bluuebunny/crossref_metadata_2025 huggingface dataset:
Length-dependent twitch contractile characteristics of skeletal muscle
Authors: Rassier Dilson E , MacIntosh Brian R
Published: October 2002

The length dependence of force development of mammalian skeletal muscles was evaluated during twitch, double-pulse, and tetanic contractions, and the relation between muscle length and the time-dependent characteristics of twitch and double-pulse contractions were determined. In situ isometric contractions of the rat gastrocnemius muscle were analyzed at seven different lengths, based on a reference length at which the maximal response to double-pulse contractions occurred (Lopt-2P). Twitch and double-pulse contractions were analyzed for developed tension (DT), contraction time (tC), average rate of force development (DT·tC1), half-relaxation time (t50%R), peak rate of relaxation (DT·dtmin1), and 90%-relaxation time (t90%R). Considering the length at which maximal tetanic DT occurred to be the optimal length (Lo-TET), the peak DT for twitch contractions and double-pulse contractions was observed at Lo-TET+ 0.75 mm (p < 0.05) and Lo-TET+ 0.1 mm (p > 0.05), respectively. When measured at the length for which maximal twitch and double-pulse contractions were obtained, tetanic DT was 95.2 ± 3 and 99.0 ± 2% of the maximal value, respectively. These observations suggest that double-pulse contractions are more suitable for setting length for experimental studies than twitch contractions. Twitch and double-pulse contraction tCwere 15.53 ± 1.14 and 25.0 ± 0.6 ms, respectively, at Lopt-2P, and increased above Lopt-2Pand decreased below Lopt-2P. Twitch t50%Rwas 12.18 ± 0.90 ms at Lopt-2P, and increased above Lopt-2Pand below Lopt-2P. Corresponding changes for double-pulse contractions were greater. Stretching the muscle leads to slower twitch contractions and double-pulse contractions, but the mechanisms of this change in time course remain unclear.Key words: muscle activation, forcelength relation, gastrocnemius muscle, Ca2+sensitivity.
Cocaine downregulates cardiac SERCA2a and depresses myocardial function in the murine model
Authors: Wang Ju-Feng , Yan Xinhua , Min Jiangyong , Sullivan Matthew F , Hampton Thomas G , Morgan James P
Published: October 2002

Cocaine has been shown to depress myocardial function, which may be linked to abnormal Ca2+ handling by the sarcoplasmic reticulum (SR). To examine whether cocaine affects Ca2+-handling proteins and myocardial performance, we injected BALB/c mice with cocaine daily (30 mg/kg, i.p.) for 14 d. Sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) levels, phospholamban (PLB) protein levels, and hemodynamic parameters were measured. After cocaine exposure, myocardial function was significantly decreased both in vivo and in vitro. Also, SERCA2a protein levels were significantly decreased in all cocaine-treated hearts (p < 0.05 compared with saline control). Normalized SERCA2a levels were 1.2 ± 0.2 (densitometric units) in the cocaine groups (p < 0.05 compared with saline control). However, there was no statistical difference in PLB protein levels between the cocaine and the saline groups. In isolated papillary muscle studies, cocaine did not block the response to extracellular Ca2+ but it did prolong the relaxation time of the muscle. These results indicate that cocaine does not block extracellular Ca2+ entrance across the cell membrane, but that it decreases SERCA2a protein levels. In conclusion, our study demonstrates that cocaine decreases SERCA2a protein levels and depresses myocardial function.Key words: cocaine, SERCA2a, phospholamban, ventricular function, mouse.
Dietary supplementation with creatine monohydrate prevents corticosteroid-induced attenuation of growth in young rats
Authors: Roy Brian D , Bourgeois Jacqueline M , Mahoney Douglas J , Tarnopolsky Mark A
Published: October 2002

Corticosteroids are used as chemotherapeutic agents in many medical conditions, despite many common and potentially serious side effects. Supplementation with creatine monohydrate (CrM) can increase strength and lean body mass in humans and, therefore, may be a viable countermeasure to the side effects of corticosteroids. Therefore, the purpose of this study was to determine if CrM could prevent the attenuation of growth associated with corticosteroid administration. Forty male SpragueDawley rats were randomized to the following groups: control (CON, n = 10), 7 mg methylprednisolone·kg1·week1 (PRED, n = 10), 2% CrM in diet (CD, n = 10), or CrM and methylprednisolone (CD-PRED, n = 10). Animals received either a weekly sham injection (saline; CON and CD) or an injection of methylprednisolone (PRED and CD-PRED) for 6 weeks. At the completion of the 6th week, body composition was determined and skeletal muscles were collected. Weight gain was attenuated in PRED as compared with all other groups (P < 0.05). Muscle total creatine and phosphocreatine were greater in the extensor digitorum longus in the CD and CD-PRED groups as compared with the CON and PRED groups (P < 0.05); however, total creatine and phosphocreatine in the soleus were not different. Mean fiber area was greater in type II fibers from the extensor digitorum longus in the CD and CD-PRED groups as compared with the CON and PRED groups (P < 0.05); no treatment effect was seen in the soleus. In conclusion, CrM supplementation prevented the attenuation of growth associated with corticosteroids and also increased type II muscle fiber area. These results could have important clinical implications for several patient populations commonly treated with corticosteroids, and further work is required to determine the specific mechanisms underlying the physiological effects that were observed. Key words: nutritional supplement, steroid myopathy, muscle atrophy.
Role of nitric oxide on the vasorelaxant effect of atrial natriuretic peptide on rabbit aorta basal tone
Authors: Romano Liliana , Coviello Alfredo , Jerez Susana , de Bruno María Peral
Published: October 2002

The role of nitric oxide (NO) on the vasorelaxant effect of atrial natriuretic peptide (ANP) on the basal tone of rabbit aortic rings conditioned to angiotensin II (Ang II) was studied. ANP aortic relaxation and nitrite release were measured in the presence and absence of endothelium and a NO-synthase inhibitor. Ang II at 108 M triggered a contractile response, conditioning the vessel to a vasorelaxant effect of ANP (108 M). This effect was significantly enhanced by endothelium removal, NG-nitro-L-arginine methyl ester (L-NAME, 104 M), and methylene blue (105 M). ANP decrease of basal tone in Ang-II-sensitized aortic rings was improved when a higher concentration of Ang II was used (106 M). Basal and Ang-II-stimulated nitrite release were measured in stretched (S) and nonstretched (NS) aortic rings. Nitrite release was significantly increased in S rings (p < 0.001). L-NAME (104 M) partially inhibited nitrite release in both basal and Ang-II-stimulated S aortic rings. In NS aortic rings, the NO inhibitor did not inhibit basal nitrite release but blunted the Ang-II-stimulated nitrite level. A significant negative correlation between nitrite release and the ANP vasorelaxant effect on basal tone was dependent on the Ang-II-sensitizing dose. The present results demonstrate that ANP relaxant effects on aortic basal tone are related to NO levels, which are regulated by S- and Ang-II-concentration-dependent NO generation and quenching.Key words: atrial natriuretic peptide, nitric oxide, vascular reactivity, basal tone, rabbit aorta.
Estrogen replacement stimulates fatty acid oxidation and impairs post-ischemic recovery of hearts from ovariectomized female rats
Authors: Grist Mark , Wambolt Richard B , Bondy Gregory P , English Dean R , Allard Michael F
Published: October 2002

Women less than 50 years of age, the majority of whom are likely premenopausal and exposed to estrogen, are at greater risk of a poor short-term recovery after myocardial ischemia than men and older women. Since estrogen enhances non-cardiac lipid utilization and increased lipid utilization is associated with poor post-ischemic heart function, we determined the effect of estrogen replacement on post-ischemic myocardial function and fatty acid oxidation. Female SpragueDawley rats, either intact (n = 15) or ovariectomized and treated with 17β-estradiol (0.1 mg·kg1·day1, s.c., n = 14) or corn oil vehicle (n = 16) for 5 weeks, were compared. Function and fatty acid oxidation of isolated working hearts perfused with 1.2 mM [9,10-3H]palmitate, 5.5 mM glucose, 0.5 mM lactate, and 100 mU/L insulin were measured before and after global no-flow ischemia. Only 36% of hearts from estrogen-treated rats recovered after ischemia compared with 56% from vehicle-treated rats (p > 0.05, not significant), while 93% of hearts from intact rats recovered (p < 0.05). Relative to pre-ischemic values, post-ischemic function of estrogen-treated hearts (26.3 ± 10.1%) was significantly lower than vehicle-treated hearts (53.4 ± 11.8%, p < 0.05) and hearts from intact rats (81.9 ± 7.0%, p < 0.05). Following ischemia, fatty acid oxidation was greater in estrogen-treated hearts than in the other groups. Thus, estrogen replacement stimulates fatty acid oxidation and impairs post-ischemic recovery of isolated working hearts from ovariectomized female rats.Key words: fatty acid oxidation, estrogen, ischemia, reperfusion.
Experimental tests of spatial association and kinship in monogamous mice (Mus spicilegus) and polygynous mice (Mus musculus domesticus)
Authors: Dobson F Stephen , Baudoin Claude
Published: October 2002

The mound-building mouse (Mus spicilegus) and house mouse (Mus musculus domesticus) are closely related species that exhibit putative characteristics of social monogamy and mate-defense polygyny, respectively. Social behaviours and group composition in these species have been well studied in the laboratory under controlled conditions, and the purpose of our study was to examine conclusions drawn from laboratory data in less constrained seminatural enclosures. Specifically, we examined spatial associations and disassociations, which we used as indices of attraction and avoidance, respectively, in both species of mice. In each enclosure and for each species, we introduced small treatment groups of either 2 or 3 female kin (sisters) or 2 or 3 unrelated females, along with an equal number of unrelated males. Initial group composition and physical environments in our enclosures were similar for the two species, therefore we preformed a modified "common garden" experiment. We expected genetically based behavioural differences between species to be revealed. Mound-building mice exhibited strong spatial associations of malefemale pairs, and also exhibited spatial avoidance of some of the other mice. House mice exhibited strong female groups of close kin that were significantly associated in space, but this species showed little spatial avoidance compared with mound-building mice. Our results support the idea of social monogamy in mound-building mice, where close reproductive associations of a paired male and female have been hypothesized from laboratory data. Our results also support more extensive evidence suggesting mate-defense polygyny in house mice.
Karyotype, reproductive organs, and pattern of gametogenesis in Zorotypus hubbardi Caudell (Insecta: Zoraptera, Zorotypidae), with discussion on relationships of the order
Authors: Kuznetsova Valentina G , Nokkala Seppo , Shcherbakov Dmitri E
Published: October 2002

For the first time, the karyotype is described in a representative of the order Zoraptera. Zorotypus hubbardi Caudell (Zorotypidae) have holokinetic chromosomes and male karotype of 2n = 38 (36 + neo-XY). Males possess two follicles in each testis and females have six panoistic ovarioles in each ovary. Oogenesis and, more closely, spermato genesis, including meiosis and sperm formation, have been studied. Based on the presence of panoistic ovaries and holokinetic chromosomes, Crampton's hypothesis that Zoraptera represent a group of Polyneoptera nearest to the origin of Paraneoptera is considered the most plausible.
Association patterns of bottlenose dolphins (Tursiops aduncus) off Point Lookout, Queensland, Australia
Authors: Chilvers B Louise , Corkeron Peter J
Published: October 2002

The social structure of animal communities is usually measured through interactions or associations of individuals within the community. However, investigating and identifying association patterns for large communities of social animals can be difficult, given the logistical difficulties of identifying a large number of individuals within a given area and time period. In this study, over 550 individuals were identified within a large community of bottlenose dolphins (Tursiops aduncus) sampled intensively during the winters of 1998 and 1999 off Point Lookout, Queensland, Australia. Association patterns within this community were analysed using the half-weight index of association, including seven criteria for selecting individuals for inclusion in the analysis. Selection criteria were based on the number of times an individual was sighted during the entire study period. Overall, the community showed a highly fluid association pattern, with only two selection criteria showing association patterns that differed significantly from random. This type of association pattern is commonly reported for large communities of cetaceans. However, without the inclusion of other population information such as estimates of the proportion of identifiable individuals in the community and of community size, it appears that association patterns for these large communities may not be accurately assessed.
Effects of forestclearcut edges on a forest-breeding songbird
Authors: Harris Rebecca J , Reed J Michael
Published: October 2002

To understand local and regional changes in Neotropical migrant songbird populations it is important to determine whether forest-breeders can use and persist in the dynamic, variegated landscapes created by modern forestry practices. We made detailed observations of a species classified as a mature-forest specialist, the black-throated blue warbler (Dendroica caerulescens), adjacent to clearcut edges and in intact forest in a large industrial forest landscape. We measured reproductive success, habitat use, resource abundance, the potential for inter- and intra-specific competition, and predator densities. Unlike most studies of edge effects, our study showed both positive and negative impacts of associations with edges. We recorded a lower density of potential avian competitors within intact forest, as well as a higher proportion of older male black-throated blue warblers at interior forest sites. In addition, proportionally more fledglings were observed in intact forest. However, males at edge sites had higher pairing success and edges had higher understory density (which is positively associated with reproductive success in other studies), evidence of higher abundance of their primary food source and lower densities of diurnal egg and nestling predators. The net result of these mixed patterns is that males gaining a territory at edge or interior sites appeared to have similar probabilities of producing fledglings.
Rainfall events and downstream drift of microcrustacean zooplankton in a Newfoundland boreal stream
Authors: Campbell Christine E
Published: October 2002

While rainfall events may lead to flushing of zooplankton from lakes, with implications for stream productivity near lake outlets, consideration also needs to be given to zooplankton transported farther downstream. To evaluate such downstream transport, daytime invertebrate drift, stream discharge, and rainfall events were monitored over 4 summers in Cook's Brook, Newfoundland, at a downstream site 1.0 km below the outlet of Big Cook's Pond and an upstream site 1.0 km upstream of the pond. Microcrustacean zooplankton were abundant in some downstream samples; high percent zooplankton abundance (8794%) corresponded to the highest total invertebrate drift densities. Percent zooplankton in downstream drift was strongly correlated with recent rainfall (rS = 0.815, p = 0.025) and stream discharge (rS = 0.964, p = 0.001). The majority of microcrustaceans in the drift were planktonic cladocerans and copepods, the species composition being similar to that in Big Cook's Pond. No zooplankton were ever collected from the upstream site. Ephemeroptera, Diptera, Trichoptera, and Ostracoda were abundant in most drift samples. Zooplankton drift (mean = 0.17 individuals/m3) in Cook's Brook appears to be catastrophic drift, with high precipitation rates and resultant increased flushing rate in Big Cook's Pond leading to "washout" of microcrustaceans 1 km downstream.
The response of stonefly (Plecoptera) nymphs to seasonal increases in predation risk
Authors: McCutchen Nicole A
Published: October 2002

The main objective of this study was to determine if predation risk accounted for the patterns of stonefly (Plecoptera) nymph abundance in the Maligne Valley watershed, Jasper National Park, Alberta. Seasonal declines in nymph density corresponded to increased use of the Maligne Lake Outlet and Lower Maligne River by harlequin ducks (Histrionicus histrionicus). Neither decline represented a shift from aperiodic to nocturnal use of surface rocks. Rather, rock use remained aperiodic throughout the season despite increases in risk. The decline that occurred in the Maligne Lake Outlet also did not represent a shift from small to large surface rocks. These results, when combined with the results of an odor experiment, suggest that nymphs tend to avoid surface rocks when in the presence of harlequin ducks. Nymph density did not decline seasonally in the Middle Maligne River, a site free of harlequin ducks but inhabited year-round by brook char (Salvelinus fontinalis) and rainbow trout (Onchorhynchus mykiss). Nymphs in this site as well as those exposed to char odor were nocturnally biased in their use of the substrate surface. Overall, predation risk appears to play a strong role in the patterns of stonefly nymph abundance in the Maligne Valley watershed, although not in the way originally expected.
DNA sequence analysis of a North Pacific humpback whale (Megaptera novaeangliae) placenta
Authors: Silvers Linda E , Rosel Patricia E , Salden Dan R
Published: October 2002

Whales residing in their natural, noncaptive environments present a particular challenge to the direct observation of parturition and the subsequent analysis of afterbirth tissues. For many years the research community has believed that the Hawaiian Islands serve as one of the winter calving grounds for the North Pacific humpback whale, Megaptera novaeangliae. Direct evidence, however, had not been reported. In 1997 the analysis of a large placenta encountered in the Hawaiian winter grounds of the humpback whale was documented but definitive identification of the source species was not possible. In this report we describe the DNA sequence analysis, by polymerase chain reaction, which was performed on the tissue obtained from that placenta to identify its source. It was concluded from the analysis that the unknown placental tissue originated from a humpback whale. These results have important implications concerning humpback whale reproduction, since this molecular confirmation serves as direct evidence of a humpback whale birth in the Hawaiian winter grounds.
Morphology and ultrastructure of a protistan pathogen in the haemolymph of shrimp (Pandalusspp.) in the northeastern Pacific Ocean
Authors: Bower Susan M , Meyer Gary R
Published: October 2002

A eukaryotic parasite of uncertain taxonomic affiliation, with superficial similarity to parasitic dinoflagellates (large plasmodia and numerous trophonts) but a different mechanism of nuclear division and a lack of organelles characteristic of parasitic dinoflagellates, is described from spot prawns (Pandalus platyceros). Up to 20% of the spot prawns examined from Malaspina Strait, British Columbia, were infected. Infections in the majority of the prawns were cryptic (asymptomatic) but of sufficient duration to affect secondary sexual characteristics and castrate the host. Cryptic infections consisted of plasmodia containing numerous nuclei. The plasmodia were observed in the haemal sinuses of all tissues. In mature plasmodia the nuclei stopped dividing and showed a peripheral chromatin ring, an internal chromatin web, and up to three tiny nucleoli. Mature plasmodia divided into numerous uninucleate trophonts, resulting in symptoms of lethargy, orange discoloration, and milky haemolymph caused by a plethora of either spherical or discoid trophonts. Symptomatic infections of the prawns fished with traps rarely exceeded 2%. In 3 of the 156 symptomatic prawns examined, about 30% of the trophonts were in the process of binary fission. During mitosis the nuclear membrane was persistent, but openings (about 0.8 µm in width) at either pole accommodated emergent spindle-pole bodies to which the few chromosomes were attached by microtubules. Attempts to transmit the infection between prawns in the laboratory were unsuccessful.
Using multiple abundance estimators to infer population trends in Atlantic Puffins
Authors: Calvert Anna M , Robertson Gregory J
Published: October 2002

We used five techniques to estimate the number of Atlantic Puffins (Fratercula arctica) using a study plot on Gull Island, Newfoundland, during the 2000 breeding season. Grubbing of burrows yielded an estimate of a breeding population of 522 (95% CI: 364668) Atlantic Puffins on this plot. Attendance counts of birds standing on the plot consistently underestimated the breeding population. A closed-population estimator with sighting heterogeneity estimated that of the 535 Atlantic Puffins banded since 1997, 370 (336404) used the plot in 2000. Using 370 birds as the marked population, a corrected LincolnPetersen index estimated a total population of 1712 (12332191) based on captured birds. Based on resights of birds, ratios of banded birds to total attendance estimated 2927 (26083335), and the Bowden estimator gave 3502 (30543950) Atlantic puffins. We projected an age-based matrix using literature values, and extracted the proportions of nonbreeding birds and young birds expected at a stable age distribution and compared the proportions with observed values. Based on the large number of nonbreeders suggested by the abundance estimates, we suspect that this population (i) is stable or increasing, (ii) includes breeding-age Atlantic Puffins that do not breed, and (iii) has been enjoying high fecundity in recent years.
Acoustic communication inDrosophila melanogastercourtship: Are pulse- and sine-song frequencies important for courtship success?
Authors: Rybak Fanny , Aubin Thierry , Moulin Bruno , Jallon Jean-Marc
Published: October 2002

During courtship, the male Drosophila melanogaster (Diptera, Drosophilidae) emits two kinds of acoustic signals by means of wing vibrations oriented towards the female: pulse song and sine song. To examine the roles of these two song types, different experimental signals were played back to single pairs of flies (with the males made mute by wing removal). To preserve the natural pattern of sound emission, all the experimental signals were constructed from a representative complete song that included both the pulse and the sine components, recorded during a successful courtship. The first experiment showed that playback of a natural complete song restored to wingless males courtship success comparable to that of normal winged males. In the second experiment, in which we distinguished between the effects of pulse song and sine song, pulse song alone was sufficient to stimulate matings between wingless males and virgin females; sine song had a less stimulating effect. In a third experiment we examined the consequences of modifying the carrier frequency of either signal. This had no particular effect on responses to either pulse or sine song. These results suggest that for both these signals, frequency is not involved in the mating success of D. melanogaster.
Relationships between external morphology and foraging behaviour: bats in the genusMyotis
Authors: Fenton M Brock , Bogdanowicz Wieslaw
Published: October 2002

A morphometric study of 41 species of Myotis revealed significant associations between morphological features and foraging styles, namely aerial feeding, gleaning, feeding over water, and trawling. Aerial feeders have small hind feet, short calcars, short ears, and narrow tragi. Gleaners have small hind feet, long ears, and wide tragi and tend to be larger in body size. Bats that feed over water have large hind feet, short calcars, short ears, and narrow tragi and tend to be smaller in body size. Trawlers have large hind feet and long calcars and tend to be larger in body size. The morphometric analysis also confirmed that some species of Myotis were intermediate in morphological features, coincid ing with alternation between foraging styles. The results support the view that the morphological features previously used to assign Myotis species to subgenera are more functional than phylogenetic, a position supported by recent genetic analyses. Examination of foraging styles from a phylogenetic perspective suggests that aerial feeding is ancestral and that subsequent diversification has been associated with partitioning and specialization into either gleaning or foraging over water and trawling. When the predictions from the multivariate analysis of the data for the genus Myotis are used with data from other bats, they suggest that 5 species of Nycteris are gleaners, while 11 species of Eptesicus are either aerial feeders or feed over water.
Cannibalism and ontogenetic changes in the response of the freshwater shrimp Mysis relicta to chemical cues from conspecific predators
Authors: Quirt Janice , Lasenby David
Published: October 2002

Laboratory feeding experiments demonstrated that juvenile and immature mysids could be susceptible to cannibalism by adult mysids. Differences in the responses to chemical cues between juvenile, immature, and adult Mysis relicta were determined by noting the distributions of test animals after a 4-h test period in a Y-tube choice-test olfactometer. Both juvenile and immature mysids avoided water that had contained adult mysids.
Phylogenetic systematics of "Bathydoris" s.l. Bergh, 1884 (Mollusca, Nudibranchia), with the description of a new species from New Caledonian deep waters
Authors: Valdés Ángel
Published: October 2002

There are six valid species in the traditional genus Bathydoris, all of them found in polar or deep waters: Bathydoris abyssorum Bergh, 1884 (from the deep equatorial Pacific Ocean), Bathydoris ingolfiana Bergh, 1899 (from Greenland), Bathydoris hodgsoni Eliot, 1907 (from Antarctic and subantarctic waters), Bathydoris clavigera Thiele, 1912 (from the Argentinean deep-sea basin and Antarctica), Bathydoris aioca Ev. Marcus and Er. Marcus, 1962 (from deep waters off California), and a new species, Bathydoris spiralis (from deep waters off New Caledonia). Bathydoris patagonica Kaiser, 1980 and Bathydoris violacea Baranets, 1993 are regarded as synonyms of B. hodgsoni and B. clavigera, respectively. Bathydoris spiralis is clearly distinguishable from other members of the genus mainly in having a triaulic reproductive system and a very elongated, spirally coiled deferent duct. Examination of the holotype of B. violacea revealed that it is a synonym of B. clavigera. Bathydoris vitjazi Minichev, 1969 is most likely a synonym of B. hodgsoni, but is provisionally regarded as nomen dubium until more material becomes available. The phylogenetic hypothesis supports the monophyly of the Anthobranchia but shows that the genus Bathydoris is paraphyletic. Species of Bathydoris are divided into two clades, one of them also containing the phanerobranch and cryptobranch dorids. Bathydoris type species B. abyssorum retains its name and diagnosis, but B. clavigera and B. spiralis are excluded from this genus. They are, however, provisionally maintained in "Bathydoris" s.l., a likely paraphyletic group. This result shows some incongruities between the traditional nomenclatural system and phylogenetic systematics.
Roosting behaviour and roost selection of female big brown bats (Eptesicus fuscus) roosting in rock crevices in southeastern Alberta
Authors: Lausen Cori L , Barclay Robert M.R
Published: October 2002

We studied big brown bats (Eptesicus fuscus) roosting in rock crevices along the South Saskatchewan River in southeastern Alberta. We documented roosting behaviour and roost selection. During pregnancy and lactation, individuals aggregated as several small groups or one large group (maternity colony). Postlactating females roosted alone more frequently. During postlactation, individuals periodically returned to roost with a group dominated by pups, between periods of roosting alone. We identified 72 roosts used by members of the colony. Adult females switched roosts frequently and few roosts (24%) were reused. During pregnancy and lactation, the colony roosted in a 1.25-km length of the river valley on the northwest side of the river. With the onset of postlactation, females began roosting on both sides of the river and within a longer section of the river valley, and roosts faced in a more southerly direction. Crevices selected as roosts were more vertical in orientation, were farther from level ground above, and had openings that were smaller than those randomly available. Roosts used during pregnancy, lactation, and postlactation differed in physical attributes; lactation roosts were deeper and had larger openings. Selection of crevices with particular attributes suggested that selection was based on microclimate and avoidance of predation.
Edge effects on survival and behaviour of juvenile red squirrels (Tamiasciurus hudsonicus)
Authors: Anderson Elizabeth M , Boutin Stan
Published: October 2002

Much research has examined parasitism and predation rates on avian nests within the context of edge effects. Few studies, however, have considered the influence that behavioural compensation for high predation risk may have on subsequent survival rates and edge effects. We attempted to determine whether juvenile red squirrels (Tamiasciurus hudsonicus) experience edge effects by comparing the survival and behaviour of individuals born along a forest edge with those of individuals born in the forest interior. A combination of telemetry, direct observation, and livetrapping was used to determine the fate of juveniles born during the summers of 1987 through 1998 and the behaviour of juveniles born during the summers of 1997 and 1998 in Kluane, Yukon. There were no differences in survival between edge and interior juveniles from birth to emergence but there was a trend towards higher survival rates for edge juveniles from emergence to weaning. Behavioural differences between edge and interior juveniles were consistent with these survival differences: edge juveniles spent less time travelling and foraging and more time resting near the time of weaning than did interior juveniles. Edge and interior mothers differed little behaviourally during the early emergence period. The significant differences in juvenile behaviour which we found suggest that behaviour may indeed moderate differences in predation risk between edge and interior habitats and thus should be considered in other studies that examine the influence of edges on survival or nest predation.
Natural infection by intestinal cestodes: variability and effect on growth in Greater Snow Goose goslings (Chen caerulescens atlantica)
Authors: Righi Mohamed , Gauthier Gilles
Published: October 2002

We determined the species of intestinal helminths in Greater Snow Goose (Chen caerulescens atlantica) goslings and examined annual variability in infection levels over a 5-year period on Bylot Island, Nunavut. The intestines of 112 wild goslings collected when near fledging were examined. We also evaluated the effect of intestinal parasites on growth and behaviour of captive goslings in a controlled experiment. In 2000, one group (n = 11) was treated with anthelmintic drugs (Piperazine 52 for nematodes and Droncit® for cestodes) and the other (n = 14) was used as a control. Four hymenolepidid cestodes were identified: Drepanidotaenia lanceolata, Hymenolepis barrowensis, Microsom acanthus setigera, and Retinometra longivaginata. No nematodes were detected. Prevalence of intestinal cestodes in wild goslings was 100% but their abundance varied among years (from 28.9 ± 2.7 to 175.2 ± 49.7 (mean ± SE) cestodes per host) and individuals. Captive goslings treated with anthelmintic drugs were free of parasites, whereas all control goslings were parasitized when sacrificed at 36 d, although cestode abundance in the latter group was much lower (4.2 ± 0.7) than in wild goslings. There was no difference in growth rates between treated and control captive goslings until they were 36 d of age. However, treated goslings spent more time feeding than control ones, which suggests an effect of cestodes on host behaviour.
Effects of a low-Ca2+environment on branchial chloride cell morphology in chum salmon fry and immunolocalization of Ca2+-ATPase in chloride cells
Authors: Uchida Katsuhisa , Hasegawa Sanae , Kaneko Toyoji
Published: October 2002

To clarify the involvement of branchial chloride cells in Ca2+uptake in fresh water (FW), chloride-cell morphology was compared in chum salmon (Oncorhynchus keta) fry acclimated to defined FWs with different Ca2+concentrations (0, 0.1, and 0.5 mM). Using immunocytochemical staining with an antiserum specific for Na+,K+-ATPase, chloride cells were detected in both filament and lamellar epithelia. The numbers and sizes of chloride cells in the lamellar epithelia were greater in the low-Ca2+groups (0 and 0.1 mM Ca2+) than in the normal-Ca2+groups (0.5 mM Ca2+and normal FW), whereas filament chloride cells were not affected in number or size by the environmental Ca2+concentration. Electron-microscope observations also revealed that enlarged lamellar chloride cells were more frequently observed in the 0 mM Ca2+group than in the 0.5 mM Ca2+group. To obtain morphological evidence for Ca2+uptake through the branchial epithelia, cellular localization of Ca2+-ATPase was examined with a monoclonal antibody specific for human erythrocyte Ca2+-ATPase. Ca2+-ATPase immunoreactivity was detected in Na+,K+-ATPase-immunoreactive chloride cells in both filament and lamellar epithelia. Using electron-microscope immunocytochemistry, Ca2+-ATPase was found to be localized in the tubular system, which is continuous with the basolateral membrane of chloride cells. These findings indicate that chloride cells in the lamellar epithelia activated by a low Ca2+concentration may constitute the extra Ca2+and NaCl uptake capacity required to maintain homeostasis in soft water.
Predation risk and nest-site selection in the Inca tern
Authors: Velando Alberto , Márquez José C
Published: October 2002

Most tern species (Sternidae) are typically open-ground breeders; the Inca tern (Larosterna inca), however, breeds in crevices. This paper reports the first analysis of nest-site characteristics, predation rates, and breeding success in this species. We tested for evidence of natural selection on nest-site preferences in a colony subjected to high rates of predation by the peregrine falcon (Falco peregrinus). Characteristics of occupied sites differed from those of non-occupied sites. Terns selected sites with longer chambers, a greater number of cavities, and more overhead and lateral cover that were located close to the cliff edge. Predation was the main cause of breeding failure, and successful sites differed from unsuccessful sites, which is evidence for ongoing natural selection. Chicks at sites in larger crevices and more cavities remained at the site longer and were less likely to be depredated by peregrine falcons. Probably in response to the presence of predators, adults flew towards the colony in flocks, which "dissolved" at the cliff edge. Sites located far from the edge were more likely to be depredated and adults breeding there fed their chicks less frequently and, consequently, reared lighter chicks. The concordance between site preference and predation pressure on nest-site selection suggests that the use of non-preferred sites imposed a cost in the form of increased nest predation.
Photolyase activity of the embryo and the ultraviolet absorbance of embryo jelly for several Ontario amphibian species
Authors: Smith M Alex , Berrill Michael , Kapron Carolyn M
Published: October 2002

Organisms whose eggs develop at or near the interface between air and water may be particularly vulnerable to damage from ultraviolet radiation. The primary form of ultraviolet B (UV-B) radiation damage to biological systems is the formation of cyclobutane pyrimidine dimers (CBPDs) in DNA. The most common method of repairing this damage is photoenzymatic repair via photolyase, whose actions are specific to CBPDs. We utilized a bacterial-transformation assay to estimate the level of photolyase activity of various tissue types in seven species of amphibians collected in south-central Ontario. In this assay, the photolyase activity of a species is measured as the rate of CBPD removal from UV-B-damaged plasmid DNA by cell-free extracts created from the tissue of the species in question. The depth of oviposition and the UV-B absorbance of the embryo jelly, two variables that alter an embryo's in situ exposure to UV-B radiation, were measured to determine whether the level of photolyase activity was correlated with expected UV-B exposure. In vitro measurements of photolyase activity for the seven species were significantly different (F[6]= 10.31, p < 0.0001) and tended to be positively correlated with expected in vivo exposure to UV-B radiation.
Species diversity of bats (Mammalia: Chiroptera) in forest fragments, primary forests, and savannas in central Amazonia, Brazil
Authors: Bernard Enrico , Fenton M Brock
Published: October 2002

The exact number of species of bats in Brazilian Amazonia is not precisely known because relatively few sites have been surveyed in detail. Here we present an updated species list of the bats of Alter do Chão at the delta of the Tapajós River in Pará State. Using mist nets and acoustic monitoring of echolocation calls we systematically surveyed 5 forest sites, 14 natural forest fragments, and 12 savanna sites. We captured 3978 bats representing 70 species, 40 genera, and 7 families. Fifty species were recorded in savannas, 44 in forest sites, and 41 in forest fragments. The mean capture rate was higher in savanna and forest sites (0.747 and 0.741 bats/mist-net-hour (mnh), respectively) than in forest fragments (0.483 bats/mnh). Our list includes new records for Brazil and extends knowledge of the distribution of some species. Species-accumulation curves and species-richness estimators indicate that 75100 bat species occur at Alter do Chão, suggesting that our inventory recorded approximately 6789% of the bat fauna there. Using cluster analysis we compared the bat fauna at Alter do Chão with the faunas from 17 other sites in the Neotropics. There was 65% similarity with the fauna from Manaus (Brazil), 60% with that from Iwokrama (Guyana), and 57% with that from Paracou (Franch Guiana). Aspects of the conservation status of some species present at Alter do Chão are discussed.
BABAR RESULTS ON CP VIOLATION
Authors: DORFAN JONATHAN
Published: October 2002

No written contribution received.
OBSERVATION OF LARGE CP VIOLATION IN THE B-MESON SYSTEM
Authors:   REPRESENTING THE BELLE COLLABORATION, OLSEN STEPHEN L.
Published: October 2002

A measurement of the CP violation parameter sin 2ϕ1 based on a 29.1 fb-1 data sample recorded at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric e+ e- collider is reported. One neutral B meson is fully reconstructed as a J/ψKS, ψ(2S)KS, χc1KS, ηcKS, J/ψKL or J/ψK*0 decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin 2ϕ1 = 0.99±0.14(stat) ±0.06(sys). Since this value is more than 6σ from zero, we can conclude that CP symmetry is violated in the neutral B meson system.
THEORY OF CP VIOLATION IN THE B-MESON SYSTEM
Authors: NEUBERT MATTHIAS
Published: October 2002

Recent developments in the theory of CP violation in the B-meson system are reviewed, with focus on the determination of sin 2β from B → J/ψ K decays, its implications for tests of the Standard Model and searches for New Physics, and the determination of γ and α from charmless hadronic B decays.
CLEO RESULTS: B DECAYS
Authors: CASSEL DAVID G.
Published: October 2002

Measurements of many Standard Model constants are clouded by uncertainties in nonperturbative QCD parameters that relate measurable quantities to the underlying parton-level processes. Generally these QCD parameters have been obtained from model calculations with large uncertainties that are difficult to quantify. The CLEO Collaboration has taken a major step towards reducing these uncertainties in determining the CKM matrix elements |Vcb| and |Vub| using new measurements of the branching fraction and photon energy spectrum of b → s γ decays. This report includes: the new CLEO measurements of b → s γ decays, |Vcb|, and |Vub|; the first results from CLEO III data - studies of B → Kπ, ππ, and [Formula: see text] decays; mention of some other recent CLEO B decay results; and plans for operating CESR and CLEO in the charm threshold region.
BELLE B PHYSICS RESULTS
Authors:   The Belle Collaboration, TAJIMA H.
Published: October 2002

B physics results from the Belle experiment are reviewed. Precise measurements of Cabbibo-Kobayashi-Maskawa matrix elements are made. Several decay modes are observed which will enable us to measure the CP angles ϕi in channels other than B0 → ψK0 modes. New rare decay modes are observed in many channels. Particular attention is paid to the first observation of the electroweak penguin-mediated decay.
BABAR B DECAY RESULTS
Authors:   On behalf of the BABAR collaboration, NASH JORDAN
Published: October 2002

Data from the first run of the BABAR detector at the PEP II accelerator are presented. Measurements of many rare B decay modes are now possible using the large data sets currently being collected by BABAR. An overview of analysis techniques and results on data collected in 2000 are described.
RECENT KTEV RESULTS
Authors: KESSLER R.
Published: October 2002

Preliminary KTEV results are presented based on the 1997 data set, and include an improved measurement of ℜ(∊′/∊), CPT tests, and precise measurements of τS and Δm.
RESULTS ON CP VIOLATION FROM THE NA48 EXPERIMENT AT CERN
Authors:   On Behalf of the NA48 Collaboration , NA48 is a Cagliari, Cambridge, CERN, Dubna, Edinburgh, Ferrara, Firenze, Mainz, Orsay, Perugia, Pisa, Saclay, Siegen, Torino, Vienna and Warsaw collaboration, ICONOMIDOU-FAYARD LYDIA
Published: October 2002

In this article the current status and latest results of the NA48 experiment at CERN are given. We present in more details the analysis performed for the Re(ε′/ε) measurement with the combined statistics accumulated during the 1998 and 1999 data periods. Reviewing the NA48 rare decay program, we select to underline the new results on the branching ratio and the aV factor for the decay K L → π0γγ and the K L → π+ π- e+ e- CP violating decay.
STATUS OF THE KLOE EXPERIMENT AT DAΦNE
Authors:   On behalf of the KLOE Collaboration, BOSSI FABIO
Published: October 2002

Since April 1999, the KLOE experiment at DAΦNE has collected about 200 pb-1 of data, produced in e+ - e- collision at the c.m. energy of 1020 MeV, the mass of the ϕ(1020) meson. This data has been used for detailed studies on the ϕ radiative decays, as well as on rare [Formula: see text] decays. The first results, based on the ~ 20 pb-1 collected in year 2000 are presented here. Perspectives for the future data taking are also discussed.
TAU AND CHARM PHYSICS HIGHLIGHTS
Authors: ROUDEAU P.
Published: October 2002

In τ physics, we are at the frontier between the completion of the LEP program and the start of analyses from b-factories, which are expected to produce results in the coming years. Nice results from CLEO are steadily delivered in the meantime. For charm, impressive progress have been achieved by fixed target experiments in the search for CP violation and [Formula: see text] oscillations. First results from b-factories demonstrate the power of these facilities in such areas. The novel measurement of the D* width by CLEO happens to be rather different from current expectations. The absence of a charm factory explains the lack or the very slow progress in the absolute scale determinations for charm decays.
QUARK MASSES AND WEAK COUPLINGS IN THE SM AND BEYOND
Authors: BARBIERI RICCARDO
Published: October 2002

I discuss two topics: i) the empirical adequacy of the Standard Model in the Flavour Sector in view of recent data; ii) the possible existence of a hidden structure in the quark masses and mixings based on textures.
RECENT PROGRESS IN HEAVY QUARK PHYSICS
Authors: WISE MARK B.
Published: October 2002

Some of the recent progress in heavy quark physics is reviewed. Special attention is paid to inclusive methods for determining Vub and factorization in nonleptonic [Formula: see text] decays. Theoretical predictions for [Formula: see text] production near threshold are also discussed.
RARE DECAYS: THEORY VS. EXPERIMENTS
Authors: ISIDORI GINO
Published: October 2002

We present an overview of rare K, D and B decays. Particular attention is devoted to those flavour-changing neutral-current processes of K and B mesons that offer the possibility of new significant tests of the Standard Model. The sensitivity of these modes to physics beyond the Standard Model and the status of their experimental study are also discussed.
TEVATRON: PRESENT STATUS AND FUTURE PROSPECTS
Authors:   For CDF and DØ Collaboration, KIM YOUNG-KEE
Published: October 2002

This article describes the present status and physics prospects for Run II at the Fermilab Tevatron accelerator. The accelerator complex and both the collider experiments, CDF and DØ, have completed extensive upgrades resulting in a significant increase in luminosity and physics capability. The sensitivity of the Tevatron Run II physics program is expected to be about 500 times that of Run I.
QUARK GLUON PLASMA - RECENT ADVANCES
Authors: ODYNIEC GRAZYNA
Published: October 2002

While heavy ion collisions at the SPS have produced excited strongly interacting matter near the conditions for quark deconfinement, the RHIC may be the first machine capable of creating quark-antiquark plasmas sufficiently long-lived to allow deep penetration into the new phase. A comprehensive experimental program addressing this exciting physics has been put into place. Presented here are preliminary results from Au+Au at √S = 130 GeV obtained during the first RHIC run and some CERN SPS results from Pb+Pb at √S = 17 GeV (particularly relevant to QGP search).
RECENT RESULTS FROM SUPER-KAMIOKANDE
Authors:   For the Super-Kamiokande Collaboration, GOODMAN J. A.
Published: October 2002

Super-Kamiokande is a 50 Kiloton water-Cherenkov that detects neutrinos in the MeV energy range that are produced in the Sun and neutrinos in the GeV energy range produced in the atmosphere by cosmic rays. The detector has been operational since April of 1996. In this paper results of our most recent analysis will be presented on both atmospheric and solar neutrinos.