bluuebunny/crossref_metadata_2025 huggingface dataset:
First description of Metridia okhotensis Brodsky, 1950 (Crustacea: Copepoda) male, with female, fifth copepodites, and notes on distribution in British Columbia inlets
Authors: Szabo Ildy , Gardner Grant A.
Published: August 2008

The male of Metridia okhotensis (Copepoda: Calanoida) is described here for the first time. It can be separated from similar species, including M. longa, a morphologically similar species found in the Atlantic and Arctic oceans, on the basis of body size, the relative length of the first antennae, and the shape of the fifth leg. Here we describe both the fifth and sixth copepodite stages of male and female M. okhotensis, and present a tabular key to members of the genus reported from the northeast Pacific Ocean. In addition, we show that M. okhotensis is widely distributed in the protected waterways of the British Columbia coast, and at times and in some places it is numerically dominant. Particularly high numbers are found in Loughborough and Portland inlets and Douglas Channel. The size of the copepod and of its population suggest it plays an important role in the zooplankton dynamics of British Columbia nearshore waters.
Redescription of Megalobatrachonema (Chabaudgolvania) elongata (Baird, 1858) n. comb. (Nematoda: Kathlaniidae) parasitic in North American salamanders
Authors: Baker M. R.
Published: August 2008

Megalobatrachonema (Chabaudgolvania) elongata (Baird, 1858) n. comb, is redescribed based on specimens from Ambystoma tigrinum, A. lacustris, Ambystoma sp., and Rhyacosideron altamirani (Ambystomatidae) from various localities in Mexico. The species is transferred to Megalobatrachonema from Falcaustra because the oesophagus lacks valves and the oesophageal bulb is reduced in size. Megalobatrachonema (C.) elongata may be differentiated from the only other species in the same subgenus, M. (C.) terdentatum (Linstow, 1890), from Triturus spp. (Salamandridae) of Europe, by differences in oesophageal and cephalic morphology, and the distribution of caudal papillae in males.
Reproductive biology of the feather star Florometra serratissima: gonadal structure, breeding pattern, and periodicity of ovulation
Authors: Mladenov Philip V.
Published: August 2008

The reproductive biology of a population of the feather star Florometra serratissima (A. H. Clark) was studied at Barkley Sound, British Columbia, Canada. Most individuals in the population are gonochoric, although hermaphrodites are present at low frequency. Large specimens (length of arms ca. 280 mm) possess about 440 genital pinnules on the 10 arms. All genital pinnules are in reproductive synchrony except for the most distal ones on the arms of females. Each gonad consists of three layers: a germinal epithelium enclosing a central lumen; an outer epithelium; and an intervening genital haemal sinus. Growing oocytes project almost fully into the genital haemal sinus and then ovulate through the germinal epithelium into the ovarian lumen where they collect and mature into ova. Gametes are emitted through transient nipplelike swellings that appear on the distal surface of each genital pinnule. Unspawned eggs are phagocytized by the germinal epithelium. Breeding pattern and periodicity of ovulation were analyzed histologically at the population and individual levels, the latter by periodic removal of genital pinnules from caged animals. Breeding of the population is continuous in that females are ovulating eggs and males possess active spermatozoa throughout the year. Individual females ovulate a small quantity of eggs (ca. 23 800 maximum) about once a month and appear to spawn them within 3 days. Although breeding is continuous, aseasonal fluctuations in the level of breeding activity were detected statistically in the female population and were clearly evident in individually monitored males and females.
Foraging rates of wapiti on green and cured pastures
Authors: Hudson R. J. , Watkins W. G.
Published: August 2008

Foraging rates of wapiti (Cervus elaphus nelsoni) were studied on green (August) and cured (October) pastures that were progressively defoliated from >3000 kg/ha to 200 kg/ha over 8–12 days. For grassland vegetation, maximum intake rates of 11 g/min on green pastures and 22 g/min on cured pasture declined by 50% at forage biomasses of 385 and 533 kg/ha, respectively. Although wapiti cropped forage more slowly on cured vegetation, bite sizes were larger at an equivalent forage biomass. Cropping bite rates declined from 50 to 25 bites/min as bite sizes increased from 0.1 to 1 g with similar relationships for green and cured forage. In forested habitats, wapiti foraged more slowly at an equivalent biomass and bite size.
Foraging strategies of the mole (Parascalops breweri, Bachman, 1842). II. The economics of finding prey
Authors: Jensen I. M.
Published: August 2008

The economics of two foraging methods are considered: (i) the mole digs through the soil in search of food, and (ii) it searches existing tunnels. Expected economic return is compared with the mole's metabolic costs at different temperatures and different prey densities. Despite the relatively higher levels of prey in undisturbed soil, it is often not worthwhile for the mole to expend the energy needed to dig it out, as enough food can usually be found in existing tunnels.
Comparaison de la structure et du volume squelettiques entre un delphinidé (Delphinus delphis L.) et un mammifère terrestre (Panthera leo L.)
Authors: Buffrénil V. de , Sire J.-Y. , Schoevaert D.
Published: August 2008

The weight and structural characteristics of bones (density, ash content, and structural compactness) were compared between a small delphinid (Delphinus delphis L.) and a terrestrial mammal (Panthera leo L.). The aim of this comparison was to show the morphological correlates of the steep reduction in skeletal mass, which is a characteristic of dolphins. The lightness of the bones in the thoracic limbs of these animals is due to a reduction of both the volume and the density of bones. In the cephalic and thoracic regions, the loss in mass of the delphinid skeleton is due only to the reduction of bone volume. Dolphin vertebrae show no modification of weight or structure, as compared with those of lions. The functional hypotheses suggested by these results are discussed in relation to aspects of bone pathology induced by disuse or abnormal gravitational conditions.
Manoeuvrability and ecological segregation in the little brown (Myotis lucifugus) and Yuma (M. yumanensis) bats (Chiroptera: Vespertilionidae)
Authors: Aldridge Hugh
Published: August 2008

The abilities of two species of sympatric insectivorous bats, Myotis lucifugus and M. yumanensis, to negotiate a series of obstacle courses were measured. One hundred percent of the tested M. yumanensis were capable of negotiating their way through vertical strings 0.21 m apart, as compared with 30% of the tested M. lucifugus. A significant difference between the two species was found for this flight performance parameter, and this difference was found to be correlated with wing loading and wingspan. Myotis yumanensis has a lower wing loading and a lower wingspan than M. lucifugus, which probably explains the differences in manoeuvrability between the two species. An attempt was made to relate this difference to differences in the foraging behavior of the two species, but this was not possible, probably because of the high degree of morphological and behavioural overlap between the two species.
Croissance et production du bivalve Mesodesma arctatum (Conrad) sur la côte nord du golfe du Saint-Laurent
Authors: Brêthes Jean-Claude F. , Desrosiers Gaston , Fortin Jr. Gilles
Published: August 2008

Samples of Mesodesma arctatum (Pelecypoda) were collected during the summer of 1983 in the subtidal zone of the Saint-Jean River delta, on the north shore of the Gulf of St. Lawrence. Age was estimated by counting successive growth lines. Maximum longevity was estimated to be about 24 years. The von Bertalanffy growth equation was Lt = 48.1 (1−e−0,23(t−0,53)) mm. The instantaneous mortality rate was 0.26, estimated from a log regression of abundance versus age. The theoretical evolution of a single cohort was calculated; according to the model, biomass, expressed in dry weight, reached its maximum at 6 years and the ratio of somatic production to biomass was estimated to be 0.27. The age at first reproduction is between 3 and 4 years. The reproductive period seems to be during July. The reproductive effort was calculated from the weight difference between the reproductive and postreproductive periods and was determined to be 47% of the total production of the cohort.
The effect of fine-scale variations in agricultural land use on the abundance of red-winged blackbirds
Authors: Clark Robert G. , Weatherhead Patrick J.
Published: August 2008

We used censuses of breeding red-winged blackbirds (Agelaius phoeniceus) and of land use to test the prediction that blackbirds should be most abundant where there is a mix of hayfield (breeding habitat) and corn production (feeding habitat) but fewer birds where either habitat predominates. Red-winged blackbird abundance increased in response to increases in both hayfields and cropland. Multivariate analysis including hayfield, cropland, and wetland abundance as explanatory variables explained substantially more variation in blackbird abundance than any of the variables could by themselves. Although our analyses indicated some evidence of a decline in numbers of blackbirds when either hayfields or cropland became very abundant, none of the areas censused approached true monoculture and therefore the conditions under which a sharp decline in the blackbird population was predicted were not encountered. However, evidence from other locations and local population trends suggest that the prediction is correct.
Fish delivery, production of young, and nest density of Osprey (Pandion haliaetus) in southwest Sweden
Authors: Eriksson Mats O. G.
Published: August 2008

For 19 pairs of Osprey breeding solitarily in southwest Sweden, the average amount of fish delivered daily per nest was estimated and related to the production of young. Initial brood size was not correlated with the rate at which fish were brought to the nest, but the daily amount offish delivered was lower among nests where nestlings died before fledging. Distances between nests were shorter where large areas of nonacidified lakes surrounded the nest. These results indicate possible mechanisms by which the decline of fish in acidified lakes may affect breeding Ospreys.
Effect of whole-tree and conventional forest harvest on soil microarthropods
Authors: Bird G. A. , Chatarpaul L.
Published: August 2008

The effect of whole-tree and conventional harvest on soil microarthropods, Collembola and Acari, was investigated in a mixed conifer–hardwood forest on the Canadian Shield. Harvesting had a major effect on their populations which declined to 56 and 68% of those on the uncut plot for the whole-tree and conventional harvest plots, respectively. Species composition was unaffected by harvesting although there were shifts in dominance. Total numbers of microarthropods and numbers of Oribatei, Prostigmata, and Mesostigmata found on the uncut plot were significantly greater (P < 0.05) than on harvested plots. Slightly higher (P > 0.05) numbers of Collembola were recorded from the conventional harvest plot than the uncut plot. Oribatei, Prostigmata, and Collembola were more abundant (P < 0.01) on the conventional harvest plot than the whole-tree harvest plot. Of the two forest harvesting methods, conventional harvest had a lesser impact on soil microarthropods. Because the forest soil fauna is intimately involved in decomposition, nutrient cycling, and soil formation, our findings suggest that long-term site productivity will be greater following conventional harvest than whole-tree harvest.
A survey of parasites of the American lobster, Homarus americanus (Crustacea: Decapoda), from the Canadian Maritimes
Authors: Brattey John , Campbell Alan
Published: August 2008

Examination of 885 lobsters (Homarus americanus) trapped in five areas of the Canadian Maritimes during 1980–1982 revealed four parasite species: Porospora gigantea (Apicomplexa: Sporozoea), Polymorphus botulus (Acanthocephala: Palaeacanthocephala), Hysterothylacium sp. (Nematoda: Secernentea), and Stichocotyle nephropis (Platyhelminthes: Trematoda). The prevalence and abundance of each parasite species did not differ significantly (p > 0.05) between lobster sexes or size groups. Lobsters in each area were characterized by a high prevalence of P. gigantea (43.6 to 84.2%) and low prevalences of P. botulus (1.3 to 9.9%) and Hysterothylacium sp. (1.1 to 5.6%). Stichocotyle nephropis was found in one lobster from German Bank. The parasite fauna were similar throughout the areas sampled, which suggests that the data were of little value for lobster stock discrimination. However, lobsters probably acquired P. botulus in the shallow coastal areas where the primary hosts of this parasite occur; therefore, the presence of P. botulus in lobsters from inshore and offshore areas south and southeast of Nova Scotia suggests some mixing between coastal lobsters and those on the continental shelf.
Mononchoides andersoni n.sp. and two new species of Koerneria (Nematoda: Diplogasteridae)
Authors: Ebsary B. A.
Published: August 2008

Mononchoides andersoni n.sp., Koerneria terranovus n.sp., and Koerneria mulveyi n.sp. are described and illustrated from Canadian localities. Mononchoides andersoni n.sp. is characterized by a body length of 1066–1246 μm, a porelike vulva at 36–39%, a tail of 403–439 μm, c′ value of 22(20–26), and telostom base with two small subventral teeth. Koerneria terranovus n.sp. and Koerneria mulveyi n.sp. are unique amongst Koerneria species because of their large a values (53–68), which are at least twice those of other species. Koerneria terranovus females differ from K′. mulveyi by the narrower cheilostom aperture (30 vs. 50% of head width), greater length (1735–1771 μm vs. 1377–1678 μm), smaller c′ value of (11–12 vs. 14(10–18)), shorter cephalic setae (3–3.5 μm vs. 5–6 μm), and linear cheilorhabdions versus isoscheles triangle shaped cheilorhbdions in K′. mulveyi. The males of K. mulveyi have cephalic setae about one half the length of those in the female while the male and female of K. terranovus have cephalic setae of equal length, and the gubernaculum is longer (14 μm vs. 11 μm) in K. mulveyi. New combinations are proposed for species transferred from Mononchoides to Koerneria: K. angarensis (Gagarin, 1983) n.comb., K. ivanegae (Gagarin, 1983) n.comb., K. ruriculus (Gagarin, 1983) n.comb., and K. strenuus (Gagarin, 1983) n.comb. Mononchoides tsalolichini Gagarin and Lemsina (1983) is a lapsus calami for Fictor tsalolichini. Mononchoides aquaticus Dassonville and Heyns (1984) is transferred to Oigolaimella becoming O. aquatica n.comb. Mononchoides fictor (Bastian, 1865) Goodey, 1963 and Koerneria bicornis (Rahm, 1929) Goodey, 1963 are considered to be species inquirendae. Keys to the species of Mononchoides and Koerneria are provided.
Régénération à différents niveaux d'une phalange chez Rana ridibunda adulte: influence de la nature des tissus blessés
Authors: Revardel J.-L. , Aoussi S. , Chapron C.
Published: August 2008

The type of tissue present at the point of amputation determines scarring or regeneration in the digits of Rana ridibunda. Scarring occurs when nonskeletal tissues proliferate; this is particularly true at the level of the proximal diaphysis, after periosteal resorption, between phalanges when the cartilage is intact in the articulation, and occasionally, at the level of the distal diaphysis when the reaction of the fibroblasts is intense. Regeneration occurs when skeletal tissues proliferate from the cartilages of either the epiphysis or the articulation, or from the periost. In such cases, centers of chondrogenesis develop into a cartilaginous axis that transforms into bone after 7 to 12 months. Nonskeletal conjunctive tissues (subcutaneous tissue, derma, synovial membrane) evolve into mesenchymal conjunctive tissue that will eventually reconstitute the structures from which it came originally.[Journal translation]
Barrière hématotesticulaire (blood–testis barrier) et variations de perméabilité du compartiment gonial dans le follicule testiculaire de Locusta migratoria implanté en milieu dépourvu d'ecdystéroïdes
Authors: Marcaillou C. , Lauverjat S.
Published: August 2008

In Locusta migratoria, the testicular follicle is made on an apical compartment that contains the youngest germ cells and a basal one in which the spermatids differentiate. As soon as it is formed during the fourth larval stage, the latter compartment becomes impervious to exogenous macromolecules. This permeability barrier, which corresponds to the blood–testis barrier defined in mammals, depends on extensive septate junctions. In this paper, testicular follicles were cultured in vivo in adult males known to be free of hemolymphatic ecdysteroids. The permeability of the apical compartment to horseradish peroxidase, used as a tracer, varied as a function of implantation time. This apical compartment became impermeable as soon as the basal compartment cells were postmeiotic. Once implanted into an adult host, a follicle that contained only gonia completed normal spermatogenesis and established a blood–testis barrier, providing a tight compartment in which meiotic processes occurred. Septate junctions developed normally. These results show that ecdysterone controls neither the differentiation of septate junctions nor the establishment of the blood–testis barrier, which appear both to be conditioned by the initiation of meiosis.
How fast should a dead whale cool?
Authors: Innes Stuart
Published: August 2008

Postmortem heat generation has recently been invoked to explain a core temperature of 28 °C in a 13-m fin whale Balaenoptera physalus 8-days after death. To investigate this suggestion further, heat transfer by a dead whale's mid-body region was modelled using finite difference equations for unsteady state conduction to predict tissue temperatures. The resulting simulations suggest that postmortem heat production is not necessary to explain Brodie's observation, and that the slow rate of cooling can be explained by the thermal inertia of a large body mass.
The effects of the insect growth regulator fenoxycarb on Rhodnius prolixus (Insecta, Hemiptera) embryogenesis
Authors: Kelly Gregory Mitchell , Huebner Erwin
Published: August 2008

Embryonic development of the hemipteran Rhodnius prolixus is perturbed by fenoxycarb (Ro 13.5223, Dr. R. Maag Ltd.), a non-neurotoxic insect growth regulator. Degree of perturbation is dependent on dose applied and embryonic stage at application time. Day 5 embryos were the most sensitive over a broad dose range. Treatment on day 8 had little effect, with normal hatching occurring 1 week later. Three developmental stages were most sensitive to perturbation: katatrepsis, dorsal closure, and eclosion. Katatrepsis, which normally occurs 168 h postoviposition, was the stage most prominently affected, suggesting that fenoxycarb interferes with basic mechanisms underlying this morphogenetic movement. Dorsal closure was the second most sensistive stage, the defect being characterized by embryos failing to completely enclose the yolk. Embryos receiving very low doses successfully completed katatrepsis and dorsal closure but were unable to hatch. Results demonstrate that fenozycarb may be a useful experimental tool for examining the normal cellular mechanisms of insect embryogenesis.
A biometric study of three populations of the European grayling, Thymallus thymallus (L.), from the French Jura Mountains
Authors: Surre C. , Persat H. , Gaillard J. M.
Published: August 2008

Three populations of grayling (Thymallus thymallus L.) from the Jura Mountains (Rhône drainage basin, France) were compared using 8 meristic and 10 morphometric characteristics; discriminant analysis clearly distinguished these populations. This result raises a number of questions about the specificity of fish populations inhabiting any given river and the usefulness of stocking that has been carried out up to now without any controls.
An experimental study on the effect of elevated temperature on the heterotrophic and autotrophic food resources of aquatic insects in a forested stream
Authors: Rempel Robert S. , Carter John C. H.
Published: August 2008

The effect of temperature on the heterotrophic and autotrophic food resources of aquatic insects was investigated in outdoor experimental channels and in the laboratory. Elevated temperatures in outdoor channels resulted in accelerated decay rates and accumulation of organic layers on introduced tiles. Heterotrophic activity (substrate respiration) increased with temperature in the laboratory for leaf strips, flocculent organic matter, and stone surface organic layers. Autotrophic activity (substrate photosynthesis) was greater in the laboratory for flocculent detritus (per milligram ash-free dry weight) than for stone surface organic layers. These results indicate that the primary food resources of shredder, collector, and scraper functional guilds are enhanced by elevated temperature, but also suggest that coarse particulate organic matter may disappear from the stream more quickly. The results also point out that substantial autotrophic activity occurs within flocculent organic detritus.
Evolution and historical biogeography of a parasite–host assemblage: Alcataenia spp. (Cyclophyllidea: Dilepididae) in Alcidae (Charadriiformes)
Authors: Hoberg Eric P.
Published: August 2008

The methodology of phylogenetic systematics was used to develop hypotheses for the evolution of eight species of Alcataenia, a group of host-specific cestodes of the Alcidae and, to a lesser extent, the Laridae (Charadriiformes). Concurrently, aspects of the early biogeography of alcids were reevaluated making it possible to study the historical and distributional relationships of parasites and hosts. The most parsimonious hypothesis for the phylogeny of Alcataenia suggested that sequential colonization or host switching with limited coevolution (coaccommodation) by parasites best explained the distributional patterns exhibited by Alcataenia spp. Morphological evolution of specific species of Alcataenia accompanied host switching, but was limited subsequent to the initial event of colonization. Thus evolution of these parasites following colonization lagged behind continuing diversification of the host group. Although alcids are an ancient group, as indicated by palaeontological and phylogenetic data, their cestode fauna is apparently not. It is postulated that Alcataenia spp. were acquired by their characteristic hosts in the late Pliocene and early Pleistocene, following diversification of the Alcidae at the generic level during the Miocene. Host distributions of respective Alcataenia spp. are more narrow than expected, considering the relatively young age of this assemblage. The current paradigm linking pronounced host specificity with coevolution of hosts and parasites in assemblages of great evolutionary age is not supported.
The genus Anonyx (Crustacea, Amphipoda) in the North Pacific and Arctic oceans: Anonyx laticoxae group
Authors: Steele D. H.
Published: August 2008

Thirteen species of the Anonyx laticoxae group (uropod 2 with the rami not broadened and with the inner ramus not constricted) are listed for the North Pacific region. Five new species, Anonyx schefferi, Anonyx stegnegeri, Anonyx gurjanovai, Anonyx hurleyi, and Anonyx petersoni are described. Anonyx japonicus is synonymized with Anonyx affinis, and Anonyx lebedi and A. orientalis are raised to full species. Eleven of these species are known only from the North Pacific region. Anonyx laticoxae and Anonyx affinis are the only two that are also found in the North Atlantic region.
Levels of tryptophan, 5-hydroxytryptamine, and dopamine in some tissues of the cockroach Periplaneta americana
Authors: Sloley B. Duff , Downer Roger G. H. , Gillott Cedric
Published: August 2008

Tryptophan, 5-hydroxytryptamine, and dopamine were measured in the frontal ganglion, corpora cardiaca, corpora allata, nerves of the suboesophageal ganglion, nerves of the thoracic ganglia, gut, testes, and ovaries of the cockroach Periplaneta americana using high performance liquid chromatography with electrochemical detection. 5-Hydroxytryptamine was demonstrated in the frontal ganglion, corpora cardiaca, corpora allata, and nerves of the suboesophageal ganglion but not in the gut, testes, ovaries, or nerves of the thoracic ganglia. These results quantitatively confirm immunohistochemical studies of 5-hydroxytryptamine in neurohaemal and nonneuronal tissues of the cockroach. Dopamine was found in all neurohaemal and nervous tissue examined. Dopamine was also found at low levels in the rectum. Tryptophan was found in all tissues examined.
Wound closure in the crab Carcinus maenas (L.)
Authors: Halcrow K. , Smith J. C.
Published: August 2008

Small holes were drilled through the integument of Carcinus maenas in one of three locations and the subsequent production of repair cuticle was followed by light and transmission electron microscopy for 105 d. Such holes were plugged by coagulated hemolymph and clumped hemocytes within 24 h. Repair cuticle began to be produced within 7 d, first at the margin of the hole, then centripetally. An epicuticle was not produced. The material synthesized was initially loosely organized but regularly lamellate cuticle was laid down later. This material continued to be produced for at least 105 d by which time its thickness might exceed that of the adjacent undamaged cuticle. The repair cuticle is not the equivalent of any of the constituents of normal procuticle, at least with respect to its ultrastructural organization.
Fine structure of the kidneys of osmotically stressed Mytilus, Mercenari, and Anodonta
Authors: Khan Hamidur R. , Ashton Mary Lou , Saleuddin A. S. M.
Published: August 2008

Osmotically induced ultrastructural changes in the kidneys of the freshwater bivalve Anodonta and the marine bivalves Mytilus and Mercenaria were studied. Osmotic stresses were given to Anodonta by keeping them in distilled water or in 6% seawater, and to Mytilus and Mercenaria by keeping them in 50% seawater for various periods. In all of these bivalves, the convoluted, single cell layered kidney epithelia displayed wide lateral intercellular spaces as well as extracellular spaces in the basal membrane infoldings during hyposmotic stress. These spaces were greatly reduced when the animals were kept in isosmotic media (i.e., isosmotic to their respective hemolymphs). The kidney cells contained abundant cytoskeletal elements and microfilaments were often observed in bundles in the basal membrane infoldings. Actin was observed in the basal membrane infoldings using the specific fluorescent stain nitrobenzoxadiazole-phallacidin. The cell contacts of the kidney epthelia were studied in platinum replicas of freeze-fractured tissues. The lateral cell membrane and basal membrane infoldings contained many gap junctions. Many rows of dense intramembrane particles of septate junctions were observed in the kidneys of animals from isosmotic media. The septate junctions in the kidneys of aminals from hyposmotic media contained either fewer intramembrane particle rows or many sinuous intramembrane particle rows. The site of prourine formation in mollusks are discussed.
Morphology and function of the support cell and the nerve tracts innervating the presoma of Moniliformis moniliformis (Acanthocephala)
Authors: Budziakowski M. Eva , Mettrick David F.
Published: August 2008

The nerve tracts emerging from the cerebral ganglion of Moniliformis moniliformis were examined using electron microscopy. Nerve cells in the cerebral ganglion Moniliformis moniliformis send their processes into the nerve tracts. Type A, B, and D neurons contributed their processes to the nerves innervating putative sensory structures located on the neck and tip of the proboscis, and were classified as putative sensory neurons. Large numbers of electron-dense vesicles observed in the type A and B axons were correlated with the presence of the catecholamine dopamine. Type C neurons were seen to innervate receptacle wall muscles. The presence of neuromuscular-type junctions, with round, clear vesicles near presynaptic membranes, was observed. The type C neurons were therefore classified as putative motor neurons. Type E processes did not contribute to the nerve tracts.
Effect of season on the retention of 137Cs and 90Sr by the yellow-bellied slider turtle (Pseudemys scripta)
Authors: Scott David E. , Whicker F. Ward , Gibbons J. Whitfield
Published: August 2008

Seasonal variation in the elimination rate constants of two radionuclides was examined in the yellow-bellied slider (Pseudemys scripta). Thirty-six turtles from waste ponds contaminated with cesium-137 and strontium-90 were placed in an uncontaminated 18 × 20 m experimental pond and fed ad libitum weekly. Total body burdens of the radionuclides were measured five times at approximately 2-month intervals. These data were used to determine seasonal and overall elimination rate constants. Elimination rate constants differed between radionuclides and among seasons. Seasonal rate constants ranged from 0.002 to 0.029 day−1 for 137Cs, and from < 0.001 to 0.006 day−1 for 90Sr. Rate constants were highest, and presumably metabolic activity was greatest, in late April through June. This period corresponds to the spring breeding season in P. scripta. The overall biological half-lives of cesium-137 and strontium-90 were 64 and 365 days, respectively.
Sensitivity of home range estimates to sample size in Peromyscus
Authors: Krohne David T.
Published: August 2008

Home range size estimates in a population of Peromyscus leucopus changed as a function of sample size, reaching an asymptote at nine captures. Despite the short life-span of this species in the wild, a trapping regime that greatly increases the likelihood of obtaining at least nine captures can be devised, although the probability is extremely sensitive to the number of trap nights per session. Home ranges appear not to shift during the time required to obtain sufficient sample sizes.
A novel association between an endemic stickleback and a parasitic dinoflagellate. 1. Seasonal cycle and host response
Authors: Reimchen T. E. , Buckland-Nicks J.
Published: August 2008

We report the first case of a dinoflagellate infection of stickleback (Gasterosteidae), discovered on an endemic population of Gasterosteus that inhabits an acidic bog lake on the Queen Charlotte Islands, western Canada. A major difference between this and other dinoflagellate infections is that the autotrophic vegetative cyst rather than the parasitic trophont is the predominant stage on the fish. During peak infection in July, 99% of the fish were infected, and cysts often covered the entire fish including the eyes. Density of cysts was highest on the dorsal surface of the fish (to 68/mm); this is possibly associated with the photosynthetic ability of the cysts. There were no consistent differences in the infection among sizes classes of fish or between the sexes. Salmonids (Oncorhynchus kisutch and Salvelinus malma), which are uncommon in the lake, also harboured cysts, but at very low densities. Host reponse to the initial infection included extensive epithelial hyperplasia, producing a layer of cells over the entire fish that enclosed the dinoflagellates. Subsequent infections were covered by additional layers of epithelium, resulting in a thick gelatinous coating. Even in cases of extreme infection, the fish exhibited no obvious behavioral indicators of pathological responses to the infection.
Abnormalities of IGF-I signaling in the pathogenesis of diseases of the bone, brain, and fetoplacental unit in humans
Authors: Laviola Luigi , Natalicchio Annalisa , Perrini Sebastio , Giorgino Francesco
Published: August 2008

IGF-I action is essential for the regulation of tissue formation and remodeling, bone growth, prenatal growth, brain development, and muscle metabolism. Cellular effects of IGF-I are mediated through the IGF-I receptor, a transmembrane tyrosine kinase that phosphorylates intracellular substrates, resulting in the activation of multiple intracellular signaling cascades. Dysregulation of IGF-I actions due to impairment in the postreceptor signaling machinery may contribute to multiple diseases in humans. This article will review current information on IGF-I signaling and illustrate recent results demonstrating how impaired IGF-I signaling and action may contribute to the pathogenesis of human diseases, including osteoporosis, neurodegenerative disorders, and reduced fetal growth in utero.
Continuously measured renal blood flow does not increase in diabetes if nitric oxide synthesis is blocked
Authors: Bell Tracy D. , DiBona Gerald F. , Biemiller Rachel , Brands Michael W.
Published: August 2008

This study used 16 h/day measurement of renal blood flow (RBF) and arterial pressure (AP) to determine the role of nitric oxide (NO) in mediating the renal vasodilation caused by onset of type 1 diabetes. The AP and RBF power spectra were used to determine the autoregulatory efficiency of the renal vasculature. Rats were instrumented with artery and vein catheters and a Transonic flow probe on the left renal artery and were divided randomly into four groups: control (C), diabetes (D), control plus nitro-l-arginine methyl ester (l-NAME; CL), and diabetes plus l-NAME (DL). Mean AP averaged 90 ± 1 and 121 ± 1 mmHg in the D and DL groups, respectively, during the control period, and RBF averaged 5.9 ± 1.2 and 5.7 ± 0.7 ml/min, respectively. Respective C and CL groups were not different. Onset of diabetes (streptozotocin 40 mg/kg iv) in D rats increased RBF gradually, but it averaged 55% above control by day 14. In DL rats, on the other hand, RBF remained essentially constant, tracking with RBF in the nondiabetic C and CL groups for the 2-wk period. Diabetes did not change mean AP in any group. Transfer function analysis revealed impaired dynamic autoregulation of RBF overall, including the frequency range of tubuloglomerular feedback (TGF), and l-NAME completely prevented those changes as well. These data strongly support a role for NO in causing renal vasodilation in diabetes and suggest that an effect of NO to blunt RBF autoregulation may play an important role.
Bradykinin B2receptor null mice harboring a Ser23-to-Ala substitution in the p53 gene are protected from renal dysgenesis
Authors: El-Dahr Samir S. , Aboudehen Karam , Dipp Susana
Published: August 2008

A physiological cross talk operates between the tumor suppressor protein p53 and the bradykinin B2receptor ( BdkrB2) during renal organogenesis. Thus, although BdkrB2 is a target for p53-mediated transcriptional activation, BdkrB2 is required to restrict p53 proapoptotic activity. We previously demonstrated that BdkrB2−/−embryos exposed to gestational salt stress develop renal dysgenesis as a result of p53-mediated apoptosis of nephron progenitors and repression of the terminal differentiation program. Compared with wild-type kidneys, BdkrB2−/−express abnormally high levels of the Checkpoint kinase (Chk1), which activates p53 via Ser23phosphorylation. To define the functional relevance of p53S23phosphorylation, we generated a compound strain of BdkrB2−/−mice harboring a homozygous Ser23-to-Ala (S23A) mutation in the p53 gene by crossing BdkrB2−/−with p53S23Aknockin mice. Unlike salt-stressed BdkrB2−/−pups, which exhibit renal dysgenesis, homozygous S23A;BdkrB2−/−littermates are protected and have normal renal development. Heterozygous S23A;BdkrB2−/−mice have an intermediate phenotype. The p53-S23A substitution was associated with amelioration of apoptosis and restored markers of nephrogenesis and tubulogenesis. Real-time quantitative RT-PCR of terminal differentiation genes demonstrated that the S23A substitution restored normal expression patterns of aquaporin-2, Na-Cl cotransporter, Na-K-2Cl cotransporter, Na-bicarbonate cotransporter, and Sglt1. We conclude that p53 phosphorylation on Ser23is an essential step in the signaling pathway mediating the susceptibility of BdkrB2−/−mutants to renal dysgenesis.
ACTN3 genotype is associated with muscle phenotypes in women across the adult age span
Authors: Walsh Sean , Liu Dongmei , Metter E. Jeffrey , Ferrucci Luigi , Roth Stephen M.
Published: August 2008

The R577X polymorphism in the α-actinin-3 encoding gene ( ACTN3) has been associated with elite athletic performance, and recently with differences in isometric and dynamic muscle strength and power in the general population. In this study we sought to determine the association of ACTN3 R577X genotype with muscle strength and mass phenotypes in men and women across the adult age span. Eight hundred forty-eight ( n = 848) adult volunteers (454 men and 394 women) aged 22–90 yr were genotyped for ACTN3 R577X. Knee extensor (KE) shortening and lengthening peak torque values were determined using isokinetic dynamometry and fat-free mass (FFM) by dual-energy X-ray absorptiometry. Women deficient in α-actinin-3 (X/X; n = 53) displayed lower KE shortening peak torque (30°/s: 89.5 ± 3.5 vs. 99.3 ± 1.4 N·m, P = 0.011; 180°/s: 60.3 ± 2.6 vs. 67.0 ± 1.0 N·m, P = 0.019) and KE lengthening peak torque (30°/s: 122.8 ± 5.7 vs. 137.0 ± 2.2 N·m, P = 0.022; 180°/s: 121.8 ± 5.8 vs. 138.5 ± 2.2 N·m, P = 0.008) compared with R/X + R/R women ( n = 341). Women X/X homozygotes also displayed lower levels of both total body FFM (38.9 ± 0.5 vs. 40.1 ± 0.2 kg, P = 0.040) and lower limb FFM (11.9 ± 0.2 vs. 12.5 ± 0.1 kg, P = 0.044) compared with R/X + R/R women. No genotype-related differences were observed in men. In conclusion, our results indicate that the absence of α-actinin-3 protein (i.e., ACTN3 X/X genotype) influences KE peak torque and FFM in women but not men.
Magnetic Resonance Imaging of Fetal Brain Abnormalities
Authors: Tao Guowei , Yew David T.
Published: August 2008

Magnetic resonance imaging (MRI) of the fetal brain is a useful adjunct to prenatal sonography, providing a more complete evaluation of fetal brain abnormalities to aid and influence clinical decision-making during pregnancy. This article will review the uses and techniques of fetal MRI, discuss the normal appearance of the fetal brain on MRI, and outline clinical applications of fetal MR imaging.
Use of Functional Magnetic Resonance Imaging (Blood Oxygenation Level-Dependent Imaging, Diffusion Tensor Imaging and Magnetic Resonance Spectroscopy) in Brain Development Research
Authors: Yang Fei Fei , Yuan Shu Guang , Yew David T.
Published: August 2008

The development of several new magnetic resonance imaging (MRI) techniques has facilitated serial observations of the developing human brain in utero. For example, the noninvasive technique of functional MRI, which is used to study brain anatomy, function and metabolism in both humans and animals, has already enhanced our understanding of brain development and behavior relations. Currently, three main kinds of functional MRI techniques are used to study the developing brain: blood oxygenation level-dependent imaging, diffusion tensor imaging and magnetic resonance spectroscopy. When used in developmental research, these techniques can detect variations and injury, which conventional MRI cannot. Thus, they offer far greater opportunities to explore the relationships between structure and function, and to interpret developmental mechanisms, as well as to detect malformations and pathologies at the cognitive, emotional and behavioral level. These methodologies and their application to brain development are reviewed in this paper.
Multifocal Epstein-Barr Virus-Associated Smooth Muscle Tumor in Adults with AIDS: Case Report and Review of the Literature
Authors: Gallien S. , Zuber B. , Polivka M. , Lagrange-Xelot M. , Thiebault J.-B. , Bertheau P. , Gray F. , Molina J.-M.
Published: August 2008

Objectives: The aim of this study was to provide a systematic review of Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) in human immunodeficiency virus (HIV)-infected adults, focusing on clinical and histopathologic features and outcome. Methods: A literature search was performed using Medline, Embase and the Cochrane Library. Results: We reviewed 35 cases including our case of a patient with a progressive multifocal EBV-SMT. Patients were mainly men (n = 24) with a mean age of 35.5 years. Median CD4 count was 21/mm3. Main locations were brain (n = 12), liver (n = 8), spinal cord (n = 7) and adrenal gland (n = 6). The tumors were multifocal in 34% of cases, whereas analysis of clonality showed different clones in tumors from different sites. Treatment included removal surgery in 17 cases and/or radiotherapy in 9 and therapeutic abstention in 4. Mean follow-up after diagnosis was 12.3 months. Nine patients died during this period essentially from opportunistic infection and only 2 from the disease. Conclusion: EBV-SMT should be added to the list of virally induced tumors in severely immunocompromised HIV-infected adults. Multifocality of independent tumor clones, especially in liver, brain, spinal cord and adrenal gland, and a slow disease progression seem to be the key features of these tumors, the treatment of which remains poorly defined.
Participation in Clinical Trials as Viewed by the Patient: Understanding Cultural and Emotional Aspects Which Influence Choice
Authors: Catania Chiara , De Pas Tommaso , Goldhirsch Aron , Radice Davide , Adamoli Laura , Medici Marta , Verri Elena , Marenghi Cristina , de Braud Filippo , Nolè Franco
Published: August 2008

Background: Patients invited to take part in a clinical trial may evoke an archetype on which they may base their decision of adherence to participation, instead of on the study itself. Methods: A 17-item, multiple choice questionnaire was developed, tested and then administered to 102 Italian-speaking patients with advanced lung or breast cancers who had never been exposed to participation in a trial. Results: The questionnaire was answered by all patients. Eighty-five percent were positive about trial participation. Demographic factors did not influence patients’ willingness to participate. Trust in the investigator (76%) or in the institute (64%) and hope of receiving a new chance for cure (78%) were cited as reasons to accept participation. A minority was concerned by potential conflicts of interest (31%) or the thought of being ‘guinea pigs’ (36%), and feared that doctors were interested in advancing their own research, even though there were more efficient drugs available (28%). Fifty percent feared receiving a little-known medicine, and 76% considered that a thorough explanation of toxicity/safety of the proposed treatment helped them decide. Conclusion: Several prejudices, fears and some hopes have been captured by the questionnaire. Understanding such specifics will improve patient information leading patients to a more conscious motivation in deciding whether to participate in a clinical trial.
Clinicopathological Significance of Caspase-8 and Caspase-10 Expression in Rectal Cancer
Authors: Xu Bing , Zhou Zong-Guang , Li Yuan , Wang Ling , Yang Lie , Zhou Bin , Liu Hai-Yi , Song Jun-Min , Zeng Yu-Jian , Wang Rong , Shen Xiao-Gang , Sun Xiao-Feng
Published: August 2008

Objectives: To investigate the expression of caspase-8 and -10 in rectal adenoma, adenocarcinoma and the corresponding normal mucosa tissue, and to clarify the relationship between their expression and clinicopathological parameters of rectal cancer. Methods: The expression of caspase-8 and -10 was determined by real-time RT-PCR and immunohistochemistry in 36 rectal adenomas, 93 rectal cancers and 93 corresponding normal rectal mucosa samples. Results: Compared with normal mucosa, the mRNA expression of caspase-8 was higher in adenomas (p = 0.003), while that of caspase-10 was lower in adenomas (p = 0.035) and cancers (p = 0.001). Immunohistochemical results showed caspase-8 up-regulation in adenomas (p = 0.014), and caspase-10 down-regulation in adenomas (p = 0.034) and cancers (p < 0.001) compared with normal mucosa samples. Cancers with poor differentiation had lower caspase-10 mRNA and protein levels than those with better differentiation (p = 0.041 and p = 0.046, respectively). The protein expression of caspase-8 and -10 was in accordance with the mRNA expression (p = 0.043 and p = 0.018, respectively). Conclusions: Caspase-8 expression was up-regulated in rectal adenomas. Caspase-10 expression was down-regulated in both rectal adenomas and cancers, and was further related to differentiation. Caspase-8 and -10 may be involved in the pathogenesis of rectal cancer.
Effect of Smoking Habit on Circulating Adipokines in Diabetic and Non-Diabetic Subjects
Authors: Al Mutairi Sana S. , Mojiminiyi Olusegun A. , Shihab-Eldeen Aida A. , Al Sharafi Ahmad , Abdella Nabila
Published: August 2008

Background: Despite the well-known inverse association between smoking and body weight, there have been conflicting reports on the association between smoking and adipokines such as leptin and adiponectin. Aim: To determine and compare whether tobacco smoking (cigarettes or sheesha) affects circulating levels of adiponectin and/or influences leptin and leptin receptor (sOb-R) concentrationsand free leptin in diabetic and non-diabetic subjects. Methods and Subjects: Fasting plasma adiponectin, leptin, sOb-R, glucose, insulin, and lipid profile were determined in 236 subjects grouped as control subjects (n = 53); non-diabetic cigarette smokers (n = 34), non-diabetic sheesha smokers (n = 38), diabetic nonsmokers (n = 75) and diabetic smokers (n = 36). Uni- and multivariate regression analyses were used to determine the associations of these variables with body mass index (BMI) and smoking. Results: When compared to control subjects, smoking cigarettes or sheesha was associated with significantly higher glucose, insulin resistance, total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) and lower serum leptin, sOb-R and free leptin. The effects of smoking on BMI, leptin and sOb-R were dose-dependent. Binary logistic regression analysis showed that smoking is a significant determinant of BMI; leptin, sOb-R, free leptin index, adiponectin and LDL-C. Conclusions: We conclude that smoking sheesha does not reduce the metabolic effects of smoking. Smoking may modify leptin receptors and modulate leptin synthesis but the weight-lowering effect may not be related to leptin-induced anorectic signals.
Dogmatism and Perceptions of Leader Behavior
Authors: Croft John C.
Published: August 2008

Though the relationships between principals' perceptions of their own leader behavior and those of their teachers and superintendents did not relate significantly to their measured open or closed mindedness in Professor Croft's study, a reexamination of the data within the framework of conceptual systems theory offers some provocative implications for research and practice. Mr. Croft is assistant professor of education and research associate in the Center for the Advanced Study of Educational Administration, both at the University of Oregon.
Ultra High Resolution Computed Tomography of Damage in Notched Carbon Fiber—Epoxy Composites
Authors: Wright P. , Fu X. , Sinclair I. , Spearing S.M.
Published: August 2008

This article presents the first use of synchrotron radiation computed tomography (SRCT) to achieve sub-micron resolution of damage in aerospace grade carbon fiber—epoxy composites. The structure and interaction of the damage can be visualized in 3-D on a scale not previously observed in practical engineering configurations. The ability to detect and accurately measure features down to individual fiber breaks provides a valuable platform for future research; from the rigorous evaluation of damage models to understanding the fundamental physical mechanisms governing crack growth in composites. In particular the key role of intra-laminar cracks and delaminations in localizing fiber fractures is unambiguously identified for the first time.