Published: May 2008

Cockles (Cerastoderma edule (L.)) were fed different diets composed of freshly collected natural sediment and cells of Tetraselmis suecica mixed in different proportions. The experimental diets were designed to reproduce a simultaneous increase in both food quantity and organic content such as that brought about by algal blooms in either phytoplankton or microphytobenthos. Clearance, ingestion, and absorption rates, absorption efficiencies of specific biochemical components, and amylase, cellulase, laminarinase, and protease activities of the digestive gland were measured after 3 days of exposure to the diets. As food availability rises, net absorption rates are maximized by means of two mechanisms: (i) feeding rates are adjusted, with resulting regulation of the total amount of food entering the digestive tube, and (ii) rates of digestive investment contributing to digestion are varied according to food quality. The mass of the digestive gland, as well as specific and total cellulase activities, show positive correlation with the organic content of the food, which results in improved absorption of carbohydrates from high-quality diets. The costs incurred would be mainly in the form of increased metabolic faecal losses, which may explain the recorded negative effects on net absorption of lipids.
Description of Tetrahymena empidokyrea n.sp., a new species in the Tetrahymena pyriformis sibling species complex (Ciliophora, Oligohymenophorea), and an assessment of its phylogenetic position using small-subunit rRNA sequences
Authors: Jerome Cheryl A. , Lynn Denis H. , Simon Ellen M.
Published: May 2008

Ciliates infected 0.25% of adult Aedes sp. mosquitoes collected in Guelph, Ontario. Morphological observations of live and stained specimens indicated that these ciliates belonged to the Tetrahymena pyriformis sibling species complex. This study provides the first well-documented case of insects being infected by a species in the T. pyriformis complex. Mating experiments demonstrated that these "mosquito" ciliates were reproductively isolated from previously described biological species in the complex, and are designated a new species, Tetrahymena empidokyrea n.sp. Phylogenetic analysis using SSrDNA sequences suggested that T. empidokyrea n.sp. is either basal to all species in the genus Tetrahymena or basal to one of the two main lineages in that genus.
The effect of the mermithid parasite Gasteromermis sp. (Nematoda: Mermithidae) on the drift behaviour of its mayfly host, Baetis bicaudatus (Ephemeroptera: Baetidae): a trade-off between avoiding predators and locating food
Authors: Vance Sarah A.
Published: May 2008

This study reports alterations in the drift behaviour of mayfly nymphs (Baetis bicaudatus) infected with the mermithid nematode parasite Gasteromermis sp. with respect to (i) their exposure to drift-feeding trout predators and (ii) the efficiency with which they locate food. Experimental stream channels and benthic and drift samples were combined to investigate drift behaviour. The drift behaviour of earlier instars did not differ between parasitized and unparasitized nymphs. Infected late-instar nymphs, however, drifted less frequently, drifted higher in the water column, and swam more frequently while drifting. Neither drift distances nor body angle while drifting were altered. Parasitized nymphs showed a reduction in food-location success in heterogeneous stream channels. The drift alterations therefore reduce both the exposure of the host to fish predators and the efficiency with which it locates food. The mayfly population is effectively divided into two groups: unparasitized nymphs (in which drift behaviour is of consequence to mayfly fecundity) and parasitized nymphs (in which drift behaviour is of consequence to mermithid survival and fecundity). It is suggested that locating food may be less important to the parasite, while the risk of trout predation may be higher for drifting parasitized individuals. Both of these factors would favour the parasite influencing its host to adopt lower drift frequencies.
Space and habitat use by the threatened Gaspé caribou in southeastern Quebec
Authors: Ouellet Jean-Pierre , Ferron Jean , Sirois Luc
Published: May 2008

The space and habitat use patterns of the threatened Gaspé caribou (Rangifer tarandus caribou) were documented using telemetry. Between 1987 and 1992, 701 radiolocations were recorded, primarily for adult females (n = 28). Five habitats available to caribou (hardwood, immature, mature fir, mature spruce, alpine) are described and biomass of arboreal lichen, an important winter food source, is estimated. Regardless of sex and age, almost all locations (91%) were recorded within the limits of Gaspé Provincial Park. Home-range size of adult females averaged 148 km2(convex polygon); 95% of adult female locations were within 107 km2and 50% within 15 km2(harmonic mean). Home-range sizes were small and did not vary seasonally or annually. Throughout the year caribou were located more frequently than expected at high elevations (> 915 m) and less frequently than expected at low elevations (0–685 m). Consequently, alpine habitat was used more frequently than expected. Caribou concentrated their activity in two distinct areas: the alpine plateaus of Mont Albert and Mont Jacques-Cartier. No caribou used both areas (with the exception of a lone female). These two caribou groups should be viewed as two subpopulations. The biomass of arboreal lichens was greatest in mature fir and spruce stands, with 50–60 kg/ha available at a height of 4 m. The altitudinal distribution of this resource may partly explain the strong selection of high-elevation sites made by caribou in winter. Our results also support the hypothesis that cow–calf groups remain at high elevations to reduce the risk of predation by coyotes (Canis latrans) and black bears (Ursus americanus). The proximity of mature forests and alpine habitat, at high elevations, in two areas of the park may explain the small extent of adult female home ranges and the segregation of Gaspé caribou into two groups.
Functional discrimination in the masticatory apparatus of juvenile and adult cougars (Puma concolor) and spotted hyenas (Crocuta crocuta)
Authors: Biknevicius Audrone R.
Published: May 2008

Functional analyses of the teeth and jaws of juvenile and adult cougars (Puma concolor) and spotted hyenas (Crocuta crocuta) indicate several key differences and similarities in the design of the masticatory apparatus between species and age groups. Data from adults indicate preferential use of the precarnassial premolars in C. crocuta for durophagy (feeding on hard foods), and in P. concolor are suggestive of the need to use their carnassials during durophagy. In juveniles, powerful biting is limited to the caudalmost corpus (i.e., excluding the deciduous precarnassial premolars in P. concolor and many specimens of C. crocuta); however, dental replacement patterns determine how many and which teeth are available for use in this function. The most limiting scenario is one in which dP4 has been shed but eruption of P4 is incomplete, leaving only dP3 and the minute M1 to deliver strong bite forces. This condition occurs well after weaning in P. concolor but coincides more closely with the age of weaning in C. crocuta. It is during this period of masticatory compromise that juvenile C. crocuta must begin to join adult clan members at carcasses and thus must be able to feed aggressively with a masticatory apparatus that is poorly equipped to do so.
Geographic variation in susceptibility of the spruce budworm,Choristoneura fumiferana(Lepidoptera: Tortricidae), toBacillus thuringiensisssp. kurstaki is limited
Authors: Frankenhuyzen Kees van , Gauthier Debbie , Dedes John
Published: May 2008

Geographic variation in susceptibility to the pathogen Bacillus thuringiensis Berliner ssp. kurstaki was assessed among five populations of the spruce budworm, Choristoneura fumiferana (Clemens), across Canada. Larvae or pupae were collected from Prince Edward Island, northern New Brunswick, central Ontario, northeastern Alberta, and northeastern British Columbia. The response of field populations to the 1980 industrial standard of the HD-1 strain of the pathogen was compared with the concurrent response of a laboratory colony as an internal standard. Equal slopes of the probit regression lines indicated homogeneity of variation in susceptibility among populations. LC50values ranged from 2.6 international units (IU) per sixth-instar larva for the most susceptible population to 8.3 IU per larva for the least susceptible. Although significant, the variation in population susceptibility was within the range of variation that is commonly observed among repeated bioassays against cohorts of a single population. We conclude that variation in susceptibility to B. thuringiensis among spruce budworm populations is low. The data provide a basis for monitoring changes in susceptibility of spruce budworm populations in response to increased use of this pathogen in forest-protection programs.
Mitochondrial DNA sequence variation among pheromotypes of the dingy cutworm, Feltia jaculifera (Gn.) (Lepidoptera: Noctuidae)
Authors: Sperling Felix , Byers Robert , Hickey Donal
Published: May 2008

The dingy cutworm, Feltia jaculifera, is a complex of at least four pheromonal races (pheromotypes). We examined mitochondrial DNA (mtDNA) sequence and restriction-site variation in the cytochrome oxidase subunit I and II genes. Among 74 specimens representing the four pheromotypes, we found three discrete mitochondrial lineages. The most divergent mtDNA within F. jaculifera, the γ lineage, was associated with pheromotype C. This result confirms an earlier allozyme survey, which also found that pheromotype C was the most genetically distinct race. Thus, pheromotype C probably represents a classic sibling species. Of the two most similar mitochondrial lineages, the α lineage was disproportionately associated with pheromotype A and the β lineage was disproportionately associated with pheromotypes B and D. Although the correspondence between mitochondrial lineages and pheromotypes was incomplete, mtDNA variation provides strong nonbehavioral evidence for genetic divergence between pheromotypes A and B + D. Allozymes revealed more minor differentiation among the A, B, and D races. For pheromotypes A and B, the presence of distinct mtDNA lineages within populations without perfect correspondence to pheromone polymorphism has several possible explanations. It may be due to retained ancestral mtDNA polymorphism, whether initial divergence of pheromone races occurred in allopatry or sympatry, or to divergence in isolation with introgression following secondary contact. The greater differences in allele frequencies of mtDNA than of allozymes may be due either to the susceptibility of mtDNA to bottleneck effects or to asymmetric selection against hybrid females.
Chondrogenesis of a non-collagen-based cartilage in the sea lamprey,Petromyzon marinus
Authors: McBurney Kim M. , Wright Glenda M.
Published: May 2008

Chondrogenesis of the trabeculae, non-collagen-based cartilages in prolarval stages of the sea lamprey, Petromyzon marinus, was examined by light and electron microscopy. Chondrogenesis of the trabecular cartilages in prolarval lampreys commenced with the formation of mesenchymal condensations. Two peaks in mesenchymal cell density occurred, one prior to condensation formation and a second immediately before cartilage differentiation. The possibility of inductive influences by epithelio-mesenchymal interactions on the initiation of chondrogenesis is discussed. Bilateral condensations first appeared by day 17 post fertilization ventromedial to the eyes in a band of tightly packed yolk-laden mesenchymal cells that represent neural crest derived tissue. Cartilage differentiation occurred by day 19 post fertilization and was indicated by the presence of matrix-synthesizing organelles and the first ultrastructural appearance in the extracellular matrix of lamprin, a structural protein unique to lamprey cartilage. Lamprin was initially deposited as discrete 15- to 40-nm globules. Subsequently, lamprin appeared as fibrils aggregated into branching and parallel arrays arranged in pericellular, territorial, and interterritorial zones. Lengthening of the trabecular cartilages was primarily by appositional growth at the rostral end. The timing of the appearance of trabecular cartilages in prolarval stages likely reflects the functional importance of these structures for supporting the brain as the lamprey initiates burrowing behaviour.
Ultrastructure and formation of the hooked setae in Owenia fusiformis delle Chiaje, 1842: implications for annelid phylogeny
Authors: Meyer Karsten , Bartolomaeus Thomas
Published: May 2008

Several members of the Annelida bear apically curved or hooked setae that are aligned in a transverse row inside the neuropodial rim. Based on the hypothesis that these specific setae characterize a monophyletic group within the Annelida, the structure and development of the hooked seta in Owenia fusiformis are analysed and compared with data from other annelids with such setae. The neuropodial hooks of O. fusiformis are arranged in multiple transversal rows or setal patches on each side of the body from the fourth setiger onwards. The setae are curved distally and consist of two identical spines lying side by side at the same level. Their tips generally point ventrofrontally. Within each patch, the setae lie inside a setal follicle that consists of a basal chaetoblast, at least one follicle cell, and varying numbers of epidermal cells. Each setal patch is basally surrounded by an extracellular matrix that is continuous with the subepidermal basal lamina. An additional discontinuous extracellular matrix lies between the epidermis and the follicle cells. It is of functional significance for the attachment of the epidermal cells and seems to be related to the special organization of the setal patches, because it is absent in juveniles; they have single neuropodial rows of hooked setae per segment. New setae are formed at the dorsal and caudal edges of each patch, whereas the degeneration of setae is observed at the frontal edge of each patch. Microvilli project from the apex of the chaetoblast into canals within the fully differentiated setae. These canals remain when the microvilli are withdrawn from the seta during formation. Each hook is formed by a single large microvillus. The results of the present paper substantiate the hypothesis of a homology of the hooked setae in the Oweniida and other Annelida. These results and data from the literature support the hypothesis that the Oweniida is the sister-group of a monophylum which consists of the Terebellida, Pogonophora, and Sabellida.
The long-horned beetles of south Florida (Cerambycidae: Coleoptera): biogeography and relationships with the Bahama Islands and Cuba
Authors: Browne Jonathan , Peck Stewart B.
Published: May 2008

South Florida is a floral and faunal transition zone between the Nearctic region and the West Indian part of the Neotropical region. Ninety-one species of Cerambycidae are known from the south Florida mainland and 53 species of Cerambycidae from the Florida Keys. The cerambycid fauna of south Florida is about equally of Neotropical (53%) and Nearctic origin (47%). Since the Florida Keys were entirely submerged several times in the Pliocene and Pleistocene epochs, the present cerambycid fauna is predominantly the result of late Pleistocene – Holocene overland dispersal from south-central Florida and overwater dispersal from the West Indies (Bahama Islands and Cuba). Species–area and species–distance relationships for the islands form significant regression lines as predicted by the equilibrium theory of island biogeography. 'The presence of a "distance effect" is surprising, since it is usually considered that only during the past 10 000 years has the southern tip of the Florida peninsula been fragmented into the present-day islands of the Keys by a rising sea level. An alternative geological scenario, supported by this study, suggests that the present islands of the Keys have appeared as the sea level fell only within the past 6000 years, and the fauna is a more recently derived one.
Individual differences in territory and growth of ayu, Plecoglossus altivelis (Osmeridae)
Authors: Katano Osamu , Iguchi Kei'ichiroh
Published: May 2008

We observed 10 categories of behaviour in 133 ayu, Plecoglossus altivelis, kept individually in isolated aquaria, and separated three individuality components, aggressiveness, activity, and slow reaction, by factor analysis. We then divided 84 of the fish into 14 groups, each comprising 6 individuals, and released each group into one of four ponds designed to simulate natural streams for a 10-day period to investigate their territory formation and growth rates. Individuals that showed aggression towards an ayu model in the aquaria tended to engage in many aggressive interactions with other individuals in the ponds. Large and active individuals from the aquaria were dominant over other individuals in the ponds. The increase in aggressive interactions and percentage of encounters won increased the territorial period of individual fish. Growth rate was significantly correlated with territorial period, indicating that individual differences were important in social organization and individual foraging success.
Transition from a hatchery to a laboratory environment induces inner-ring monodeiodination pathways for thyroid hormones in liver of rainbow trout, Oncorhynchus mykiss
Authors: Johnston C. E. , Gordillo C. , Eales J. G.
Published: May 2008

In laboratory-acclimated rainbow trout (Oncorhynchus mykiss) the main hepatic deiodination pathway for thyroid hormones is L-thyroxine (T4) outer-ring deiodination (T4ORD), which produces biologically active 3,5,3′-triiodo-L-thyronine (T3); T4 inner-ring deiodination (T4IRD) as well as T3ORD and T3IRD activities are low or undetectable. Surprisingly, trout transported 48 h previously from a local hatchery to the laboratory demonstrated not only low T4ORD activity but also significant T4IRD and T3IRD activities. To test if the transition from hatchery to laboratory environment had induced the unexpected inner-ring deiodinations, we measured hepatic deiodinase activities over the same time frame in trout recently transported to the laboratory and also in trout retained undisturbed at the hatchery. Undisturbed hatchery trout showed typical hepatic deiodinase function: T4ORD activity predominated, while T3IRD, T4IRD, and T3ORD activities were basal. However, after 1–3 days in the laboratory, hepatic T4ORD activity was reduced and T4IRD and T3IRD activities were increased. By 5 days, deiodinase activities of laboratory trout reverted to the levels of hatchery trout. We conclude that physical disturbance can temporarily depress thyroidal status by simultaneously decreasing hepatic production of biologically active T3 and inducing degradation of T4 and T3.
Avoidance of encapsulation in the absence of VLP by a braconid parasitoid of Drosophila larvae: an ultrastructural study
Authors: Eslin Patrice , Giordanengo Philippe , Fourdrain Yvelise , Prévost Geneviève
Published: May 2008

The hymenopteran Asobara tabida Nees (Braconidae: Alysiinae) parasitizes the larval stages of Drosophila species. In D. melanogaster, 90% of A. tabida eggs avoid encapsulation and are found embedded within the tissues (digestive tube, fat body, tracheae, etc.) of their larval host. Electron microscopy was used to investigate if the embedment of the parasitic egg within the tissues of its host may prevent encapsulation. Study revealed that the outer layer of the A. tabida egg consists of a fibrous exochorion that exhibits adhesive properties within the tissues of D. melanogaster. Three hours after oviposition, any basement membrane surrounding the host tissues that is in contact with the parasitic egg is stuck to the exochorion. Attachment rapidly increases. Nine hours post oviposition, the A. tabida egg is almost totally surrounded by a sheath of host tissue, with only limited areas of the surface remaining uncovered and exposed to attack by the host hemocytes. It is therefore concluded that the adhesion of A. tabida eggs to the host tissues is likely to contribute to their protection from encapsulation during embryogenesis. Also, electron microscopy reveals that no virus-like particles occur in A. tabida, unlike any other braconid parasitoid studied. The absence of virus-like particles is discussed with regard to the importance of host regulation of the particles in other braconid species.
Coyote responses to visual and olfactory stimuli related to familiarity with an area
Authors: Windberg Lamar A.
Published: May 2008

Individual coyotes (Canis latrans) are infrequently captured within their familiar areas of activity. Current hypotheses are that the differential capture vulnerability may involve neophobia or inattentiveness. To assess the effect of familiarity, I measured coyote responsiveness to sensory cues encountered in familiar and novel settings. Seventy-four captive coyotes were presented with visual and olfactory stimuli in familiar and unfamiliar 1-ha enclosures. The visual stimuli were black or white wooden cubes of three sizes (4, 8, and 16 cm per side). The olfactory stimuli were fatty acid scent, W-U lure (trimethylammonium decanoate plus sulfide additives), and coyote urine and liquefied feces. Overall, coyotes were more responsive to stimuli during exploration in unfamiliar than in familiar enclosures. None of 38 coyotes that responded were neophobic toward the olfactory stimuli. The frequency of coyote response, and the resulting degrees of neophobia, did not differ between the black and white visual stimuli. Regardless of context, the largest visual stimuli were recognized at the greatest distance and evoked the strongest neophobic response. A greater proportion of coyotes were neophobic toward the small and medium-sized stimuli in familiar than in unfamiliar enclosures. This study demonstrated that when encountered in familiar environments, visual cues are more likely to elicit neophobic responses by coyotes than are olfactory stimuli.
Sexual dichromatism in snakes: support for the flicker-fusion hypothesis
Authors: Lindell Lars Erik , Forsman Anders
Published: May 2008

In a recent review of the distribution and evolution of sexual dichromatism in the Old World viperid snakes of the genus Vipera, Shine and Madsen proposed that males in sexually dichromatic taxa had evolved bright contrasting colour patterns because these function to confuse visually guided predators by inducing a "flicker-fusion" illusion and thus enhance survival of males that move about rapidly in search of mates. Here we provide support for the flicker-fusion hypothesis obtained from a capture – recapture study of a colour polymorphic population of the adder, V. berus, that consists of a sexually dichromatic zigzag colour morph and a monochromatic melanistic colour morph. We used mark – recapture data to estimate and compare annual capture and survival probabilities of melanistic and zigzag male and female individuals. Our results revealed that in any given year zigzag males survived significantly better than did melanistic males, whereas melanistic females survived better than zigzag females. This is consistent with the flicker-fusion hypothesis and suggests that selection from visually guided predators acts on the interaction between colour pattern and behaviour.
Do arctic-breeding Red Knots (Calidris canutus) accumulate skeletal calcium before egg laying?
Authors: Piersma Theunis , Gudmundsson Gudmundur A. , Davidson Nick C. , Morrison R. I. Guy
Published: May 2008

Earlier studies have indicated that the diet of egg-laying female birds which eat only terrestrial arthropods has to be supplemented with calcium if they are to produce high-quality eggshells without interruption. During egg laying, females of tundra-breeding shorebird species may supplement their diet with fragments of mammalian skeletons, but as an alternative strategy they might store skeletal calcium before egg formation. We examine the possibility of calcium storage on the basis of temporal changes in the ash mass (a good indicator of skeletal mass) of male and female Red Knots (Calidris canutus islandica) collected during their stopover in Iceland in May and July, and after arrival on the breeding grounds in northernmost Ellesmere Island, Canada, in late May and early June. Significantly higher ash masses of females than of males, an increase in ash mass of females before the period of egg formation in mid-June in combination with a subsequent decrease, and the notable absence of temporal changes in ash mass of males, lead us to propose that female Red Knots do store skeletal calcium before egg laying. The rate of calcium storage would be 2.3 times higher after arrival on Ellesmere Island than during the stopover in Iceland, but the dietary components through which storage is achieved remain unclear. With an almost 50% change in the skeletal mass of females, Red Knots currently hold the record with respect to skeletal calcium dynamics in free-living egg-laying birds. The stored skeletal mass would allow them to produce at least half the clutch without further calcium intake.
FLUCTUATION-ENHANCED CHEMICAL/BIOLOGICAL SENSING AND PROMPT IDENTIFICATION OF BACTERIA BY SENSING OF PHAGE-TRIGGERED ION CASCADE (SEPTIC)
Authors: KISH L. B. , SCHMERA G. , KING M. D. , CHENG M. , YOUNG R. , GRANQVIST C. G.
Published: May 2008

Both selectivity and sensitivity of chemical sensors can be significantly improved by exploiting the information contained in microfluctuations present in the sensor system. We call our collection of methods to extract information from these microfluctuations Fluctuation-Enhanced Sensing (FES). In this review paper we discuss general FES principles and two types of applications; gas sensing with commercial solid state sensors and the Sensing of Phage-Triggered Ion Cascde (SEPTIC) technique to detect and identify bacteria.
CHIRPED-PULSE FOURIER TRANSFORM MICROWAVE SPECTROSCOPY: A NEW TECHNIQUE FOR RAPID IDENTIFICATION OF CHEMICAL AGENTS
Authors: PAJSKI JASON J. , LOGAN MATTHEW D. , DOUGLASS KEVIN O. , BROWN GORDON G. , DIAN BRIAN C. , PATE BROOKS H. , SUENRAM RICHARD D.
Published: May 2008

We have developed a new broadband Chirped-Pulse Fourier Transform Microwave (CP-FTMW) spectrometer that allows the microwave spectrum in the 7.5-18.5 GHz range to be measured in a single data event. This technique produces a pure rotational spectrum that can be used for unambiguous identification of any species having a permanent electric dipole moment. CP-FTMW is a gas phase technique that is ideally suited for the detection of airborne chemical warfare agents (CWA) which must be detected in trace amounts (<10 ppm in air). The high resolution of the technique allows the identification of complex mixtures without the need for a preliminary separation step, such as gas chromatography, which significantly reduces analysis time. The technique is “blind” to major atmospheric components ( N 2, O 2, CO 2, H 2 O ) as they either do not posses a permanent dipole moment or do not absorb in the range of the spectrometer, thereby eliminating large background signals. In this paper we will present preliminary results that are focused on early detection of airborne CWA, including acquisition time, sensitivity limits, and sample handling requirements for several of these species.
ENVIRONMENTAL EFFECTS INFLUENCING THE VIBRATIONAL MODES OF DNA: NANOSTRUCTURES COUPLED TO BIOMOLECULES
Authors: RAMADURAI DINAKAR , YAMANAKA TAKAYUKI , VASUDEV MILANA , LI YANG , SANKAR VISWANATH , DUTTA MITRA , STROSCIO MICHAEL A. , RAJH TIJANA , SAPONJIC ZORAN , XU SONG
Published: May 2008

The interactions of charges in DNA with the vibrational modes in DNA depend on the spectra of these vibrational modes. Using (a) the Su-Schrieffer-Heeger (SSH) Hamiltonian approach, (b) integrated structures of DNA and manmade nanostructures, and (c) gel electrophoresis techniques,1 the interaction between charges in DNA and the vibrational modes of DNA are investigated. As is well-known, DNA has a rich spectrum of modes in the THz spectral regime. The use of manmade nanostructures integrated with DNA facilitates the engineering of nanoscale systems useful in studying the role of environmental effects on the vibrational modes of DNA as well as the interaction of these modes with charge carriers in DNA. Among the DNA-based structures considered in this account are: B-DNA and Z-DNA strands related by a conformational change; and DNA molecules bound on one terminal to indirect bandgap semiconductor quantum dots. Gel electrophoresis is used as a tool for the analysis of carrier interactions in novel integrated DNA-manmade-nanostructure complexes, and models based on the SSH Hamiltonian2 are employed as a means of analyzing the interactions between the vibrational modes of DNA and charge carriers in DNA.3-4
SURFACE-PLASMON-RESONANCE BASED OPTICAL SENSING
Authors: HORING NORMAN J. MORGENSTERN , CUI H. L.
Published: May 2008

Over the past twenty years, surface plasmon resonance has been developed as an effective technique for use in real-time biotechnological measurements of the kinetics of label-free biomolecular interactions with high sensitivity.1-16 On a fundamental level, it is the dielectric-imaging involvement of the adsorbed biomolecular layer (DNA for example) in shifting the surface plasmon resonance (SPR) frequency by means of electrostatic coupling at the interface with the metal film substrate that facilitates SPR-based optical sensing. Of course, there are various factors that can influence surface plasmon resonance, including plasma nonlocality, phonons, multiplicity of layers, all of which should be carefully examined. Moreover, tunable SPR phenomenology based on the role of a magnetic field (both classically and quantum mechanically) merits consideration in regard to the field's effects on both the substrate17 and the adsorbed layer(s).18 This paper is focused on the establishment of the basic equations governing surface plasmon resonance, incorporating all the features cited above. In it, we present the formulation and closed-form analytical solution for the dynamic, nonlocal screening function of a thick substrate material with a thin external adsorbed layer, which can be extended to multiple layers. The result involves solution of the random phase approximation (RPA) integral equation for the spatially inhomogeneous system of the substrate and adsorbed layer,19-25 given the individual polarizabilities of the thick substrate and the layer. (This is tantamount to the space-time matrix inversion of the inhomogeneous joint dielectric function of the system.) The frequency poles of the resulting screening function determine the shifted surface (and bulk) plasmon resonances and the associated residues at the resonance frequencies provide their relative excitation amplitudes. The latter represent the response strengths of the surface plasmon resonances (oscillator strengths), and will be of interest in optimizing the materials to be employed.
ULTRASENSITIVE WIDEBAND INTEGRATED SPECTROMETER FOR CHEMICAL AND BIOLOGICAL AGENT DETECTION
Authors: VERNIK IGOR V.
Published: May 2008

A novel concept of a compact mm/submm integrated spectrometers for environmental monitoring for hazardous materials of chemical and biological origin as well as for remote monitoring of the Earth atmosphere is discussed. The agents will be exactly identified by their unique spectral signatures. The assembled on a multi-chip module, cryocooler-mounted Superconducting Integrated SPectromer (SISP) exploits the superior performance of superconducting Josephson junction technology and unique on-chip integration of analog components, analog-to-digital converter, and digital components. Analog components include a superconductor-insulator-superconductor (SIS) mixer with integrated quasioptical antenna, mm-wave local oscillator, and SQUID amplifier for the down-converted (IF) signals. Upon amplification, the IF signal is digitized using a bandpass delta-sigma modulator, followed by real time processing with rapid single flux quantum (RSFQ) circuitry. Experimental results showing both operation of spectrometer components and the way to their successful integration are presented.
COMPACT OPTICAL CHARACTERIZATION PLATFORM FOR DETECTION OF BIO-MOLECULES IN FLUIDIC AND AEROSOL SAMPLES
Authors: KIESEL PETER , SCHMIDT OLIVER , BASSLER MICHAEL , JOHNSON NOBLE
Published: May 2008

An optical characterization unit based on fluorescence spectroscopy-on-a-chip is described. It comprises a compact fluidic platform that is integrated onto a chip-size spectrometer. The analyte is continuously excited within a novel waveguide. Fluorescence spectra are recorded as the analyte traverse the detection area.

In order to achieve a strong interaction between excitation light and analyte we use an anti-resonant waveguide, in which the light is guided within the target-containing medium, thereby enabling a continuous excitation of a large volume. The excitation light is guided in the lower-refractive-index fluid when the light is coupled into the waveguide at an appropriate angle.

Compact spectrometers can be integrated along the fluidic channel. The spectrometers are composed of a detector array which is coated with a linear variable band-pass filter. The filter converts the spectral fluorescence information into a spatially dependent signal that is analyzed by the detector array. These chip-size spectrometers are especially applicable for characterization of moving analytes.
STUDY OF LENNARD-JONES CLUSTERS: EFFECTS OF ANHARMONICITIES FAR FROM SADDLE POINTS
Authors: CHEN L. Y. , HORING N. J. M.
Published: May 2008

We study the transition pathways of a Lennard-Jones cluster of seven particles in three dimensions. Low lying saddle points of the LJ cluster, which can be reached directly from a minimum without passing through another minimum, are identified without any presumption of their characteristics, nor of the product states they lead to. The probabilities are computed for paths going from a given minimum to the surrounding saddle points. These probabilities are directly related to prefactors in the rate formula. This determination of the rate prefactors includes all anharmonicities, near or far from saddle points, which are pertinent in the very sophisticated energy landscape of LJ clusters and in many other complex systems.