bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of alternative oxidase and uncoupling protein lowers hydrogen peroxide formation in amoeba Acanthamoeba castellanii mitochondria
Authors: Czarna Malgorzata , Jarmuszkiewicz Wieslawa
Published: May 2005

Mitochondria of amoeba Acanthamoeba castellanii were used to determine the role of two energy‐dissipating systems, i.e., a free fatty acid (FFA)‐activated, purine nucleotide‐inhibited uncoupling protein (AcUCP) and a FFA‐insensitive, purine nucleotide‐activated ubiquinol alternative oxidase (AcAOX), in decreasing reactive oxygen species production in unicellular organisms. It is shown that the activation of AcUCP by externally added FFA resulted in a strong decrease in H2O2 production, whilst the inhibition of the FFA acid‐induced AcUCP activity by GDP or addition of bovine serum albumin (BSA) enhanced production of H2O2. Similarly, the activation of antimycin‐resistant AcAOX‐mediated respiration by GMP significantly lowered H2O2 production, while inhibition of the oxidase by benzohydroxamate cancelled the GMP‐induced effect on H2O2 production. When active together, both energy‐dissipating systems revealed a cumulative effect on decreasing H2O2 formation. The results suggest that protection against mitochondrial oxidative stress may be a physiological role of AOX and UCP in unicellulars, such as A. castellanii.
Prediction of protein secondary structure based on residue pair types and conformational states using dynamic programming algorithm
Authors: Sadeghi Mehdi , Parto Sahar , Arab Shahriar , Ranjbar Bijan
Published: May 2005

We have used a statistical approach for protein secondary structure prediction based on information theory and simultaneously taking into consideration pairwise residue types and conformational states. Since the prediction of residue secondary structure by one residue window sliding make ambiguity in state prediction, we used a dynamic programming algorithm to find the path with maximum score. A score system for residue pairs in particular conformations is derived for adjacent neighbors up to ten residue apart in sequence. The three state overall per‐residue accuracy, Q
3, of this method in a jackknife test with dataset created from PDBSELECT is more than 70%.
Co‐expressed recombinant human Translin‐Trax complex binds DNA
Authors: Gupta Gagan D. , Makde Ravindra D. , Kamdar Radhika P. , D‧Souza Jacinta S. , Kulkarni Meeta G. , Kumar Vinay , Rao Basuthkar J.
Published: May 2005

Trax, expressed alone aggregates into insoluble complexes, whereas upon co‐expression with Translin becomes readily soluble and forms a stable heteromeric complex (∼430 kDa) containing both proteins at nearly equimolar ratio. Based on the subunit molecular weights, estimated by MALDI‐TOF‐MS, the purified complex appears to comprise of either an octameric Translin plus a hexameric Trax (calculated MW 420 kDa) or a heptamer each of Trax and Translin (calculated MW 425 kDa) or a hexameric Translin plus an octameric Trax (calculated MW 431 kDa). The complex binds single‐stranded/double‐stranded DNA. ssDNA gel‐shifted complex shows both proteins at nearly equimolar ratio, suggesting that Translin “chaperones” Trax and forms heteromeric complex that is DNA binding competent.
Functional characterization of sensory rhodopsin II from Halobacterium salinarum expressed in Escherichia coli
Authors: Mironova O.S. , Efremov R.G. , Person B. , Heberle J. , Budyak I.L. , Büldt G. , Schlesinger R.
Published: May 2005

Sensory rhodopsin II (SRII) from Halobacterium salinarum is heterologously expressed in Escherichia coli with a yield of 3–4 mg of purified SRII per liter cell culture. UV/Vis absorption spectroscopy display bands characteristic for native SRII. The resonance Raman spectrum provides evidence for a strongly hydrogen‐bonded Schiff base like in mammalian rhodopsin but unlike to the homologous pSRII from Natronobacterium pharaonis. Laser flash spectroscopy indicates that SRII in detergent as well as after reconstitution into polar lipids shows its typical photochemical properties with prolonged photocycle kinetics. The first functional heterologous expression of SRII from H. salinarum provides the basis for studies with its cognate transducer HtrII to investigate the molecular processes involved in phototransduction as well as in chemotransduction.
Vitamins C and E in the latency period in women with preterm premature rupture of membranes
Authors: Borna S. , Borna H. , Daneshbodie B.
Published: May 2005

Objective: To determine whether supplementation with vitamins C and E after preterm premature rupture of membranes (PPROM) is associated with an increased latency period. Methods: In this double‐blind, randomized, controlled trial, 60 women with singleton pregnancies of 26 to 34 weeks' duration and PPROM were randomly assigned to vitamin C (500 mg/day) and vitamin E (400 IU/day) or placebo until delivery. All women received 2 doses of betamethasone in the first 24 h after admission as well as broad‐spectrum antibiotic prophylaxis. Results: Important demographic, as well as clinical characteristics such as number of cases of chorioamnionitis, early neonatal sepsis, and respiratory distress syndrome, were similar in the 2 groups. A statically significant difference in the mean ± S.D. number of days of latency was found between the groups (10.5 ± 5.2 days vs. 3.5 ± 4.0 days (P = 0.03). Conclusion: Vitamins C and E supplementation of after PPROM is associated with a longer latency before delivery.
Velamentous cord insertion and atypical variable decelerations with no accelerations
Authors: Hasegawa J. , Matsuoka R. , Ichizuka K. , Sekizawa A. , Farina A. , Okai T.
Published: May 2005

Objectives: To examine intrapartum fetal heart rate (FHR) patterns in the presence of velamentous cord insertion (VCI). Methods: The site of cord insertion was determined in 1460 women on antenatal ultrasonographic and postnatal examinations. Each of 24 women with pregnancies complicated with VCI was matched at the onset of labor with 10 women who had a normal pregnancy, and FHR patterns were analyzed for both cases and controls. Results: Compared with controls, cases of variable decelerations with no accelerations (VDNA) during the first and second stages of labor were more frequent in women with VCI (first stage: 25% vs. 5.1%, second stage: 65.0% vs. 21.7%, P < 0.001). The adjusted odds ratio associated with VDNA occurrence in women with VCI was 3.83 (95% confidence interval [CI]: 1.51–9.72, P = 0.005). The mean odds ratio associated with length of aberrant vessels in women with VCI plus VDNA was 1.38 (95% CI: 1.04–1.83, P = 0.026). Conclusion: Pregnancies complicated with VCI are associated with a higher rate of VDNA.
Ukraine’s 1994 elections as an economic event
Authors: Kravchuk Robert S. , Chudowsky Victor
Published: May 2005

This article explores the political, economic, and social forces underlying the east/west cleavage in the 1994 Ukrainian presidential and parliamentary elections. We demonstrate that economic factors—notably, variations in regional economic strength and changes in employment in the period preceding the elections—are stronger predictors of country-wide voting behavior and candidate support than ethnic and linguistic factors. The exceptions are the extreme eastern and western oblasts, where the analysis suggests the existence of significant differences in political culture.
A PROBABILISTIC REPRESENTATION FOR THE VORTICITY OF A THREE-DIMENSIONAL VISCOUS FLUID AND FOR GENERAL SYSTEMS OF PARABOLIC EQUATIONS
Authors: Busnello Barbara , Flandoli Franco , Romito Marco
Published: May 2005

A probabilistic representation formula for general systems of linear parabolic equations, coupled only through the zero-order term, is given. On this basis, an implicit probabilistic representation for the vorticity in a three-dimensional viscous fluid (described by the Navier–Stokes equations) is carefully analysed, and a theorem of local existence and uniqueness is proved. The aim of the probabilistic representation is to provide an extension of the Lagrangian formalism from the non-viscous (Euler equations) to the viscous case. As an application, a continuation principle, similar to the Beale–Kato–Majda blow-up criterion, is proved.
EXISTENCE OF TWO NON-TRIVIAL SOLUTIONS FOR A CLASS OF QUASILINEAR ELLIPTIC VARIATIONAL SYSTEMS ON STRIP-LIKE DOMAINS
Authors: Kristály Alexandru
Published: May 2005

In this paper we study the multiplicity of solutions of the quasilinear elliptic system

\begin{equation} \left. \begin{aligned} -\Delta_pu\amp=\lambda F_u(x,u,v)\amp\amp\text{in }\varOmega, \\ -\Delta_qv\amp=\lambda F_v(x,u,v)\amp\amp\text{in }\varOmega, \\ u=v\amp=0\amp\amp\text{on }\partial\varOmega, \end{aligned} \right\} \end{equation} \tag{S$_\lambda$}

where $\varOmega$ is a strip-like domain and $\lambda>0$ is a parameter. Under some growth conditions on $F$, we guarantee the existence of an open interval $\varLambda\subset(0,\infty)$ such that for every $\lambda\in\varLambda$, the system (S$_\lambda$) has at least two distinct, non-trivial solutions. The proof is based on an abstract critical-point result of Ricceri and on the principle of symmetric criticality.
POSITIVE SOLUTIONS OF HIGHER-ORDER BOUNDARY-VALUE PROBLEMS
Authors: Kong Lingju , Kong Qingkai
Published: May 2005

We consider a class of even-order boundary-value problems with nonlinear boundary conditions and an eigenvalue parameter $\lambda$ in the equations. Sufficient conditions are obtained for the existence and non-existence of positive solutions of the problems for different values of $\lambda$.
Incidence and distribution of first-episode mania by age: results from a 35-year study
Authors: KENNEDY N. , EVERITT B. , BOYDELL J. , VAN OS J. , JONES P. B. , MURRAY R. M.
Published: May 2005

Background. Few epidemiological studies have investigated incidence by age or age at onset distributions for mania or bipolar disorder. The current study aimed to determine these in a defined area in south-east London, over a 35-year period.

Method. All cases of first-episode mania presenting to psychiatric services in Camberwell, south-east London, between 1965 and 1999 were identified. Incidence rates by age, using 5-year age-at-onset bands, were estimated and the structure of the age-at-onset distribution for first-episode mania was investigated using finite mixture distributions (admixture analysis).

Results. The incidence of DSM-IV bipolar I disorder (BP I), first manic episode peaked in early adult life (16·38/100000 population per year in the 21–25 years band) with a much smaller peak in mid-life. A two-component normal mixture distribution fitted age at onset better than either a single normal distribution or a three-component mixture, implying the existence of early and later onset subgroups. The early onset group had a stronger family history of bipolar disorder, and showed more acute, severe and atypical symptoms during their first manic episode.

Conclusions. The incidence of mania peaks in early adult life but there is clear evidence of early and later onset subgroups which may represent different forms of disorder.
One size fits some: the impact of patient treatment attitudes on the cost-effectiveness of a depression primary-care intervention
Authors: PYNE JEFFREY M. , ROST KATHRYN M. , FARAHATI FARAH , TRIPATHI SHANTI P. , SMITH JEFFREY , KEITH WILLIAMS D. , FORTNEY JOHN , COYNE JAMES C.
Published: May 2005

Background. Despite their impact on outcomes, the effect of patient treatment attitudes on the cost-effectiveness of health-care interventions is not widely studied. This study estimated the impact of patient receptivity to antidepressant medication on the cost-effectiveness of an evidence-based primary-care depression intervention.

Method. Twelve community primary-care practices were stratified and then randomized to enhanced (intervention) or usual care. Subjects included 211 patients beginning a new treatment episode for major depression. At baseline, 111 (52·6%) and 145 (68·7%) reported receptivity to antidepressant medication and counseling respectively. The intervention trained the primary-care teams to assess, educate, and monitor depressed patients. Twelve-month incremental (enhanced minus usual care) total costs and quality-adjusted life years (QALYs) were calculated.

Results. Among patients receptive to antidepressants, the mean incremental cost-effectiveness ratio was $5864 per QALY (sensitivity analyses up to $14689 per QALY). For patients not receptive to antidepressants, the mean incremental QALY score was negative (for both main and sensitivity analyses), or the intervention was at least no more effective than usual care.

Conclusions. These findings suggest a re-thinking of the ‘one size fits all’ depression intervention, given that half of depressed primary-care patients may be non-receptive to antidepressant medication treatment. A brief assessment of treatment receptivity should occur early in the treatment process to identify patients most likely to benefit from primary-care quality improvement efforts for depression treatment. Patient treatment preferences are also important for the development, design, and analysis of depression interventions.
Stopping and changing in adults with ADHD
Authors: BEKKER E. M. , OVERTOOM C. C. , KENEMANS J. L. , KOOIJ J. J. , DE NOORD I. , BUITELAAR J. K. , VERBATEN M. N.
Published: May 2005

Background. A lack of inhibitory control has been suggested to be the core deficit in children with attention deficit hyperactivity disorder (ADHD). This means that a primary deficit in behavioral inhibition mediates a cascade of secondary deficits in other executive functions, such as arousal regulation. Clinical observations have revealed that with increasing age symptoms of hyperactivity and impulsivity decline at a higher rate than those of inattention. This might imply that a deficit in attention rather than a lack of inhibitory control is the major feature in adult ADHD.

Method. To study whether an attentional or inhibitory deficit predominates, the stop-signal task and the stop-change task were presented to 24 adults with ADHD combined subtype and 24 controls.

Results. Relative to controls, the stop-signal reaction time (SSRT) was significantly more prolonged than the go-stimulus reaction time (RT) in patients with ADHD. This disproportionate elongation of the SSRT was comparable across tasks, even though the stop-change task exerted more complex (or at least different) demands on the inhibitory system than the stop-signal task. ADHD patients had a higher proportion of choice errors, possibly reflecting more premature responses. Specifically in the stop-change task, patients had more variable choice responses and made more inappropriate change responses, which may also reflect enhanced impulsivity.

Conclusions. The results support a core deficit in behavioral inhibition in adults with ADHD. We further suggest that there is more evidence for a critical role of deficient inhibitory control in adults than in children with ADHD.
Diet specialization of Olrog's Gull Larus atlanticus during the breeding season at Golfo San Jorge, Argentina
Authors: HERRERA GONZALO , PUNTA GABRIEL , YORIO PABLO
Published: May 2005

We studied the diet of breeding Olrog's Gulls Larus atlanticus during 1994 at two colonies in Golfo San Jorge, Argentina, through the analysis of 207 regurgitated pellets. The diet at Isla Felipe and Isla Vernaci Sudoeste comprised only a few items (9 vs 7 respectively), of which crabs were the main component. At Isla Felipe, the crabs Cyrtograpsus altimanus and C. angulatus were present in 91.2% and 89.2% of pellets, respectively, while the percentage contribution of each species was 76.1% and 21.7%, respectively. At Isla Vernaci Sudoeste, the figures were similar (96.2% and 80% of pellets, and percentage contributions 79.4% and 19.5%). All other taxa were present in less than 11% of pellets. No significant differences were found between colonies in the number of prey items, prey individuals per pellet, and consumption of crabs. Percentage contribution of crabs differed significantly between stages of the breeding cycle at Isla Felipe but not at Isla Vernaci Sudoeste. At both colonies, the proportion of male C. altimanus in pellets was larger than that of females. The proportion of female C. angulatus in pellets at Isla Vernaci Sudoeste was larger than that of males, but no significant differences were found in the consumption of each sex at Isla Felipe. Mean maximum carapace width of male crabs in pellets was not significantly different from that of females at either Isla Felipe or Isla Vernaci. Our study at Golfo San Jorge confirms that Olrog's Gull is fairly specialized, feeding mainly on crabs during the breeding season.
Medium energy pitch angle distribution during substorm injected electron clouds
Authors: Åsnes A. , Stadsnes J. , Friedel R. W. , Østgaard N. , Thomsen M.
Published: May 2005

An investigation of pitch angle resolved electron data of energy <47 keV made by the MPA instrument on LANL geosynchronous satellites reveals a signature of symmetric peaks in the pitch angle distributions, observed to expand from being nearly at perpendicular pitch angles (∼90°) to nearly field aligned at lower energies. This feature is seen in almost every interval of increased fluxes at geosynchronous orbit. A closer examination reveals the expansion of the peak in pitch angle to be such that the corresponding parallel velocity (along B) is constant. In some time intervals there are simultaneous symmetric peaks in more than one energy band and the parallel energy corresponding to the symmetric peaks is seen to vary as function of time. The observations might be explained by particles interacting with whistler mode chorus through Landau resonance, diffusing particles with parallel velocity near the phase velocity of the waves.
Imaging of the crust using aftershocks of the 2000 western Tottori prefecture earthquake
Authors: Nakagawa Shigeki , Hirata Naoshi , Sato Hiroshi
Published: May 2005

On October 6, 2000, a large earthquake occurred in the western part of Tottori prefecture, Japan. To reveal the crustal structure in the fault area of this earthquake, we conducted aftershock observations using a multi‐channel seismic array. Since natural earthquakes are not located on the surface of the earth, we developed a new method, the natural earthquake reflection profiling (NERP) method, to image the crust using natural earthquakes. We applied the NERP method to the aftershock data. The shallow area of the upper crust is reflective and the aftershock distribution is diffused three dimensionally in this area. Also found in this area are small less‐reflective zones, in which brittle fracture does not occur and stable‐slip deformation is dominant. It is possible that the stable‐slip areas are distributed in the upper crust, which may contribute to the major characteristics of this earthquake.
Ionospheric contribution to Saturn's inner plasmasphere
Authors: Moore Luke , Mendillo Michael
Published: May 2005

Ion densities from the three‐dimensional Saturn thermosphere‐ionosphere model are extended above the plasma exobase using the formalism of Pierrard and Lemaire (1996) which evaluates the balance of gravitational, centrifugal, and electric forces on plasma in a rotating dipole field. The parameter space of ionospheric contributions to Saturn's inner plasmasphere (to within 1 Saturnian radius above the limb, L < 2) is explored by comparing results that span the observed extremes of plasma temperature, 650–1700 K, and the range of velocity distribution functions, Lorentzian (or Kappa, with κ = 2) to Maxwellian (i.e., a Lorentzian with κ = ∞). Plasmaspheric densities are generated for solstice and equinox conditions using solar maximum and solar minimum solar fluxes. Magnetic flux tubes in Saturn's inner plasmasphere are modeled to have less plasma above the exobase (∼4000 km) than below it in contrast to the terrestrial situation. Calculations are made for plasma densities along the path of the Cassini spacecraft's orbital insertion on 1 July 2004. The full range of modeled electron density at closest approach is 0.02–220 cm−3, although increased knowledge of either plasma temperature or velocity distribution at Saturn's plasma exobase would tighten this range considerably. There is reason to favor the higher values of the calculated electron density as the plasma population at Saturn's plasma exobase is more likely to exhibit a non‐Maxwellian velocity distribution. There is a wide range of combinations of κ and plasma temperature that leads to predictions of order 100 el cm−3 at Cassini's closest approach, 1.3 RS.
Uncertainty of absolute gravity measurements
Authors: Van Camp Michel , Williams Simon D. P. , Francis Olivier
Published: May 2005

A total of 96 absolute gravity (AG) measurements at the Membach station and 221 at the Proudman Oceanographic Laboratory (POL) is analyzed for noise content. The lengths of the series were around 10 years (POL) and 8 years (Membach). First the noise at frequencies lower than 1 cpd is studied. This noise consists in setup‐dependent offsets and geophysical colored sources. The setup white noise is estimated using continuous relative superconducting gravity (SG) measurements at Membach. The colored environmental noise affecting both AG and SG is estimated using the maximum likelihood estimation technique to fit two types of stochastic models to the SG time series, power law noise, and first‐order Gauss Markov (FOGM) noise. We estimate the noise amplitudes of a white noise process plus power law model while simultaneously solving for the spectral index and the noise amplitudes of a white noise process plus FOGM noise model is also estimated. The gravity rate of change and the associated uncertainties as a function of the noise structure are then computed. At frequencies higher than 1 cpd, a time‐varying white noise component usually dominates AG time series. Finally, the POL and Membach experiments are applied to estimate the uncertainties for AG campaigns repeated once or twice a year to monitor crustal deformation. Such repeated AG measurements should allow one to constrain gravity rate of change with an uncertainty of 1 nm s−2 yr−1 (or 0.5 mm yr−1) after 14 or 24 years, depending on the noise model. Therefore long‐term measurements using absolute gravimeters are appropriate for monitoring slow vertical tectonic deformation.
Particle deposition on water: Surface source versus upwind source
Authors: Hoppel W. A. , Caffrey P. F. , Frick G. M.
Published: May 2005

The deposition velocity for aerosols on natural water surfaces is investigated with emphasis (1) on the difference between the deposition of particles that originate above the surface (or upwind) and those which originate from a local uniform surface source such as sea‐salt aerosol, and (2) on extending the deposition velocity formulation into the size range where the gravitationally induced gradients require corrections to the well‐mixed case. The following cases are explored: (1) uniform surface source in equilibrium with deposition, (2) surface source with removal above the surface layer in addition to surface deposition, (3) surface deposition when the source is from above (upwind), and (4) surface deposition when the turbulent flux is downward but opposed by a surface source. The following are shown: (1) For a surface source of aerosols, the problem can be formulated such that the deposition processes occurring within the molecular interfacial layer do not enter the expression for the deposition velocity, provided the surface source function and deposition are defined for a point at or above the top of the molecular interfacial layer. This is useful because measurements of the surface source function are made above the interface layer and the microscopic processes occurring in the interface layer are poorly characterized. (2) For a surface source with removal above the surface layer (net upward flux), the deposition velocity is a function of the removal height and strength of the removal process. However, if the reference height is much lower than the removal height, the equilibrium deposition velocity is an acceptable approximation. (3) If the filling/emptying time for an aerosol is much longer than the turbulent mixing time, as is usually the case in the boundary layer, a quasi steady state is established. The deposition velocity for the quasi steady state is the same as for steady state, making the steady state deposition velocity useful for dynamic modeling. The results of this study have important implications on how sea‐salt particles are introduced and removed from the lowest layer of numerical models, as well as retrieval of the surface source function from measurements of the size distribution at some reference height.
Seafloor expression of sediment extrusion and intrusion at the El Arraiche mud volcano field, Gulf of Cadiz
Authors: Van Rensbergen Pieter , Depreiter Davy , Pannemans Bart , Henriet Jean‐Pierre
Published: May 2005

The El Arraiche mud volcano field consists of eight mud volcanoes up to 255 m high and 5.4 km wide, located in the Moroccan margin of the Gulf of Cadiz at water depths between 700 and 200 m. Available data include detailed swath bathymetry over the entire area, dense grids of high‐resolution seismic data, very high resolution deep tow subbottom profiles, side scan sonar mosaics over the major structures, selected underwater video lines, and sediment samples. The main morphological aspects of the mud volcanoes are, from the margin toward the center, a subsidence rim or moat, the mud volcano slope, in some cases a deep crater, and a recent central mud dome at the top. The slope is characterized by radial outward sediment flow deposits or by a concentric pattern of terraces and steps. The sediment flow deposits can be divided into elongate outflows that accumulate at the base of the slope and short bulky outflow deposits that freeze on the steep slope. The crater hosts extruded sediment ranging from fluidized sand to mud breccia with centimeter‐ to meter‐sized rock clasts issued from several vents within the crater. The concentric slope terraces and the central mud dome are interpreted to result from several phases of uplift caused by sediment intrusion or shallow diapirism. The mud volcano growth is thus interpreted to result from a combination of extrusive and intrusive processes.
METHODOLOGICAL DEVELOPMENTS IN GEOPHYSICAL ASSIMILATION MODELING
Authors: Christakos George
Published: May 2005

This work presents recent methodological developments in geophysical assimilation research. We revisit the meaning of the term “solution” of a mathematical model representing a geophysical system, and we examine its operational formulations. We argue that an assimilation solution based on epistemic cognition (which assumes that the model describes incomplete knowledge about nature and focuses on conceptual mechanisms of scientific thinking) could lead to more realistic representations of the geophysical situation than a conventional ontologic assimilation solution (which assumes that the model describes nature as is and focuses on form manipulations). Conceptually, the two approaches are fundamentally different. Unlike the reasoning structure of conventional assimilation modeling that is based mainly on ad hoc technical schemes, the epistemic cognition approach is based on teleologic criteria and stochastic adaptation principles. In this way some key ideas are introduced that could open new areas of geophysical assimilation to detailed understanding in an integrated manner. A knowledge synthesis framework can provide the rational means for assimilating a variety of knowledge bases (general and site specific) that are relevant to the geophysical system of interest. Epistemic cognition‐based assimilation techniques can produce a realistic representation of the geophysical system, provide a rigorous assessment of the uncertainty sources, and generate informative predictions across space‐time. The mathematics of epistemic assimilation involves a powerful and versatile spatiotemporal random field theory that imposes no restriction on the shape of the probability distributions or the form of the predictors (non‐Gaussian distributions, multiple‐point statistics, and nonlinear models are automatically incorporated) and accounts rigorously for the uncertainty features of the geophysical system. In the epistemic cognition context the assimilation concept may be used to investigate critical issues related to knowledge reliability, such as uncertainty due to model structure error (conceptual uncertainty).
Biphasic neurogenic vasodilatation in the bovine intraocular long posterior ciliary artery: involvement of nitric oxide and an additional unidentified neurotransmitter
Authors: Overend Jill , Wilson William S , Martin William
Published: May 2005

We have investigated the neurogenic factors inducing relaxation in the intraocular segment of the bovine long posterior ciliary artery.

In precontracted vessels, electrical field stimulation (EFS, 0.5–128 Hz, 10 s trains) in the presence of guanethidine (30 μM) evoked biphasic relaxation: optimal relaxation for the first and second components occurred at 10 and 50 s, respectively. The first component, but not the second, was abolished by L‐NAME (100 μM) or ODQ (3 μM).

Relaxation to exogenous CGRP (0.1–300 nM) was inhibited by the CGRP antagonist, CGRP8–37 (1–5 μM), but neither component of neurogenic relaxation was affected. Preincubation with the sensory nerve excitotoxin, capsaicin (1 μM), had no effect on either the first or second components of neurogenic relaxation.

Substance P (0.1 nM–0.1 μM) induced relaxation, but rapid and complete desensitisation occurred within minutes. Neither desensitisation to substance P (0.1 μM) nor incubation with the NK1 antagonist, L‐733,060 (0.3 μM), had any effect on the first or second components of neurogenic relaxation.

VIP (0.1 nM–0.3 μM) induced relaxation and this was followed by substantial desensitisation. Neither desensitisation to VIP (0.6 μM) nor treatment with the protease, α‐chymotrypsin (10 U ml−1), had any effect on the first or second components of neurogenic relaxation.

The results indicate that nitric oxide mediates the first component of neurogenic relaxation in the bovine intraocular ciliary artery. The neurotransmitter mediating the second component remains to be determined but is unlikely to be CGRP, substance P or VIP.

British Journal of Pharmacology (2005) 145, 1001–1008. doi:10.1038/sj.bjp.0706264
Mast cell involvement in the adenosine mediated airway hyper‐reactivity in a murine model of ovalbumin‐induced lung inflammation
Authors: Wyss Daniel , Bonneau Olivier , Trifilieff Alexandre
Published: May 2005

Airway hyper‐reactivity to inhaled adenosine, mediated via mast cell activation, is a cardinal feature of asthma. Animal models have been developed in several species to mimic this phenomenon, but only in the rat has a mast cell involvement been clearly defined. In this study, a model of ovalbumin‐induced adenosine hyper‐reactivity was developed in BALB/c mice to determine whether mast cells are involved in this phenomenon.

Sensitised mice were challenged one, two or three times, on a daily basis, and airway responses to the stable adenosine analogue NECA (5′‐N‐ethylcarboxamido adenosine) determined 4 and 24 h after each challenge. Airway hyper‐reactivity was observed in ovalbumin‐challenged mice 4 h after a single challenge and to a minor extent 24 h after a single challenge and 4 h after two challenges.

Cromolyn (20 mg ml−1), given by aerosol an hour before the NECA provocation, fully inhibited the airway hyper‐reactivity observed 4 h after a single allergen challenge, suggesting a role for mast cells in this response. The airway space cellular inflammation was not affected by cromolyn.

As observed in human asthma, an acute treatment with steroid (budesonide 3 mg kg−1, given an hour before the allergen challenge) inhibited the NECA airway hyper‐reactivity and significantly inhibited the airway space cellular inflammation.

These data suggest that the ovalbumin‐challenged BALB/c mice can be considered as a suitable model to study the adenosine‐induced airway hyper‐reactivity phenomenon observed in human asthma.

British Journal of Pharmacology (2005) 145, 845–852. doi:10.1038/sj.bjp.0706271
Isolation of Mutant Lines with Decreased Numbers of Chloroplasts per Cell from a Tagged Mutant Library of the Moss Physcomitrella patens
Authors: Hayashida A. , Takechi K. , Sugiyama M. , Kubo M. , Itoh R. D. , Takio S. , Fujita T. , Hiwatashi Y. , Hasebe M. , Takano H.
Published: May 2005

Abstract: Eleven mutant lines exhibiting decreased numbers of chloroplasts per cell were isolated from 8 800 tagged mutant lines of Physcomitrella patens by microscopic observations. Chloronema subapical cells in wild‐type plants had a mean of 48 chloroplasts, whereas chloroplast numbers in subapical cells in mutant lines 215 and 222 decreased to 75 % of that in the wild type. Seven mutant lines ‐ 473, 122, 221, 129, 492, 207, and 138 ‐ had about half as many chloroplasts as the wild type. Mutant line 11 had a few remarkably enlarged chloroplasts, and mutant line 347 had chloroplasts of various sizes. Whereas the cell volume was the same as in the wild type in mutant lines 222, 473, 221, 129, 492, and 207, the cell volume of the other mutants increased. The chloroplast number of leaf cells was the same as that of chloronema cells in each mutant line when gametophores could be formed. Treatment with ampicillin decreased the number of chloroplasts in all mutant lines. Southern hybridization using DNA in tags as probes showed that only one insertion occurred in mutant lines 473 and 221. To determine whether the tagged DNA inserted into the known genes for plastid division, we isolated the PpMinD1, PpMinD2, and PpMinE1 genes. Genomic polymerase chain reaction analysis showed that the PpFtsZ and PpMinD/E genes were not disrupted by the insertion of the tags in mutant lines 11 and 347, respectively.
Transcript Profiling in Plastid Arginine tRNA‐CCG Gene Knockout Moss: Construction of Physcomitrella patens Plastid DNA Microarray
Authors: Nakamura T. , Sugiura C. , Kobayashi Y. , Sugita M.
Published: May 2005

Abstract: The moss Physcomitrella patens is a newly established model plant that is widely used for the characterization of gene function by targeted gene knockout or over‐expression. The target gene disruption occurs in both the nuclear and chloroplast genomes. We applied DNA microarray technology to the P. patens plastid genome for large‐scale analysis of transcripts. A microarray was constructed containing 108 DNA fragments to detect all annotated plastid genes. We analyzed the transcript profile in a knockout transformant for the arginine tRNA gene, trnR‐CCG, and confirmed previous results that rbcL and psaI transcripts accumulate in similar levels to wild‐type moss, and accD transcript level is higher than those of wild‐type moss. Additionally, the plastid DNA microarray revealed that most plastid genes were expressed at similar levels in wild‐type and transformant mosses. This indicates that trnR‐CCG is not essential for the expression of plastid genes.
Isolation and Characterization of New MIKC‐Type MADS‐Box Genes from the Moss Physcomitrella patens
Authors: Riese M. , Faigl W. , Quodt V. , Verelst W. , Matthes A. , Saedler H. , Münster T.
Published: May 2005

Abstract: MADS‐box genes encode for a large family of transcription‐regulating proteins, which were isolated from all groups of eukaryotic organisms. The plant‐specific MIKC‐type MADS‐box genes have been intensively analyzed for their roles in controlling developmental processes. Well‐known are the MADS‐box genes acting as homeotic selector genes in the differentiation of whorls of floral organs in seed plants. The MADS‐box gene family has also been studied in non‐flowering plants, such as lycophytes, pteridophytes, and bryophytes. The analysis of MADS‐box genes in the moss Physcomitrella patens led to the identification of a new class of MIKC‐type genes, designated as MIKC‐type genes. The MIKC‐type genes possess a number of structural features which clearly distinguish them from the already known MIKC‐type genes. Recently, orthologues of the Physcomitrella MIKC‐type genes were found in Arabidopsis thaliana, demonstrating the conservation of these genes in tracheophytes. Here, we report the isolation of two new MIKC‐type MADS‐box genes from Physcomitrella. Structural features and expression patterns of these genes were analyzed. The contribution of our findings to a better understanding of the evolution of MIKC‐type genes in land plants is discussed.
Patterning of active organic materials by direct transfer for organic electronic devices
Authors: Kim Changsoon , Cao Yifang , Soboyejo Winston O. , Forrest Stephen R.
Published: May 2005

We demonstrate the localized patterning of organic thin films based on direct material transfer from a stamp to a substrate. This process, based on van der Waals bonding between contacting organic films, extends the range of application of patterning via stamping to devices where the active organic materials must be locally deposited on the substrate. A mechanical analysis combined with finite element numerical simulations successfully describes the details of the material transfer process over substrate irregularities and step edges. To demonstrate local patterning, we fabricate an array of organic light-emitting devices, showing that the organic-organic interface formed by the transfer process does not significantly affect device performance. This technique expands the application of a unique attribute of organic materials—the ability to compositionally pattern materials to locally modify, or optimize a device function or property within the substrate plane.
Anomalous volumetric behavior of water-hexane and water-decane mixtures in the vicinity of the critical region as studied by infrared spectroscopy
Authors: Ishikawa Yuki , Arai Sigenori , Furutaka Seiya , Ikawa Shun-ichi
Published: May 2005

Infrared spectra of binary mixtures of water with hexane and decane were measured at temperatures and pressures in the 473–648K and 70–350bar ranges, respectively. Volumetric concentrations of water and the hydrocarbons in the mixtures were obtained from absorption intensities of the fundamental OH stretching band of HDO and combination transitions of the hydrocarbons. Using both the concentrations, densities of the aqueous mixtures were estimated and compared with densities before mixing, which were calculated using literature densities of the neat liquids. It is found that anomalously large volume expansion on mixing occurs in the vicinity of the critical region of the mixtures.
Temperature dependence of homogeneous nucleation rates for water: Near equivalence of the empirical fit of Wölk and Strey, and the scaled nucleation model
Authors: Hale Barbara N.
Published: May 2005

It is pointed out that the temperature fitting function of Wölk and Strey [J. Phys. Chem. 105, 11683 (2001)], recently shown to convert the Becker–Döring [Ann. Phys. (Leipzig) 24, 719 (1935)] nucleation rate into an expression in agreement with much of the experimental water nucleation rate data, also converts the Becker–Döring rate into a form nearly equivalent with the scaled nucleation rate model, Jscaled=Jocexp[−16πΩ3(Tc∕T−1)3∕3(lnS)2]. In the latter expression Joc is the inverse thermal wavelength cubed/sec, evaluated at Tc.
Static and dynamical properties of heavy water at ambient conditions from first-principles molecular dynamics
Authors: Sit P. H.-L. , Marzari Nicola
Published: May 2005

The static and dynamical properties of heavy water have been studied at ambient conditions with extensive Car–Parrinello molecular-dynamics simulations in the canonical ensemble, with temperatures ranging between 325 and 400K. Density-functional theory, paired with a modern exchange-correlation functional (Perdew–Burke–Ernzerhof), provides an excellent agreement for the structural properties and binding energy of the water monomer and dimer. On the other hand, the structural and dynamical properties of the bulk liquid show a clear enhancement of the local structure compared to experimental results; a distinctive transition to liquidlike diffusion occurs in the simulations only at the elevated temperature of 400K. Extensive runs of up to 50ps are needed to obtain well-converged thermal averages; the use of ultrasoft or norm-conserving pseudopotentials and the larger plane-wave sets associated with the latter choice had, as expected, only negligible effects on the final result. Finite-size effects in the liquid state are found to be mostly negligible for systems as small as 32molecules per unit cell.
Kinetic modeling of ion conduction in KcsA potassium channel
Authors: Mafé Salvador , Pellicer Julio , Cervera Javier
Published: May 2005

KcsA constitutes a potassium channel of known structure that shows both high conduction rates and selectivity among monovalent cations. A kinetic model for ion conduction through this channel that assumes rapid ion transport within the filter has recently been presented by Nelson. In a recent, brief communication, we used the model to provide preliminary explanations to the experimental current-voltage J-V and conductance-concentration g-S curves obtained for a series of monovalent ions (K+,Tl+, and Rb+). We did not assume rapid ion transport in the calculations, since ion transport within the selectivity filter could be rate limiting for ions other than native K+. This previous work is now significantly extended to the following experimental problems. First, the outward rectification of the J-V curves in K+ symmetrical solutions is analyzed using a generalized kinetic model. Second, the J-V and g-S curves for NH4+ are obtained and compared with those of other ions (the NH4+ J-V curve is qualitatively different from those of Rb+ and Tl+). Third, the effects of Na+ block on K+ and Rb+ currents through single KcsA channels are studied and the different blocking behavior is related to the values of the translocation rate constants characteristic of ion transport within the filter. Finally, the significantly decreased K+ conductance caused by mutation of the wild-type channel is also explained in terms of this rate constant. In order to keep the number of model parameters to a minimum, we do not allow the electrical distance (an empirical parameter of kinetic models that controls the exponential voltage dependence of the dissociation rate) to vary with the ionic species. Without introducing the relatively high number of adjustable parameters of more comprehensive site-based models, we show that ion association to the filter is rate controlling at low concentrations, but ion dissociation from the filter and ion transport within the filter could limit conduction at high concentration. Although some experimental data from other authors were included to allow qualitative comparison with model calculations, the absolute values of the effective rate constants obtained are only tentative. However, the relative changes in these constants needed to explain qualitatively the experiments should be of significance.
Modeling of crossflow jet-type singlet oxygen generator
Authors: Watanabe Goro , Sugimoto Daichi , Vyskubenko Oleg , Tei Kazuyoku , Nanri Kenzo , Fujioka Tomoo
Published: May 2005

A quasi-two-dimensional model has been developed to predict the performance of a crossflow jet singlet oxygen generator. The model takes into account HO2− depletion, gas temperature variation due to the pooling deactivation of O2(Δ1), and the stretch effect of gas/liquid interaction area due to the jet-induced pressure loss. The modeling results compare favorably with the test data measured over a wide range of geometries and operation conditions. The overall agreements between measured and calculated values in terms of root-mean-square errors for utilization, yield, and gas temperature are 0.030, 0.035, and 16.23K, respectively.
Delayed failure in a shock-loaded silicon carbide
Authors: Millett J. C. F. , Bourne N. K. , Dandekar D. P.
Published: May 2005

The shock response of a silicon carbide has been investigated using the methods of plate impact, and monitored using manganin stress gauges mounted so as to be responsive to lateral stress. Close to the impact face, a two-step stress response is observed, indicating the presence of delayed failure at the impact face. As the shock front moves through the target, the failure wave appears to slow, before arresting between 4 and 6mm from the impact face. Measured shear stresses (ahead of the failure front) are in good agreement with the calculated elastic response, and with similar measurements made by both ourselves in other grades of silicon carbide and other authors. In gauge traces where the failure wave was not observed, a slight decrease in lateral stress (and thus a corresponding increase in shear strength) has been noticed. A similar response in some metals (in combination with recovery work in other ceramics) has led us to suggest that a degree of plastic deformation, in combination with a more brittle response, has occurred.
EPR spectrum and magnetic ordering of copper orotate
Authors: Kutko K. V. , Kaplienko A. I. , Nikolova E. P. , Anders A. G. , Shishkin O. V. , Zubatuk R. I.
Published: May 2005

An x-ray diffraction study and measurements of the EPR spectrum of a copper orotate single crystal [Cu(C5H3N2O4)(H2O)2] are carried out. At room temperature a one-center EPR spectrum of orthorhombic symmetry is observed. The extremal values of the g factors are determined. Low-temperature broadening of the resonance lines is observed. It is assumed that it is due to the formation of short-range antiferromagnetic order, which arises when the temperature approaches the Néel point TN=3.2 K.
On the polyamorphism of fullerite-based orientational glasses
Authors: Aleksandrovskii A. N. , Dolbin A. V. , Esel’son V. B. , Gavrilko V. G. , Manzhelii V. G. , Bakai A. S. , Cassidy D. , Gadd G. E. , Moricca S. , Sundqvist B.
Published: May 2005

A dilatometric investigation in the temperature range 2–28 K shows that a first-order polyamorphous transition occurs in the orientational glasses based on C60 doped with H2, D2 and Xe. A polyamorphous transition is also detected in C60 doped with Kr and He. It is observed that the hysteresis of thermal expansion caused by the polyamorphous transition (and, hence, the transition temperature) is essentially dependent on the type of doping gas. Both positive and negative contributions to the thermal expansion are observed in the low-temperature phase of the glasses. The relaxation time of the negative contribution turns out to be much longer than that of the positive contribution. The positive contribution is found to be due to phonon and libron modes, while the negative contribution is attributed to tunneling states of the C60 molecules. The characteristic time of the phase transformation from the low-T phase to the high-T phase is found for the C60–H2 system at 12 K. A theoretical model is proposed to interpret these observed phenomena. The theoretical model proposed includes a consideration of the nature of polyamorphism in glasses, as well as the thermodynamics and kinetics of the transition. A model of noninteracting tunneling states is used to explain the negative contribution to the thermal expansion. The experimental data obtained are considered within the framework of the theoretical model. From the theoretical model the order of magnitude of the polyamorphous transition temperature is estimated. It is found that the late stage of the polyamorphous transformation is described well by the Kolmogorov law with an exponent of n=1. At this stage of the transformation, the two-dimensional phase boundary moves along the normal, and the nucleation is not important.
Phonon spectrum and electron-phonon interaction in technetium
Authors: Sichkar S. M. , Antonov V. N.
Published: May 2005

Ab initio calculations of the phonon spectrum, spectral function of the electron-phonon interaction, and transport properties (resistivity) of technetium are carried out in the framework of linear response theory. Good agreement with the experimental data is obtained.