bluuebunny/crossref_metadata_2025 huggingface dataset:
Myocardial gene transfer and long‐term expression following intracoronary delivery of adeno‐associated virus
Authors: Kaspar Brian K. , Roth David M. , Chin Lai N. , Drumm Jeffrey D. , Erickson Dawn A. , McKirnan M. Dan , Hammond H. Kirk
Published: March 2005

Adeno‐associated viral vectors (AAV) can direct long‐term gene expression in post‐mitotic cells. Previous studies have established that long‐term cardiac gene transfer results from intramuscular injection into the heart. Cardiac gene transfer after direct intracoronary delivery of AAV in vivo, however, has been minimal in degree, and indirect intracoronary delivery, an approach used in an increasing number of studies, appears to be receiving more attention. To determine the utility of indirect intracoronary gene transfer of AAV, we used aortic and pulmonary artery cross clamping followed by proximal aortic injection of AAV encoding enhanced green fluorescent protein (AAV.EGFP) at 1011 DNase resistant particles (drp; high‐performance liquid chromatography (HPLC)‐purified) per rat. Gene expression was quantified by fluorescent microscopy at four time points up to 1 year after vector delivery, revealing 20–32% transmural gene expression in the left ventricle at each time point. Histological analysis revealed little or no inflammatory response and levels of transgene expression were low in liver and undetectable in lung. In subsequent studies in pigs, direct intracoronary delivery into the left circumflex coronary artery of AAV.EGFP (2.64–5.28 × 1013 drp; HPLC‐purified) resulted in gene expression in 3 of 4 pigs 8 weeks following injection with no inflammatory response in the heart. PCR analysis confirmed AAV vector presence in the left circumflex perfusion bed. These data indicate that intracoronary delivery of AAV vector is associated with transgene expression in the heart, providing a means to obtain long‐term expression of therapeutic genes. Copyright © 2004 John Wiley & Sons, Ltd.
AdVEGF165 gene transfer increases survival in overdimensioned skin flaps
Authors: Giunta R. E. , Holzbach T. , Taskov C. , Holm P. S. , Konerding M. A. , Schams D. , Biemer E. , Gänsbacher B.
Published: March 2005

Background

Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis. VEGF A also plays an important role in wound healing of the skin by promoting angiogenesis and by stimulating blood vessel growth. Therefore we tested the hypothesis that flap survival could be increased by the preoperative injection of AdVEGF165.

Methods

We studied the effect of AdVEGF165 in an overdimensioned ischemic random‐pattern‐flap model in the rat (n = 50) with a length‐to‐width ratio of 4 : 1. VEGF cDNA was administered in two concentrations of 5 × 108 plaque‐forming units (pfU) and 1 × 109 pfU using a recombinant adenoviral vector. Recombinant virus was injected subdermally 7, 3 or 0 days prior to flap harvest for the lower concentration and 7 days prior for the higher concentration. Flap survival and necrosis were observed at day 7, the day the animals were sacrificed.

Results

Adenoviral gene transfer with VEGF165 3 and 7 days before flap harvest showed a significantly increased flap survival of 50% together with a significantly reduced necrosis (p < 0.01). Injection using a titer of 1 × 109 pfU 7 days prior to surgery increased flap survival even more, though failing to reach statistical significance compared to the lower concentration. VEGF protein concentration in the injected skin was significantly higher than in controls (p < 0.01). Flap perfusion was increased as well, demonstrated by indocyanine green (ICG) fluoroscopy (p < 0.001).

Conclusions

Our results confirm the important role of VEGF165 on angiogenesis in ischemic flaps. Indeed by injecting VEGF165 at 3 to 7 days preoperatively in a concentration of 1 × 109 pfU our data show that length‐to‐width ratio for random‐pattern‐flaps could be increased from 2 : 1 to 3 : 1 and therefore may allow a wider range of applications of this simple flap technique. Copyright © 2004 John Wiley & Sons, Ltd.
Influence of resource abundance on the structure of the insect community attracted to fermented tree sap
Authors: Yoshimoto Jiichiro , Kakutani Takehiko , Nishida Takayoshi
Published: March 2005

There has been little or no documentation of the insect community attracted to fermented tree sap, despite our familiarity with it. This study describes the influence of resource abundance (exudate quantity) on species richness, insect abundance, and diversity at the patch level in order to elucidate the mechanisms responsible for community structure. Resource abundance was positively correlated with species richness and insect abundance, negatively correlated with the equitability index (J′), and not significantly correlated with diversity (Simpson's index of diversity; 1/D). Both correlation analyses and canonical correspondence analysis based on taxonomic categories indicated that responses to resource abundance were much greater in parasitoid wasps (Ichneumonoidea), drosophilid flies (Drosophilidae), and rove beetles (Staphylinidae). Field experiments showed that patches with more of the resource had greater species richness and greater hornet abundance. These results indicate that resource abundance is an important factor that affects community structure at the patch level, although it does not influence diversity directly, due to differences in the response to a resource across subgroups; drosophilid flies, the most abundant group that was heavily dependent on tree sap, make an especially large contribution to the change in J′. Various factors influence the variation in the response to resource abundance, including population size, feeding habits, and resource utilization patterns (i.e. whether the species uses patches as habitat).
Seasonal changes in the response of oystercatchersHaematopus ostralegusto human disturbance
Authors: Stillman Richard A. , Goss‐Custard John D.
Published: March 2005

The response of foraging animals to human disturbance can be considered as a trade‐off between the increased perceived predation risk of tolerating disturbance and the increased starvation risk of not feeding and avoiding disturbance. We show how the response of overwintering oystercatchersHaematopus ostralegusto disturbance is related to their starvation risk of avoiding disturbance. As winter progresses, oystercatcher energy requirements increase and their feeding conditions deteriorate. To survive they spend longer feeding and so have less spare time in which to compensate for disturbance. Later in winter, birds approach a disturbance source more closely and return more quickly after a disturbance. Their behavioural response to disturbance is less when they are having more difficulty surviving and hence their starvation risk of avoiding disturbance is greater. These results have implications for studies which assume that a larger behavioural response means that a species is more vulnerable to disturbance. The opposite may be true. To more fully understand the impact of disturbance, studies should measure both behavioural responses and the ease with which animals are meeting their requirements. Conservation effort should be directed towards species which need to spend a high proportion of their time feeding, but still have a large response to disturbance.
Variance in prey abundance influences time budgets of breeding seabirds: evidence from pigeon guillemots Cepphus columba
Authors: Litzow Michael A. , Piatt John F.
Published: March 2005

We use data on pigeon guillemots Cepphus columba to test the hypothesis that discretionary time in breeding seabirds is correlated with variance in prey abundance. We measured the amount of time that guillemots spent at the colony before delivering fish to chicks (“resting time”) in relation to fish abundance as measured by beach seines and bottom trawls. Radio telemetry showed that resting time was inversely correlated with time spent diving for fish during foraging trips (r=−0.95). Pigeon guillemots fed their chicks either Pacific sand lance Ammodytes hexapterus, a schooling midwater fish, which exhibited high interannual variance in abundance (CV=181%), or a variety of non‐schooling demersal fishes, which were less variable in abundance (average CV=111%). Average resting times were 46% higher at colonies where schooling prey dominated the diet. Individuals at these colonies reduced resting times 32% during years of low food abundance, but did not reduce meal delivery rates. In contrast, individuals feeding on non‐schooling fishes did not reduce resting times during low food years, but did reduce meal delivery rates by 27%. Interannual variance in resting times was greater for the schooling group than for the non‐schooling group. We conclude from these differences that time allocation in pigeon guillemots is more flexible when variable schooling prey dominate diets. Resting times were also 27% lower for individuals feeding two‐chick rather than one‐chick broods. The combined effects of diet and brood size on adult time budgets may help to explain higher rates of brood reduction for pigeon guillemot chicks fed non‐schooling fishes.
Consequences of foraging trip duration on provisioning behaviour and fledging condition of common murres Uria aalgae
Authors: Davoren Gail K. , Montevecchi William A.
Published: March 2005

We examine the provisioning constraints of a pursuit‐diving seabird in a cold ocean regime by comparing the behaviour of common murres Uria aalge rearing chicks at two colonies in the Northwest Atlantic during 1998‐2000. Funk Island is the largest (340,000–400,000 breeding pairs) and most offshore (60 km) colony of common murres in eastern Canada. Seventy‐five percent of the Northwest Atlantic population of common murres breeds on this island. Great Island is one island within the Witless Bay Ecological Reserve, which is the second largest breeding aggregation (100 000 breeding pairs) and is located near‐shore (2 km). The primary forage fish species in Newfoundland waters is capelin Mallotus villosus, which spawns on or near coastal beaches during summer. Therefore, the two study colonies differ in their distance to food resources and colony size. It is within this natural context that we compare: (1) prey types and frequency of delivery (amount of prey), (2) parental time budgets, and (3) the mass and condition (mass/wing length) of fledglings at both colonies. Similarly sized female capelin (100–150 mm) were delivered to chicks at both colonies. Foraging time per day per parent, a proxy of foraging effort, was similar at both colonies (Great Island: 5.1 h; Funk Island: 5.5 h), as was the percentage of time spent with mates (Great Island: 12.3%; Funk Island: 10.9%). Foraging trips, however, were longer at Funk Island (4.1 h) than at Great Island (2.9 h). This resulted in lower feeding rates of chicks (0.17 feeds per h) and poorer condition of fledglings (2.9 g/mm) at Funk Island compared to those at Great Island (0.22 feeds per h; 3.9 g/mm). We hypothesize that provisioning efforts are constrained at Funk Island by (1) distant food resources and increased competitor density, resulting in longer foraging trip durations and (2) the time spent paired with mates at the colony, which may reflect a minimum time required to maintain breeding sites due to higher breeding densities at Funk Island compared to Great Island. Demographic consequences of this poor fledgling condition at Funk Island are unknown, but fledglings may sufficiently accelerate growth at sea due to their closer proximity to an important nursery area. If fledgling survival is compromised, however, the lower potential for growth at Funk Island will impact the entire Northwest Atlantic population of common murres.
Temporal changes in the migration phenology of turtle doves Streptopelia turtur in Britain, based on sightings from coastal bird observatories
Authors: Browne Stephen J. , Aebischer Nicholas J.
Published: March 2005

Using daily counts of birds seen at six coastal bird observatories in southern and eastern England, we explored the migration phenology of turtle doves during the period 1963 to 2000. Annual totals increased threefold up to the late 1970s then decreased again, in accordance with the BTO Common Birds Census (CBC) index of abundance. Median annual spring arrival and autumn departure dates of turtle doves were not related to abundance (CBC index) or mean temperature in spring or summer respectively. Although median annual spring arrival date has not altered over the 38‐year period, median annual autumn departure date has become earlier by 8 days. This has resulted in a shortening of the breeding season by 12 days, which ties in with a reduction in average number of nesting attempts per pair observed by a recent autecological study. It is possible that breeding turtle doves are now out of phase with peaks in food availability. This may have resulted in reduced breeding performance and earlier termination of the breeding season, and may have partly contributed to the decline of the species.
Repeated grazing of a salt marsh grass by moulting greylag geese Anser anser– does sequential harvesting optimise biomass or protein gain?
Authors: Fox Anthony D. , Kahlert Johnny
Published: March 2005

The effects of simulated goose grazing on common saltmarsh‐grass Puccinellia maritima plants were tested on a Danish salt marsh during the flightless moulting period of greylag geese Anser anser (3–21 June 1998). Plants in an area exclosed from the influence of grazing and the nutrient effects of goose faeces were subject to removal of youngest lamina at 3‐, 6‐, 9‐ and 18‐day intervals during this period. Average biomass and protein accumulation between harvests was highest at defoliation intervals of 9 days or more. Field observations from two separate study areas demonstrated geese returned to regraze the Puccinellia sward after 6–8 days and oesophageal contents from feeding geese showed selection for lamina lengths consistent with the results of clipping every 6 days. Geese therefore regrazed Puccinellia patches at shorter intervals than expected were they to maximise their intake of biomass or protein at each visit. However, total cumulative lamina elongation, equivalent to the long term gain during the entire moult period, showed no significant difference between the three most intensive defoliation treatments, which were significantly greater than those of plants defoliated at 18 day intervals. Highest overall lamina protein levels were maintained at 6‐ and 9‐day defoliation intervals. This suggests geese regrazed Puccinellia patches at a rate that maximised their number of harvests during the flightless period, but maintained highest protein levels and overall biomass in the sward. This suggests, in line with earlier studies, that moulting greylag geese combine dietary selection, reduced nitrogen excretion and regrazing patterns to meet protein demands during regrowth of flight feathers.
PP amplitude bias caused by interface scattering: are diffracted waves guilty?
Authors: Favretto‐Cristini Nathalie , De Bazelaire Eric
Published: March 2005

This paper is concerned with the problem of interpretation of anomalous seismic amplitudes, induced by the amplitude‐scattering phenomenon. This phenomenon occurs in the vicinity of a crack distribution at the interface between elastic layers. The purpose of this work is to obtain a better understanding of the physics of this distinctive phenomenon, in order to interpret correctly the amplitudes of the reflected events. By analogy with studies in optics and in acoustics, we suggest that diffraction is widely involved in the amplitude‐scattering phenomenon. Analytical evaluation of the amount of energy carried by the reflected and the diffracted waves shows that neglecting diffraction in numerical models leads to local underestimation of the amplitude of waves reflected at interfaces with gas‐filled crack distribution.
Seismic characterization of vertical fractures described as general linear‐slip interfaces
Authors: Grechka Vladimir , Bakulin Andrey , Tsvankin Ilya
Published: March 2005

Fluid flow in many hydrocarbon reservoirs is controlled by aligned fractures which make the medium anisotropic on the scale of seismic wavelength. Applying the linear‐slip theory, we investigate seismic signatures of the effective medium produced by a single set of ‘general’ vertical fractures embedded in a purely isotropic host rock. The generality of our fracture model means the allowance for coupling between the normal (to the fracture plane) stress and the tangential jump in displacement (and vice versa). Despite its low (triclinic) symmetry, the medium is described by just nine independent effective parameters and possesses several distinct features which help to identify the physical model and estimate the fracture compliances and background velocities. For example, the polarization vector of the vertically propagating fast shear wave S1 and the semi‐major axis of the S1‐wave normal‐moveout (NMO) ellipse from a horizontal reflector always point in the direction of the fracture strike. Moreover, for the S1‐wave both the vertical velocity and the NMO velocity along the fractures are equal to the shear‐wave velocity in the host rock.

Analysis of seismic signatures in the limit of small fracture weaknesses allows us to select the input data needed for unambiguous fracture characterization. The fracture and background parameters can be estimated using the NMO ellipses from horizontal reflectors and vertical velocities of P‐waves and two split S‐waves, combined with a portion of the P‐wave slowness surface reconstructed from multi‐azimuth walkaway vertical seismic profiling (VSP) data. The stability of the parameter‐estimation procedure is verified by performing non‐linear inversion based on the exact equations.
VSP traveltime inversion for anisotropy in a buried layer
Authors: Slawinski Michael A. , Lamoureux Michael P. , Slawinski Raphael A. , Brown R. James
Published: March 2005

We present a method for calculating the anisotropy parameter of a buried layer by inverting the total traveltimes of direct arrivals travelling from a surface source to a well‐bore receiver in a vertical seismic profiling (VSP) geometry. The method assumes two‐dimensional media. The medium above the layer of interest (and separated from it by a horizontal interface) can exhibit both anisotropy and inhomogeneity. Both the depth of the interface as well as the velocity field of the overburden are assumed to be known. We assume the layer of interest to be homogeneous and elliptically anisotropic, with the anisotropy described by a single parameter χ. We solve the function describing the traveltime between source and receiver explicitly for χ. The solution is expressed in terms of known quantities, such as the source and receiver locations, and in terms of quantities expressed as functions of the single argument xr, which is the horizontal coordinate of the refraction point on the interface. In view of Fermat's principle, the measured traveltime T possesses a stationary value or, considering direct arrivals, a minimum value, . This gives rise to a key result ‐‐ the condition that the actual anisotropy parameter . Owing to the explicit expression , this result allows a direct calculation of in the layer of interest. We perform an error analysis and show this inverse method to be stable. In particular, for horizontally layered media, a traveltime error of one millisecond results in a typical error of about 20% in the anisotropy parameter. This is almost one order of magnitude less than the error inherent in the slowness method, which uses a similar set of experimental data. We conclude by detailing possible extensions to non‐elliptical anisotropy and a non‐planar interface.
Inversion for elliptically anisotropic velocity using VSP reflection traveltimes
Authors: Zhang Z. , Lin G. , Chen J. , Harris J.M. , Han L.
Published: March 2005

This paper presents a traveltime inversion approach, using the reflection traveltimes from offset VSP data, to reconstruct the horizontal and vertical velocities for stratified anisotropic media. The inverse problem is reduced to a set of linear equations, and solved by the singular value decomposition (SVD) technique. The validity of this inversion scheme is verified using two sets of synthetic data simulated using a finite‐difference method, one for an isotropic model and the other for an elliptically anisotropic model. The inversion result demonstrates that our anisotropic velocity inversion scheme may be applied to both isotropic and anisotropic media. The method is finally applied to a real offset VSP data set, acquired in an oilfield in northwestern China.
Electron and hole spin dynamics in semiconductor quantum dots
Authors: Gündoğdu K. , Hall K. C. , Koerperick E. J. , Pryor C. E. , Flatté M. E. , Boggess Thomas F. , Shchekin O. B. , Deppe D. G.
Published: March 2005

We report direct measurement of the spin dynamics of electrons and holes in self-assembled InAs quantum dots (QDs) through polarization-sensitive time-resolved photoluminescence experiments on modulation-doped quantum dot heterostructures. Our measured hole spin decay time is considerably longer than in bulk and quantum well semiconductor systems, indicating that the removal of near degenerate hole states with different spin quantization axes through three-dimensional confinement slows hole spin relaxation in semiconductors. The electron and hole spin decay times we observe (electrons: 120ps; holes: 29ps) are consistent with spin relaxation via phonon-mediated virtual scattering between the lowest two confined levels in the QDs, which have a mixed spin character due to the spin–orbit interaction.
Molecular dynamics simulation of entropy driven ligand escape process in heme pocket
Authors: Sheu Sheh-Yi
Published: March 2005

Molecular dynamics simulations were performed to investigate the gate effect of protein motion on the escape of O2 from the heme pocket. The existing geometric entropy in a spherical cavity pushes the ligand toward the cavity surface, and then the ligand escape along the cavity surface is controlled by the gate size and gate modulation, i.e., protein dynamics regulate the gating behavior, which is an inherent feature of proteins such as myoglobin. Our simulation results confirm that the ligand escape process is basically entropy driven.
Optimizing the driving function for nonequilibrium free-energy calculations in the linear regime: A variational approach
Authors: de Koning Maurice
Published: March 2005

We consider the issue of optimizing linear-regime nonequilibrium simulations to estimate free-energy differences. In particular, we focus on the problem of finding the best-possible driving function λ(t) that, for a given thermodynamic path, simulation algorithm, and amount of computational effort, minimizes dissipation. From the fluctuation-dissipation theorem it follows that, in the linear-response regime, the dissipation is controlled by the magnitude and characteristic correlation time of the equilibrium fluctuations in the driving force. As a result, the problem of finding the optimal switching scheme involves the solution of a standard problem in variational calculus: the minimization of a functional with respect to the switching function. In practice, the minimization involves solving the associated Euler–Lagrange equation subject to a set of boundary conditions. As a demonstration we apply the approach to the simple, yet illustrative problem of computing the free-energy difference between two classical harmonic oscillators with very different characteristic frequencies.
Transparent thin-film transistors with zinc indium oxide channel layer
Authors: Dehuff N. L. , Kettenring E. S. , Hong D. , Chiang H. Q. , Wager J. F. , Hoffman R. L. , Park C.-H. , Keszler D. A.
Published: March 2005

High mobility, n-type transparent thin-film transistors (TTFTs) with a zinc indium oxide (ZIO) channel layer are reported. Such devices are highly transparent with ∼85% optical transmission in the visible portion of the electromagnetic spectrum. ZIO TTFTs annealed at 600 °C operate in depletion-mode with threshold voltages −20 to −10V and turn-on voltages ∼3V less than the threshold voltage. These devices have excellent drain current saturation, peak incremental channel mobilities of 45–55cm2V−1s−1, drain current on-to-off ratios of ∼106, and inverse subthreshold slopes of ∼0.8V∕decade. In contrast, ZIO TTFTs annealed at 300 °C typically operate in enhancement-mode with threshold voltages of 0–10V and turn-on voltages 1–2V less than the threshold voltage. These 300 °C devices exhibit excellent drain–current saturation, peak incremental channel mobilities of 10–30cm2V−1s−1, drain current on-to-off ratios of ∼106, and inverse subthreshold slopes of ∼0.3V∕decade. ZIO TTFTs with the channel layer deposited near room temperature are also demonstrated. X-ray diffraction analysis indicates the channel layers of ZIO TTFTs to be amorphous for annealing temperatures up to 500 °C and polycrystalline at 600 °C. Low temperature processed ZIO is an example of a class of high performance TTFT channel materials involving amorphous oxides composed of heavy-metal cations with (n−1)d10ns0(n⩾4) electronic configurations.
Scanning transmission electron microscopy of ErAs nanoparticles embedded in epitaxial In0.53Ga0.47As layers
Authors: Klenov Dmitri O. , Driscoll Daniel C. , Gossard Arthur C. , Stemmer Susanne
Published: March 2005

We use high-angle annular dark-field imaging in scanning transmission electron microscopy to investigate the crystal structure and particle morphology of semimetallic ErAs nanoparticles embedded in epitaxial In0.53Ga0.47As layers. Deposition of increasing amounts of Er results in a higher density of particles and particles coalescence for high amounts. Despite overlap with the matrix through the thickness of the sample used for transmission electron microscopy, the crystal structure of ErAs particles is unambiguously identified as rock salt. The As sublattice is continuous across the interface between the particle and the zinc-blende semiconductor.
Phase-shift effect on a two-dimensional surface-emitting photonic-crystal laser
Authors: Miyai Eiji , Noda Susumu
Published: March 2005

Theoretical analysis was performed by means of the finite-difference time-domain method to examine the mode properties of two-dimensional surface-emitting photonic-crystal lasers with elliptical air holes. It was found that a single-lobed beam pattern could be obtained from the device surface by introducing a phase shift to the center of the crystal. The effects of the shift on the polarization mode and on two-dimensional optical coupling (which is needed for single-mode lasing over a large area) were also investigated. It was shown that the phase shift emphasized the linear polarization of the emitted beam due to symmetry reversal. On the other hand, it was also found that the shift did not spoil the two-dimensional optical coupling.
Evidence for two recA genes mediating DNA repair in Bacillus megaterium
Authors: Nahrstedt Hannes , Schröder Christine , Meinhardt Friedhelm
Published: March 2005

Isolation and subsequent knockout of arecA-homologous gene inBacillus megateriumDSM 319 resulted in a mutant displaying increased sensitivity to mitomycin C. However, this mutant did not exhibit UV hypersensitivity, a finding which eventually led to identification of a second functionalrecAgene. Evidence forrecAduplicates was also obtained for two otherB. megateriumstrains. In agreement with potential DinR boxes located within their promoter regions, expression of both genes (recA1andrecA2) was found to be damage-inducible. Transcription from therecA2promoter was significantly higher than that ofrecA1. Since arecA2knockout could not be achieved, functional complementation studies were performed inEscherichia coli. Heterologous expression in a RecA null mutant resulted in increased survival after UV irradiation and mitomycin C treatment, proving bothrecAgene products to be functional in DNA repair. Thus, there is evidence for an SOS-like pathway inB. megateriumthat differs from that ofBacillus subtilis.
The processing of sound duration after left hemisphere stroke: Event‐related potential and behavioral evidence
Authors: Ilvonen T.‐M. , Kujala T. , Tervaniemi M. , Salonen O. , Näätänen R. , Pekkonen E.
Published: March 2005

The ability of left‐hemisphere stroke patients (n= 8) and healthy control subjects (n= 8) to process sounds preattentively and attentively was studied by recording auditory event‐related potentials (ERPs) and behavioral responses. For the right‐ear stimulation, the mismatch negativity (MMN) was significantly smaller in the patients than control subjects over both hemispheres. For the left‐ear stimuli, the MMN was significantly smaller in the patient group than in the control group over the left hemisphere, whereas no group differences were obtained over the right hemisphere. In addition, the N1 amplitude was reduced bilaterally for the right‐ear stimulation (with the reduction being larger over the left hemisphere), whereas no significant effects on the N1 amplitude were found for the left‐ear stimulation. Behaviorally, the patients detected significantly fewer deviant tones than did the control subjects irrespective of the stimulated ear. The present results thus suggest that the long‐latency ERPs can be used to probe such auditory processing deficits that are difficult to define with behavioral measures. Especially by recording MMN to monaural stimuli, the discrimination accuracy can be separately determined for the left and right temporal lobes.
Event‐related brain potentials evoked by verbs and nouns in a primed lexical decision task
Authors: Rösler Frank , Streb Judith , Haan Hubertus
Published: March 2005

We investigated whether verbs and nouns evoke comparable behavioral and N400 effects in a primed lexical decision task. Twenty‐nine students were tested, 13 in a pilot study in which only response times and error rates were collected and 16 in a study in which ERPs were recorded from 124 scalp electrodes. Stimuli were noun–noun and verb–verb pairs with the targets bearing either a strong, a moderate, or no semantic association to the prime or being a pseudoword. Behavioral data revealed comparable priming effects for both word categories. These proved to be independent from the SOA (250 and 800 ms) and they followed the well‐known pattern of decreasing response times and error rates with increasing relatedness between target and prime. ERPs revealed pronounced N400 effects for both word categories with a larger amplitude for noun than for verb pairs. A systematic analysis of topographic differences between noun‐ and verb‐evoked ERPs and N400 effects, respectively, gave no convincing support to the hypothesis that the two word categories activate distinct neuronal networks.
Awareness of the role of folic acid, dietary folate intake and plasma folate concentration in Japan
Authors: Kondo Atsuo , Kamihira Osamu , Shimosuka Yoichi , Okai Ikuyo , Gotoh Momokazu , Ozawa Hideo
Published: March 2005

Aim: To investigate awareness of the role of folic acid in the prevention of neural tube defects, dietary intake of folate, and plasma folate concentration.

Methods: Postal questionnaires were collected from 1190 lay female subjects in three different groups and from seven groups of 3067 health‐care providers. Dietary folate was investigated by assessing food frequency charts that were kept for 3 days by 245 women, and plasma folate was assessed by analyzing the blood serum of 194 women.

Results: Less than 15% of citizens and mothers who had live births knew that there was a link between folic acid and neural tube defects. The exception was with myelodysplastic families, in which awareness was 92%. Awareness among health‐care professionals was generally low. The highest level was found in obstetricians–gynecologists (76%) and the lowest in nurses (12%). Dietary folate intake and plasma concentration were highest in pregnant women (356 µg/day and 11.9 ng/mL) and the lowest in student nurses (217 µg/day and 6.8 ng/mL). When the recommended dietary allowance of folate in Japan is taken into consideration, 22% of the non‐pregnant women and 71% of the pregnant women did not fulfill the recommended dietary allowance.

Conclusions: Information on the role of periconceptional intake of folic acid is not sufficiently disseminated to young women and health‐care professionals alike. Pregnant women should be repeatedly recommended to take folic acid supplements of 400 µg/day.
The relationship between particle‐size distribution by laser granulometry and image analysis by transmission electron microscopy in a soil clay fraction
Authors: Dur J. C. , Elsass F. , Chaplain V. , Tessier D.
Published: March 2005

The aim of this study was to validate the use of laser granulometry in studies concerning fractions < 2 µm in soils. The study was carried out on the clay fraction of a loamy soil from northeast Thailand. Granulometry by light scattering requires the determination of the refractive indexes of the solid phases. Once these values have been established, laser granulometry can provide a detailed description of the particle‐size distribution within the clay fractions. Laser granulometry showed a multimodal distribution in the clay fraction of this soil.

The analysis of images obtained by transmission electron microscopy provided numerical distributions of soil particles, from which representations by surface area and by volume obtained by laser granulometry and by transmission electron microscopy could be compared. The representation of particle‐size distribution by surface area, assuming that particles are similar to circles, is adequate and, in this range of particle size, minimizes the effect of larger diameters. The representation of the particle‐size distribution assuming that particles are similar to platy discs is better than the current representation that assumes particles are similar to spheres. We used transmission electron microscopy to validate laser granulometry in the fractions < 2 µm.

Elemental microanalysis was used to identify the mineralogy of the clay particles: illite, illite‐smectite and kaolinite at a magnification of 31 000, corresponding to the clay fraction < 0.8 µm of the particle‐size distribution. Quartz and illite were identified at a magnification of 3300, corresponding to the fraction between 0.8 and 2 µm. The mineral constituents of the soil are correlated with the modes of the particle‐size distribution.
Health Policy Roundtable—Policy by Numbers: The Role of Budget Estimates and Scoring in Health Care Reform
Authors: Folz Christina E.
Published: March 2005

The purpose of this roundtable is to explore the imperfect art of estimating the budget costs of health insurance proposals—called scoring when done by government agencies. The panel addresses the complexities involved in generating these estimates, which usually depend on many untested and untestable assumptions. For example, the Medicare prescription drug “donut hole” was invented so that policymakers could achieve budget targets. These budget scores play a critical role in the design of health policies, as well as in the reform proposals put forth by candidates in an election. The roundtable discusses how policymakers can and do use health policy estimates and budget scores.
Visualization of Helicobacter Species Within the Murine Cecal Mucosa Using Specific Fluorescence In Situ Hybridization
Authors: Chan Vivian , Crocetti Gregory , Grehan Martin , Zhang Li , Danon Stephen , Lee Adrian , Mitchell Hazel
Published: March 2005

Background.  Members of the genus Helicobacter have been associated with colitis development in a number of immunodeficient animal models. While it is known that these organisms can initiate colitis development, the location and spatial distribution of these bacteria within the intestinal tract is currently unknown. In this study, we developed and optimized fluorescence in situ hybridization (FISH) probes specifically for Helicobacter species.

Materials and Methods.  Based on 16S‐RNA gene alignments, two probes specific for the entire family Helicobacteraceae and two probes specific for Helicobacter ganmani and Helicobacter hepaticus were designed. Evaluation of these probes was determined using ATCC reference strains and cecum samples from ten IL‐10 knockout mice. The presence of Helicobacter species was determined using FISH and verified using PCR‐DGGE and microscopic examination of silver stained sections.

Results.  Analysis of the ATCC reference strains revealed that the probes HEL274/HEL717 were specific for the family Helicobacteraceae, while HEP642 was specific for H. hepaticus and GAN1237 for H. ganmani. Using these probes, a pattern of spatial localization of the two different Helicobacter species was observed in the cecum tissues of IL‐10 knockout mice. This consistently showed that H. ganmani was localized to the lower regions and H. hepaticus to the mid‐upper regions of the crypts.

Conclusion.  We have developed FISH probes specific for the family Helicobacteraceae as well as two individual Helicobacter species. This study will allow the future use of the FISH to better understand host‐pathogen interactions in vitro.
Comparative study of eye defective worm ‘menashi’ and regenerating wild‐type in planarian, Dugesia ryukyuensis
Authors: Sato Yukiko , Kobayashi Kazuya , Matsumoto Midori , Hoshi Motonori , Negishi Sumiko
Published: March 2005

Inbreeding of the sexualized planarian, Dugesia ryukyuensis, produces eye‐defective worms, menashi, in the F1 population. To study the effects of this mutation on the eye, we observed the eye‐region of menashi using electron microscopy and compared it with the regenerating eye in wild‐type worms. The intact eye of wild‐type planarians consisted of a few pigment cells and a number of visual cells. Pigment cells containing spherically‐shaped electron‐dense melanosomes contacted each other and enclosed rhabdomes of visual cells. Rhabdomes had numerous tubular microvilli extending radially and touching the pigment cells. However, in menashi, various lengths of tubular microvilli were irregularly distributed near the pigment cells, which contained numerous electron‐lucent premelanosomes, and no adhesive structures were found between the pigment cells. The premelanosomes of menashi were equal in size to those seen after 2 days of regeneration in wild‐type planarians and were similar in maturation to those found after 3 days of regeneration in wild‐type planarian. These results suggest that menashi is defective in the mechanism(s) of developing pigment granules and constructing visual cells. These findings also suggest that pigment cells in menashi are defective in the mechanism(s) involved with cell adhesion.
Energetic consequences of diet shifts in Lake Erie rainbow smelt (Osmerus mordax)
Authors: Stetter SL Parker , Witzel L D , Rudstam L G , Einhouse D W , Mills E L
Published: March 2005

The diet of eastern Lake Erie rainbow smelt (Osmerus mordax) has changed since the 1960s, reflecting food resource shifts due to phosphorus reductions and the invasion of exotic species (dreissenid mussels and Bythotrephes longimanus). Since rainbow smelt growth was lower in the 1990s than in the 1960s, we considered diet changes as an explanation. A decrease in the proportion of zooplankton occurred in the summer (MayAugust) diet of two size classes (6388 and 89114 mm fork length) between 1961 and 1999. Within the zooplankton, the proportion of Bythotrephes increased. In spite of these changes, energy density (joules per gram) of the summer (JuneAugust) diet has not changed since 1961. However, during the late-summer and fall, predation on Bythotrephes, and therefore the proportion of indigestible spines in the stomach, increases. Using bioenergetics models, we show that Lake Erie rainbow smelt could achieve 66%155% greater growth between June and October if Bythotrephes spines were replaced with digestible prey items, resulting in end-of-season weights and lengths similar to the 19851990 period. Our results indicate that indigestible Bythotrephes spines may reduce growth by occupying space in the stomach but providing no nutritional value to the fish, thereby reducing the realized daily ration for rainbow smelt.
Effects of riparian canopy opening and salmon carcass addition on the abundance and growth of resident salmonids
Authors: Wilzbach Margaret A , Harvey Bret C , White Jason L , Nakamoto Rodney J
Published: March 2005

We studied the concurrent effects of riparian canopy opening and salmon carcass addition on salmonid biomass, density and growth rates in small streams over 2 years. In each of six streams in the Smith and Klamath River basins in northern California, red alder (Alnus rubra) and other hardwoods were removed along both banks of a 100-m reach to increase incident radiation. A second 100-m reach, with an intact canopy, was established in each stream as a light control. Salmon carcasses were added each year to both cut and uncut riparian sections in three of the six streams. Differences in total density and biomass of cutthroat trout (Oncorhynchus clarki) and rainbow trout (Oncorhynchus mykiss) from pretreatment levels responded positively to canopy removal but were not detectably affected by carcass addition. Differences in specific growth rates of the fish between open and closed canopy reaches were greater in sites without carcasses than in sites with carcasses. In light-limited settings where temperature gains associated with canopy opening are not problematic for aquatic resources, gains in salmonid production might be achieved by selective trimming of riparian hardwoods.
Climatic Impact of Vegetation Change in the Asian Tropical Region. Part II: Case of the Northern Hemisphere Winter and Impact on the Extratropical Circulation
Authors: Mabuchi Kazuo , Sato Yasuo , Kida Hideji
Published: March 2005

Several numerical simulations were performed, using a global climate model that includes a realistic land surface model, to investigate the impact of Asian tropical vegetation changes on the climate. The control simulation, under conditions of the actual vegetation, and three vegetation-change impact experiments were performed. The horizontal resolution of the model used in these simulations was finer than those of the models used in previous vegetation-change impact studies. In Part I, which is a companion of this paper, the results of the Northern Hemisphere summer June–July–August (JJA) case were described. In the present paper, the results of the analysis concern the Northern Hemisphere winter; that is, the December–January–February (DJF) case are discussed as Part II.

It was clarified, from the results of the bare soil and C4 grass experiments, that the decrease in the roughness length, and from the results of the green-less experiment, that the decrease in the latent heat flux exert strong influences on horizontal and convective atmospheric circulations and the distribution of precipitation. Other energy and water balances at the land surface are also significantly influenced by the vegetation changes.

The vegetation changes were implemented only in the Asian tropical region. There were, however, possible influences of the vegetation change on the midlatitude atmospheric circulation. It was considered that the vegetation changes from the forest type to grassland or bare soil induced modifications in the Hadley and Walker circulations. In particular, the divergence/convergence anomaly pattern that appeared at the upper-atmospheric level in the C4 grass experiment was very similar to that of an ENSO event. The height anomalies at the 500-hPa level were also similar to those found in an ENSO event. The possibility exists that the deforestation of the Asian tropical region could induce similar teleconnections as those associated with ENSO events.
Northeast Atlantic and North Sea Storminess as Simulated by a Regional Climate Model during 1958–2001 and Comparison with Observations
Authors: Weisse Ralf , von Storch Hans , Feser Frauke
Published: March 2005

An analysis of the storm climate of the northeast Atlantic and the North Sea as simulated by a regional climate model for the past 44 yr is presented. The model simulates the period 1958–2001 driven by the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis. Comparison with observations shows that the model is capable of reproducing impact-related storm indices such as the number of severe and moderate storms per year or the total number of storms and upper intra-annual percentiles of near-surface wind speed. The indices describe both the year-to-year variability of the frequency, as well as changes in the average intensity of storm events. Analysis of these indices reveals that the average number of storms per year has increased near the exit of the North Atlantic storm track and over the southern North Sea since the beginning of the simulation period (1958), but the increase has attenuated later over the North Sea and the average number of storms per year has been decreasing over the northeast Atlantic since about 1990–95. The frequency of the most severe storms follows a similar pattern over the northeast North Atlantic while too few severe storms occurred in other areas of the model domain, preventing a statistical analysis for these areas.
Molecular mechanisms in uterine epithelium during trophoblast binding: the role of small GTPase RhoA in human uterine Ishikawa cells
Authors: Heneweer Carola , Schmidt Martina , Denker Hans-Werner , Thie Michael
Published: March 2005

Background

Embryo implantation requires that uterine epithelium develops competence to bind trophoblast to its apical (free) poles. This essential element of uterine receptivity seems to depend on a destabilisation of the apico-basal polarity of endometrial epithelium. Accordingly, a reorganisation of the actin cytoskeleton regulated by the small GTPase RhoA plays an important role in human uterine epithelial RL95-2 cells for binding of human trophoblastoid JAR cells. We now obtained new insight into trophoblast binding using human uterine epithelial Ishikawa cells.

Methods

Polarity of Ishikawa cells was investigated by electron microscopy, apical adhesiveness was tested by adhesion assay. Analyses of subcellular distribution of filamentous actin (F-actin) and RhoA in apical and basal cell poles were performed by confocal laser scanning microscopy (CLSM) with and without binding of JAR spheroids as well as with and without inhibition of small Rho GTPases by Clostridium difficile toxin A (toxin A). In the latter case, subcellular distribution of RhoA was additionally investigated by Western blotting.

Results

Ishikawa cells express apical adhesiveness for JAR spheroids and moderate apico-basal polarity. Without contact to JAR spheroids, significantly higher signalling intensities of F-actin and RhoA were found at the basal as compared to the apical poles in Ishikawa cells. RhoA was equally distributed between the membrane fraction and the cytosol fraction. Levels of F-actin and RhoA signals became equalised in the apical and basal regions upon contact to JAR spheroids. After inhibition of Rho GTPases, Ishikawa cells remained adhesive for JAR spheroids, the gradient of fluorescence signals of F-actin and RhoA was maintained while the amount of RhoA was reduced in the cytosolic fraction with a comparable increase in the membrane fraction.

Conclusion

Ishikawa cells respond to JAR contact as well as to treatment with toxin A with rearrangement of F-actin and small GTPase RhoA but seem to be able to modify signalling pathways in a way not elucidated so far in endometrial cells. This ability may be linked to the degree of polar organisation observed in Ishikawa cells indicating an essential role of cell phenotype modification in apical adhesiveness of uterine epithelium for trophoblast in vivo.