bluuebunny/crossref_metadata_2025 huggingface dataset:
Inotropic effects on mammalian skeletal muscle change with contraction frequency
Authors: Barclay J K , Reading S A , Murrant C L , Woodley N E
Published: September 2003

Over the last decade, we have attempted to determine if mammalian skeletal muscle's steady-level force development as established by mechanical and stimulation parameters can be increased or decreased by physiological signals. In these experiments, nitric oxide (NO), endothelin-1 (ET-1), adenosine (Ado), and β-adrenergic agonists (β) modified force production in the soleus and (or) the extensor digitorum longus (EDL) of the mouse. NO and β increased the force produced by 0.5-s tetanic contractions at 0.6 contractions/min in both muscles. While EDL did not respond to either Ado or ET-1, the developed force of the soleus was amplified by Ado but attenuated by ET-1. Increased cAMP analogue concentrations amplified developed force in both muscles, but a cGMP analogue had no effect on either muscle. Following an increase in the contraction frequency of the soleus, the increased force in response to NO disappeared, as did the decreased force to ET-1. The increase in force due to a cAMP analogue disappeared during fatigue but reappeared quickly during recovery. Thus, steady-level developed force can be modified by a number of substances that can be released from locations in the body or muscle. The response to a given compound is determined by a complex interaction of metabolic and intracellular signals on the force-generating cascade.Key words: endothelium-derived factors, cAMP, cGMP, isoproterenol, adenosine.
Functional study of intracellular P-gp- and MRP1-mediated pumping of free cytosolic pirarubicin into acidic organelles in intrinsic resistant SiHa cells
Authors: Laochariyakul Ponpun , Ponglikitmongkol Mathurose , Mankhetkorn Samlee
Published: September 2003

We sought to determine the efficiency of the intracellular functional P-gp- and MRP1-mediated pumping of THP into acidic organelles in SiHa cells and etoposide-resistant SiHa/VP16 cells. The expression of both MDR1 and MRP1 genes of SiHa and SiHa/VP16 cells was clearly shown by using RTPCR. The functional studies of both intracellular functional P-gp- and MRP1-mediated pumping were performed by using THP in a conventional spectrofluorometer, and they demonstrated that SiHa and SiHa/VP16 cells are good models to illustrate the functional role of intracellular P-gp and MRP1 in the transport of free cytosolic drug into acidic organelles. The functional P-gp and MRP1 proteins were identified both on plasma membranes and on intracellular vesicle membranes. Within the limit of experimental error, similar efficiencies in THP transport were observed in the two proteins at both locations in SiHa and SiHa/VP16 cells. The P-gp- and MRP1-mediated pump coefficient (kav), MichealisMenten's constant (Kmv), and maximal pumping rate (Vmaxv) values of those located on vesicular membranes were 1.87 ± 0.30 pL·cell1·s1, 1.63 ± 0.21 μM, and 4.95 ± 0.45 nM·s1, respectively. Drug retention inside acidic organelles (Cvmon) of SiHa cells was significantly higher than that of SiHa/VP16 cells, perhaps a consequence of slower movement of recycling endosomes and (or) lysosomes to the cell membrane of SiHa cells, leading to distended organelles and cell death. Our results suggest that intracellular P-gp and MRP1 proteins play an important role in the transport of free drug from cytosol to cytoplasmic acidic organelles.Key words: intrinsic resistance, multidrug resistance, intracellular functional P-glycoprotein and MRP1, acidic organelle, fluorescence spectroscopy, kinetic parameters.
Modulation of endogenous production of H2S in rat tissues
Authors: Zhao Weimin , Ndisang Joseph Fomusi , Wang Rui
Published: September 2003

H2S is an important gasotransmitter with a vasorelaxant property. The modulation of endogenous H2S generation from different tissues and the functional consequence of this modulation are not clear. In the present study, the production of H2S from vascular tissues as well as the liver and ileum of rats was measured. The H2S production rate was significantly greater in rat liver than rat vascular tissues. H2S production in rat aortae, ileum, and liver tissues was upregulated by sodium nitroprusside in a cGMP-dependent fashion. Amino-oxyacetate (AOA) (1 mM) abolished H2S production in liver tissues and partially inhibited H2S production in the ileum, while D,L-propargylglycine (PPG) at a similar concentration only slightly inhibited H2S production in liver. Intraperitoneal injection PPG, but not AOA, significantly suppressed H2S production in liver, aorta, and ileum tissues. The systolic blood pressure of rats was significantly increased 23 weeks after i.p. injection of PPG. It is concluded that the endogenous production of H2S could be modulated by NO. AOA and PPG have different capacities in regulating the endogenous production of H2S in different types of tissues.Key words: gasotransmitter, cGMP, hydrogen sulfide, nitric oxide, vascular tissues.
Colitis induced by proteinase-activated receptor-2 agonists is mediated by a neurogenic mechanism
Authors: Nguyen Cathy , Coelho Anne-Marie , Grady Eileen , Compton Steven J , Wallace John L , Hollenberg Morley D , Cenac Nicolas , Garcia-Villar Rafael , Bueno Lionel , Steinhoff Martin , Bunnett Nigel W , Vergnolle Nathalie
Published: September 2003

Proteinase-activated receptor-2 (PAR2) activation induces colonic inflammation by an unknown mechanism. We hypothesized that PAR2agonists administered intracolonically in mice induce inflammation via a neurogenic mechanism. Pretreatment of mice with neurokinin-1 and calcitonin-gene-related peptide (CGRP) receptor antagonists or with capsaicin showed attenuated PAR2-agonist-induced colitis. Immunohistochemistry demonstrated a differential expression of a marker for the type-1 CGRP receptor during the time course of PAR2-agonist-induced colitis, further suggesting a role for CGRP. We conclude that PAR2-agonist-induced intestinal inflammation involves the release of neuropeptides, which by acting on their receptors cause inflammation. These results implicate PAR2as an important mediator of intestinal neurogenic inflammation.Key words: trypsin, proteinase-activated receptor-2, colitis, neurogenic inflammation, substance P, neurokinin-1 receptors, calcitonin-gene-related peptide.
Comparative effects of tamoxifen and angiotensin II type-1 receptor antagonist therapy on the hemodynamic profile of the ovariectomized female rat
Authors: Pham-Dang My-Lan , Clement Robert , Mercier Isabelle , Calderone Angelino
Published: September 2003

Hormonal replacement therapy (HRT) has failed to provide a cardioprotective action in postmenopausal women, and thus alternative pharmacological approaches are required. The present study examined the therapeutic potential of the partial estrogen receptor agonist tamoxifen and the angiotensin II type-1 receptor antagonist irbesartan on the hemodynamic profile of ovariectomized (OVX) female SpragueDawley rats (911 weeks). Three weeks following ovariectomy, uterine atrophy was evident and body weight was increased as compared with sham-operated animals. Left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), and mean arterial pressure (MAP) were significantly increased in the OVX rats as compared with sham rats. One week following ovariectomy, rats were treated with either tamoxifen (10 mg kg1 day1) or irbesartan (40 mg kg1 day1) for a period of 2 weeks. The administration of tamoxifen to OVX rats partially reversed uterine atrophy and prevented body weight gain, albeit body weight remained significantly lower than in sham-operated animals. LVSP and LVEDP were normalized in the tamoxifen-treated OVX rats, whereas MAP remained elevated. Irbesartan partially reduced the body weight gain of the OVX rats and did not influence uterine atrophy. LVSP and MAP were normalized in irbesartan-treated OVX rats, whereas LVEDP remained elevated. These data demonstrate that irbesartan rather than tamoxifen was efficacious in normalizing MAP in the OVX rats without a secondary effect on the uterus.Key words: ovariectomy, hemodynamics, tamoxifen, AT1 receptor antagonists.
Habitat selection and home-range dynamics of the Gaspé caribou: a hierarchical analysis
Authors: Mosnier Arnaud , Ouellet Jean-Pierre , Sirois Luc , Fournier Nelson
Published: September 2003

We used several spatial and temporal scales to determine space and habitat use of the caribou (Rangifer tarandus caribou) of the Gaspé Peninsula. Thirty-five radio-collared caribou were followed from November 1998 to April 2001. Habitat use was studied by superimposing radiolocations on ecoforestry maps using five predefined habitat types (deciduous, immature, mature spruce, mature fir, and barren). At a finer scale, we tracked caribou in forested areas during winter 2000 and 2001 in order to describe physical and biological characteristics of foraging tracks and used stands. Our results indicated that the distribution of caribou extended beyond the limits of Gaspé Conservation Park. Patterns of space use showed the existence of three groups, which formed a metapopulation. These groups consisted of spatially distinct units that used space and habitat differently. At the home-range level, caribou preferred barren areas found in alpine and subalpine zones at all times of the year. The most frequently used forested habitat type was the mature fir. At the finer scale of foraging tracks, caribou selected fir stands characterized by dense snow conditions and large diameter trees bearing greater quantities of lichen. Our results demonstrated the importance of protecting areas outside the park that are likely to become used or reused by caribou, and of managing these areas to increase settlement by caribou. Lastly, management plans must be adapted to each of the three groups forming this metapopulation.
Home-range size of northern flickers (Colaptes auratus) in relation to habitat and parental attributes
Authors: Elchuk C L , Wiebe K L
Published: September 2003

Energetic requirements during the breeding season and environmental factors such as food abundance and habitat quality may influence spatial use of the landscape by adult birds. We determined home-range and core-area sizes for 52 adult northern flickers (Colaptes auratus) during the brood-rearing period in 1999 and 2000 in British Columbia. We examined the relationship between home-range size and correlates of energetic demands (age, sex, body size, brood size, nest density, laying attempt). We also examined the association between vegetation type at the landscape scale and ground-cover characteristics at the foraging scale with home-range size, core-area size, and maximum distance flown from the nest to forage. Mean home-range size was 25 ha, with a mean core area of 7 ha. Home-range size was positively related to laying attempt and nearest neighbour distance. No significant relationships were found at the landscape level between vegetation type and home-range size or between ground-cover characteristics and core-area size. However, flickers flew farther to forage in home ranges with tall vegetation and bare ground. Home-range size of flickers may be related to both energetic demands on the adults and on the spatial arrangement of quality foraging patches around the nest site.
Misinterpretation of character scaling: a tale of sexual dimorphism in body shape of common lizards
Authors: Kratochvíl Luká , Fokt Michael , Rehák Ivan , Frynta Daniel
Published: September 2003

Male-biased sexual dimorphism in head, limbs, and tail scaled to snoutvent length has been reported in many lizard species. Consequently, various hypotheses have been proposed to explain observed body-shape dimorphism. According to the majority of them, the proportions of body components are adaptively related to sexual differences in ecology as well as in reproductive behaviour. Our study shows an alternative, much more parsimonious explanation in the common lizard (Lacerta vivipara). According to our analyses, the exaggeration of a single trait, specifically trunk length in females, may explain the whole pattern of sexual differences in body shape. The only consistent adaptive hypothesis, then, is that females with a larger abdominal cavity, and consequently a longer trunk, have a reproductive advantage. Size-adjusted heads, limbs, and tails traditionally reported to be larger in males than in females, features ascribed to numerous evolutionary mechanisms, thus appear to be just an artifact of inappropriate scaling to a sexually dimorphic trait (snoutvent length). As scaling to a single trait has been routinely used in many studies carried out in animals, we warn against quick interpretations based on such analyses and recommend more cautious inspection of allometries.
Coyote foraging ecology and vigilance in response to gray wolf reintroduction in Yellowstone National Park
Authors: Switalski T Adam
Published: September 2003

Coyotes (Canis latrans) in Yellowstone National Park (YNP) have lived in the absence of wolves (Canis lupus) for over 60 years. I examined whether wolf reintroduction in 1995 and 1996 in YNP influenced coyote vigilance and foraging ecology. From December 1997 to July 2000, my co-workers and I collected 1708 h of coyote activity budgets. Once wolves became established in the Park, they once again provided a continuous source of carrion in the Lamar Valley and we found that coyotes began feeding on carcasses throughout the year. Although we documented that wolves killed coyotes, it also became clear that surviving coyotes quickly adjusted their behaviors when wolves were present. When coyotes were near wolves or in areas of high wolf use, they fed on carcasses much more; however, they increased the amount of time spent in vigilance activities and decreased rest. There appears to be a trade-off in which wolf kills provide a quick source of food that is energetically advantageous to coyotes; however, attendant costs included increased vigilance, decreased rest, and a higher risk of being killed. Changes in the behavior of coyotes in response to the reintroduction of this large carnivore may ultimately have wide-ranging cascading effects throughout the ecosystem.
Sexual difference in modes of selection on the pleopods of crayfish (Decapoda: Astacoidea) revealed by the allometry of developmentally homologous traits
Authors: Kato Naoko , Miyashita Tadashi
Published: September 2003

Crayfish have five pairs of abdominal limbs called pleopods. In males, the first and second pairs of pleopods are used for transferring spermatophores to the female during copulation. The remaining pleopods in males have no obvious function. Female crayfish use their pleopods to carry eggs. Accordingly, it is expected that the selection pressures that act on the pleopods differ between males and females. To test this hypothesis, we estimated modes of selection on pleopods in two species of crayfish (Procambarus clarkii and Pacifastacus trowbridgii) by comparing allometric relationships in functional and nonfunctional pleopods. Since pleopods are serially homologous traits, developmental constraints on these traits appear to be minimal. The lengths of the first male pleopods, used in copulation, showed lower allometric values and less dispersion around the regression line, suggesting that they have been under stabilizing selection. This likely occurs because the major selective force is the ability of males to copulate with females of various sizes. The pleopods of females showed higher allometric values than pleopods of males without an assigned function. This suggests that the pleopods of females have been under directional selection, most likely because they are longer and can therefore carry more eggs.
Seasonal and diurnal activity of sixgill sharks (Hexanchus griseus) on a shallow water reef in the Strait of Georgia, British Columbia
Authors: Dunbrack Robert , Zielinski Robert
Published: September 2003

The bluntnose sixgill shark (Hexanchus griseus) is a large, deepwater, cosmopolitan species whose range includes the Strait of Georgia, British Columbia. Although this species is probably the top predator on most of the world's continental shelves, there is little information on its population biology or behaviour. At a unique site off Flora Islets, in the Strait of Georgia, a number of H. griseus individuals show unexpected diurnal activity on a shallow reef. Regular movements of these sharks along the base of the reef wall allowed us to use an automated, time-lapse video system to make the first extensive observations of their behaviour between June 2001 and July 2002. Sixgill shark frequency (no. of sharks observed/h) increased in June and reached a peak between mid-June and mid-July. Sixgill sharks were not observed between October and May. Sixgill shark frequency was highest in the afternoon and the sharks tended to move as individuals rather than in groups. The observations suggest that this shallow-water activity is not related to either reproduction or feeding and its purpose remains unclear.
Moult intensity and chronology of Tundra Swans during spring and fall migration at Long Point, Lake Erie, Ontario
Authors: Craigie G Eoin , Petrie Scott A
Published: September 2003

Moult intensity and chronology in staging Eastern-Population (EP) Tundra Swans (Cygnus columbianus columbianus) were studied during spring in 1999 and 2000 (n = 35) and during fall in 1999, 2000, and 2001 (n = 47) at Long Point, Lake Erie, Ontario. To test for age, sex, and seasonal differences in moult intensity, 20 feather regions were scored according to the proportion of growing feathers. Adult, subadult, and juvenile Tundra Swans moulted contour feathers at low intensities during spring and fall. Males and females of all three age classes had similar patterns and intensities of moult during spring and fall. Shared costs of incubation and brood rearing, perennial monogamy, and lack of a breeding plumage could be some of the pressures selecting for intersexual similarities in feather replacement during migration. Adult, subadult, and juvenile Tundra Swans moulted more intensively during fall than spring. Larger lipid reserves and seasonal dietary differences may allow fall-staging Tundra Swans to moult more intensively than spring-staging birds at Long Point. Overlap of nutritionally costly events (moult and migration) may be necessary as Tundra Swans spend half of their annual cycle on spring and fall staging areas. However, reduced daily nutritional costs associated with moulting at low intensities and migrating slowly apparently permits the overlap of these two life-cycle events.
Estimating diet composition for mountain hares in newly established native woodland: development and application of plant-wax faecal markers
Authors: Rao Shaila J , Iason Glenn R , Hulbert Ian AR , Mayes Robert W , Racey Paul A
Published: September 2003

Knowledge of the feeding ecology of mammalian herbivores is fundamental in predicting their responses to habitat change. Where native woodlands are newly established in open moorland, the extent to which trees form part of the diet of mountain hares (Lepus timidus) is unknown. This information is necessary for predicting the potential effects of mountain hare browsing on woodland establishment. The n-alkanes and a long-chain fatty alcohols found in the cuticular wax of diet plants and faeces (N = 240) were used as markers to estimate the composition of the diet of mountain hares in an area of moorland with newly established Pinus sylvestris and Betula pubescens woodland. During winter, the diet of mountain hares was dominated by Calluna vulgaris, but there was a seasonal shift to a diet dominated by grasses, sedges, and rushes in summer. Pinus sylvestris and B. pubescens were minor dietary components in all seasons. A higher proportion of grasses, sedges, and rushes was found in the diet of lactating females. Results suggest that when an alternative browse species such as C. vulgaris is widely available, mountain hares may not have a large impact on the establishment of native woodland. The dietary results from this study are in broad agreement with those from previous studies using other techniques.
Ontogenetic variation in antipredator behavior of Iberian rock lizards (Lacerta monticola): effects of body-size-dependent thermal-exchange rates and costs of refuge use
Authors: Martín José , López Pilar
Published: September 2003

In lizards, ontogenetic changes in body size affect thermal-exchange rates. This simple physical property may have consequences for thermoregulation, and also for antipredator behavior. We examined how ontogenetic changes in body mass affect rates of heating and cooling of the lizard Lacerta monticola, confirming the general result obtained for other lizards. We further analyzed the differences between juveniles and adults in approach distances to a simulated predator and in time to emerge from refuges. Juvenile lizards have a lower absolute running speed, making them more vulnerable to predation. However, in contrast to results expected from optimal-escape theory, approach distances were shorter for juveniles than for adults. Juveniles may be confident in their small size and only flee when the probability of being detected is high. On the other hand, differences in thermal properties might affect costs of refuge use. Thus, juveniles might delay fleeing because their costs of hiding are higher, as they cool faster than adults. Differences in thermal costs may also explain the juveniles' shorter times of emergence from refuges. Because of the behavioral adjustments involved in antipredator behavior, the physiological costs of reaching a low body temperature in refuges probably do not differ between age classes.
Evidence of chemical communication in the spiny rat Trinomys yonenagae (Echimyidae): anal scent gland and social interactions
Authors: Manaf Paulo , Brito-Gitirana Lycia de , Oliveira Elisabeth Spinelli
Published: September 2003

Behavioral and histological data reveal that Trinomys yonenagae, a colonial and fossorial caviomorph rodent, emits direct chemical signals through a single, highly developed, eversible anal sebaceous gland. Connective tissue covers the secretory portion of the gland, dividing it into smaller incomplete lobules. Well-defined layers of striated muscle fibers, which are organized in a crisscrossed manner, surround the external surface of the gland. These features indicate active secretion, and may be important for gland eversion. The frequency of gland eversion was zero when either males or females explored a new territory singly. However, when two unacquainted adults were paired independently of the sex, the anal gland was everted without scent being applied to the substrate or conspecifics. The chemical signaling was concomitant with the occurrence of investigative behaviors such as nosenose, noserump, and noseanus contact. Anal-gland protrusion did not evoke avoidance responses and agonistic behaviors were never observed. The data do not support the function of the short-lived signal as either a sex attractant or a scent mark. The potential importance of chemical signaling in T. yonenagae by means of an eversible gland may lie in recognizing individuals or classes of individuals, minimizing aggression, and increasing social cohesion, all of which are important to colonial animals.
Variable sex-specific mortality due to shorebird predation on a fiddler crab
Authors: Ribeiro Pablo D , Iribarne Oscar O , Jaureguy Luciano , Navarro Diego , Bogazzi Eugenia
Published: September 2003

Male fiddler crabs compete for access to mates mainly by displaying an enlarged claw. One cost of this large claw is presumed to be higher exposure to predators. The fiddler crab Uca uruguayensis is used as a food source by several Neotropical migratory shorebirds. We investigated whether crab density and male claw-waving behaviour increase predation by shorebirds. The sex ratio of crabs on the surface was strongly male biased. Male crabs showed a daily succession of feedingwavingfeeding activities and their dry mass at the site decreased with a high density of crabs, suggesting stronger malemale competition than at sites with a low density of crabs. Sex-specific predation varied according to shorebird species. The Ruddy Turnstone (Arenaria interpres) preyed intensively on male crabs when they were courting and at sites with a high density of crabs, the Black-bellied Plover (Pluvialis squatarola) and the Lesser Golden Plover (Pluvialis dominica) preyed on crabs of both sexes, and the Whimbrel (Numenius phaeopus) foraged intensively on females. When estimating the net effect of all predators, we found that the four shorebird species together were able to consume between 0.1 and 0.2% of the crab population, and consumption did not differ between the sexes of crabs. These mortality rates indicate a low source of mortality, likely unable to produce deviations in the sex ratio of the population. Thus, our results indicate that a trait thought to be sexually selected does not necessarily lead to a disproportionate increase in mortality due to predation.
Role of antioxidant defenses during estivation and anoxia exposure in the freshwater snailBiomphalaria tenagophila(Orbigny, 1835)
Authors: Ferreira Marcus V.R , Alencastro Antonieta C.R , Hermes-Lima Marcelo
Published: September 2003

The effects of 24 h of exposure to underwater anoxia and 15 days of estivation (at 2627°C) on the enzymatic antioxidant system of the hepatopancreas of the freshwater snail Biomphalaria tenagophila (Planorbidae) are described. The effect of 24 h of recovery was also investigated. Catalase activity dropped by 31% during 24 h of anoxia, and superoxide dismutase (SOD) activity was reduced by 43% during the 15 days of estivation. This is consistent with the overall decrease in metabolic rate during estivation or anoxia. Indeed, the heartbeat diminished by 2836% during estivation (determination was possible for only 4 days) and by 66% after 24 h of anoxia. On the other hand, selenium-dependent glutathione peroxidase (Se-GPX) activity increased during anoxia (from 10 to 14 mU/mg protein) and estivation (by 14%). Glutathione S-transferase (GST) and glutathione reductase activities remained unchanged during estivation and anoxia. Glucose 6-phosphate dehydrogenase activity was unchanged during estivation and recovery. Recovery restored SOD activity. Catalase, Se-GPX, and GST activities during recovery were significantly lower than those of the respective controls. Lipid peroxidation, determined as the level of thiobarbituric acid-reactive substances, was unchanged in the hepatopancreas after 15 days of estivation and 26 h of recovery from estivation. It is possible that the increase in Se-GPX activity during anoxia and estivation, and the maintenance of GST activity, are relevant in minimizing the effects of reactive oxygen species that can be formed upon resumption of aerobic metabolism. Thus, B. tenagophila may have a biochemical strategy of preparation for oxidative stress such as that observed in several other species of anoxia/hypoxia-tolerant animals.
Time budget and habitat use of the Common Crane wintering in dehesas of southwestern Spain
Authors: Avilés Jesus M
Published: September 2003

In many bird species juvenile inexperience drastically reduces their survival, and parents must provide for them. I tested whether time budget and habitat use in adult wintering Common Cranes (Grus grus) in dehesas (pastoral woodland) of western Spain were affected by the presence of juveniles. Juvenile cranes devote less time to vigilance and spend more time feeding than adults in dehesas. Likewise, juveniles are involved in fewer aggressive encounters than adult cranes. Contrary to expectation, adults accompanied by juveniles devoted the same amount of time to vigilance and feeding and had the same intake rate than adults without juveniles in attendance. However, adult cranes with offspring in attendance were involved in more aggressive encounters than adults without juveniles in attendance when both adult groups were involved in large flocks. In contrast, when adults accompanied by juveniles were in small flocks they were involved in fewer aggressive encounters than adults without juveniles. I also detected a differential use of dehesas by adult cranes that was linked to juvenile presence and explained by the vulnerability of juvenile cranes in intraspecific social relationships. Adults with juveniles in attendance preferred dehesas with livestock where flock sizes were smaller than those in dehesas without livestock, and therefore where they might reduce the number of aggressive encounters with other cranes.
Diving behavior of an epipelagically feeding alcid, the Rhinoceros Auklet (Cerorhinca monocerata)
Authors: Kuroki Maki , Kato Akiko , Watanuki Yutaka , Niizuma Yasuaki , Takahashi Akinori , Naito Yasuhiko
Published: September 2003

The diving behavior of Rhinoceros Auklets (Cerorhinca monocerata) breeding at Teuri Island, Hokkaido, Japan, was studied using small bird-borne timedepth dataloggers. The eight auklets made dives without an obvious horizontal bottom phase to a median depth of 14.0 ± 1.8 (mean ± SD) m (maximum 57 m) for 53 ± 8 s (maximum 148 s) between the hours of 0300 and 2000. They made undulations (rapid depth changes), considered to represent prey pursuit, in 35% of the dives. Of the undulations, 57% occurred during the deep (>80% of maximum depth) parts of the dives and 26% during the ascent phase. The auklets performed 26 ± 31 dives continuously during dive bouts of 32 ± 34 min. Dive bouts at the end of the day were twice as long as in the morning and at midday. During dive bouts, the auklets showed consistent trends in dive depth, decreasing (23% of bouts), increasing (32%), or stable (19%), but sometimes they showed hectic depth changes (26%). V-shaped dives (with no horizontal bottom phase), potential prey pursuit in both the deep parts and ascent phases of the dives, and variable depth changes within dive bouts indicate the auklets' epipelagic feeding habits.
The MACRO Experiment
Authors: Giacomelli G. , Margiotta A.
Published: September 2003

In this paper we describe the main results obtained by the MACRO experiment: final stringent upper limits on GUT magnetic monopoles and nuclearites, results on atmospheric neutrino oscillations, high energy muon neutrino astronomy, searches for WIMPs, search for low energy stellar gravitational collapse neutrinos, several studies with high energy downgoing muons and determination of the primary cosmic ray composition at knee energies.
On Super-Kamiokande's Multi-Ring Analysis
Authors: Foot R.
Published: September 2003

The super-Kamiokande collaboration have used multi-ring events to discriminate between the νμ→ντ and νμ→νs solutions to the atmospheric neutrino anomaly. We show that the effect of systematic uncertainties in cross sections is so significant that the usefulness of multi-ring data to distinguish between these two solutions is doubtful.
Nonlinear unsteady flow problems by multidimensional singular integral representation analysis
Authors: Ladopoulos E. G.
Published: September 2003

A two‐dimensional nonlinear aerodynamics representation analysis
is proposed for the investigation of inviscid flowfields of
unsteady airfoils. Such problems are reduced to the solution of
a nonlinear multidimensional singular integral equation as the
source and vortex strength distributions are dependent on the
history of these distributions on the NACA airfoil surface. A
turbulent boundary layer model is further investigated, based on
the formulation of the unsteady behaviour of the momentum integral
equation. An application is finally given to the determination of
the velocity and pressure coefficient field around an aircraft by
assuming linear vortex distribution.
CS‐modules and annihilator conditions
Authors: Kamal Mahmoud A. , Menshawy Amany M.
Published: September 2003

We study S − R‐bimodules SMR with the
annihilator condition S = lS(A) + lS(B) for any closed submodule
A, and a complement B of A, in MR. Such annihilator
condition has a direct connection with the CS‐condition for
MR. We make use of this to give a new characterization of
CS‐modules. Bimodules SMR for which rMlS(A) = A (for
every closed submodule A of MR) are also dealt with. Such
modules are called W∗‐modules. We give the extra added
annihilator conditions to W∗‐modules to be equivalent to the
continuous (quasicontinuous) modules.
Nietzsche and the Eternal Return of Sacrifice
Authors: Keenan Dennis King
Published: September 2003

In the work of Nietzsche, sacrifice can only sacrifice itself over and over (in an eternal return of the same) because what it seeks to overcome (the nihilistic revelation of truth that sublates sacrifice's negation) makes this sacrifice of itself both necessary and useless. The truth is eternally postponed in a necessary sacrificial gesture that can only sacrifice itself, thereby rendering itself useless. In the attempt to step beyond nihilism, that is, in the attempt to negate (or sacrifice) nihilism, one repeats the negation characteristic of nihilism. One becomes inextricably implicated in the move of nihilistic sacrifice. The sacrifice of the sacrifice characteristic of nihilism, that is, the sacrifice of sacrifice, can only take place as (perform itself as) the impossibility (or eternally postponed possibility) of its realization. One, therefore, produces or performs an interminable step/not beyond, an incessant step beyond that eternally returns.
A New Method to Fabricate Single‐Molecule Nanoarrays Using Dendrimer‐Based Templates
Authors: Tokuhisa H. , Kubo T. , Koyama E. , Hiratani K. , Kanesato M.
Published: September 2003

Dendrimer architectures are used as spacing‐templates to fabricate single molecule nanoarrays. It is shown that this new method (see Figure for illustration) fabricates a nanoarray of single thioctic acids separated by a distance related to the dendron size on Au. This approach could be used for assembling single functional molecules for nanotechnology in areas such as molecular electronics.
Synthesis and Magnetic Behavior of Periodic Nickel Sphere Arrays
Authors: Xu L. , Tung L.D. , Spinu L. , Zakhidov A.A. , Baughman R.H. , Wiley J.B.
Published: September 2003

Inverse opal polymer replicas serve as excellent templates for the formation of metal sphere arrays (see Figure). Here nickel sphere arrays have been prepared by electrodeposition into poly(methyl methacrylate) templates. Angle‐dependent magnetic measurements indicate that these properties are dominated by shape anisotropy.
Fabricating Two‐Dimensional Molecular Gradients via Asymmetric Deformation of Uniformly‐Coated Elastomer Sheets
Authors: Genzer J. , Fischer D.A. , Efimenko K.
Published: September 2003

Molecular gradients comprising two‐dimensional in‐plane variation of density of substrate‐grafted molecules (see Figure, darker regions in the plot denote regions with higher substrate density) have been fabricated. This is achieved by utilizing the technology of “mechanically assembled monolayers” in conjunction with in‐plane asymmetric stretching of elastomeric substrates uniformly‐coated with organosilane precursors.
Phenotypic identification of rat rostroventrolateral medullary presympathetic vasomotor neurons inhibited by exogenous cholecystokinin
Authors: Sartor Daniela M. , Verberne Anthony J.M.
Published: September 2003

Systemic administration of the gastrointestinal hormone cholecystokinin (CCK) selectively inhibits splanchnic sympathetic vasomotor discharge and differentially affects presympathetic vasomotor neurons of the rostroventrolateral medulla (RVLM). Stimulation of the sympathoexcitatory region of the periaqueductal grey (PAG) produces profound mesenteric vasoconstriction. In this study, our aim was to identify phenotypically different populations of RVLM presympathetic vasomotor neurons using juxtacellular neuronal labelling and immunohistochemical detection of the adrenergic neuronal marker phenylethanolamine‐N‐methyl transferase (PNMT) and to determine whether the PAG provides functional excitatory input to these neurons. Fifty‐eight percent (36/62) of RVLM presympathetic neurons were inhibited by systemic administration of CCK. These cells had conduction velocities (3.6 ± 0.2 m/sec) in the non‐C‐fiber range consistent with neurons possessing lightly myelinated spinal axons. Of these, 79% (22/28) were excited by PAG stimulation, and 59% (10/17) were not immunoreactive for PNMT. Conversely, 42% (26/62) of RVLM presympathetic neurons were either unaffected or activated by CCK administration and had slower conduction velocities (1.4 ± 0.3 m/sec) than cells inhibited by CCK. Fifty percent (11/22) of these cells were driven by PAG stimulation, and most (11/14 or 79%) were PNMT‐positive. These results suggest that cardiovascular responses elicited by PAG stimulation occur via activation of non‐C1 and C1 RVLM presympathetic neurons. RVLM neurons inhibited by CCK were more likely to be driven by PAG stimulation and may be a subset of neurons responsible for driving gastrointestinal sympathetic vasomotor tone. CCK‐induced inhibition of a subpopulation of RVLM presympathetic neurons may be implicated in postprandial hyperemia and postprandial hypotension. J. Comp. Neurol. 465:467–479, 2003. © 2003 Wiley‐Liss, Inc.
Innervation of the heart of the adult fruit fly, Drosophila melanogaster
Authors: Dulcis Davide , Levine Richard B.
Published: September 2003

The innervation of the adult abdominal heart of Drosophila melanogaster was studied by neuronal staining with green fluorescent protein and immunocytochemical techniques. The investigation was undertaken to determine whether the adult heart receives neuronal input or whether its complex activity must be considered independent from the nervous system. The larval heart lacks innervation, suggesting that the cardiac impulse is totally myogenic. At metamorphosis, segmental neural processes grow onto the myocardium. A pair of transverse nerves innervates bilaterally each cardiac chamber and its alary muscles. These nerve terminals are immunoreactive to glutamate and form unique synaptic structures on the ventral layer of longitudinal cardiac muscles of the conical chamber. This characteristic cardiac synapse may represent part of the neural mechanism controlling the retrograde heartbeat, and, thus, the cardiac reversal that is characteristic of adults. In addition, crustacean cardioactive peptide–immunoreactive fibers originating from peripheral, bipolar neurons (BpNs) fasciculate with the transverse nerve projections and terminate segmentally throughout the abdominal heart. An additional cluster composed of four large, CCAP‐positive neurons innervates the terminal chamber. The cardioacceleratory effect of CCAP release at this location may modulate the properties of a pacemaker producing the anterograde heartbeat. J. Comp. Neurol. 465:560–578, 2003. © 2003 Wiley‐Liss, Inc.
Time‐Resolved Spectroscopic Study on Photoinduced Electron‐Transfer Processes in Zn(II)porphyrin–Zn(II)chlorin–Fullerene Triad
Authors: Ha Jeong‐Hyon , Cho Hyun Sun , Kim Dongho , Lee Jong‐Cheol , Kim Tae‐Young , Shim Young Key
Published: September 2003

Femtosecond time‐resolved transient absorption studies have been performed to investigate the photoinduced energy and electron‐transfer processes in Zn(II)porphyrin–Zn(II)chlorin–fullerene triad in which energy and oxidation potential gradients are directed along the donor–acceptor‐linked arrays. Fast energy transfer (≈450 fs) from photoexcited Zn(II)porphyrin to Zn(II)chlorin was observed upon selective photoexcitation of Zn(II)porphyrin unit in the triad. In a nonpolar solvent such as toluene, the energy transfer from the excited singlet state of Zn(II)chlorin to fullerene occurs and is followed by the formation of an intermediate state with a time constant of nanoseconds, which was attributed to the intramolecular exciplex between Zn(II)chlorin and fullerene. In benzonitrile, on the other hand, the photoexcitation of the triad results in the fast electron transfer (<1 ps) from photoexcited Zn(II)chlorin to fullerene. The generated charge‐separated species recombine with a time constant of ≈12 ps. The relatively fast charge separation and charge recombination rates imply that the strong electronic coupling between Zn(II)chlorin and fullerene moieties is probably induced by the folded conformation between Zn(II)chlorin and fullerene moieties which enhances direct through‐space interaction between the proximately contacted π systems.
Capacity improvement with a multihop access scheme in broadband CDMA cellular systems
Authors: Fujiwara Atsushi , Takeda Shinji , Yoshino Hitoshi , Otsu Toru , Yamao Yasushi
Published: September 2003

The use of multihop connection, in which a station in between the mobile station and the base station performs hopping relay of the transmission, in CDMA cellular systems should expand the area coverage and reduce the transmitted power per hop. There is a possibility that interference power may be reduced and that system capacity may be enlarged by this approach. Depending on the method of application, however, the system capacity may be decreased due to the interference during hopping. In this study, a basic investigation of interference reduction by multihop connection is first presented. Then, a procedure for selection of the hop stations with a strong capability for reducing the interference power is proposed. Considering a multicellular environment with a CDMA (code division multiple access) cellular scheme, the characteristics of multihop connections are evaluated by computer simulation, assuming packet access. It is shown that multihop connection has the effect of improving system capacity. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(10): 17–24, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10185
Design of an adaptive observer for sensorless vector control of induction machines under regenerating conditions
Authors: Tamura Yuichi , Sato Ikuya , Kubota Hisao , Ohta Hisayoshi , Hori Yoichi
Published: September 2003

The objective of this investigation is to stabilize a sensorless vector control system of induction motors by means of an adaptive observer in regenerating mode at very low speed. The adaptive observer gain is designed by means of the Routh–Hurwitz criterion. It is verified by simulation and experiment that the proposed system is stable. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(4): 78–87, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10202
A three‐phase voltage‐source PWM inverter system characterized by sinusoidal output voltage with neither common‐mode voltage nor normal‐mode voltage
Authors: Hasegawa Hiroshi , Doumoto Takafumi , Akagi Hirofumi
Published: September 2003

This paper deals with an inverter system integrating a small‐rated passive EMI filter with a three‐phase voltage‐source PWM inverter. The purpose of the EMI filter is to eliminate both common‐mode and normal‐mode voltages from the output voltage of the inverter. The motivation of this research is based on the well‐known fact that the higher the carrier or switching frequency, the smaller and the more effective the EMI filter. An experimental system consisting of a 5‐kVA inverter, a 3.7‐kW induction motor, and a specially designed passive EMI filter was constructed to verify the viability and effectiveness of the EMI filter. As a result, it is shown experimentally that both three‐phase line‐to‐line and line‐to‐neutral output voltages look purely sinusoidal as if the inverter system were an ideal variable‐voltage, variable‐frequency power supply when viewed from the motor terminals. This results in complete solution of serious issues related to common‐mode and normal‐mode voltages produced by the inverter. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(4): 88–96, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10206
Comparative experiments of co‐ and counter‐helicity merging in the compact toroid merging device TS‐4
Authors: Tsuruda Mayuko , Ono Yasushi , Katsurai Makoto
Published: September 2003

For the past 15 years, the TS‐3 merging project has explored several new types of CT/ST (Compact Tori and Spherical Tokamak): merging formation of FRCs (Field Reversed Configuration), magnetic reconnection experiment, and ultrahigh beta ST formation. The successful results of these experiments have enabled us to construct an upscaled merging device, namely, the TS‐4. The new TS‐4 has two flux cores (major radius = 0.5 m) for inductive plasma formation, a center coil (external toroidal field coil and OH coil), for q value control and plasma sustaining, and DC external field coils. The initial operation of the TS‐4 (since 2001) demonstrated co‐helicity and counter‐helicity merging of two spheromaks. The counter‐helicity merging revealed annihilation of toroidal magnetic field with a significant overshoot motion of reconnected field lines. It resulted in the formation of a high‐beta (≈ 0.8) FRC. The produced FRC has a significant field deformation, suggesting a contribution of the toroidal plasma flow to its equilibrium. The co‐helicity merging doubled the toroidal fluxes of spheromak, causing its flux conversion from toroidal to poloidal. The merging spheromaks relaxed into another spheromak with beta ≈ 0, suggesting the large thermal energy loss due to its non‐aximetric dynamo activity. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(4): 1–11, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10207
Potential of neurotoxicity after a single oral dose of 4‐bromo‐, 4‐chloro‐, 4‐fluoro‐ or 4‐iodoaniline in rats
Authors: Okazaki Yoshimasa , Yamashita Kotaro , Ishii Hiroyuki , Sudo Masato , Tsuchitani Minoru
Published: September 2003

The potential for neurotoxicity after a single oral dose of four halogenated aniline derivatives — 4‐bromoaniline (4‐BA), 4‐chloroaniline (4‐CA), 4‐ﬂuoroaniline (4‐FA) and 4‐iodoaniline (4‐IA) — was given to rats was investigated at or near the lethal dosage level. Hindlimb paralysis was found in the 4‐BA, 4‐CA and 4‐FA groups on clinical observation, with the maximum incidence of 100% in the 4‐BA and 4‐FA groups and 66.7% in the 4‐CA group. Detailed clinical observations with functional tests identiﬁed the following effects: reduced response of hindlimb extensor thrust, gait abnormality in the open ﬁeld and decreased grip strength in the fore‐ or hindlimbs in the 4‐BA, 4‐CA and 4‐FA groups; decreased number of supported rearing episodes in the open ﬁeld in the 4‐BA and 4‐CA groups; abnormal landing in the aerial righting reﬂex in the 4‐BA and 4‐FA groups; and prolonged surface righting reﬂex in the 4‐BA group. Spongy change in the white matter of the spinal cord and brainstem and nerve ﬁbre degeneration in the peripheral nerves were found in all haloaniline‐treated groups. The central and peripheral nervous systems were most severely affected in the 4‐BA group and the lesions in the 4‐IA group were limited in grade. This study demonstrates that a bolus dose of 4‐haloanilines to rats induces a neurotoxicity similar in character to that evoked by the parent aniline. The decreasing order of neurotoxic potential appears to be 4‐BA >> 4‐FA ≥ 4‐CA >> 4‐IA when comparing at or near the lethal dosage level. Copyright © 2003 John Wiley & Sons, Ltd.