bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of inhibition of nitric oxide synthase on the vasopressor response to ephedrine
Authors: Dabisch Paul A , Liles John T , Kadowitz Philip J
Published: October 2003

Ephedrine is a mixed adrenergic agonist, stimulating both α- and β-adrenergic receptors. The effects of ephedrine use include increases in heart rate, cardiac output, peripheral resistance, and blood pressure, and its use is associated with serious cardiovascular events such as stroke, arrhythmias, and myocardial infarction. The vascular endothelium plays a fundamental role in the regulation of vascular tone by releasing vasoactive factors such as nitric oxide (NO). The loss of NO bioactivity, often referred to as endothelial dysfunction, is characterized by the loss of endothelium-dependent vasodilation and is thought to be a common pathway for cardiovascular events such as vasospasm, hypertension, and myocardial infarction. Since endothelial dysfunction is characterized by loss of NO activity, and since ephedrine and endothelial dysfunction may be associated with similar cardiovascular events, the current study was undertaken to determine the effect of inhibition of NO production on responses to ephedrine in the rat. A sodium nitroprusside (SNP) infusion procedure was used to restore baseline vascular parameters to pre-L-NAME levels, allowing for direct comparison of agonist responses before and after NOS inhibition. The results demonstrate that the vascular response to ephedrine in the rat is modulated by NO and that NO production in response to ephedrine may be secondary to β2-receptor stimulation.Key words: nitric oxide, ephedrine, endothelial dysfunction, L-NAME.
The effects of temperature and age on calling song in a field cricket with a complex calling song,Teleogryllus oceanicus(Orthoptera: Gryllidae)
Authors: Walker Sean E , Cade William H
Published: October 2003

We examined the effects of temperature and age on calling song in the field cricket Teleogryllus oceanicus. Teleogryllus oceanicus has a complex calling song made up of two different kinds of chirp, long and short. The long chirp is made up of three to eight single pulses of sound and the short chirp consists of several paired pulses. The properties of T. oceanicus calling song did not vary with age, but almost every property of the song varied with temperature. Pulse duration, interpulse interval, and pulse rate in both the long and the short chirp varied with temperature. The number of pulses in the long chirp, number of chirps in the short chirp, chirp rate in the short chirp, duration of the long chirp, carrier frequency of both the short and long chirps, and total song duration were also affected by temperature. The duration of the short chirp and the degree of frequency modulation were the only characteristics that did not vary with temperature. Temperature does not affect the properties of the long and short chirps in the same manner. The long chirp decreases in duration with temperature and has fewer pulses, while the short chirp stays the same in duration and contains a higher number of chirps. These data demonstrate that temperature influences calling-song parameters in a field cricket with a complex calling song.
Competition for basking places between the endangered European pond turtle (Emys orbicularis galloitalica) and the introduced red-eared slider (Trachemys scripta elegans)
Authors: Cadi A , Joly P
Published: October 2003

Large numbers of red-eared sliders (Trachemys scripta elegans) have been imported into Europe for several years as part of the pet trade. These alien turtles have entered habitats where they interact with native pond turtles (Emys orbicularis). We investigated competition for basking sites, because optimal basking sites may be a restricted resource in the wild. We used experimental ponds to compare basking-place selection between single-species groups and mixed-species groups. Both species preferred basking places in open deep water. In mixed groups the sliders outcompeted the European turtles for preferred basking places. Although competition for basking places is only one component of resource partitioning between these two species, it provided an insight into the relationships between an introduced and a native species. Behavioural asymmetries like those detected in our experiments argue for the caution principle in the animal trade.
Recruitment sex ratios in gray-tailed voles (Microtus canicaudus) in response to density, sex ratio, and season
Authors: Bond Monica L , Wolff Jerry O , Krackow Sven
Published: October 2003

We tested predictions associated with three widely used hypotheses for facultative sex-ratio adjustment of vertebrates using eight enclosed populations of gray-tailed voles, Microtus canicaudus. These were (i) the population sex ratio hypothesis, which predicts that recruitment sex ratios should oppose adult sex-ratio skews, (ii) the local resource competition hypothesis, which predicts female-biased recruitment at low adult population density and male-biased recruitment at high population density, and (iii) the first cohort advantage hypothesis, which predicts that recruitment sex ratios should be female biased in the spring and male biased in the autumn. We monitored naturally increasing population densities with approximately equal adult sex ratios through the spring and summer and manipulated adult sex ratios in the autumn and measured subsequent sex ratios of recruits. We did not observe any significant sex-ratio adjustment in response to adult sex ratio or high population density; we did detect an influence of time within the breeding season, with more female offspring observed in the spring and more male offspring observed in the autumn. Significant seasonal increases in recruitment sex ratios indicate the capacity of female gray-tailed voles to manipulate their offspring sex ratios and suggest seasonal variation in the relative reproductive value of male and female offspring to be a regular phenomenon.
The migratory behaviour of narwhals (Monodon monoceros)
Authors: Heide-Jørgensen Mads Peter , Dietz Rune , Laidre Kristin L , Richard Pierre , Orr Jack , Schmidt Hans Christian
Published: October 2003

Sixteen female narwhals (Monodon monoceros) were tracked by satellite in 2000 and 2001 from their summering ground near Somerset Island in the Canadian High Arctic to their wintering ground in central Baffin Bay. The wintering ground location was spatially discrete from another narwhal wintering ground in southern Baffin Bay. Area extent of the summering ground was approximately 9464 km2and area extent of the wintering ground was 25 846 km2. Two of the narwhals were tracked for more than 12 consecutive months. These whales used three focal areas between their spring and autumn migration: a coastal area in the open-water season in August in the Canadian High Arctic, a wintering area from November through April in the consolidated pack ice of Baffin Bay, and an early summer area in front of the receding fast ice edge in Lancaster Sound. The whales showed remarkable site fidelity to summering grounds and had specific migratory routes that followed sea ice formation and recession.
Photoperiod differentially affects energetics of immunity in pregnant and lactating Siberian hamsters (Phodopus sungorus)
Authors: Drazen Deborah L , Trasy Anjali , Nelson Randy J
Published: October 2003

Both immune and reproductive (i.e., pregnancy and lactation) functions are energetically demanding processes that fluctuate seasonally. Winter is energetically demanding because energy availability is limited and energy demands are high. The goal of the present study was to assess the trade-off of resources between immunity and reproduction by examining antibody production during pregnancy and lactation, when energy requirements are high. Female Siberian hamsters (Phodopus sungorus) were held in either long or short days, and anti-keyhole limpet hemocyanin antibody production was assessed in pregnant, lactating, or nulliparous animals. Pregnancy and lactation both suppressed humoral immunity (primary antibody production) in long-day Siberian hamsters. However, although antibody production was reduced in short-day females compared with long-day animals, pregnancy and lactation did not reduce antibody body production any further. Interestingly, the size and mass of the litters produced by females in both long and short days did not differ. Taken together, these results suggest that the processes of pregnancy and lactation are costly enough to reduce humoral immunity, and they suggest that immunity may be compromised as a result of energy allocation to these reproductive processes.
Correlates to survival of juvenile sea otters in Prince William Sound, Alaska, 19921993
Authors: Ballachey B E , Bodkin J L , Howlin S , Doroff A M , Rebar A H
Published: October 2003

We estimated survival of sea otters (Enhydra lutris) for 1 year post weaning during 19921993 in Prince William Sound (PWS), location of the 1989 Exxon Valdez oil spill. We sampled 38 pups in eastern PWS (EPWS), an unoiled area occupied by sea otters for <15 years, and 33 pups from oiled western PWS (WPWS), occupied for >25 years. We compared survival between areas, sexes, and condition groups. We also examined the relation of blood parameters to survival. Survival was estimated at 0.74 in EPWS and 0.52 in WPWS. Female survival was 0.86 in EPWS and 0.64 in WPWS, whereas male survival was lower, 0.61 in EPWS and 0.44 in WPWS. Sea otters from EPWS were in better condition (mass/length) than WPWS sea otters. Pups in better condition had higher survival in EPWS but not in WPWS. Foraging success was greater in EPWS than in WPWS, consistent with either an effect of length of occupation or the effects of oil on the prey base or a combination of these effects. Area differences in blood parameters suggested liver damage in WPWS sea otters, perhaps resulting from continued exposure to oil. Thus, both length of occupation and oiling history likely influenced juvenile survival in PWS.
Effects of stomach stones on the buoyancy and equilibrium of a floating crocodilian: a computational analysis
Authors: Henderson Donald M
Published: October 2003

A three-dimensional mathematical/computational model of the crocodilian Alligator mississippiensis has been developed to investigate the influence of gastroliths on crocodilian buoyancy. The model is self-correcting, recovers from large perturbations, and can replicate the body orientations and degrees of immersion seen in living crocodilians that have attained equilibrium with respect to the competing forces of buoyancy and weight. For a range of lung deflations where the model was still positively buoyant, adding gastroliths of mass equal to 1% of the body mass has the effect of lowering the body, on average, by 2.6% of the maximum trunk depth while simultaneously increasing the inclination of the body with its sagittal plane. With the lungs fully inflated, the model would become negatively buoyant only when loaded with stones weighing more than 6% of the total body mass. Without gastroliths the body would sink when the lungs were deflated by 40%50%. In all situations the model was resistant to capsizing. The relatively small amounts of gastroliths (<2% body mass) found in aquatic tetrapods are considered to be inconsequential for buoyancy and stability, and the lungs are the principle agent for hydrostatic buoyancy control.
Convergent and divergent evolution in rain-forest populations and communities of cyprinodontiform fishes (Aphyosemion and Rivulus) in Africa and South America
Authors: Brosset André
Published: October 2003

When the African and American continents separated 65125 million years ago, populations and communities of plants and animals of the same lineage became isolated and evolved independently. Today, however, the cyprinodontiform fishes on the two sides of the Atlantic Ocean are morphologically similar, especially the American genus Rivulus and the African genus Aphyosemion. The evolutionary-inertia hypothesis is rejected as an explanation of this similarity because of evidence that the speciation process is ongoing. This study concerns processes that are probably responsible for the convergent and divergent evolution in the composition, structure, and dynamics of populations and communities, respectively. Basic data were obtained during a long-term study in the field, at the M'Passa biological station in Gabon and the St. Elie biological station in French Guiana. At the same time, rearing experiments were conducted from the Laboratoire d'Écologie at the Muséum National d'Histoire Naturelle in Paris. The composition, structure, and dynamics of the populations at M'Passa and St. Elie are similar. Parallel evolution of the habitats may explain the parallel evolution of the populations of cyprinodontiform fishes in Africa and America, leading to similar fish populations in similar habitats. Conversely, the composition, structure, and dynamics of the communities at St. Elie and M'Passa are different. The cause of this divergent evolution may be the absence of specific predators and competitors at M'Passa and the presence of highly specialized predators and competitors at St. Elie. The predators and competitors present at St. Elie all belong to the Characidae, a very successful group of fishes in America, without an equivalent in the Old World. Analogous processes of competitive exclusion are also observed in other orders of tropical American vertebrates: batrachians, reptiles, birds, and bats.
Behavioural evidence for social units in long-finned pilot whales
Authors: Ottensmeyer C Andrea , Whitehead Hal
Published: October 2003

In general, mammal species show geographic or social dispersal by one or both sexes. Long-term behavioural observations and genetic evidence have confirmed that fish-eating resident killer whales, Orcinus orca, are a rare exception. Female and male offspring travel with their mothers for their whole lives: this is natal group philopatry. It is suspected that pilot whales, Globicephala spp., also follow this social pattern, but longitudinal data on the social structure of live long-finned pilot whales, Globicephala melas, are rare. We observed G. melas through July and August of 19982000 off northern Nova Scotia, Canada. Estimated group sizes ranged from 2 to 135 (mean = 20, SD = 17, median = 15, n = 249). We distinguished 322 individuals on the basis of distinctive marks on the dorsal fin, with estimated mark rates of 0.336 (proportion) (SE = 0.041) and 0.352 (mean of estimates) (SE = 0.036). Permutation testing rejected the null hypothesis of random association between individuals (p < 0.0005). The best fit model of the standardized lagged association rate suggests short-term associations of individuals over hours to days and long-term associations with a subset of those individuals over years. When scaled according to mark rate, sets of long-term associates average approximately 1112 individuals, a much lower estimate than that presented previously from drive-fishery data from the Faroe Islands. Genetic sampling of behaviourally studied individuals is recommended.
Shorebirds, mud snails, andCorophiumvolutatorin the upper Bay of Fundy, Canada: predicting bird activity on intertidal mud flats
Authors: Hamilton Diana J , Barbeau Myriam A , Diamond Antony W
Published: October 2003

The upper Bay of Fundy is a critical staging area for migrating semipalmated sandpipers (Calidris pusilla), which feed extensively on the amphipod Corophium volutator. Recent changes in the distributions of birds around the bay have generated interest in understanding the factors that influence shorebirds' habitat use. To examine some of these factors, we surveyed four mud flats during summer 2000. Abundance of shorebirds and density of C. volutator and mud snails (Ilyanassa obsoleta) were assessed in two focused areas and on two broad-scale transects per mud flat. Shorebird abundance varied widely across sites, and was positively correlated with C. volutator availability, though the relationship had little predictive ability. A strong negative relationship was identified between shorebirds and mud snails counted before birds arrived, especially in the focused areas. This relationship probably stems from a negative effect of mud snails on C. volutator. Snails present in July may reduce recruitment of C. volutator, and therefore reduce the prey base for shorebirds arriving later in the summer. By considering mud snail abundance, we have identified a simple and effective method of predicting shorebird habitat use several weeks before birds arrive. This will enhance our ability to study these birds in future, and will contribute to our understanding of shorebird habitat use and movements and the importance of conserving particular mud flats.
Patterns of larval amphibian distribution along a wetland hydroperiod gradient
Authors: Babbitt Kimberly J , Baber Matthew J , Tarr Tracy L
Published: October 2003

We investigated the response of pond-breeding amphibian assemblages to wetland hydroperiod and associated predator changes (invertebrates (abundance and richness) and fish (presence/absence)) in relatively undisturbed landscapes in southern New Hampshire, U.S.A. We sampled 42 wetlands for larval amphibians in 14 spatial blocks (each with a short-, intermediate-, and permanent-hydroperiod wetland) in 1998 and 1999. Assemblages in short-hydroperiod wetlands (<4 months) were depauperate (4 species only) compared with intermediate-hydroperiod (non-permanent but >4 months) and permanent wetlands, which included 7 and 9 species, respectively. Total amphibian abundance did not vary among hydroperiod categories. Species distributions along the hydrological gradient also differed. Rana sylvatica dominated wetlands with short and intermediate hydroperiods, whereas Rana catesbeiana, Bufo americanus, Rana clamitans, and Pseudacris crucifer dominated in those with a longer hydroperiod. Among permanent wetlands, amphibian species richness and abundance did not differ with respect to the presence of predatory fish, although there were species-compositional differences. Amphibian species richness and abundance were positively correlated with the abundance and richness of predatory invertebrates, suggesting that both amphibian and macroinvertebrate predator assemblages may be responding similarly to differences in wetland characteristics (e.g., dissolved oxygen concentration). Overall, our results indicate that wetland hydroperiod has an important influence on amphibian distribution and should be incorporated into regulations and legislation designed to protect biologically diverse isolated wetlands.
Use of photo-identification data to quantify mothercalf association patterns in bottlenose dolphins
Authors: Grellier Kate , Hammond Philip S , Wilson Ben , Sanders-Reed Carol A , Thompson Paul M
Published: October 2003

For social mammals living in fissionfusion societies, the motherinfant bond is long and extends beyond the nursing period. We successfully developed a technique, using photo-identification data, to quantify mothercalf association patterns in a small population of bottlenose dolphins, Tursiops truncatus, off eastern Scotland. By statistically comparing association indices between young calves and their associates we assigned 17 individual adults as mothers to 20 young calves with a 5% level of probability. The mean index of association between calves and mothers remained high until at least year 8 of life. While calves were still found in the same schools as their mother, they surfaced beside her less often as their age increased. This is the first time that the mothercalf bond has been quantitatively assessed for any bottlenose dolphin population inhabiting temperate waters. Results are compared with those from subtropical populations and are discussed with respect to the viability of this population.
Historical dynamics of the Australian fur seal population: evidence of regulation by man?
Authors: Arnould J P.Y , Boyd I L , Warneke R M
Published: October 2003

The Australian fur seal (Arctocephalus pusillus doriferus) was severely over-exploited in the 18th and 19th centuries and until relatively recently its population had remained steady at well below estimated presealing levels. However, the population is now increasing rapidly (6%20% per annum) throughout its range and there is a need to understand its dynamics in order to assess the potential extent and impact of interactions with fisheries. Age distribution (n = 156) and pregnancy rate (n = 110) were determined for adult females collected at a breeding colony on Seal Rocks, southeast Australia, in 19711972. Mean ± SE and maximum observed ages were 9.37 ± 0.41 and 20 years (n = 1), respectively. A stochastic modelling approach was used to fit an age distribution to the observed age-structure data and calculate rates of recruitment and adult survival. Annual adult female survival and recruitment rates between 1954 and 1971 were 0.478 ± 0.029 (mean ± SE) and 0.121 ± 0.007, respectively, suggesting that the population was experiencing a decline during the 1960s. The pregnancy rate increased from 78% at 3 years of age to an average of 85% between 413 years of age before significantly decreasing in older females (the oldest was 19 years of age). There was no significant effect of body mass or condition on the probability of a female being pregnant (P > 0.5 in both cases) and the nutritional burden of lactation did not appear to affect pregnancy rates or gestational performance. These findings suggest that the low survivorship was due to density-independent effects such as mortality resulting from interactions with fishers, which are known to have been common at the time. The recent increase in the population is consistent with anecdotal evidence that such interactions have decreased as fishing practices have changed.
Organization of pharyngeal hard parts and musculature inGnathostomula armata(Gnathostomulida: Gnathostomulidae)
Authors: Sørensen Martin V , Tyler Seth , Hooge Matthew D , Funch Peter
Published: October 2003

The pharynx of Gnathostomula armata, like that of other members of the phylum Gnathostomulida, consists of a set of jaws, a basal plate, and a muscular bulb that encloses these cuticularized hard parts. Field-emission scanning electron microscopy (SEM) provides additional information about the hard parts and shows that the dentition of the jaws is arranged in three rows: 710 teeth in a dorsal row, 1620 teeth in a medial row, and 20 teeth in a ventral row, a pattern different from that reported from light microscopy (LM). SEM also shows that the dentition of the basal plate is more like that of other Gnathostomula species than was previously discerned. Confocal laser scanning microscopy shows the musculature of the pharyngeal bulb to comprise diductors that open and tilt the jaws, looplike abductors that retract them as they snap shut by recoil, and a pair of inclinators and pair of levators that also participate in tilting the jaws back and forth. A constrictor running ventral to and behind the jaws may work to protrude them. Two arc-shaped muscles attached to the basal plate pull it forward and tilt it down to scrape food from the substratum so that it can be grabbed by the jaws. Paired retractor muscles pull the basal plate back into the mouth.
The heat increment of feeding and its thermoregulatory implications in the short-tailed shrew (Blarina brevicauda)
Authors: Hindle Allyson G , McIntyre Ian W , Campbell Kevin L , MacArthur Robert A
Published: October 2003

The nature and potential thermoregulatory benefits of the heat increment of feeding (HIF) were investigated in short-tailed shrews (Blarina brevicauda). At thermoneutrality, the postprandial rate of oxygen consumption ([Formula: see text]O2) of shrews increased by an average of 18% beyond fasting levels for ca. 2 h following the consumption of 3.5 g of earthworms. Over the same period, body temperature increased by an average of 0.6 °C. The digesta-retention time calculated from nickel alloy tracer excretion rates (168.1 ± 11.4 min (mean ± SE); n = 7) exceeded the duration of HIF (117.5 ± 10.4 min; n = 6) by 43%. This finding suggests that the mechanical costs of feeding may be a relatively mi nor component of HIF in this species. Regression of resting [Formula: see text]O2on ambient temperature (Ta) below thermo neutrality yielded similar slopes (P = 0.71) and intercepts (P = 0.33) for fed and fasted animals, suggesting that HIF substitutes, at least partially, for facultative thermogenesis at low Ta. We found no evidence that HIF enhanced microclimate warming of an insulated, open-flow metabolic chamber occupied by recently fed shrews. Occupancy of this chamber by shrews increased microclimate Tafrom 5 to 9.09.5 °C regardless of their nutritional status.
Gametogenesis in capelin, Mallotus villosus (Müller), in the northwest Atlantic Ocean
Authors: Flynn S R , Burton M P.M
Published: October 2003

Capelin (Mallotus villosus) can be regarded as the most important prey item in the northwest Atlantic Ocean. The health and availability of this species are of fundamental importance for the successful growth and reproduction of many other fishes, whales, and birds. In spite of the clear need to understand this species, the life history of the capelin, especially its reproductive biology, is not well understood. This study substantially improves our knowledge of the reproductive biology of capelin and should be of particular interest to resource managers and administrators. Capelin gonads were analysed over three successive seasons using fish collected during beach spawning (June and July 1993, July 1994, July 1995) or trawled between spawnings, with 11 separate samples (fall, winter, and spring from October 1993 to June 1995). Few immature fish were collected in the trawls; 13/130 (10%) males and 3/150 (2%) females. No recovering (postspawning) males were found in the trawls, but 8/150 (5.3%) recovering females were identified on the basis of large residual oocytes (ovulated or unovulated) and (or) (in the fall) a thicker ovarian wall. Recovering females were identified as late as 10 months post spawning on the basis of residual oocytes. The essential semelparity of males was supported by a lack of apparent spermatogonia during advanced spermatogenesis, whereas the females' capacity to spawn in a subsequent year (iteroparity) was confirmed by the presence of small nonvitellogenic oocytes when other cells were in late oogenesis, in addition to the identification of recovering fish. Oocytes were separable into four stages (potential year classes) and changes occurred in all oocyte stages throughout the cycle of oogenesis. Gametogenesis was more advanced in longer fish, indicating that larger fish spawn earlier than smaller fish.
Isotopic fractionation and turnover in captive Garden Warblers (Sylvia borin): implications for delineating dietary and migratory associations in wild passerines
Authors: Hobson Keith A , Bairlein Franz
Published: October 2003

There is currently a great deal of interest in using stable-isotope methods to investigate diet and migratory connections in wild passerines. To apply these methods successfully, it is important to understand how stable isotopes discriminate or change between diet and the tissue of interest and what the element-turnover rates are in metabolically active tissues. Of particular use are studies that sample birds non-destructively through the use of blood and feathers. We investigated patterns of isotopic discrimination between diet and blood and feathers of Garden Warblers (Sylvia borin) raised on an isotopically homogeneous diet (48% C, 5% N) and then switched to one of two experimental diets, mealworms (56.8% C, 8.3% N) and elderberries, Sambucus niger (47.4% C, 1.5% N). We established that the discrimination factors between diet and blood appropriate for stable carbon (δ13C) and nitrogen (δ15N) isotopes are +1.7‰ and +2.4‰, respectively. For feathers, these values were +2.7‰ and +4‰, respectively. Turnover of elemental nitrogen in whole blood was best approximated by an exponential-decay model with a half-life of 11.0 ± 0.8 days (mean ± SD). Corresponding turnover of carbon was estimated to range from 5.0 ± 0.7 to 5.7 ± 0.8 days. We conclude that this decoupling of nitrogen- and carbon-turnover rates can be explained by differences in metabolic routing of dietary macromolecules. Our results suggest that tracking frugivory in migratory passerines that switch diets between insects and fruits may be complicated if only a trophic-level estimate is made using δ15N measurements.
Another one bites the dust: Does incisor-arcade size affect mass gain and survival in grazing ungulates?
Authors: Hardenberg Achaz von , Shipley Bill , Festa-Bianchet Marco
Published: October 2003

Incisor-arcade size affects foraging efficiency in grazing ungulates and should be under strong selective pressure. We investigated individual variation in incisor-arcade size and its relationship with body mass and survival in bighorn sheep (Ovis canadensis) at Ram Mountain, Alberta, Canada, over 9 years. In adult ewes, incisor-arcade breadth and depth decreased with age, probably as a result of tooth wear. We found no effects of incisor-arcade size on survival of lambs or adult ewes. In adult ewes, an apparent positive effect of incisor-arcade size on survival disappeared when age was accounted for. Incisor-arcade breadth and depth had no effect on summer mass gain in lambs or adult ewes. Although linear models suggested that arcade breadth in lambs was correlated with summer mass gain, a latent variable path analysis model revealed that the correlation was due to an allometric relationship of arcade breadth with body size. Variation in incisor-arcade size in bighorn sheep appears to be due to individual variation in body size and age rather than to directional selection.
Food-hoarding behavior of gray squirrels and North American red squirrels in the central hardwoods region: implications for forest regeneration
Authors: Goheen Jacob R , Swihart Robert K
Published: October 2003

The North American red squirrel (Tamiasciurus hudsonicus) has expanded its geographic range into the state of Indiana concurrently with a decline in populations of gray squirrels (Sciurus carolinensis) throughout portions of the central hardwoods region of the United States that have been converted to intensive agriculture. Red squirrels construct larder hoards and function as seed predators throughout much of their geographic range. In contrast, gray squirrels construct scatter hoards and thus function as seed dispersers in addition to eating seeds. We conducted field observations to discern whether hoarding behavior differed between the two species in a deciduous forest stand near the southern limit of the range of red squirrels. Red squirrels were more likely to hoard walnuts and acorns in larders or trees, whereas gray squirrels were more likely to scatter-hoard mast items. We present a simple model to illustrate the potential impact of interspecific differences in hoarding on germination success of black walnut. Our results suggest that red squirrels are unable to compensate completely for the loss of gray squirrels as seed dispersers in portions of the central hardwoods region that have been transformed by agriculture.
Spatial home-range overlap and temporal interaction in eastern coyotes: the influence of pair types and fragmentation
Authors: Atwood Todd C , Weeks, Jr. Harmon P
Published: October 2003

No data exist regarding the linkage between the dispersion of critical resources and the spatial distribution of eastern coyotes (Canis latrans). From February 2000 to January 2002, we investigated landscape-level correlates of fragmentation with coyote spacing patterns and interaction in west-central Indiana to determine whether habitat fragmentation may influence spatiotemporal home-range overlap. Eleven pairs of coyotes (four malefemale, four malemale, three femalefemale) displayed spatial overlap in portions of their home-range utilization distributions; seven pairs interacted temporally. Percent home-range overlap of space-sharing pairs averaged 55%. Area of forested habitat within the overlap zone, pair type, and mean squared difference of nearest-neighbor distances between forested patches explained substantial amounts of variation in percent home-range overlap (R2= 0.83, P < 0.001). Extent of temporal interaction differed by pair type, as malemale pairs interacted substantially more than malefemale and femalefemale pairs. Five (two malemale, three malefemale) of seven temporally interacting pairs exhibited simultaneous attraction to the overlap zone. The complex combination of environmental pressures present in human-dominated landscapes may facilitate spatiotemporal home-range overlap in coyotes.
The influence of predator threat on the timing of a life-history switch point: predator-induced hatching in the southern leopard frog (Rana sphenocephala)
Authors: Johnson James B , Saenz Daniel , Adams Cory K , Conner Richard N
Published: October 2003

We tested the hypotheses that potential egg predators, crayfish Procambarus nigrocinctus and dytiscid Cybister sp. larvae, would accelerate the timing of hatching and that a larval predator, dragonfly naiad Anax junius, would delay hatching in the southern leopard frog (Rana sphenocephala). We also tested the hypothesis that differences in response would be proportional to predator lethality. Our results indicate that our hypotheses were partially supported. The presence of an efficient egg predator (crayfish) induces hatching faster than a less efficient predator (dytiscid larvae). However, the presence of a larval predator (naiads) did not delay hatching. Eggs that developed in the presence of egg predators produced hatchlings that were shorter (total length) than those reared in the presence of larval predators or those reared in the absence of predators. We suggest that earlier hatching times should decrease vulnerability to egg predators but result in shorter hatchlings.
Body condition in Svalbard reindeer and the use of blood parameters as indicators of condition and fitness
Authors: Milner Jos M , Stien Audun , Irvine R Justin , Albon Steve D , Langvatn Rolf , Ropstad Erik
Published: October 2003

Body condition is an important determinant of ecological fitness but is difficult to measure in field studies of live animals. Live mass and subcutaneous fat are often used as proxies for body condition and related to fitness. We investigated the relationship between blood-chemistry parameters and live mass and back-fat thickness and assessed their usefulness as predictors of ecological fitness in a wild arctic ungulate population, Svalbard reindeer (Rangifer tarandus platyrhynchus). Female reindeer were sampled in late winter between 1995 and 2002 and concentrations of blood parameters were related to subsequent survival and successful calving. There was marked annual variation in all blood parameters, live mass, and back-fat thickness, reflecting variation in weather and food availability. At the individual level, variation in blood-parameter concentrations was not closely related to variation in live mass or back-fat thickness, instead reflecting shorter term nutritional status. Blood parameters could therefore provide useful additional information, enhancing the predictive power of fitness models based on live mass. The urea:creatinine ratio significantly improved adult survival models, while β-hydroxybutyric acid and creatinine concentrations were significant predictors of calving success. The applications for blood parameters in ecological investigations look promising and should be tested more widely in other field studies.
Seasonal changes in the diel surfacing behaviour of the bimodally respiring turtleRheodytes leukops
Authors: Gordos Matthew A , Franklin Craig E , Limpus Colin J
Published: October 2003

The purpose of this study was to determine whether a relationship existed between the diel surfacing trends of the bimodally respiring freshwater turtle Rheodytes leukops and daily fluctuations in specific biotic and abiotic factors. The diel surfacing behaviour of adult R. leukops was recorded over four consecutive seasons (Austral autumn 2000  summer 2001) within Marlborough Creek, central Queensland, Australia, using pressure-sensitive timedepth recorders. Additionally, diurnal variations in water temperature and aquatic PO2level, as well as the turtle's behavioural state (i.e., active versus resting), were monitored. In autumn and summer, surfacing frequency increased significantly during the daylight hours, with peak levels normally occurring around dawn (05000700) and dusk (17001900). However, no consistent diel surfacing trend was recorded for the turtles in winter or spring, owing to considerable variation among individual R. leukops. Diurnal surfacing trends recorded for R. leukops in autumn and summer are attributed to periods of increased activity (possibly associated with foraging) during the daylight hours and not to daily variations in water temperature or aquatic PO2level. Turtles generally remained at a depth greater than 1 m throughout the day, where the effect of diel fluctuations in water temperature (<0.5 °C) and aquatic PO2level (<15 mm Hg (1 mm Hg = 133.322 Pa)) was considered to be negligible.
Effects of Emitted Qi on In Vitro Natural Killer Cell Cytotoxic Activity
Authors: Lee Myeong Soo , Huh Hwa Jeong , Jang Hye-Sook , Han Chang Sub , Ryu Hoon , Chung Hun-Taeg
Published: October 2003

The present study investigated the effects of Korean Qi-therapy, ChunSoo Energy Healing, on natural killer (NK) cell cytotoxicity in vitro depending on Qi-treatment time and the types of cells treated. NK cell cytotoxicity was assayed by measuring LDH release from tumor target cells (K562 cell lines). NK activity was significantly increased by emitted-Qi treatment of 30 sec duration. Three and 5 minutes of Qi projection created the greatest increase in NK cell activity when mixtures of NK cells and K562 cells were treated (1.81 and 2.12 fold for 4 hr culture; 1.54 and 1.36 for 16 hr culture, respectively). NK cell activity increased significantly in Qi-treated K562 cells alone (1.13 fold, p < 0.05) compared to control. These results are consistent with in vivo Qi-therapy on humans and suggests that emitted-Qi has an acute stimulatory effect on NK cell activity. This study provides direct scientific support that Qi as such may positively affect human cellular immunity.
Effects of a 10-Minute Back Rub on Cardiovascular Responses in Healthy Subjects
Authors: Boone Tommy , Tanner Michelle , Radosevich Angela
Published: October 2003

This study determined the cardiovascular responses to a 10-minute back rub. Twelve healthy, college-age males and females (mean age = 22 years) volunteered to participate as subjects. Using an ABA design, the subjects tested for 10 minutes (Control #1) on a padded plinth lying on one side. During the Treatment period, the back rub was administered, which was followed by Control #2. Oxygen consumption (VO2) was determined via the Medical Graphics CPX/D metabolic analyzer, which also estimated cardiac output (Q) using the CO2 rebreathing (equilibrium) method. A repreated measures ANOVA was performed to statistically compare the cardiovascular responses across the three periods. The back rub, when compared to Control #1, had no significant effect on VO2, but the central and peripheral components of VO2 were changed. Cardiac output was decreased as a result of the decreased stroke volume (SV), as a function of the increased peripheral vascular resistance (PVR). We also found an increase in the extraction of oxygen (a-vO2 diff) in the peripheral tissues. These results indicate that the VO2 response during the back rub was achieved by reciprocal central (SV,Q) and peripheral (a-vO2 diff) adjustemtns. Following the back rub, (i.e., Control #2 vs. Treatment), the decrease in VO2, VCO2, Ve, and a-vO2 diff appears to indicate that it was effective in inducing relaxation. Since HR, SV, and Q were unchanged, the VO2 response was result of the decreased a-vO2 diff. Hence, the findings certain positive implications for the health care industry.
Studies on the Psychosomatic Functioning of Ill-health According to Eastern and Western Medicine: 5. Psychosomatic Characteristics of Anxiety and Anxiety-Affinitive Constitution
Authors: Takeichi Masashi , Sato Takeshi , Takefu Masasuke , Shigematsu Masahito , Shimohira Hiroko , Katsuki Takeshi
Published: October 2003

In successive studies of the pscyhosomatic functioning of ill-health according to Oriental and Western medicine in medical students, we established the existence of the psychosomatic characteristics we have provisionally terned the anxiety-affinitive constitution at the core of ill-health. Therefore, we conducted this research because our pervious investigation showed this constitution included a high complexity of respiratory movement and eye movement with a significant correlation to the State Trait Anxiety Inventory (STAI). We examined the correlation between the STAI and somatic function of 88 medical students to identify the psychosomatic characteristics of anxiety and the anxiety-affinitive constitution. These tests included STAI, fractal (EEG, EOG, plethysmogram, respiratory curves, and EMG) and non-fractal (accelerated plethysmogram) dimension analyses, and malocclusion (based on Angle's classification). In particular, EOG, plethysmogram, and respiratory curves are known to have close association with trait anxiety. We were able to discover the correlation between (1) trait anxiety and thoracic and abdominal respiratory movements, and malocculusion (Class III), and (2) the correlation of state anxiety with thoracic respiratory movement, horizontal eye movement, a plethysmogram and an EEG-Pz (in males only). In subsequent study the relation between thoracic dominance and state-trait anxiety and between abdominal dominance and state-trait anxiety should be assessed to develop this research regarding the psychosomatic characteristics of anxiety and the anxiety-affinitive constitution. Further, it is essential to create an anxiety-affinitive constitution index based on multi-regression analysis.
Effect of Choto-san on Microcirculation, Serum Nitric Oxide and Lipid Peroxides in Patients with Asymptomatic Cerebral Infarction
Authors: Goto Hirozo , Yang Qiao , Kita Toshiaki , Hikiami Hiroaki , Shimada Yutaka , Terasawa Katsutoshi
Published: October 2003

The effects of Choto-san on microcirculation, serum nitric oxide and lipid peroxides were investigated. Fifteen patients with asymptomatic cerebral infarction were investigated before and after a four-week administration of Choto-san. The variables of microcirculation of the bulbar conjunctive, which were the internal diameter of vessels, flow velocity and flow volume rate, were increased. Serum [Formula: see text] tended to increase and lipid peroxides were decreased. Total serum cholesterol was also decreased. These results suggest that Choto-san may improve microcirculation affected by endothelial function and fat metabolism.
Effect of CDA-II, Urinary Preparation on Lipofuscin, Lipid Peroxidation and Antioxidant Systems in Young and Middle-Aged Rat Brain
Authors: Lin Wen-Chuan , Wu Yueh-Wern , Lai Tung-Yuan , Liau Ming-Cheng
Published: October 2003

The levels of lipofuscin and lipid peroxidation reflect the degree of free radical-induced oxidative damage in the brain. We examined the effects of CDA-ll, a preparation of human urine, on lipofuscin and lipid peroxidation in the brain of young (3.5 months) and middle-aged rats (17 months). The rats were given CDA-ll orally at dosages of 0.3 or 1.0 g/kg daily for 8 weeks. CDA-ll significantly suppressed the contents of lipofuscin and lipid peroxidation in both young and middle-aged rats. CDA-ll also elevated the activity of superoxide dismutase, and the amounts of glutathione and ascorbic acid in the middle-aged rats, but not in the young ones. Our results suggest that the protection against oxidative damage by CDA-ll in the young rat brain may be due to its scavenging activity against free radicals. In the middle-aged rats, in addition to the scavenging activity, the levels of endogenous antioxidants were also enhanced by the CDA-ll treatment.
Anti-oxidative Herbs and Indomethacin-Induced Rat Gastric Mucosal Lesions: Protection byGamiHyangsa-Yukgunja
Authors: Shin Heung Mook
Published: October 2003

This study investigates the protective effects of GamiHyangsa-Yukgunja (GHY, a popular herbal medicine formula) on indomethacin-induced gastric mucosal lesions and morphological change in rats. Subcutaneous injection of indomethacin (25 mg/kg) produced the following gastric morphological alterations; mucosa hermorrhagic infarct, mucosa cell necrosis, leukocyte infiltration, mucosa hemorrhagic erosion, and gastric pit disappearance. Tissue damages were accompanied by increased oxidative stress, lipid peroxidation, and decreases in superoxide dismutase (SOD), and catalase (CAT) activities, and glutathione (GSH) concentrations. Our results show that pretreatment of the rats with orally administered GHY extract (3.3 ml/kg/day) significantly reduced gastric lesion formation and caused the amelioration of several pathological changes in the above-mentioned gastric mucosal lesions. Concomuitantly, GHY-pretreatment increased gastric mucosal SOD and CAT activities and GSH concentrations. We therefore propose that GHY exerts a prophylactic effect on the indomethacin-induced gastric mucosal lesions by enhancing antioxidant defense systems.
The Inhibitory Effect of Herbal Medicine -Dai Kenchu To (DKT)- on the Colonic Motility in Rats In Vitro
Authors: Tulimat Mohammad Alhakam , Ishiguchi Tadashi , Kurosawa Susumu , Nakamura Takashi , Takahashi Toku
Published: October 2003

Dai-Kenchu-To (DKT) is a herbal medicine and is currently used as the treatment of paralytic ileus in Japan. We investigated the mechanism of beneficial effects of DKT in vitro. DKT-extract powder (DKT-EP; 30–300 μg/ml) caused a significant inhibition on carbachol (CCH; 10-6)-induced contraction in a concentration dependent manner of the rat distal colon. DKT-EP (100 μg/ml) consists of 20 μg/ml of Zanthoxylum Fruit, 30 μg/ml of Ginseng Root and 50 μg/ml of Ginger Rhizome. Although each of them had no effect on CCH-induced muscle contraction, the combination of three ingredients caused a significant inhibition on CCH-induced contraction.
Effects of Orengedoku-to and Senkanmeimoku-to, Traditional Herbal Medicines, on the Experimental Herbal Medicines, on the Experimental Elevation of Aqueous Flare in Pigmental Rabbits
Authors: Nagaki Yasunoru , Hayasaka Seiji , Kadoi Chiharu , Matsumoto Masayuki , Nakamura Nobuo , Hayasaka Yoriko
Published: October 2003

We investigated the effects of Orengedoku-to (Huanglian-Jie-Du-Tang in Chinese) and Senkanmeimoku-to (Xygan-Ming-Mu-Tang in Chinese), traditional herbal medicines, on experimantal elevation of aqueous flare in pigmented rabbits. To produce the elevation of aqueous flare in rabbits, prostagalandin E2 (PGE2) was applied to the cornea with use of a glass cylinder, or lipopolysaccharides (LPS) were injected into the ear vein. Animals were pretreated by the oral administration of 150 g/day of food containing 0.7%, 0.2% or 0.07% (w/w) Orengedoku-to, or 2%, 0.6% or 0.2% (w/w) Senkanmeimoku-to for 5 days. Aquenous flare was measured with a laser flare-cell meter. Pretreatment with 0.7% or 0.2% Orengedoku-to and 2% Senkanmeimoku-to did suppress significantly (P < 0.05) elevation of aqueous flare induced by PGE2. Pretreatment with 0.7% or 0.2% Orengedoku-to and 2% or 0.6% Senkanmeimoku-to significantly suppressed (P < 0.001) elevation of aqueous flare induced by LPS. It is possible that Orengedoku-to and Senkanmeimoku-to may migrate some forms of uveitis.