bluuebunny/crossref_metadata_2025 huggingface dataset:
Pristionchus pacificus: a well‐rounded nematode
Authors: Hong Ray L. , Sommer Ralf J.
Published: May 2006

Nematodes pervade Earth's biosphere and occupy innumerable ecological niches. The role of Caenorhabditis elegans as a model for developmental processes has encouraged us to cultivate a second nematode, Pristionchus pacificus, as a comparative counterpoint to address questions in development, behavior and ecology in nematode evolution. We hope that this endeavor, now more than a decade underway, will allow us to project findings onto other comparative models for biological processes. To this end, our laboratory has made an extensive genetic map and mutant screens to understand changes in developmental programs. Recently, we have been capitalizing on the whole genome sequence of P. pacificus to describe more thoroughly the molecular basis for these changes, as well as to better integrate our molecular knowledge with the biodiversity of Pristionchus species. BioEssays 28: 651–659, 2006. © 2006 Wiley Periodicals, Inc.
A golden clue to human skin colour variation
Authors: Müller Jeanette , Kelsh Robert N.
Published: May 2006

Variations in human skin pigmentation are obvious, but how have skin colour differences evolved? Although clearly a polymorphic trait, the number and identity of key variants has remained unclear. Investigation of pigmentation phenotypes in model organisms provides a route to identify these genes and showed MC1R to be one key locus. Now, cloning of a classic zebrafish mutant, golden, identifies slc24a5 as a gene involved in fish skin pigmentation.1 Strikingly this study identifies the human orthologue, SLC24A5, as likely to make a major contribution to the pale skin colouration of Western Europeans. BioEssays 28: 578–582, 2006. © 2006 Wiley Periodicals, Inc.
Regulation of functional diversity within the Nedd4 family by accessory and adaptor proteins
Authors: Shearwin‐Whyatt Linda , Dalton Hazel E. , Foot Natalie , Kumar Sharad
Published: May 2006

Ubiquitination is essential in mediating diverse cellular functions including protein degradation and trafficking. Ubiquitin‐protein (E3) ligases determine the substrate specificity of the ubiquitination process. The Nedd4 family of E3 ligases is an evolutionarily conserved family of proteins required for the ubiquitination of a large number of cellular targets. As a result, this family regulates a wide variety of cellular processes including transcription, stability and trafficking of plasma membrane proteins, and the degradation of misfolded proteins. The modular architecture of the proteins, comprising a C2 domain, multiple WW domains and a catalytic domain, enables diverse intermolecular interactions and recruitment to various subcellular locations. The WW domains commonly mediate interaction with substrate proteins; however, an increasing number of Nedd4 targets do not contain obvious WW domain‐interaction motifs suggesting the involvement of accessory proteins. This review discusses recent insights into how accessory and adaptor proteins modulate the activities of Nedd4 family members, including recruitment of novel substrates, alteration of subcellular localisation and effects on ubiquitination. BioEssays 28: 617–628, 2006. © 2006 Wiley Periodicals, Inc.
Central nervous system recurrence in adult patients with acute lymphoblastic leukemia
Authors: Sancho Juan‐Manuel , Ribera Josep‐Maria , Oriol Albert , Hernandez‐Rivas Jesus‐Maria , Rivas Concepcion , Bethencourt Concepcion , Parody Ricardo , Deben Guillermo , Bello Jose‐Luis , Feliu Evarist
Published: May 2006

Recurrence of acute lymphoblastic leukemia (ALL) in the central nervous system (CNS) confers a poor prognosis, although to the authors' knowledge, only a few studies have analyzed this issue in adults. For the current study, the authors analyzed the frequency, predictive factors, and prognosis of CNS involvement and recurrence in adult patients with ALL who did not receive cranial irradiation for CNS prophylaxis. Four hundred sixty‐seven adult patients (age ≥15 years) with ALL were treated on 4 protocols: ALL‐89 (standard‐risk and high‐risk ALL; n = 108 patients), ALL‐93 (high‐risk ALL; n = 222 patients), ALL‐96 (standard‐risk ALL; n = 84 patients), and ALL3‐97 (Burkitt leukemia; n = 53 patients). CNS prophylaxis consisted of intrathecal methotrexate, cytarabine, and hydrocortisone together with high‐dose systemic methotrexate and cytarabine. The mean age (± standard deviation) was 33 years (± 16 years), and 272 patients were males. ALL subtypes included an early pre‐B phenotype (15%), a common phenotype (45%), a pre‐B phenotype (5%), a mature B phenotype (11%), and a T phenotype (24%). CNS involvement at diagnosis was observed in 18 patients (3.9%). Of 159 recurrences, 22 occurred (5.8%) in the CNS (14 isolated and 8 combined). A lactate dehydrogenase level >1000 U/L was the only factor associated with the risk of CNS recurrence. A complete remission was attained in 7 of 22 patients (32%). The median overall survival after recurrence was 0.7 years for patients with isolated CNS recurrence, 0.13 years for patients with combined recurrence, and 0.41 years for patients with bone marrow recurrence (P = .11). The only 2 survivors underwent stem cell transplantation. The frequency of CNS recurrence in adult patients with ALL who do not receive radiotherapy for CNS prophylaxis was similar to the frequency observed in protocols that included cranial irradiation. A lactate dehydrogenase value >1000 U/L was the only factor found to be associated with CNS recurrence. The prognosis for patients who develop CNS recurrence is poor, identical to that for patients who develop bone marrow recurrence. Cancer 2006. © 2006 American Cancer Society.
Optimization of integrated Earth System Model components using Grid‐enabled data management and computation
Authors: Price A. R. , Xue G. , Yool A. , Lunt D. J. , Valdes P. J. , Lenton T. M. , Wason J. L. , Pound G. E. , Cox S. J.
Published: May 2006

In this paper, we present the Grid enabled data management system that has been deployed for the Grid ENabled Integrated Earth system model (GENIE) project. The database system is an augmented version of the Geodise Database Toolbox and provides a repository for scripts, binaries and output data in the GENIE framework. By exploiting the functionality available in the Geodise toolboxes we demonstrate how the database can be employed to tune parameters of coupled GENIE Earth System Model components to improve their match with observational data. A Matlab client provides a common environment for the project Virtual Organization and allows the scripting of bespoke tuning studies that can exploit multiple heterogeneous computational resources. We present the results of a number of tuning exercises performed on GENIE model components using multi‐dimensional optimization methods. In particular, we find that it is possible to successfully tune models with up to 30 free parameters using Kriging and Genetic Algorithm methods. Copyright © 2006 John Wiley & Sons, Ltd.
Towards the Total Synthesis of Vibsanin E, 15‐O‐Methylcyclovibsanin B,3‐Hydroxyvibsanin E, Furanovibsanin A, and 3‐O‐Methylfuranovibsanin A
Authors: Schwartz Brett D. , Tilly David P. , Heim Ralf , Wiedemann Stefan , Williams Craig M. , Bernhardt Paul V.
Published: May 2006

Studies detailing synthetic approaches to a variety of biosynthetically related vibsanin‐type diterpenes (i.e. vibsanin E, 15‐O‐methylcyclovibsanin B, 3‐hydroxy‐vibsanin E, furanovibsanin A, and 3‐O‐methylfuranovibsanin A) are discussed. Biogenetically modelled approaches are coupled with an investigation of classical and modern six‐ to seven‐membered ring‐expansion protocols, which gain access to the central core of these natural products. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Too much to bear: An introduction to crisis intervention and therapy
Authors: Brown Frieda F. , Rainer Jackson P.
Published: May 2006

This brief article introduces the issue of the Journal of Clinical Psychology: In Session devoted to crisis, its aftermath, and its psychological treatment. We begin by defining crisis and its probable roles in the psychotherapist's practice. The following seven articles focus on specific guidelines for crisis work with multiple populations. A summary of each article is provided. We close with suggestions for incorporating the wisdom of each article in concrete, meaningful ways. © 2006 Wiley Periodicals, Inc. J Clin Psychol: In Session 62: 953–957, 2006.
A note on Bar Induction in Constructive Set Theory
Authors: Rathjen Michael
Published: May 2006

Bar Induction occupies a central place in Brouwerian mathematics. This note is concerned with the strength of Bar Induction on the basis of Constructive Zermelo‐Fraenkel Set Theory, CZF. It is shown that CZF augmented by decidable Bar Induction proves the 1‐consistency of CZF. This answers a question of P. Aczel who used Bar Induction to give a proof of the Lusin Separation Theorem in the constructive set theory CZF. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A novel analytical solution for constant‐head test in a patchy aquifer
Authors: Yang Shaw‐Yang , Yeh Hund‐Der
Published: May 2006

A mathematical model describing the hydraulic head distribution for a constant‐head test performed in a well situated at the centre of a patchy aquifer is presented. The analytical solution for the mathematical model is derived by the Laplace transforms and the Bromwich integral method. The solution for the hydraulic head has been shown to satisfy the governing equations, related boundary conditions, and continuity requirements for the hydraulic head and flow rate at the interface of the patch and outer regions. An efficient numerical approach is proposed to evaluate the solution, which has an integral covering an integration range from zero to infinity and an integrand consisting the product and square of the Bessel functions. This solution can be used to produce the curves of dimensionless hydraulic head against dimensionless time for investigating the effect of the contrast of formation properties on the dimensionless hydraulic head distribution. Define the ratio of outer‐region transmissivity to patch‐region transmissivity as α. The dimensionless hydraulic head for α=0.1 case is about 2.72 times to that for α=10 case at dimensionless large time (e.g. τ⩾106) when the dimensionless distance (ρ) equals 10. The results indicate that the hydraulic head distribution highly depends on the hydraulic properties of two‐zone formations. Copyright © 2006 John Wiley & Sons, Ltd.
Photoluminescence and edge‐incident wavelength modulation transmittance spectroscopy characterizations of InGaN/GaN multiple‐quantum‐well structures
Authors: Lin D. Y. , Chen W. L. , Lin W. C. , Shiu J. J. , Han J.
Published: May 2006

A novel edge‐incident wavelength modulation transmittance spectroscopy (WMTS) technique combined with conventional photoluminescence (PL) measurements is developed to investigate the optical properties of two InGaN/GaN multiple‐quantum‐well (MQW) structures in the temperature range between 15 and 300 K. The S‐shaped PL shift with temperature and the InGaN A1 (LO) phonon replicas were observed in temperature‐dependent PL measurements. It can be explained by the localization of self‐organized InN clusters within the InGaN layers. Besides, we for the first time use the edge‐incident WMTS technique to eliminate the multireflection interference effect, which in the conventional transmittance or absorption measurements usually causes spectral oscillation to make the optical features difficult to identify. The excitonic transitions and absorption edge of GaN layers have been revealed clearly. Compared to an envelope‐function calculation taking into account the quantum confined Stark effect (QCSE), the origins of these spectral features are assigned. The parameters that describe the temperature dependence of the excitonic transition energies are also evaluated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of vacancies in the red luminescence from Mg‐doped GaN
Authors: Zeng S. , Aliev G. N. , Wolverson D. , Davies J. J. , Bingham S. J. , Abdulmalik D. A. , Coleman P. G. , Wang T. , Parbrook P. J.
Published: May 2006

The red (1.8 eV) photoluminescence (PL) band often observed in Mg‐doped GaN has been suggested to be due to a recombination process involving vacancy‐related deep defects. To identify the defects concerned, optically‐detected magnetic resonance (ODMR) and positron annihilation spectroscopy (PAS) experiments have been combined. A correlation between the PL spectra, the ODMR signals and the PAS data has been observed in as‐grown layers as the magnesium doping level is increased. The experiments provide strong evidence that the origin of the red PL is recombination of electrons from both shallow and deep donors with holes at deep acceptors, the deep donors being complexes formed from nitrogen vacancies associated with substitutional magnesium ions and the deep acceptors being gallium vacancies or related centers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Protective effect of BR‐16A, a polyherbal preparation against social isolation stress: possible GABAergic mechanism
Authors: Kumar Anil , Kulkarni S. K.
Published: May 2006

The antistress effects of BR‐16A, a polyherbal preparation and its interaction with GABAergic modulators against social isolation‐induced stress were investigated in the present study. Isolation stress was induced by keeping the mice (Laca strain) individually in each cage for 3 weeks and various drug treatments were given for a period of 5 days before the start of the experiments. The various behavioural parameters examined included pentobarbitone‐induced sleep (sleep latency and duration), analgesia (tail‐ßick test) and locomotor activity, respectively. BR‐16A (100 mg/kg and 200 mg/kg) treatment for 5 days significantly reversed the social isolation stress‐induced prolongation of onset and decrease in pentobarbitone‐induced sleep, increased total motor activity and stress‐induced antinociception. When diazepam (0.5 mg/kg), a benzodiazepine agonist, was co‐administered with BR‐16A (100 mg/kg), it significantly potentiated the reversal of pentobarbitone‐induced shortening of sleep time effects; increased locomotor activity and stress induced antinociceptive effects. However, the sleep latency was not decreased significantly. Further, ßumazenil (2 mg/kg), a benzodiazepine receptor antagonist and FG 7142 (10 mg/kg), an inverse agonist, when co‐administered with BR‐16A (100 mg/kg), showed no significant reversal on pentobarbitone‐induced hypnosis, locomotor activity and social isolation‐induced antinociception compared with their effects per se. The present study demonstrated the antistress effects of BR‐16A preparation against social isolation‐induced stress. The present study also suggests that the GABAergic system may be involved in its antistress effect. Copyright © 2006 John Wiley & Sons, Ltd.
Proctocolectomy for ulcerative colitis
Authors: Lee Emanoel C. G. , Truelove Sidney C.
Published: May 2006

The majority of patients with ulcerative colitis can be managed satisfactorily throughout their lives by medical treatment, but a minority require colectomy. In severe attacks, emergency surgery is often required to save the patient's life. In chronic disease not responding well to medical treatment, elective colectomy will restore the patient to good health. Colectomy is also necessary for certain local complications, such as cancer, severe fistulas, and strictures. Prophylactic colectomy is indicated in patients with long‐standing disease in whom there are factors associated with a high risk of developing cancer of the large bowel. For all these indications, it is our opinion that single‐stage proctocolectomy is the operation of choice in the great majority of patients. Finally, we consider that the best results are obtained when the physician and the surgeon work together in the closest possible cooperation.
Realistic expectations of surgical treatment of aortic dissections: The stanford experience
Authors: Craig Miller D. , Stinson Edward B. , Shumway Norman E.
Published: May 2006

Over a 16‐year span, 125 unselected patients with acute and chronic aortic dissections underwent uniform surgical treatment. Fifty‐three had acute type A(Ac‐A), 29 had chronic type A(Ch‐A), 20 had acute type B(Ac‐B), and 23 had chronic type B(Ch‐B) dissections. Major preoperative complications were encountered frequently; 14% of dissections had ruptured. All patients underwent aortic replacement with tubular grafts; concomitant aortic valve replacement (AVR) was performed in 11% of the Ac‐A patients and 38% of Ch‐A patients. The primary intimal tear was resected in 78% of operations. Follow‐up averaged 4.5 years and extended beyond 13 years. Overall operative mortality rate was 34% for Ac‐A, 14% for Ch‐A, 45% for Ac‐B, and 22% for Ch‐B patients. Between January, 1974 and October, 1979 these mortality rates (63 patients Ac‐A, 17 Ch‐A, 7 Ac‐B, 12 Ch‐B) declined to 22%, 18%, 14%, and 17%, respectively. Actuarial survival rates (± SEM) for the entire series were 54±5% at 5 years and 26±7% at 10 years. Excluding operative deaths, these were 76±5% and 37±10% at similar intervals. Multiple preoperative variables correlated with both operative risk and long‐term survival, but the survival rate appeared not to be influenced by whether AVR was performed (type A patients) or by whether the primary intimal tear was resected (all patients). No differences in long‐term survival were evident between the 4 subgroups of patients. Survivors generally sustained satisfactory functional results and experienced good rehabilitation.

The results of this investigation argue for immediate operative treatment of acute type A dissections and, possibly, of acute type B dissections as well. Furthermore, surgical resection of symptomatic and/or expanding chronic type A and chronic type B dissections ameliorates symptoms and provides satisfactory long‐term survival. Surgical treatment does not “cure” the disease. However, as evidenced by the declining operative risk, acceptable durability of repair, and improved long‐term survival, surgical therapy can result in salvage of a substantial majority of patients with life threatening dissection of the aorta.
Changes in dorsal root ganglion CGRP expression in a chronic inflammatory model of the rat knee joint: Differential modulation by rofecoxib and paracetamol
Authors: Staton Penny C. , Wilson Alex W. , Bountra Chas , Chessell Iain P. , Day Nicola C.
Published: May 2006

Neuropeptide‐expressing small diameter sensory neurones are thought to be vital in generating inflammatory hyperalgesic responses. Within the dorsal root ganglion (DRG), both the levels of the neuropeptide calcitonin gene‐related peptide (CGRP) and the numbers of CGRP‐immunoreactive (CGRP‐IR) DRG neurones have been shown to increase in a number of acute adjuvant‐induced inflammatory pain models. The aim of this study was to look specifically at changes in numbers of CGRP‐IR DRG neurones in a chronic model of inflammatory joint pain following complete Freund's adjuvant (CFA) injection into the rat knee. In this model, there were significant increases in the number of ipsilateral CGRP‐IR small DRG neurones at days 1, 16 and 35 following intra‐articular CFA, compared to saline‐injected sham animals. This correlated with the behavioural readouts of hypersensitivity and knee joint inflammation at the same time points. There was also a significant increase in the number of ipsilateral CGRP‐IR medium DRG neurones and contralateral CGRP‐IR small DRG neurones at day 1. Following dosing of CFA‐injected rats with rofecoxib (Vioxx™) or paracetamol, there was a significant decrease in the number of ipsilateral CGRP‐IR small and medium DRG neurones in rofecoxib‐ but not paracetamol‐treated rats. These data also correlated with behavioural readouts where hypersensitivity and knee joint inflammation were significantly reduced by rofecoxib but not paracetamol treatment. In conclusion, these data show that changes in ipsilateral CGRP expression within small DRG neurones are consistent with behavioural readouts in both time course, rofecoxib and paracetamol studies in this model of chronic inflammatory pain.
Life events exposure before a treated major depressive episode depends on the number of past episodes
Authors: Corruble Emmanuelle , Falissard Bruno , Gorwood Philip
Published: May 2006

A cross-sectional survey investigated the relationship between the number of previous depressive episodes and life events, testing the kindling hypothesis, in a sample of 13,377 treated patients with unipolar depression. A linear decline of average life events exposure is observed for more frequent past episodes, even when age, gender and severity are taken into account.
Characterization of the expression of the hypoxia‐induced genes neuritin, TXNIP and IGFBP3 in cancer
Authors: Le Jan Sébastien , Le Meur Nolwenn , Cazes Aurélie , Philippe Josette , Le Cunff Martine , Léger Jean , Corvol Pierre , Germain Stéphane
Published: May 2006

By triggering an adaptive response to hypoxia which is a common feature of tumor microenvironments, endothelial cells contribute to the onset of angiogenic responses involved in tumor growth. Therefore, identifying hypoxic markers represent a challenge for a better understanding of tumor angiogenesis and for the optimization of anti‐angiogenic therapeutic strategy. Using representational difference analysis combined with microarray, we here report the identification of 133 hypoxia‐induced transcripts in human microendothelial cells (HMEC‐1). By Northern blot, we confirm hypoxia‐induced expression of insulin‐like growth factor binding protein 3 (igfbp3), thioredoxin‐interacting protein (txnip), neuritin (nrn1). Finally, by performing in situ hybridization on several types of human tumors, we provide evidence for nrn1 and txnip as hypoxic perinecrotic markers and for igfbp3 as a tumor endothelial marker. We propose these hypoxia‐induced genes could represent relevant prognostic tools and targets for therapeutic intervention in cancers.
Electron transfer among the CuA‐, heme b‐ and a3‐centers of Thermus thermophilus cytochrome ba3
Authors: Farver Ole , Chen Ying , Fee James A. , Pecht Israel
Published: May 2006

The 1‐methyl‐nicotinamide radical (MNA∗), produced by pulse radiolysis has previously been shown to reduce the CuA‐site of cytochromes aa
3, a process followed by intramolecular electron transfer (ET) to the heme a but not to the heme a
3 [Farver, O., Grell, E., Ludwig, B., Michel, H. and Pecht, I. (2006) Rates and equilibrium of CuA to heme a electron transfer in Paracoccus denitrificans cytochrome c oxidase. Biophys. J. 90, 2131–2137]. Investigating this process in the cytochrome ba
3 of Thermus thermophilus (Tt), we now show that MNA∗ also reduces CuA with a subsequent ET to the heme b and then to heme a
3, with first‐order rate constants 11 200 s−1, and 770 s−1, respectively. The results provide clear evidence for ET among the three spectroscopically distinguishable centers and indicate that the binuclear a
3‐CuB center can be reduced in molecules containing a single reduction equivalent.
The Cellular Effect of a Single Interrupted Suture on Tendon
Authors: WONG J. K. F. , CEROVAC S. , FERGUSON M. W. J. , MCGROUTHER D. A.
Published: May 2006

The effects on cell and matrix morphology of a single interrupted suture are described in rabbit (vascular) and mouse (avascular) digital flexor tendons. This model of tendon injury is reproducible and suitable for quantitative histological analysis. Tendons analysed at day 1, 3, 5, 7 and 14 after wounding demonstrated a well-demarcated “acellular zone” around the suture within 24 hours and persisting over 14 days. The placement of an untied suture in tendon did not produce this effect but tying and releasing the tied knot did. The rapidity of onset suggests that cells move from the zone of injury into less mechanically strained tissue. The acellular zone was apparent in rabbit hind paw flexor tendon which is vascularised and the corresponding tendon in mouse which has no intrinsic blood vessels. This phenomenon highlights biological events that must be considered in parallel with the current trend for multistrand locking flexor tendon suture repairs.
Radiometric validation of the Atmospheric Infrared Sounder over the Antarctic Plateau
Authors: Walden V. P. , Roth W. L. , Stone R. S. , Halter B.
Published: May 2006

Validation of infrared satellite instruments, after they have been launched into orbit, has traditionally relied on views of the relatively warm sea surface. The Antarctic Plateau provides a complementary validation target from space because it is also homogeneous over large areas, yet it is relatively cold. During summer, cloud‐free conditions occur often and the atmospheric humidity is very low with values of total column water vapor around 1 mm. Radiance validation experiments were conducted at Dome C, Antarctica (75°S, 123°E; 3280 m), in January 2003 and again in December 2003/January 2004 for the Atmospheric Infrared Sounder (AIRS). The Polar Atmospheric Emitted Radiance Interferometer (PAERI) measured upwelling and downwelling infrared radiance at the surface during overpasses of NASA's Earth Observing System Aqua satellite. Radiosondes were launched coincidentally with many of these overpasses. These data are used to calculate the outgoing spectral radiance at the top of the atmosphere (TOA), which is then compared with spectral radiance measurements from AIRS in selected frequency bands. At the 95% confidence level, the brightness temperature differences are −0.12 ± 0.24 K (M‐07), −0.15 ± 0.23 K (M‐08), and −0.13 ± 0.24 K (M‐09). These results validate the AIRS radiances at low temperatures (230 to 250 K) relative to the TOA calculations between 788 and 973 cm−1. The cold bias may be partially explained by subvisible or undetected clouds. Ground‐based validation experiments over the Antarctic Plateau can yield valuable information about the low‐radiance performance of infrared satellite instruments. However, one must use ground‐based instruments with a large enough field of view to average over the significant radiance variations that exist across individual snow dunes. Validation of AIRS at low radiance is important because many of the geophysical parameters that are of scientific interest are actually retrieved from low radiance values, including upper tropospheric humidity and properties of high clouds.
Application of an orbital radar sounder model to detecting Martian polar subsurface features
Authors: Xu Yanbin , Cummer Steven A. , Farrell William M.
Published: May 2006

A model to simulate the complete planetary orbital radar sounder problem is presented in this paper. The subsurface features and the ionosphere will not only bring ambiguity to the collected radar sounder data, but also critically affect instrument capabilities. These environmental uncertainties generate a compelling need for meaningful quantitative simulation of the orbital radar sounder problem. Our model combines finite difference time domain (FDTD) and analytical methods and splits the computational volume into two pieces owing to the large size of the simulation space. The near‐surface and subsurface fields are computed with the FDTD method to improve the simulation flexibility of the surface and subsurface features. The two‐way ionospheric propagation is treated with the simpler but accurate near‐far field transformation method to maximize computational efficiency. With the capability of including all of the important radar sounder effects that can be difficult to compute analytically, the model enables accurate numerical experimentation with realistic instrumental and environmental parameters, and can handle an arbitrarily two‐dimensionally inhomogeneous ground and an arbitrary ionospheric profile. Simulation results are given on the application of detecting Martian polar subsurface water, and we place bounds on the ionospheric losses and the subsurface conductivity through which water can be detected. We find that a basal lake located ∼2.5 km below the surface is near the limit of detectability. The ionospheric losses should be no larger than 10 dB and the average subsurface conductivity should be no larger than 4 × 10−6 S/m for the basal lake to be detectable.
Glaciers and Ice Sheets Mapping Orbiter concept
Authors: Jezek Kenneth , Rodríguez Ernesto , Gogineni Prasad , Freeman Anthony , Curlander John , Wu Xiaoqing , Paden John , Allen Chris
Published: May 2006

We describe a concept for a spaceborne radar system designed to measure the surface and basal topography of terrestrial ice sheets and to determine the physical properties of the glacier bed. Our primary objective is to develop this new technology for obtaining spaceborne estimates of the thickness of the polar ice sheets with an ultimate goal of providing essential information to modelers estimating the mass balance of the polar ice sheets and estimating the response of ice sheets to changing climate. Our new technology concept employs VHF and P‐band interferometric radars using a novel clutter rejection technique for measuring surface and bottom topographies of polar ice sheets from aircraft and spacecraft. Our approach will enable us to reduce signal contamination from surface clutter, measure the topography of the glacier bed at better than 1 km intervals with an accuracy of 20 m, and paint a picture of variations in bed characteristics. The technology will also have applications for planetary exploration including studies of the Martian ice caps and the icy moons of the outer solar system. Through the concept developed here we believe that we can image the base and map the three‐dimensional basal topography beneath an ice sheet at up to 5 km depth.
Orientation and distribution of recent gullies in the southern hemisphere of Mars: Observations from High Resolution Stereo Camera/Mars Express (HRSC/MEX) and Mars Orbiter Camera/Mars Global Surveyor (MOC/MGS) data
Authors: Balme Matthew , Mangold Nicolas , Baratoux David , Costard Francois , Gosselin Matthieu , Masson Philippe , Pinet Patrick , Neukum Gerhard
Published: May 2006

Geologically recent small gullies on Mars display morphologies consistent with erosion by water or by debris flows. Suggested formation models are divided into two main categories: (1) groundwater or (2) melting of near‐surface ice/snow sourced from the atmosphere. We have measured location and orientation and recorded the local contexts of gullies to constrain the likely models of gully formation. More than 22,000 Mars Orbiter Camera Narrow Angle (MOC NA) and >120 Mars Express High Resolution Stereo Camera (HRSC) images in the southern hemisphere were searched for gullies. Discrete gullied slope sections with consistent orientation were recorded rather than individual gullies. Slope setting (impact crater, valley wall, etc.), location, and orientation were recorded for each slope section. More than 750 MOC images with gullies (>900 distinct gullied slope sections) and more than 40 HRSC images (>380 distinct gullied slope sections) were identified. From both MOC and HRSC, gullies were found to be most common between −30 and −50 degrees latitude and to have an overall pole facing preference. The preferred gully orientation for HRSC is southeast rather than south in MOC, owing to illumination effects that make gullies difficult to detect on south‐ to southwest‐facing slopes in HRSC. In both MOC and HRSC surveys, higher‐latitude gullies show less preference for pole facing than those at mid latitudes. Both data sets produced similar results, demonstrating that our data are reliable. We suggest that the observed latitudinal and orientation distributions of gullies show that insolation and atmospheric conditions play a key role in gully formation.
Effects of the resonant modes on the magnetic footprint patterns in a tokamak wall
Authors: da Silva Elton C. , Roberto Marisa , Caldas Iberê L. , Viana Ricardo L.
Published: May 2006

Magnetic footprints, or deposition patterns of chaotic magnetic field lines in a tokamak wall, are studied for a configuration with resonant modes due to an ergodic limiter. The formation of magnetic footprints using a nontwist symplectic mapping for a nonmonotonic safety factor radial profile is investigated numerically. The radial position of the resonant mode we focus on changes drastically the magnetic footprints. Deeper resonant modes produce a concentrated field line deposition pattern, whereas a resonant mode closer to the plasma edge yields a broader deposition pattern. Although these shearless equilibria can present robust transport barriers, the magnetic footprints are still present and can deteriorate the plasma confinement quality.
Effect of noise on the classical and quantum mechanical nonlinear response of resonantly coupled anharmonic oscillators
Authors: Goj Anne , Loring Roger F.
Published: May 2006

Multidimensional infrared spectroscopy probes coupled molecular vibrations in complex, condensed phase systems. Recent theoretical studies have focused on the analytic structure of the nonlinear response functions required to calculate experimental observables in a perturbative treatment of the radiation-matter interaction. Classical mechanical nonlinear response functions have been shown to exhibit unbounded growth for anharmonic, integrable systems, as a consequence of the nonlinearity of classical mechanics, a feature that is absent in a quantum mechanical treatment. We explore the analytic structure of the third-order vibrational response function for an exactly solvable quantum mechanical model that includes some of the important and theoretically challenging aspects of realistic models of condensed phase systems: anharmonicity, resonant coupling, fluctuations, and a well-defined classical mechanical limit.
Stacking of oligo- and polythiophene cations in solution: Surface tension and dielectric saturation
Authors: Scherlis Damián A. , Fattebert Jean-Luc , Marzari Nicola
Published: May 2006

The stacking of positively charged (or doped) terthiophene oligomers and quaterthiophene polymers in solution is investigated applying a recently developed unified electrostatic and cavitation model for first-principles calculations in a continuum solvent. The thermodynamic and structural patterns of the dimerization are explored in different solvents, and the distinctive roles of polarity and surface tension are characterized and analyzed. Interestingly, we discover a saturation in the stabilization effect of the dielectric screening that takes place at rather small values of ϵ0. Moreover, we address the interactions in trimers of terthiophene cations, with the aim of generalizing the results obtained for the dimers to the case of higher-order stacks and nanoaggregates.
The structures of ozone and HOx radicals in aqueous solution from combined quantum/classical molecular dynamics simulations
Authors: Chalmet Stéphanie , Ruiz-López Manuel F.
Published: May 2006

Ozone in aqueous solution decomposes through a complex mechanism that involves initial reaction with a hydroxide ion followed by formation of a variety of oxidizing species such as HO, HO2, and HO3 radicals. Though a number of hydrogen-bonded complexes have been described in the gas phase, both theoretically and experimentally, the structures of ozone and HOx in liquid water remain uncertain. In this work, combined quantum/classical computer simulations of aqueous solutions of these species have been reported. The results show that ozone undergoes noticeable electron polarization but it does not participate in hydrogen bonds with liquid water. The main contribution of the solvation energy comes from dispersion forces. In contrast, HOx radicals form strong hydrogen bonds. They are better proton donors but weaker proton acceptors than water. Their electronic and geometrical structures are significantly modified by the solvent, especially in the case of HO3. In all cases, fluctuations in amplitudes of electronic properties are considerable, suggesting that solvent effects might play a crucial role on oxidation mechanisms initiated by ozone in liquid water. These mechanisms are important in a broad range of domains, such as atmospheric processes, plant response to ambient ozone, and medical and industrial applications.
The spectrum of CH2 near 1.36 and 0.92μm: Reevaluation of rotational level structure and perturbations in ã(010)
Authors: Kobayashi Kaori , Hall Gregory E. , Sears Trevor J.
Published: May 2006

The spectrum of methylene in the 1.3–1.4 and 0.89–0.94μm wavelength regions has been recorded in absorption using frequency-modulated cw diode and Ti:sapphire laser sources. The spectral lines have Doppler-limited resolution and have been assigned to bands in the b̃B11←ãA11 electronic spectrum of the radical. In three of the four bands studied, the lower state is the bend excited, υ2″=1, level of the ã state and two of the upper levels lie below the energy of the degenerate linear configuration of the b̃∕ã pair. Together with previously measured data pertaining to υ2″=1, the data have been used to refine the precision of the experimentally determined rotational structure in this level. Although several K″=1 levels do show shifts of more than 0.1–0.2cm−1, multiple strong perturbations due to near-resonant background X̃B13 rovibrational levels, such as are known to occur in the ãA11, υ2″=0 level have not been found in υ2″=1. Absorption lines due to the predominantly triplet X̃(040) 414 level, responsible for most of the perturbation of ã(010) 515, have been identified in the spectra. The data also fix the energies of the b̃(0,0,0)2, ã(0,7,0)1, b̃(0,2,0)3, and ã(0,10,0)2 upper vibronic levels, where the numbers in parentheses are the vibrational quantum numbers with superscript K, the projection of the total angular momentum on the a-inertial axis.
Metamagnetic shape memory effect in a Heusler-type Ni43Co7Mn39Sn11 polycrystalline alloy
Authors: Kainuma R. , Imano Y. , Ito W. , Morito H. , Sutou Y. , Oikawa K. , Fujita A. , Ishida K. , Okamoto S. , Kitakami O. , Kanomata T.
Published: May 2006

Shape memory and magnetic properties of a Ni43Co7Mn39Sn11 Heusler polycrystalline alloy were investigated by differential scanning calorimetry, the sample extraction method, and the three-terminal capacitance method. A unique martensitic transformation from the ferromagnetic parent phase to the antiferromagneticlike martensite phase was detected and magnetic-field-induced “reverse” transition was confirmed in a high magnetic field. In addition, a large magnetic-field-induced shape recovery strain of about 1.0% was observed to accompany reverse martensitic transformation, and the metamagnetic shape memory effect, which was firstly reported in a Ni45Co5Mn36.7In13.3 Heusler single crystal, was confirmed in a polycrystalline specimen.
Single shot positron annihilation lifetime spectroscopy
Authors: Cassidy D. B. , Deng S. H. M. , Tanaka H. K. M. , Mills A. P.
Published: May 2006

Recent developments in positron trapping technology have made possible experimentation with dense interacting positronium gases. Along with these capabilities comes a need for suitable measurement techniques, and accordingly we have developed a method to measure positronium lifetimes from a single intense burst of positrons. Our method is based on recording the anode signal from a photomultiplier with a fast oscilloscope following a short-time positron burst which allows us to measure transitory effects as well as high density positronium interactions.
Whispering gallery mode of modified octagonal quasiperiodic photonic crystal single-defect microcavity and its side-mode reduction
Authors: Lee Po-Tsung , Lu Tsan-Wen , Tsai Feng-Mao , Lu Tien-Chang , Kuo Hao-Chung
Published: May 2006

Single-mode lasing action is obtained from a modified octagonal quasiperiodic photonic crystal single-defect microcavity which supports a well-confined whispering gallery mode with ultralow threshold and high-quality factor. Side-mode reduction is achieved by inserting a central air-hole in the cavity region.
Activation of FIP1L1-PDGFRα requires disruption of the juxtamembrane domain of PDGFRα and is FIP1L1-independent
Authors: Stover Elizabeth H. , Chen Jing , Folens Cedric , Lee Benjamin H. , Mentens Nicole , Marynen Peter , Williams Ifor R. , Gilliland D. Gary , Cools Jan
Published: May 2006

Genetic abnormalities that result in expression of chimeric tyrosine kinase proteins such as BCR-ABL1 and ETV6-PDGFRβ are common causes of hematopoietic malignancies. The paradigm for constitutive activation of these fusion tyrosine kinases is enforced homodimerization by self-association domains present in the fusion partner proteins. The unique interstitial deletion on chromosome 4q12 that leads to expression of the FIP1L1-PDGFRα fusion tyrosine kinase was recently identified as a cause of chronic eosinophilic leukemia. In this report, we demonstrate that FIP1L1 is completely dispensable for PDGFRα activation
in vitro
and
in vivo
. Instead, truncation of PDGFRα between two conserved tryptophan residues in the juxtamembrane (JM) domain is required for kinase activation and transforming potential of FIP1L1-PDGFRα. The presence of a complete JM domain in FIP1L1-PDGFRα is inhibitory, but this autoinhibition can be overcome by enforced homodimerization. Similar effects of the JM domain in the context of PDGFRβ were observed. These results suggest that disruption of the autoinhibitory JM domain is an alternative, dimerization-independent mechanism by which chimeric tyrosine kinases are constitutively activated and induce leukemogenesis.
Does bladder voiding during sleep and wakefulness change the behavioural state of infants?
Authors: ZOTTER HEINZ , SAUSENG WERNER , URLESBERGER BERNDT , MUELLER WILHELM , PICHLER GERHARD , KERBL REINHOLD
Published: May 2006

Aim: To evaluate whether bladder voiding in healthy infants is accompanied by body movements or any changes in heart rate (HR), respiratory frequency (RF) or electroencephalogram (EEG) frequency during sleep and during wakefulness. Methods: Polygraphic recordings were performed on 33 healthy infants (17 female) born at term. The infants' age at study entry was 41±10 d, and actual body weight was 4876±403 g (mean±SD). Bladder voiding was recorded by an adapted enuresis detector connected to the polygraphic computer unit. Results: Awakening was observed in 12 (36%) infants 77±9 s before bladder voiding. Twenty‐one infants (64%) continued sleeping during bladder voiding. In sleeping infants, bladder voiding occurred during non‐REM sleep only, and was accompanied by a cortical arousal. During wakefulness, RF was lower, and HR and EEG frequency were higher, but stayed constant during bladder voiding.

Conclusion: Our observations demonstrate that bladder voiding in healthy infants during sleep is accompanied by body movements and changes in HR and EEG frequency, indicating cortical arousals, whereas during wakefulness these changes cannot be observed.
Paediatric metabolic syndrome and associated anthropometric indices: The CASPIAN Study
Authors: KELISHADI ROYA , ARDALAN GELAYOL , GHEIRATMAND RIAZ , ADELI KHOSROW , DELAVARI ALIREZA , MAJDZADEH REZA ,   For The Caspian Study Group
Published: May 2006

Aim:To determine the prevalence of paediatric metabolic syndrome (MetS) and its best predictive anthropometric index.Methods:This national study was conducted among 4811 students (2248 boys and 2563 girls) aged 6–18 y. This is the first study of its kind in Iran and, to our knowledge, in Asia as well. Two definitions were used for the MetS: type A was defined based on criteria analogous to ATP III, and type B was defined according to the cut‐offs obtained from NHANES III. Both types A and B define high fasting blood sugar as > 100 mg/dl and systolic/diastolic blood pressure as > 90th percentile.Results:The mean (SD) age of students studied was 12.07±3.2 y. MetS type A was seven times more prevalent than type B (14% vs 2%, respectively, p<0.0001), and had no significant gender difference. The most frequent components of both definitions of the MetS were low high‐density lipoprotein cholesterol (HDL‐C) and high triglyceride (TG). Waist circumference (WC) and waist‐to‐hip ratio (WHR) had the strongest and weakest associations, respectively, with the MetS.

Conclusion:Establishment of a uniform set of criteria for the MetS in children is needed. Routine WC measurement in the paediatric population may be clinically useful.
On the cloaking effects associated with anomalous localized resonance
Authors: Milton Graeme W , Nicorovici Nicolae-Alexandru P
Published: May 2006

Regions of anomalous localized resonance, such as occurring near superlenses, are shown to lead to cloaking effects. This occurs when the resonant field generated by a polarizable line or point dipole acts back on the polarizable line or point dipole and effectively cancels the field acting on it from outside sources. Cloaking is proved in the quasistatic limit for finite collections of polarizable line dipoles that all lie within a specific distance from a coated cylinder having a shell permittivity

where

is the permittivity of the surrounding matrix, and

is the core permittivity. Cloaking is also shown to extend to the Veselago superlens outside the quasistatic regime: a polarizable line dipole located less than a distance
d
/2 from the lens, where
d
is the thickness of the lens, will be cloaked due to the presence of a resonant field in front of the lens. Also a polarizable point dipole near a slab lens will be cloaked in the quasistatic limit.
Bovine respiratory syncytial virus lacking the virokinin or with a mutation in furin cleavage site RA(R/K)R109 induces less pulmonary inflammation without impeding the induction of protective immunity in calves
Authors: Valarcher J.-F. , Furze J. , Wyld S. G. , Cook R. , Zimmer G. , Herrler G. , Taylor G.
Published: May 2006

The BRSV fusion (F) protein is cleaved at two furin consensus sequence sites, resulting in the generation of disulphide-linked F1 and F2 subunits and the release of an intervening peptide of 27 amino acids (pep27), which is converted into a biologically active tachykinin (virokinin). The role of the virokinin and the importance of one of the furin cleavage sites, FCS-2 [RA(R/K)R109], in the pathogenesis of BRSV infection and in the subsequent development of immunity was studied in gnotobiotic calves infected with a recombinant BRSV (rBRSV) lacking pep27 (rBRSVΔp27) or with rBRSV108/109, which contains two amino acid substitutions in FCS-2 (RANN109). Although replication of the mutant viruses and the parental wild-type (WT) rBRSV in the lungs was similar, the extent of gross and microscopic lesions induced by the mutant viruses was less than that induced by WT rBRSV. Furthermore, the numbers of eosinophils in the lungs of calves infected with the mutant viruses were significantly less than that in calves infected with WT virus. These observations suggest a role for the virokinin in the pathogenesis of BRSV infection. Following mucosal immunization with rBRSVΔp27, the levels of BRSV-specific serum antibodies were similar to those induced by WT virus. In contrast, the level of neutralizing antibodies induced by rBRSV108/109 was 10-fold lower than that induced by WT virus. Nevertheless, resistance to BRSV challenge induced by the mutant and WT viruses was similar, suggesting that neither pep27 nor FCS-2 plays a major role in the induction of protective immunity.