bluuebunny/crossref_metadata_2025 huggingface dataset:
Feeding Fauna and Foraging Habits of Tiger Beetles Found in Agro‐ecosystems in Western Ghats, India1
Authors: Sinu P. A. , Nasser M. , Rajan P. D.
Published: June 2006

Cicindela (Calochroa) whithilli(Hope) andCicindela (Calochroa) flavomaculataHope (Cicindelidae: Coleoptera) are seasonally dominant predatory insects in the cultivated, and irrigated rice paddy fields of the South Indian peninsula. While studying the feeding ecology of these tiger beetles in rice paddy agro‐ecosystems in Sringeri area of the central Western Ghats, we examined their potential as biocontrols on the major rice paddy pest populations available in this region. Earthworms and tadpoles were significant prey organisms during the early cultivation period, while other traditional prey organisms like ants and spiders (mainly wolf and jumping spiders) were more common as prey organisms toward the mid‐season. The results showed that the feeding fauna of tiger beetles can extend to prey items beyond arthropods, to include vertebrates.Cicindela (Calochroa) dupontiDejean is another common species that occurs abundantly in theArecaorchards and on the bunds that separate rice paddy fields from adjacent uncultivated lands. We performed laboratory tests to determine the feeding guild of these beetles, and to investigate their possible role as a predator of the rice paddy pests. Although preliminary in nature, the results suggest that bothC. whithilliandC. flavomaculataare ineffective as biocontrol agents of rice paddy agro‐ecosystems. They appear to have only a marginal impact on the larvae ofLeptocorisa acuta, a major insect pest of paddy rice, but further experimental and observational studies are needed to firmly establish the significance of this observation.
Turbulent diffusion in protoplanetary discs: the effect of an imposed magnetic field
Authors: Johansen A. , Klahr H. , Mee A. J.
Published: June 2006

We study the effect of an imposed vertical magnetic field on the turbulent mass diffusion properties of magnetorotational turbulence in protoplanetary discs. It is well-known that the effective viscosity generated by the turbulence depends strongly on the magnitude of such an external field. In this Letter we show that the turbulent diffusion of the flow also changes, but that the diffusion coefficient does not rise with increasing vertical field as fast as the viscosity does. The vertical Schmidt number, i.e. the ratio between viscosity and vertical diffusion, can be close to 20 for high field magnitudes, whereas the radial Schmidt number is increased from below unity to around 3.5. Our results may have consequences for the interpretation of observations of dust in protoplanetary discs and for chemical evolution modelling of these discs.
Colitis‐induced oxidative damage of the colon and skeletal muscle is ameliorated by regular exercise in rats: the anxiolytic role of exercise
Authors: Kasımay Özgür , Güzel Esra , Gemici Ali , Abdyli Asead , Sulovari Admir , Ercan Feriha , Yeğen Berrak Ç.
Published: June 2006

Epidemiological studies have shown that exercise protects the gastrointestinal tract, reducing the risk of diverticulosis, gastrointestinal haemorrhage and inflammatory bowel disease, while many digestive complaints occurring during exercise are attributed to the adverse effects of exercise on the colon. In order to assess the effects of regular exercise on the pathogenesis of colitis, Sprague–Dawley rats of both sexes were either kept sedentary or given exercise on a running wheel (0.4 km h−1, 30 min for 3 days week−1). At the end of 6 weeks, under anaesthesia, either saline or acetic acid (4%, 1 ml) was given intracolonically. Holeboard tests were performed for the evaluation of anxiety at 24 h before and 48 h after induction of colitis. Increased ‘freezing time’ in the colitis‐induced sedentary group, representing increased anxiety, was reduced in the exercised colitis group (P < 0.05). On the third day following the colonic instillation, the rats were decapitated under brief ether anesthesia and the distal 8 cm of the colons were removed. In the sedentary colitis group, macroscopic and microscopic damage scores, malondialdehyde level and myeloperoxidase activity were increased when compared to the control group (P < 0.01–0.001), while exercise prior to colitis reduced all the measurements with respect to sedentary colitis group (P < 0.05–0.001). The results demonstrate that low‐intensity, repetitive exercise protects against oxidative colonic injury, and that this appears to involve the anxiolytic effect of exercise, suggesting that exercise may have a therapeutic value in reducing stress‐related exacerbation of colitis.
Ca2+‐dependent regulation of a non‐selective cation channel fromAplysiabag cell neurones
Authors: Lupinsky Derek A. , Magoski Neil S.
Published: June 2006

Ca2+‐activated, non‐selective cation channels feature prominently in the regulation of neuronal excitability, yet the mechanism of their Ca2+activation is poorly defined. In the bag cell neurones ofAplysia californica, opening of a voltage‐gated, non‐selective cation channel initiates a long‐lasting afterdischarge that induces egg‐laying behaviour. The present study used single‐channel recording to investigate Ca2+activation in this cation channel. Perfusion of Ca2+onto the cytoplasmic face of channels in excised, inside‐out patches yielded a Ca2+activation EC50of 10 μmwith a Hill coefficient of 0.66. Increasing Ca2+from 100 nmto 10 μmcaused an apparent hyperpolarizing shift in the open probability (Po)versusvoltage curve. Beyond 10 μmCa2+, additional changes in voltage dependence were not evident. Perfusion of Ba2+onto the cytoplasmic face did not alterPo; moreover, in outside‐out recordings,Powas decreased by replacing external Ca2+with Ba2+as a charge carrier, suggesting Ca2+influx through the channel may provide positive feedback. The lack of Ba2+sensitivity implicated calmodulin in Ca2+activation. Consistent with this, the application to the cytoplasmic face of calmodulin antagonists, calmidazolium and calmodulin‐binding domain, reducedPo, whereas exogenous calmodulin increasedPo. Overall, the data indicated that the cation channel is activated by Ca2+through closely associated calmodulin. Bag cell neurone intracellular Ca2+rises markedly at the onset of the afterdischarge, which would enhance channel opening and promote bursting to elicit reproduction. Cation channels are essential to nervous system function in many organisms, and closely associated calmodulin may represent a widespread mechanism for their Ca2+sensitivity.
Synaptic GABAergic and glutamatergic mechanisms underlying alcohol sensitivity in mouse hippocampal neurons
Authors: Proctor W. R. , Diao Lihong , Freund R. K. , Browning M. D. , Wu P. H.
Published: June 2006

This study was designed to examine the neuronal mechanisms of ethanol sensitivity by utilizing inbred short sleep (ISS) and inbred long sleep (ILS) mouse strains that display large differences in sensitivity to the behavioural effects of ethanol. Comparisons of whole‐cell electrophysiological recordings from CA1 pyramidal neurons in hippocampal slices of ISS and ILS mice indicate that ethanol enhances GABAA receptor‐mediated inhibitory postsynaptic currents (GABAA IPSCs) and reduces NMDA receptor‐mediated excitatory postsynaptic currents (NMDA EPSCs) in a concentration‐ and strain‐dependent manner. In ILS neurons, these receptor systems are significantly more sensitive to ethanol than those in ISS neurons. To further examine the underlying mechanisms of differential ethanol sensitivities in these mice, GABAB activity and presynaptic and postsynaptic actions of ethanol were investigated. Inhibition of GABAB receptor function enhances ethanol‐mediated potentiation of distal GABAA IPSCs in ILS but not ISS mice, and this blockade of GABAB receptor function has no effect on the action of ethanol on NMDA EPSCs in either mouse strain. Thus, subregional differences in GABAB activity may contribute to the differential ethanol sensitivity of ISS and ILS mice. Moreover, analysis of the effects of ethanol on paired‐pulse stimulation, spontaneous IPSC events, and brief local GABA or glutamate application suggest that postsynaptic rather than presynaptic mechanisms underlie the differential ethanol sensitivity of these mice. Furthermore, these results provide essential information to focus better on appropriate target sites for more effective drug development for the treatment of alcohol abuse.
A Brief Evaluation of Approximation Methods for Microcrack Shielding Problems
Authors: Yan Xiangqiao
Published: June 2006

This note can be regarded as a supplement of a paper entitled “On the Use of Approximation Methods for Microcrack Shilding Problems” (H. Cai and K. T. Faber, 1992, ASME J. Appl. Mech. 59, 497–501). In this note, an effective approximation method for microcrack shielding problems is introduced briefly and is further used to study the examples given in the Cai and Faber paper for the interaction of a macrocrack with microcracks. It is found that the applicability range of the present approximation method in which the errors are acceptably small is much larger than that of the approximation methods listed in the Cai and Faber paper.
Ice or Snow in the Tempel 1 Comet?
Authors: Pugno Nicola M.
Published: June 2006

An estimation of the Tempel 1 comet strength is deduced as intermediate between that of snow and ice.
Elastic Bending of Steel-Polymer-Steel (SPS) Laminates to a Constant Curvature
Authors: Weiss M. , Rolfe B. F. , Dingle M. , Duncan J. L.
Published: June 2006

The shear strain of the interlayer in the elastic regime for a Steel-Polymer-Steel (SPS) laminate material has been studied during bending to a constant curvature. An analytical model is developed and the influence of process parameters are analyzed. The tension in the cover sheets is also determined and, finally, a moment diagram is calculated. The results show that the moment in the SPS laminate is nonuniform along the bent strip even though the curvature is constant because of the tension and compression forces introduced in the cover sheets by the shear reaction force of the interlayer material.
An Experimental Study
of the Enhancement of Air-Cooling Limits for Telecom/Datacom Heat Sink Applications Using an
Impinging Air Jet
Authors: Sansoucy Eric , Oosthuizen Patrick
H. , Refai-Ahmed Gamal
Published: June 2006

An experimental study was conducted to investigate the heat transfer from a parallel flat plate heat sink under a turbulent impinging air jet. A horizontal nozzle plate confined the target surface. The jet was discharged from a sharp-edged nozzle in the nozzle plate. Average Nusselt numbers are reported for Pr=0.7, 5000⩽Re⩽30,000, L∕d=2.5, and 0.833 at H∕d=3 where L, H, and d define the length of the square heat source, nozzle-to-target spacing, and nozzle diameter, respectively. Tests were also conducted for an impinging flow over a flat plate, flush with the top surface of the target plate. The average Nusselt numbers from the heat sink were compared to those for a flat plate to determine the overall performance of the heat sink in a confined impingement arrangement. The experimental results were compared with the numerical predictions obtained in an earlier study. Although the average Nusselt numbers obtained from numerical simulations differed from the experimental measurements by 18%, the disagreement is much less significant when related to the junction temperature. Under typical conditions, it was shown that such discrepancy in the Nusselt number lead to an error of 6% in the prediction of the junction temperature of the device.
Complex Flow Dynamics in Dense Granular Flows—Part I: Experimentation
Authors: Zamankhan Piroz , Bordbar Mohammad Hadi
Published: June 2006

By applying a methodology useful for analysis of complex fluids based on a synergistic combination of experiments, computer simulations, and theoretical investigation, a model was built to investigate the fluid dynamics of granular flows in an intermediate regime where both collisional and frictional interactions may affect the flow behavior. In Part I, the viscoelastic behavior of nearly identical sized glass balls during a collision have been studied experimentally using a modified Newton’s cradle device. Analyzing the results of the measurements, by employing a numerical model based on finite element methods, the viscous damping coefficient was determined for the glass balls. Power law dependence was found for the restitution coefficient on the impact velocity. In order to obtain detailed information about the interparticle interactions in dense granular flows, a simplified model for collisions between particles of a granular material was proposed to be of use in molecular dynamic simulations, discussed in Part II.
The Arithmetic Mean Theorem of Eshelby Tensor for Exterior Points Outside the Rotational Symmetrical Inclusion
Authors: Wang Min-Zhong , Xu Bai-Xiang
Published: June 2006

In 1957, Eshelby proved that the strain field within a homogeneous ellipsoidal inclusion embedded in an infinite isotropic media is uniform, when the eigenstrain prescribed in the inclusion is uniform. This property is usually referred to as the Eshelby property. Although the Eshelby property does not hold for the non-ellipsoidal inclusions, in recent studies we have successfully proved that the arithmetic mean of Eshelby tensors at N rotational symmetrical points inside an N-fold rotational symmetrical inclusion is constant and equals the Eshelby tensor for a circular inclusion, when N⩾3 and N≠4. The property is named the quasi-Eshelby property or the arithmetic mean theorem of Eshelby tensors for interior points. In this paper, we investigate the elastic field outside the inclusion. By the Green formula and the knowledge of complex variable functions, we prove that the arithmetic mean of Eshelby tensors at N rotational symmetrical points outside an N-fold rotational symmetrical inclusion is equal to zero, when N⩾3 and N≠4. The property is referred to as the arithmetic mean theorem of Eshelby tensors for exterior points. Due to the quality of the Green function for plane strain problems, the fourfold rotational symmetrical inclusions are excluded from possessing the arithmetic mean theorem. At the same time, by the method proposed in this paper, we verify the quasi-Eshelby property which has been obtained in our previous work. As corollaries, two more special properties of Eshelby tensor for N-fold rotational symmetrical inclusions are presented which may be beneficial to the evaluation of effective material properties of composites. Finally, the circular inclusion is used to test the validity of the arithmetic mean theorem for exterior points by using the known solutions.
Modeling of Natural
Convection in Electronic Enclosures
Authors: Teertstra Peter
M. , Michael
Yovanovich M. , Richard Culham J.
Published: June 2006

An analytical model is developed for natural convection from a single circuit board in a sealed electronic equipment enclosure. The circuit card is modeled as a vertical isothermal plate located at the center of an isothermal, cuboid shaped enclosure. A composite model is developed based on asymptotic solutions for three limiting cases: pure conduction, laminar boundary layer convection, and transition flow convection. The conduction shape factor and natural convection models are validated using data from CFD simulations for a wide range of enclosure geometries and flow conditions. The model is shown to be in good agreement, to within 10% RMS, with the numerical data for all test configurations.
The Importance of Demographic Niches to Tree Diversity
Authors: Condit Richard , Ashton Peter , Bunyavejchewin Sarayudh , Dattaraja H. S. , Davies Stuart , Esufali Shameema , Ewango Corneille , Foster Robin , Gunatilleke I. A. U. N. , Gunatilleke C. V. S. , Hall Pamela , Harms Kyle E. , Hart Terese , Hernandez Consuelo , Hubbell Stephen , Itoh Akira , Kiratiprayoon Somboon , LaFrankie James , de Lao Suzanne Loo , Makana Jean-Remy , Noor Md. Nur Supardi , Kassim Abdul Rahman , Russo Sabrina , Sukumar Raman , Samper Cristián , Suresh Hebbalalu S. , Tan Sylvester , Thomas Sean , Valencia Renato , Vallejo Martha , Villa Gorky , Zillio Tommaso
Published: June 2006

Most ecological hypotheses about species coexistence hinge on species differences, but quantifying trait differences across species in diverse communities is often unfeasible. We examined the variation of demographic traits using a global tropical forest data set covering 4500 species in 10 large-scale tree inventories. With a hierarchical Bayesian approach, we quantified the distribution of mortality and growth rates of all tree species at each site. This allowed us to test the prediction that demographic differences facilitate species richness, as suggested by the theory that a tradeoff between high growth and high survival allows species to coexist. Contrary to the prediction, the most diverse forests had the least demographic variation. Although demographic differences may foster coexistence, they do not explain any of the 16-fold variation in tree species richness observed across the tropics.
AFLP analysis of genetic variation within the two economically important Anatolian grapevine (Vitis viniferaL.) varietal groups
Authors: Ergül Ali , Kazan Kemal , Aras Sümer , Çevik Volkan , Çelik Hasan , Söylemezoğlu Gökhan
Published: June 2006

The Anatolian region of modern-day Turkey is believed to have played an important role in the history of grapevine (Vitis vinifera L.) domestication and spread. Despite this, the rich grape germplasm of this region is virtually uncharacterized genetically. In this study, the amplified fragment length polymorphisms (AFLP)-based genetic relations of the grapevine accessions belonging to the 2 economically important Anatolian table grape varietal groups known as V. vinifera 'Misket' (Muscat) and V. vinifera 'Parmak' were studied. Thirteen AFLP primer combinations used in the analyses revealed a total of 1495 (35.5% polymorphic) and 1567 (34.6% polymorphic) DNA fragments for the 'Misket' and 'Parmak' varietal groups, respectively. The unweighted pair-group method with arthimetic averaging (UPGMA) cluster analysis and principal coordinate analysis (PCA) conducted on polymorphic AFLP markers showed that both varietal groups contain a number of synonymous (similar genotypes known by different names) as well as homony mous (genetically different genotypes known by the same name) accessions. Our results also showed that 6 of the Anatolian 'Misket' genotypes were genetically very similar to V. vinifera 'Muscat of Alexandria', implying that these genotypes might have played some role in the formation of this universally known grape cultivar. Finally, the close genetic similarities found here between 'Muscat of Alexandria' and V. vinifera 'Muscat of Hamburg' support the recent suggestion that 'Muscat of Hamburg' probably originated from 'Muscat of Alexandria' through spontaneous hybridizations. Overall, the results of this study have implications for not only preservation and use of the Anatolian grape germplasm, but also better understanding of the historical role that this region has played during the domestication of grapes.Key words: 'Misket', 'Parmak', AFLP, Vitis vinifera L.
Variations in abundance of 2 repetitive sequences inLeymusandPsathyrostachysspecies
Authors: Wang R R.-C , Zhang J.-Y , Lee B S , Jensen K B , Kishii M , Tsujimoto H
Published: June 2006

The Ns genome of the genus Psathyrostachys is a component of the polyploid genome in the genus Leymus. Using fluorescence in situ hybridization (FISH), the occurrence and abundance of 2 tandem repetitive sequences from Leymus racemosus (Lam.) Tzvelev, pLrTaiI-1 (TaiI family) and pLrPstI-1 (1 class of 350-bp family), were assayed in 4 species of the genera Psathyrostachys and Leymus. The pLrPstI-1 sequence was absent in all 4 Psathyrostachys species. While P. fragilis and P. huashanica did not have the pLrTaiI-1 sequence, 15 accessions of P. juncea and 2 accessions of P. lanuginosa had pLrTaiI-1 sites ranging in number from 7 to 16 and from 2 to 21, respectively. The numbers of pLrTaiI-1 and pLrPstI-1 sites were 1-24 and 0-30, respectively, in L. ramosus; 2-31 and 5-36 in L. racemosus; 0-4 and 0 in L. mollis; 2-9 and 24-27 in L. secalinus. The FISH assay on pLrTaiI-1 was successfully converted to a sequence-tagged-site polymerase chain reaction (STS-PCR) test using a primer pair designed from the sequence of this repetitive DNA. Seventy-three accessions representing 27 Leymus species were assayed for the abundance of pLrTaiI-1 by STS-PCR. With a few exceptions of uniformity in some accessions, nearly all Leymus species observed were heterogeneous for the abundance of pLrTaiI-1 sequence and no Leymus species was totally devoid of this repetitive sequence. These findings may have significance for the understanding of phylogeny, nature of polyploidy, adaptive ranges, and breeding potential of Leymus species.Key words: FISH, genome, polyploid, 350 bp family, pLrTaiI-1, STS-PCR.
Development of a wide population of chromosome single-segment substitution lines in the genetic background of an elite cultivar of rice (Oryza sativaL.)
Authors: Xi Zhang-Ying , He Feng-Hua , Zeng Rui-Zhen , Zhang Ze-Min , Ding Xiao-Hua , Li Wen-Tao , Zhang Gui-Quan
Published: June 2006

Naturally occurring allelic variations underlying complex traits are useful resources for the functional analysis of plant genes. To facilitate the genetic analysis of complex traits and the use of marker-assisted breeding in rice, we developed a wide population consisting of 217 chromosome single-segment substitution lines (SSSLs) using Oryza sativa L. 'Hua-Jing-Xian74' (HJX74), an elite Indica cultivar, as recipient, and 6 other accessions, including 2 Indica and 4 Japonica, as donors. Each SSSL contains a single substituted chromosome segment derived from 1 of the 6 donors in the genetic background of HJX74. The total size of the substituted segments in the SSSL population was 4695.0 cM, which was 3.1 times that of rice genome. To evaluate the potential application of these SSSLs for quantitative trait loci detection, phenotypic variations of the quantitative traits of days to heading and grain length in the population consisting of 210 SSSLs were observed under natural environmental conditions. The results demonstrated that there was a wide range of phenotypic variation in the traits in the SSSL population. These genetic materials will be powerful tools to dissect complex traits into a set of monogenic loci and to assign phenotypic values to different alleles at the locus of interest.Key words: rice, mapping population, single segment substitution lines, marker-assisted selection, quantitative trait loci.
Characterization equations for steel column base connections
Authors: Dumas Martin , Beaulieu Denis , Picard André
Published: June 2006

This paper presents partial results of a research program under way at Laval University for which the main goal is to introduce the behaviour of steel connections into commercial structural analysis software. The objective of this paper is to derive analytical characterization equations for three commonly used steel column base connections. The procedure to derive these equations is based on a curve standardization theory that requires a number of experimental results in the form of moment–rotation curves that characterize the behaviour of column base connections. Because of a lack of available experimental results, data were obtained from finite element models. The design of a simple steel structure introducing the semi-rigid behaviour of column bases is presented as an example. It shows that consideration of the semi-rigidity of column base connections increases the accuracy of the analysis results and leads to a decrease in structure weight and deformation.Key words: analysis, base, behaviour, column, connection, frame, partial, rigidity, steel, structure.
Tension and shear block failure of bolted gusset plates
Authors: Huns Bino B.S , Grondin Gilbert Y , Driver Robert G
Published: June 2006

Despite the large database of test results for tension and shear block failure in gusset plates, the exact progression of the failure mechanism is not clear. Although current design equations predict the capacity of gusset plates fairly well, it is important for a design equation to not only predict the capacity reliably but also reflect the failure mode accurately. Recent experimental and numerical research has indicated that current design equations do not always predict the failure behaviour accurately. A finite element model was therefore developed to predict the sequence of events that leads to the tear-out of a block of material from a bolted gusset plate in tension. The model was developed to provide a useful tool for studying tension and shear block failure in gusset plates and other structural elements. This paper presents the development of the finite element model and procedure for prediction of tension and shear block failure in gusset plates. Making use of the finite element model, the database of test results is also expanded to include gusset plates with a larger number of transverse lines of bolts than what has been obtained experimentally. A reliability analysis is used to assess several design equations, including the equation adopted in CAN/CSA-S16-01 and a unified equation proposed recently for several types of bolted connections. From this work, a limit states design equation is proposed for gusset plates.Key words: gusset plate, limit states design, reliability, shear rupture, tension rupture, finite element analysis, failure criterion.
Persistence of endocrine-disrupting chemicals in agricultural soils
Authors: Lorenzen Angela , Burnison Kent , Servos Mark , Topp Edward
Published: June 2006

Biosolids and animal wastes can contain natural hormones or synthetic chemicals that have the potential to disrupt endocrine function in wildlife should they move offsite. The persistence in soil of estrogenic substances that could reach agricultural land via fertilization with organic amendments has been evaluated. 4-Nonylphenol, ethynylestradiol, estradiol, and estrone are rapidly dissipated in soils under a range of conditions typical of a temperate growing season with half-lives ranging from a few hours to a few days. We conclude that these chemicals are rapidly removed from aerated soils under temperate growing conditions such that application methods that minimize preferential flow or runoff of animal or human wastes should protect adjacent water from contamination. The use of recombinant yeast and cell culture estrogen receptor gene transcription bioassays were investigated as potential tools to detect non-labile estrogenic or anti-estrogenic substances in runoff from soils receiving liquid swine slurry or biosolids. Key words: biosolids, manures, endocrine disruption, estrogen, nonylphenol, soil persistence, bioassay.
Dewatering and coliform inactivation in biosolids using electrokinetic phenomena
Authors: Esmaeily Ali , Elektorowicz Maria , Habibi Shiva , Oleszkiewicz Jan
Published: June 2006

The feasibility of using electrokinetic processes for dewatering and fecal coliform (FC) inactivation was evaluated on a bench scale. Six electrokinetic cells were filled with biosolids from an attached growth biological wastewater treatment plant in Auteuil, Quebec. A conditioning liquid containing nitrate and ammonia was also added to two cells. Potential gradients of 0.5, 1.0, and 1.5 V/cm were applied to the cells. The highest total solids content (62% TS) was achieved in the cell with the highest applied voltage and in the presence of the conditioner. No fecal coliforms were observed in the cells with conditioner. The cells without the conditioner exhibited FC inactivation in the anode area and lack of inactivation in the cathode area. Key words: dewatering, biosolids, electrokinetics, electroosmose, pathogen inactivation, coliform.
Dynamics of anti-Borreliaantibodies in Black-legged Kittiwake (Rissa tridactyla) chicks suggest a maternal educational effect
Authors: Gasparini Julien , McCoy Karen D. , Staszewski Vincent , Haussy Claudy , Boulinier Thierry
Published: June 2006

In the presence of parasites, mothers can transfer specific immunoglobulins to their offspring. These antibodies are typically thought to provide protection until the juvenile produces its own immune response, but they may also act to educate the developing immune system so as to prepare the individual for future parasite challenge. We examined this hypothesis in a natural host–parasite system involving the Black-legged Kittiwake ( Rissa tridactyla (L., 1758)), the seabird tick ( Ixodes ( Ceratixodes ) uriae White, 1852), and the Lyme disease bacterium ( Borrelia burgdorferi s.l. (Johnston, 1984)). We compared the dynamics of anti-Borrelia antibodies in chicks between ages 5 and 20 days that received a large amount of maternal anti-Borrelia antibodies to those that did not. The results suggest that the presence of maternal antibodies against Borrelia increases the overall production of anti-Borrelia immunoglobulins by chicks and support the existence of an adaptive maternal effect. Experimental approaches are now called for to better appraise the ecological and evolutionary consequences of the maternal transfer of antibodies in host–parasite interactions.
Thermoregulation and roosting behaviour of reproductive and nonreproductive female western long-eared bats (Myotis evotis) in the Rocky Mountains of Alberta
Authors: Solick Donald I. , Barclay Robert M.R.
Published: June 2006

Entering torpor can yield significant energy savings for temperate-zone bats but can be costly for reproductive females by slowing fetal development and reducing milk production. We studied western long-eared bats (Myotis evotis (H. Allen, 1864)) in the Rocky Mountains of Alberta to test the hypothesis that different costs of torpor result in different patterns of thermoregulation and roosting behaviour for reproductive and nonreproductive females. We radio-tracked bats to monitor body temperatures and locate roosts. We took roost measurements and inserted temperature data loggers to measure roost microclimate. Bats entered torpor frequently, but nonreproductive females spent longer periods in torpor, had lower minimum body temperatures, and entered deep torpor more often than reproductive females did, supporting the hypothesis that entering torpor is more costly for reproductive individuals. Roosts were located mainly in rock fields on steep, open, south-facing slopes. Reproductive females roosted in crevices between rocks located above or on the surface of the ground. Roosts warmed rapidly and reached warm daytime temperatures. Females roosted alone during pregnancy but formed small colonies within roosts during lactation when ambient conditions were cooler. Clustering may reduce thermoregulatory costs for both adults and young. Nonreproductive females roosted mainly alone in crevices in the ground. These roosts had cooler, more stable microclimates, allowing females to enter deeper bouts of torpor and remain torpid longer.
Resident beavers (Castor canadensis) do not discriminate between castoreum scent marks from simulated adult and subadult male intruders
Authors: Herr J. , Müller-Schwarze D. , Rosell F.
Published: June 2006

Subadult intruding beavers (Castor spp.) could be expected to pose a higher threat than adults to territory holders because, unlike adults who usually own a territory, subadults need to acquire a territory and a mate to reproduce successfully. We tested the responses of territorial beavers ( Castor canadensis Kuhl, 1820) to simulated intrusions by adult and subadult males. Territorial intrusion was simulated through scent playback experiments that exposed residents to castoreum from adult and subadult strangers simultaneously. We obtained responses from 13 resident beavers. Neither sniffing response nor physical or total responses differed between castoreum from adults and subadults. This was true for both sexes combined and separate. There was also no significant correlation between the mass of the scent donor and the response intensity. We found no evidence that territorial beavers responded differentially to castoreum scent marks from intruders of different ages. Either beavers consider all strange intruders as posing a high threat and hence do not treat them differentially or castoreum does not contain sufficient information to allow beavers to discriminate between age classes. We suggest that rather than directly assessing intruders by means of intrinsic information contained in the scent mark, beavers assess their competitors through scent matching.
Coda vocalizations recorded in breeding areas are almost entirely produced by mature female sperm whales (Physeter macrocephalus)
Authors: Marcoux Marianne , Whitehead Hal , Rendell Luke
Published: June 2006

We investigated the use and function of coda communication by sperm whales ( Physeter macrocephalus L., 1758 (= Physeter catodon L., 1758)). Codas are stereotyped patterns of clicks often made by sperm whales in social contexts. We used the pulsed structure of coda clicks recorded from socializing female/immature groups to estimate the body-length distribution of the animals producing the codas. Ninety-five percent of the 10 653 codas that we measured were produced by whales measuring from 9 to 11 m. This size range corresponds to the lengths of mature females. We compared these data to a length distribution calculated from photographic measurements of individuals from the same groups encountered during the same studies. There were more whales shorter than 8.5 m (10.0%) and longer than 12.5 m (2.7%) in the photographic length distribution than in that of the coda producers (0.30% and 0.08%, respectively). Since males leave their natal group when they are shorter than 9 m and return to breeding areas when they measure 13 m or more, our data show that the codas were produced almost entirely by mature females. We suggest that coda communication serves several functions, including social bonding.
Analysis of human skeletal muscle after 48 h immobilization reveals alterations in mRNA and protein for extracellular matrix components
Authors: Urso Maria L. , Scrimgeour Angus G. , Chen Yi-Wen , Thompson Paul D. , Clarkson Priscilla M.
Published: June 2006

We examined the effects of 48 h of knee immobilization on alterations in mRNA and protein in human skeletal muscle. We hypothesized that 48 h of immobilization would increase gene expression and respective protein products for ubiquitin-proteasome pathway (UPP) components. Also, we used microarray analysis to identify novel pathways. Biopsies were taken from the vastus muscle of five men (20.4 ± 0.5 yr) before and after 48-h immobilization. Global changes in gene expression were analyzed by use of Affymetrix GeneChips. Candidate genes were confirmed via quantitative RT-PCR. Western blotting (WB) was used to quantify protein products of candidate genes and to assess Akt pathway activation. Immunohistochemistry was used to localize proteins found to be altered when assessed via WB. The greatest percentage of genes showing altered expression with the GeneChip included genes involved in the UPP, metallothionein function, and extracellular matrix (ECM) integrity. Quantitative RT-PCR analysis confirmed increases in mRNA for UPP components [USP-6, small ubiquitin-related modifier (SUMO-1)] and the metallothioneins (MT2A, MT1F, MT1H, MT1X) and decreases in mRNA content for matrix metalloproteinases (MMP-28, TIMP-1) and ECM structural components [collagen III (COLIII) and IV (COLIV)]. Only phosphorylated Akt (Ser473, Thr308), COLIII and COLIV protein levels were significantly different postimmobilization (25, 10, 88, and 28% decrease, respectively). Immunohistochemistry confirmed WB showing decreased staining for collagens postimmobilization. Our results suggest that 48 h of immobilization increases mRNA content for components of the UPP and metallothionein function while decreasing mRNA and protein for ECM components as well as decreased phosphorylation of Akt.
Ventilatory response to hypercapnia and hypoxia after extensive lesion of medullary serotonergic neurons in newborn conscious piglets
Authors: Penatti E. M. , Berniker A. V. , Kereshi B. , Cafaro C. , Kelly M. L. , Niblock M. M. , Gao H. G. , Kinney H. C. , Li A. , Nattie E. E.
Published: June 2006

Acute inhibition of serotonergic (5-HT) neurons in the medullary raphé (MR) using a 5-HT1Areceptor agonist had an age-dependent impact on the “CO2response” of piglets ( 33 ). Our present study explored the effect of chronic 5-HT neuron lesions in the MR and extra-raphé on the ventilatory response to hypercapnia and hypoxia in piglets, with possible implications on the role of 5-HT in the sudden infant death syndrome. We established four experimental groups. Group 1 ( n = 11) did not undergo any treatment. Groups 2, 3, and 4 were injected with either vehicle or the neurotoxin 5,7-dihydroxytryptamine in the cisterna magna during the first week of life ( group 2, n = 9; group 4, n = 11) or second week of life ( group 3, n = 10). Ventilation was recorded in response to 5% CO2(all groups) and 12% O2( group 2) during wakefulness and sleep up to postnatal day 25. Surprisingly, the piglets did not reveal changes in their CO2sensitivity during early postnatal development. Overall, considerable lesions of 5-HT neurons (up to 65% decrease) in the MR and extra-raphé had no impact on the CO2response, regardless of injection time. Postlesion raphé plasticity could explain why we observed no effect. 5,7-Dihydroxytryptamine-treated males, however, did present a lower CO2response during sleep. Hypoxia significantly altered the frequency during sleep in lesioned piglets. Further studies are necessary to elucidate the role of plasticity, sex, and 5-HT abnormalities in sudden infant death syndrome.
Prenatal Diagnosis of Congenital Epulis
Authors: Thoma V. , Idrissi B. , Kohler M. , Becmeur F. , Viville B. , Favre R.
Published: June 2006

Congenital granular epulis is a rare benign tumour situated on the alveolar ridge, which usually presents as a single tumour of variable size. Prenatal diagnosis of epulis has rarely been reported in medical literature. A possible complication is airway obstruction, which is essentially determined by the size of the tumour. Because of the potential risk of neonatal respiratory distress, prenatal diagnosis is valuable in the organization of a safe delivery. The case presented here is the prenatal diagnosis of a congenital epulis discovered in the 32nd week of pregnancy.
Rapid Prenatal Diagnosis of Aneuploidy for Chromosomes 21, 18, 13, and X by Quantitative Fluorescence Polymerase Chain Reaction
Authors: Ochshorn Yifat , Bar-Shira Anat , Jonish Anat , Yaron Yuval
Published: June 2006

Objective: Quantitative fluorescence polymerase chain reaction (QF-PCR) is a rapid method for detection of chromosome copy number by amplification of repeat sequences at polymorphic loci. Our objective was to assess the performance of QF-PCR in detecting common aneuploidies in prenatal diagnosis. Study Design: The study group consisted of pregnant women referred for amniocentesis or chorionic villus sampling (CVS) due to increased risk of fetal aneuploidy. Samples were collected from known affected and normal pregnancies. These were blindly screened for trisomy of chromosomes 21, 18, 13, and sex chromosome abnormalities, using QF-PCR. DNA from uncultured amniocytes was directly extracted using a modified alkaline lysis method. DNA from CVS was extracted by the phenol-chloroform procedure. Ten short tandem repeat (STR) markers were used for detection of fetal aneuploidy and gender. The STRs were selected for high heterozygosity rates and efficiency of the PCR amplification. The forward primer of each pair was labeled with a unique fluorescent dye. Amplified products were detected by an ABI Prism® 310 Genetic Analyzer and results were analyzed using GeneScan® Analysis Software. Results: A total of 65 amniotic fluid and CVS samples were collected from affected and normal pregnancies. Two samples were contaminated with blood and were therefore excluded from the analysis. All 29 cases of aneuploidy were correctly diagnosed by QF-PCR, including 17 cases of trisomy 21, 7 cases of trisomy 18, and 5 cases with trisomy 13. The 34 normal samples were also correctly diagnosed as such. Thus, all results were in agreement with the standard cytogenetic results. There were no false-positive or false-negative results. Conclusion: We conclude that QF-PCR is a rapid, reliable, and reproducible method that may be used to provide rapid results in prenatal diagnosis of aneuploidy.
Doppler Sonography of the Fetal Middle Cerebral Artery in the Management of Massive Fetomaternal Hemorrhage
Authors: Eichbaum M. , Gast A.S. , Sohn C.
Published: June 2006

Massive fetomaternal hemorrhage (FMH) is a rare complication in pregnancy that may cause hydrops or can even be life-threatening for the fetus. We report on the case of a 19-year-old gravida I, para 0, who presented to our clinic at 32 weeks of gestation due to decreased fetal movements. The initial fetal heart rate tracing at admission showed a sinusoidal pattern without decelerations. The ultrasound examination performed immediately described a normally developed fetus with normal amounts of amniotic fluid and without abnormities of the placental structure. Doppler sonography of the fetal middle cerebral artery gave rise to the strong suspicion of fetal anemia, so that a cordocentesis was prepared for potential intrauterine blood transfusion. Meanwhile, the rate of fetal hemoglobin (HbF) cells in the maternal blood was found to be markedly increased with 66 ‰. Correspondingly, cardiotocographic findings worsened with repeated decelerations, thus an immediate cesarean section was performed based on the suspected diagnosis of an acute FMH. A fetus weighing 1,860 g was delivered, who had severe anemia with hemoglobin level of 4.0 g/dl. After a direct blood transfusion, HbF levels normalized rapidly, the fetus stabilized, and a normal recovery has thus far been reported. The presented case demonstrates the successful and straightforward diagnosis, as well as the management of a case of severe FMH and illustrates the special value of Doppler sonography in this context.
An Experience of Laser Surgery for Feto-Fetal Transfusion Syndrome Complicated with Unexpected Feto-Fetal Hemorrhage in a Case of Monochorionic Triamniotic Triplets
Authors: Ishii Keisuke , Murakoshi Takeshi , Numata Masahiro , Kikuchi Akira , Takakuwa Koichi , Tanaka Kenichi
Published: June 2006

Feto-fetal transfusion syndrome (FFTS) in monochorionic triplets is a rare clinical entity which may share the principal adverse perinatal outcomes of twin-twin transfusion syndrome. Recently, favorable prognoses regarding morbidity and mortality in twins after selective laser photocoagulation of placental communicating vessels (SLPCV) have been described. But descriptions of this procedure in monochorionic triplet cases are limited. This is the case report of an experience of SLPCV applied to monochorionic triamniotic triplets with FFTS. Triplet A had polyhydramnios, while absent end-diastolic flow in the umbilical artery of triplet B, the triplet with anhydramnios, was persistent. Triplet C looked normal, vertical amniotic pocket and Doppler studies yielding normal results. At the beginning of the SLPCV procedure, feto-fetal hemorrhage, subsequent to the fetal death of the donor triplet, occurred. Both surviving cofetuses showed persistent bradycardia; and 1 fetus died while the other recovered from the fetal bradycardia. All vascular anastomoses between the 3 triplets could be identified and obliterated, requiring two trocars. Our fetoscopic observation revealed feto-fetal hemorrhage after demise of monochorionic triplet, which led to injury of other fetuses due to hypovolemia in an instant. In conclusion, SLPCV might be a valid option for FFTS in triplet cases, while further experience is required in order to evaluate the risks and benefits of this procedure in triplet cases.
Prenatal Diagnosis and Therapy of Persistent Cloaca: A Case Report
Authors: Morikawa Mamoru , Yamada Takashi , Cho Kazutoshi , Yamada Hideto , Minakami Hisanori
Published: June 2006

Persistent cloaca is a rare abnormality that occurs only in females and is characterized by a direct communication between the gastrointestinal, urinary, and genital structures resulting in a single perineal opening. A case with massive ascites, two cystic structures arising from the fetal pelvis, bilateral hydroureters, calcified meconium, and cardiac anomalies, in which this condition was diagnosed prenatally is presented here.
Successful in utero Treatment of Fetal Goitrous Hypothyroidism: Case Report and Review of the Literature
Authors: Hashimoto H. , Hashimoto K. , Suehara N.
Published: June 2006

In this report, we present a case of fetal goiter with overdistended fetal neck and mild polyhydramnios. Amniocentesis and cordocentesis were conducted at 32 weeks’ gestation and fetal goitrous hypothyroidism was diagnosed. Intra-amniotic injection of l-thyroxine (T4) was performed with a weekly dose of 150 µg four times between 33 and 36 weeks’ gestation. In response to this in utero treatment, the goiter was reduced and polyhydramnios was improved. The mother gave birth to a healthy live male infant with normal thyroid function. From our case report and review of previous literature, we recommend that the amount of l-thyroxine start as low as 150 µg, and that repeat cordocentesis be avoided as long as other clinical and laboratory parameters indicate improvement of the fetal conditions.
Chemotaxis of Human Peripheral Blood Eosinophils to 2-Arachidonoylglycerol: Comparison with Other Eosinophil Chemoattractants
Authors: Kishimoto Seishi , Oka Saori , Gokoh Maiko , Sugiura Takayuki
Published: June 2006

Background: 2-Arachidonoylglycerol (2-AG), an endogenous ligand for the cannabinoid receptors (CB1 and CB2), has been shown to exhibit a variety of cannabimimetic activities in vitro and in vivo. Recently, we found that human eosinophilic leukemia EoL-1 cells and human peripheral blood eosinophils express the CB2 receptor. We also found that 2-AG induces the migration of these cells in a CB2 receptor-dependent manner. In this study, we investigated whether the 2-AG-induced migration of human eosinophils is due to chemotaxis or chemokinesis. We also compared the ability of 2-AG to induce the migration of eosinophils with those of other eosinophil chemoattractants. Methods: Eosinophils were separated from the peripheral blood of healthy donors. The migration of eosinophils to various stimulants was examined using Transwell™ inserts. In view of the fact that 2-AG is rapidly metabolized by cells, we employed 2-AG ether, an ether-linked nonhydrolyzable analog of 2-AG, instead of 2-AG to determine whether the 2-AG-induced migration is due to chemotaxis or chemokinesis. Results: 2-AG ether induced the migration of human eosinophils, like 2-AG. The 2-AG ether-induced migration was reduced by the coincubation of eosinophils with 2-AG ether in the upper compartment of the Transwell inserts, indicating that the migration is attributable to chemotaxis. The concentration of 2-AG required to induce the eosinophil migration appears to be pathophysiologically relevant, although the order of the pharmacologically effective concentration of 2-AG was approximately ten times lower than those of platelet-activating factor, RANTES and eotaxin. Conclusion: These results strongly suggest that 2-AG is involved in the infiltration of eosinophils during allergic inflammation.