bluuebunny/crossref_metadata_2025 huggingface dataset:
Seismic velocity and attenuation structures in the top 400 km of the Earth's inner core along equatorial paths
Authors: Yu Wen‐che , Wen Lianxing
Published: July 2006

We study seismic velocity and attenuation structures in the top 400 km of the Earth's inner core based on modeling of differential traveltimes, amplitude ratios, and waveforms of the PKiKP‐PKIKP phases observed at the epicentral distance range of 120°–141° and the PKPbc‐PKIKP phases observed at the distance range of 146°–160° along equatorial paths. Our data are selected from the seismograms recorded in the Global Seismographic Network from 1990 to 2001 and many regional seismic networks. The observed PKiKP‐PKIKP and PKPbc‐PKIKP phases exhibit distinctive “east‐west” hemispheric patterns: (1) At the distance ranges of 131°–141° and 146°–151°, PKIKP phases arrive about 0.3 s earlier than the theoretical arrivals based on the Preliminary Reference Earth Model (PREM) for the PKIKP phases sampling the “eastern hemisphere” (40°E–180°E) of the inner core and about 0.4 s later for those sampling the “western hemisphere” (180°W–40°E). At the distance range of 151°–160°, PKIKP phases arrive about 0.7 s earlier than the predicted arrivals based on PREM for those sampling the eastern hemisphere and about 0.1 s later for those sampling the western hemisphere. (2) Amplitude ratios of the PKIKP/PKiKP phases at the distance range of 131°–141° and of the PKIKP/PKPbc phases at the distance range of 146°–151° are, in general, smaller for the PKIKP phases sampling the eastern hemisphere than for those sampling the western hemisphere. At distances greater than 151°, the PKIKP/PKPbc amplitude ratios become indistinguishable for the two hemispheres. These observations can be best explained by two different types of seismic velocity and attenuation models along equatorial paths, one for each hemisphere, in the top 400 km of the inner core. For the eastern hemisphere, the velocity structure has a velocity increase of 0.748 km/s across the inner core boundary (ICB), a small velocity gradient of 0.0042 (km/s)/100 km in the top 235 km, followed by a steeper velocity gradient of 0.1 (km/s)/100 km extending from 235 km to 375 km, and a velocity gradient of 0.01 (km/s)/100 km in the deeper portion of the inner core; the attenuation structure has an average Q value of 300 in the top 300 km and an average Q value of 600 in the deeper portion of the inner core. For the western hemisphere, the velocity structure has a velocity increase of 0.645 km/s across the ICB and a velocity gradient of 0.049 (km/s)/100 km in the top 375 km; the attenuation structure has an average Q value of 600 in the top 375 km of the inner core. Our results suggest that the inner core hemispheric variations in velocity extend deeper than 375 km below the ICB and the top 235 km of the inner core in the eastern hemisphere is anomalous compared to the rest of the inner core in having a small velocity gradient, high velocity, and high attenuation.
Stratospheric global winds on Titan at the time of Huygens descent
Authors: Kostiuk T. , Livengood T. A. , Sonnabend G. , Fast K. E. , Hewagama T. , Murakawa K. , Tokunaga A. T. , Annen J. , Buhl D. , Schmülling F. , Luz D. , Witasse O.
Published: July 2006

Measurements of stratospheric zonal winds on Titan were made in preparation for and during the time of the descent of the Huygens Probe into Titan's atmosphere on 14 January 2005. Fully resolved emission lines from ethane near 11.7 μm were measured on the east, center, and west positions on Titan using the NASA/GSFC Heterodyne Instrument for Planetary Wind And Composition, HIPWAC, mounted on the National Astronomical Observatory of Japan 8.2 m Subaru Telescope on Mauna Kea, Hawaii. Analysis of the Doppler shifts of the emission line shapes yielded mean prograde gas velocity ∼60 ± 65 m/s at altitudes below ∼120 km (∼5 mbar). This result is consistent with retrievals from the Huygens Doppler Wind Experiment and from other observations near this altitude range. Current spectral line shapes, however, differed significantly from those obtained in similar measurements on Subaru in 2004 and on the NASA IRTF in 1993–1996, which retrieved prograde zonal winds 190 ± 90 m/s at 230 km (∼0.4 mbar). The cores of the emission lines, which probe the high‐altitude region, could not be fitted as before to retrieve wind directly using the accepted atmospheric model for Titan. They imply an approximately tenfold increase in ethane mole fraction (1.2 × 10−4) with strong wind shear above the stratopause, providing a potential probe of the lower mesosphere and possible evidence of temporal and spatial variability. Results contribute to coordinated measurements of winds by various techniques providing information on the altitude distribution of wind velocity in Titan's atmosphere from near the surface to the lower mesosphere.
Sexual Regimes and Migration Controls: Reproducing the Irish Nation-State in Transnational Contexts
Authors: Luibhéid Eithne
Published: July 2006

This article examines the ways that state sexual regimes intersect with migration controls to re-make exclusionary nation-states and geopolitical hierarchies among women. I focus on two important Irish Supreme Court rulings: the X case (1992) and the O case (2002), respectively. X was a raped, pregnant, 14-year-old who sought an abortion in Britain. While the Supreme Court ultimately permitted her to procure an abortion, women's right to travel across international borders without government inquiry into their reproductive status came into question. The O case concerned a Nigerian asylum seeker who invoked the fact that she was pregnant in an effort to avoid deportation. The Supreme Court, however, affirmed that she could be deported, despite the Irish Constitution's pledge to protect the ‘right to life of the unborn.’ Considered together, these cases reveal how overlapping sexual/migration control regimes both reinscribe hierarchies among women based on geopolitical location, and rebound the exclusionary nation-state despite growing transnationalism.
Moral Ambivalence and Irregular Practices: Contextualizing Male-to-Male Sexualities in Calcutta/India
Authors: Boyce Paul
Published: July 2006

Male-to-male sexuality in India has been described as both heavily stigmatized and implicitly tolerated. This paper examines these apparently contradictory attitudes, arguing that they reflect broader moral ambivalence about homosexuality in Indian culture and society. While the effects of homophobia in India are very real, simultaneous social latitude allows for relatively un-scrutinized same-sex sexual contact. The paper explores this scenario as a post-colonial legacy and considers the consequences for contemporary sexual subjectivity, particularly in respect of irregular responses to emerging gay identities and socially ambiguous male-to-male sexualities. Conceiving of men who have sex with men as subject to both prejudice and tolerance raises complex questions for HIV/AIDS related policy, programming and activism. The paper argues that understanding male-to-male sexualities in India as practiced within a climate of ambiguous moral censure offers critical insights for the future promotion of health.
Ab initio prediction of the potential energy surface and vibration-rotation energy levels of BeH2
Authors: Koput Jacek , Peterson Kirk A.
Published: July 2006

The equilibrium structure and potential energy surface of beryllium dihydride BeH2 in its ground electronic state have been determined from highly accurate ab initio calculations. The vibration-rotation energy levels of three isotopomers BeH2, BeD2, and BeHD were predicted using the variational method. The calculated spectroscopic constants are in remarkably good agreement with the existing experimental data (sub-cm−1 accuracy) and should be useful in a further analysis of high-resolution vibration-rotation spectra of all three isotopomers.
Response to “Comment on ‘Global thermodynamics of hydrophobic cavitation, dewetting, and hydration’  [J. Chem. Phys. 123, 184504 (2005)]”
Authors: Ben-Amotz Dor
Published: July 2006

This reply clarifies the difference between the entropy convergence and zero-crossing temperatures of hydrophobic solutes in water, as well as the relation of the latter temperature to hydrophobic dewetting, using the aqueous partial molar volume of methane at high temperatures as an example.
How does solvent molecular size affect the microscopic structure in polymer solutions?
Authors: Li Yunqi , Huang Qingrong , Shi Tongfei , An Lijia
Published: July 2006

Monte Carlo simulation has been used to investigate the effects of linear solvent molecular size on polymer chain conformation in solutions. Increasing the solvent molecular size leads to shrinkage of the polymer chains and increase of the critical overlap concentrations. The root-mean-square radius of gyration of polymer chains (Rg) is less sensitive to the variation of polymer concentration in solutions of larger solvent molecules. In addition, the dependency of Rg on polymer concentration under normal solvent conditions and solvent molecular size is in good agreement with scaling laws. When the solvent molecular size approaches the ideal end-to-end distance of the polymer chain, an extra aggregation of polymer chains occurs, and the solvent becomes the so-called medium-sized solvent. When the size of solvent molecules is smaller than the medium size, the polymer chains are swollen or partially swollen. However, when the size of solvent molecules is larger than the medium size, the polymer coils shrink and segregate, enwrapped by the large solvent molecules.
Time-of-flight secondary ion mass spectroscopy analysis of Na adatoms interacting with water-ice film
Authors: Souda Ryutaro
Published: July 2006

The origins of a slow reaction rate between the sodium adatoms and the water-ice film have been investigated by analyzing the surface composition using time-of-flight secondary ion mass spectroscopy in the temperature range of 13–230K. An unhydrated NaOH layer is formed at the water-Na interface at 13K which is followed by the growth of the metallic Na layer, whereas domains of both NaOH and unreacted Na are created only in the multilayer regime at 100K. The NaOH layer plays a role as a separator between the water and Na layers, and its poor solubility in water is responsible for the small reaction rate of Na on glassy water. The solubility of NaOH in the deeply supercooled liquid water is low as well, but the mobile water molecules diffusing to the surface react with the Na adatoms, thereby quenching the growth of the metallic Na overlayer.
Description of depolarization effects in double-quantum solid state nuclear magnetic resonance experiments using multipole-multimode Floquet theory
Authors: Ramachandran Ramesh , Griffin Robert G.
Published: July 2006

Using an analytical model based on multipole-multimode Floquet theory (MMFT), we describe the polarization loss (or depolarization) observed in double-quantum (DQ) dipolar recoupling magic angle spinning (MAS) experiments. Specifically, the factors responsible for depolarization are analyzed in terms of higher order corrections to the spin Hamiltonian in addition to the usual phenomenological decay rate constant. From the MMFT model and the effective Hamiltonians, we elucidate the rationale behind the inclusion of a phenomenological damping term in DQ recoupling experiments. As a test of this theoretical approach, the recoupling efficiency of one class of C13–C13 and C13–N15 resonance width dipolar recoupling experiments are investigated at different magnetic field strengths and compared with the more exact numerical simulations. In contrast to existing analytical treatments, the role of higher order corrections is clearly explained in the context of the MMFT approach leading to a better understanding of the underlying spin physics. Furthermore, the analytical model presented herein provides a general framework for describing coherent and incoherent effects in homonuclear and heteronuclear DQ MAS recoupling experiments.
Thermal transport in the DIII-D edge pedestal
Authors: Stacey W. M. , Groebner R. J.
Published: July 2006

A new procedure for inferring χi,eexp in the plasma edge from experimental data and integrated modeling code calculations has been developed that takes into account atomic physics and radiation effects and convective as well as conductive heat flux profiles. Application to DIII-D [J. Luxon, Nucl. Fusion 42, 614 (2002)] shots indicates that proper inference of χi,eexp in the edge pedestal (sharp gradient region) depends on accounting for the variation in electron and ion heat fluxes and in the convective fraction of each over the edge region. The frequently observed steep edge temperature gradients are found to depend as much on the variation in conductive and convective heat fluxes as on a reduction in χi,e. Inferred χi,eexp are compared with theoretical predictions.
Direct computed tomographic reconstruction for directional-derivative projections of computed tomography of diffraction enhanced imaging
Authors: Huang Zhi-Feng , Kang Ke-Jun , Li Zheng , Zhu Pei-Ping , Yuan Qing-Xi , Huang Wan-Xia , Wang Jun-Yue , Zhang Di , Yu Ai-Min
Published: July 2006

X-ray diffraction enhanced imaging based on synchrotron radiation has extremely high sensitivity of weakly absorbing low-Z samples in medical and biological fields. This letter is dedicated to a direct reconstruction algorithm for directional-derivative projections of computed tomography of diffraction enhanced imaging. It is a “one-step” algorithm and does not require any restoration processing compared with the current “two-step” methods. The actual values of the sample’s refractive index decrement can be estimated from its reconstruction images directly. The algorithm is proven by the actual experiment at the Beijing Synchrotron Radiation Facility and the reconstructed images are described finally.
Convergence of Chapman-Enskog calculation of transport coefficients of magnetized argon plasma
Authors: Bruno D. , Catalfamo C. , Laricchiuta A. , Giordano D. , Capitelli M.
Published: July 2006

Convergence properties of the Chapman-Enskog method in the presence of a magnetic field for the calculation of the transport properties of nonequilibrium partially ionized argon have been studied emphasizing the role of the different collision integrals. In particular, the Ramsauer minimum of electron-argon cross sections affects the convergence of the Chapman-Enskog method at low temperature, while Coulomb collisions affect the results at higher temperatures. The presence of an applied magnetic field mitigates the slow convergence for the components affected by the field.
High structural quality InN∕In0.75Ga0.25N multiple quantum wells grown by molecular beam epitaxy
Authors: Ohashi Tatsuo , Holmström Petter , Kikuchi Akihiko , Kishino Katsumi
Published: July 2006

In N ∕ In 0.75 Ga 0.25 N multiple quantum wells (MQWs) were grown by rf plasma-assisted molecular beam epitaxy. The high-resolution transmission electron microscope and x-ray diffraction measurements showed evidence of growth of atomically smooth and sharp interface and good periodicity. Room-temperature photoluminescence emissions from InN quantum wells were observed at the wavelength range from 1.59to1.95μm by changing the well thickness. The unstrained valence band offset of InN∕GaN was estimated to be ΔEv=0.9eV by comparing the experimental transition wavelengths of the MQWs and a theoretical calculation considering strain effects and built-in, mainly piezoelectric, fields.
The response of a capacitively coupled discharge to the formation of dust particles: Experiments and modeling
Authors: Denysenko I. , Berndt J. , Kovacevic E. , Stefanovic I. , Selenin V. , Winter J.
Published: July 2006

The influence of dust particles on the properties of a capacitively coupled Ar–C2H2 discharge is studied both experimentally and theoretically. The results of measurements of the intensity and spatial distribution of the emitted light, the line width of the fast component of Hα line and of the electron density during the particle growth are presented. To analyze the experimental results a one-dimensional discharge model is developed. Using the model the effects of dust grains on the power absorption (taking into account stochastic and Ohmic heating in the plasma sheaths), the optical emission intensity profile, the sheath size, the rf electric field and on the energy of positive ions bombarding the electrodes are investigated. In particular, it is shown that the decrease of the power absorption in the sheaths of complex plasmas is due to the dependence of the stochastic and Ohmic heating in the plasma sheaths on the electron temperature and the current flowing across the discharge plates. The results of the calculations are compared with the available experimental data and found to be in good agreement.
Selective area atomic layer deposition of rhodium and effective work function characterization in capacitor structures
Authors: Park K. J. , Parsons G. N.
Published: July 2006

Atomic layer deposition (ALD) of rhodium was investigated using rhodium(III) acetylacetonate and oxygen, and capacitance versus voltage is used to extract the effective work function in metal/insulator/semiconductor structures. Self-limiting growth was observed, and the resistivity of Rh deposited at 300°C is ∼10μΩcm, approximately a factor of 2 larger than the Rh bulk resistivity (4.3μΩcm). Selective area deposition is achieved using patterned resist layers, enabling capacitor fabrication without Rh etching. In the as-deposited state, the effective work function was measured to be 5.43 and 5.25eV on SiO2 and HfO2 dielectrics, respectively. The ALD Rh films formed under conditions used likely contain residual oxygen which can affect oxygen vacancy creation and the effective work function at the metal/dielectric interface.
Degradation-robust single mode continuous wave operation of 1.46μm metamorphic quantum dot lasers on GaAs substrate
Authors: Kettler T. , Karachinsky L. Ya. , Ledentsov N. N. , Shchukin V. A. , Fiol G. , Kuntz M. , Lochmann A. , Schulz O. , Reissmann L. , Posilovic K. , Bimberg D. , Novikov I. I. , Shernyakov Yu. M. , Gordeev N. Yu. , Maximov M. V. , Kryzhanovskaya N. V. , Zhukov A. E. , Semenova E. S. , Vasil’ev A. P. , Ustinov V. M. , Kovsh A. R.
Published: July 2006

Narrow ridge lasers of 1.5μm range based on InAs∕InGaAs quantum dots grown on metamorphic (In,Ga,Al)As layers deposited on GaAs substrates using defect reduction technique are studied. It is shown that the lasers operate continuous wave (cw) in a single transverse mode. Single-mode 800mW output power in the pulsed regime is obtained for a 6μm ridge width. The dynamic studies of the lasers show a modulation bandwidth of ∼3GHz. Aging tests demonstrate >800h of cw operation at ∼50mW at 10°C (60°C) and >200h at 20°C (70°C) heat sink (junction) temperature without noticeable degradation.
THz spectroscopic characterization of biomolecule/water systems by compact sensor chips
Authors: Kitagawa J. , Ohkubo T. , Onuma M. , Kadoya Y.
Published: July 2006

We demonstrate the terahertz (THz) spectroscopic performance of highly integrated sensor chips based on microstrip lines by measuring biomolecule/water systems. The concentration resolution of the present chips reaches down to 0.05g∕ml. We have confirmed that the number of bound water molecules per biomolecule can be obtained with precision using solid state transmission lines. The chips are highly suitable for the inspection of small amounts of specimen and for the application to a wide range of water rich materials. Our method may therefore be a good candidate for a simple liquid sensor working in the THz regime.
Tuning photonic nanocavities by atomic force microscope nano-oxidation
Authors: Hennessy K. , Högerle C. , Hu E. , Badolato A. , Imamoğlu A.
Published: July 2006

The authors demonstrate a technique to achieve high-precision tuning of photonic crystal nanocavities by atomic force microscope nano-oxidation of the cavity surface. Relative tuning between two nanocavity modes is achieved though careful choice of the oxide pattern, allowing them to restore the spectral degeneracy conditions necessary to create polarization-entangled quantum states. Tuning steps less than the linewidth (1Å) of the high quality factor modes are obtained, allowing for virtually continuous tuning ability.
Spectral and temporal evolutions of ultrashort pulses diffracted through a slit near phase singularities
Authors: Poyyil Veetil Suhas , Viswanathan Nirmal K. , Vijayan C. , Wyrowski Frank
Published: July 2006

The authors present the evolution of ultrashort pulses diffracted through a slit in the complementary space-frequency and space-time domains. Spectral anomalies near phase singularities are found to influence the pulse evolution in the space-time domain. The results of this work have important implications in free-space information transmission.
On the photoluminescence from Si nanocrystals in Er-doped silica by a double-pulse technique
Authors: Borsella E. , Falconieri M. , Gourbilleau F. , Rizk R.
Published: July 2006

The mechanism of photoluminescence (PL) from Si nanocrystals (Si-nc’s) in Er-doped silica is investigated by a double-pulse technique. It is shown that the decay time and the spectral intensity of PL emission from Si-nc’s do not change when Si-nc’s are reexcited by a delayed pulse in the presence of still excited Er ions. Results are compatible with a strong quenching of photoexcited Si-nc’s through trap states and/or Auger-like interaction between Si-nc’s and Er ions, both in the excited states, while PL emission originates from excitonic recombination in Si-nc’s that do not couple to Er3+.
Modulation of competing memory systems by distraction
Authors: Foerde Karin , Knowlton Barbara J. , Poldrack Russell A.
Published: July 2006

Different forms of learning and memory depend on functionally and anatomically separable neural circuits [Squire, L. R. (1992)
Psychol. Rev.
99, 195–231]. Declarative memory relies on a medial temporal lobe system, whereas habit learning relies on the striatum [Cohen, N. J. & Eichenbaum, H. (1993)
Memory, Amnesia, and the Hippocampal System
(MIT Press, Cambridge, MA)]. How these systems are engaged to optimize learning and behavior is not clear. Here, we present results from functional neuroimaging showing that the presence of a demanding secondary task during learning modulates the degree to which subjects solve a problem using either declarative memory or habit learning. Dual-task conditions did not reduce accuracy but reduced the amount of declarative learning about the task. Medial temporal lobe activity was correlated with task performance and declarative knowledge after learning under single-task conditions, whereas performance was correlated with striatal activity after dual-task learning conditions. These results demonstrate a fundamental difference in these memory systems in their sensitivity to concurrent distraction. The results are consistent with the notion that declarative and habit learning compete to mediate task performance, and they suggest that the presence of distraction can bias this competition. These results have implications for learning in multitask situations, suggesting that, even if distraction does not decrease the overall level of learning, it can result in the acquisition of knowledge that can be applied less flexibly in new situations.
Tension-dependent DNA cleavage by restriction endonucleases: Two-site enzymes are “switched off” at low force
Authors: Gemmen Gregory J. , Millin Rachel , Smith Douglas E.
Published: July 2006

DNA looping occurs in many important protein–DNA interactions, including those regulating replication, transcription, and recombination. Recent theoretical studies predict that tension of only a few piconewtons acting on DNA would almost completely inhibit DNA looping. Here, we study restriction endonucleases that require interaction at two separated sites for efficient cleavage. Using optical tweezers we measured the dependence of cleavage activity on DNA tension with 15 known or suspected two-site enzymes (BfiI, BpmI, BsgI, BspMI, Cfr9I, Cfr10I, Eco57I, EcoRII, FokI, HpaII, MboII, NarI, SacII, Sau3AI, and SgrAI) and six one-site enzymes (BamHI, EcoRI, EcoRV, HaeIII, HindIII, and DNaseI). All of the one-site enzymes were virtually unaffected by 5 pN of tension, whereas all of the two-site enzymes were completely inhibited. These enzymes thus constitute a remarkable example of a tension sensing “molecular switch.” A detailed study of one enzyme, Sau3AI, indicated that the activity decreased exponentially with tension and the decrease was ≈10-fold at 0.7 pN. At higher forces (≈20–40 pN) cleavage by the one-site enzymes EcoRV and HaeIII was partly inhibited and cleavage by HindIII was enhanced, whereas BamHI, EcoRI, and DNaseI were largely unaffected. These findings correlate with structural data showing that EcoRV bends DNA sharply, whereas BamHI, EcoRI, and DNaseI do not. Thus, DNA-directed enzyme activity involving either DNA looping or bending can be modulated by tension, a mechanism that could facilitate mechanosensory transduction
in vivo
.
Constitutively activated FLT3 phosphorylates BAD partially through Pim‐1
Authors: Kim Kyu‐Tae , Levis Mark , Small Donald
Published: July 2006

Constitutively activating internal tandem duplication (ITD) mutations of the receptor tyrosine kinase FLT3 (Fms‐like tyrosine kinase 3) play an important role in leukaemogenesis and their presence is associated with a poor prognosis in acute myeloid leukaemia (AML). Examining the anti‐ and pro‐apoptotic proteins in constitutively activated FLT3 signalling in BaF3/ITD and MV4‐11 cells, we found that the level of Bcl‐2 antagonist of cell death (BAD) phosphorylation was greatly decreased in response to FLT3 inhibition. Both Ser‐112 and Ser‐136 of BAD are rapidly dephosphorylated after treatment with the FLT3 inhibitor CEP‐701 in BaF3/ITD and MV4‐11 cells. In confirmation of the cell line data, BAD was highly phosphorylated in both constitutively activated wild‐type and mutant FLT3 primary AML samples, and rapidly dephosphorylated after treatment of the primary samples with CEP‐701. Upstream proteins known to phosphorylate BAD include Akt, extracellular signal‐regulated kinase/mitogen‐activated protein kinase (Erk/MAPK), Pim‐1 and Pim‐2. We and other groups have shown that constitutively activated FLT3 induces multiple signalling pathways, including phosphatidylinositol 3‐kinase (PI3K)/Akt, Erk/MAPK and Janus kinase/signal transducers and activators of transcription (Jak/STAT). Thus, BAD may be a nexus point upon which these multiple signalling pathways converge in FLT3‐mediated cell survival. In support of this, siRNA knockdown of BAD expression in MV4‐11 cells conferred resistance to CEP‐701‐mediated apoptosis. Our data suggests that Pim‐1 is one of the principal kinases mediating the anti‐apoptotic function of FLT3/ITD signalling via the phosphorylation of BAD.
Nine years of enriched CO2 changes the function and structural diversity of soil microorganisms in a grassland
Authors: Drissner D. , Blum H. , Tscherko D. , Kandeler E.
Published: July 2006

To gain insight into microbial function following increased atmospheric CO2 concentration, we investigated the influence of 9 years of enriched CO2 (600 μl litre−1) on the function and structural diversity of soil microorganisms in a grassland ecosystem under free air carbon dioxide enrichment (FACE), as affected by plant species (Trifolium repens L. and Lolium perenne L. in monocultures and mixed culture) and nitrogen (N) supply. We measured biomass and activities of enzymes covering cycles of the most important elements (C, N and P). The microbial community was profiled by molecular techniques of phospholipid fatty acid (PLFA) and denaturing gradient gel electrophoresis (DGGE) analysis. The enrichment in CO2 increased soil microbial biomass (+48.1%) as well as activities of invertase (+36.2%), xylanase (+22.9%), urease (+23.8%), protease (+40.2%) and alkaline phosphomonoesterase (+54.1%) in spring 2002. In autumn, the stimulation of microbial biomass was 25% less and that of enzymes 3–12% less than in spring. Strong correlations between activities of invertase, protease, urease and alkaline phosphomonoesterase and microbial biomass were found. The stimulation of microbial activity in the enriched atmosphere was probably caused by changes in the quantity and kind of root litter and rhizodeposition. The response of soil microorganisms to enriched CO2 was most pronounced under Trifolium monoculture and under greater N supply. The PLFA analysis revealed that total PLFA contents were greater by 24.7% on average, whereby the proportion of bioindicators representative of Gram‐negative bacteria increased significantly in the enriched CO2 under less N‐fertilized Lolium culture. Discriminant analysis showed marked differences between the PLFA profiles of the three plant communities. Shannon diversity indices calculated from DGGE patterns were greater (+12.5%) in the enriched CO2, indicating increased soil bacterial diversity. We conclude that greater microbial biomass and enzyme activity buffer the potential increase in C sequestration occurring from greater C addition in enriched CO2 due to greater mineralization of soil organic matter.
A combination of HbA1c, fasting glucose and BMI is effective in screening for individuals at risk of future type 2 diabetes: OGTT is not needed
Authors: NORBERG M. , ERIKSSON J. W. , LINDAHL B. , ANDERSSON C. , ROLANDSSON O. , STENLUND H. , WEINEHALL L.
Published: July 2006

Objective.  To identify a screening model that predicts high risk of future type 2 diabetes and is useful in clinical practice.

Design and methods.  Incident case‐referent study nested within a population‐based health survey. We compared screening models with three risk criteria and calculated sensitivity, specificity, positive (PPV) and negative (NPV) predictive values and attributable proportion. We used fasting plasma glucose (FPG) alone or with an oral glucose tolerance test (OGTT), glycosylated haemoglobin A (HbA1c) (normal range 3.6–5.3%), body mass index (BMI), triglycerides and family history of diabetes (FHD).

Setting.  Participants in a health survey at all primary care centres (n = 33 336) and subjects with diagnosed type 2 diabetes in primary and hospital care (n = 6088) in Umeå during 1989–2001.

Subjects.  Each of the 164 subjects who developed clinically diagnosed type 2 diabetes (median time to diagnosis of 5.4 years) and 304 sex‐ and age‐matched referents without diabetes diagnosis.

Results.  Screening models with at least one criterion present had sensitivities of 0.90–0.96, specificities of 0.43–0.57 and PPVs of 8–9%. Combinations of the criteria, FPG ≥ 6.1 mmol L−1 (capillary plasma), HbA1c ≥ 4.7% and BMI ≥ 27 in men and BMI ≥ 30 in women, had sensitivities, specificities and PPVs of 0.66%, 0.93% and 32%, and 0.52%, 0.97% and 46% respectively. Using FHD as one of three risk criteria showed comparable results. Addition of triglycerides or OGTT did not improve the prediction.

Conclusions.  The combination of HbA1c, FPG and BMI are effective in screening for individuals at risk of future clinical diagnosis of type 2 diabetes. OGTT or FHD is not necessary.
Diagnostic accuracy of a fibrosis serum panel (FIBROSpect II) compared with Knodell and Ishak liver biopsy scores in chronic hepatitis C patients
Authors: Christensen C. , Bruden D. , Livingston S. , Deubner H. , Homan C. , Smith K. , Oh E. , Gretch D. , Williams J. , McMahon B.
Published: July 2006

Summary.  Liver biopsy is the primary method of assessing liver injury in hepatitis C patients. FIBROSpect II (FS), a diagnostic panel of three extracellular matrix remodelling markers, may be useful as a noninvasive alternative to this procedure. The purpose of this study was to correlate FS results with liver fibrosis scores to determine if this test is sufficiently accurate to be a viable alternative to liver biopsy. A total of 142 serum specimens were evaluated for fibrosis with FS and were compared with Knodell and Ishak fibrosis scores. FS reports an index score ranging from 0.1 to 1.0, which corresponds to the probability of progressive liver fibrosis. Using a FS index cut‐off of 0.42, 50 of 54 patients with Ishak 3–6 were classified as having advanced fibrosis (METAVIR F2–F4) and 58 of 88 patients with Ishak 0–2 as having no/mild fibrosis (METAVIR F0–F1), resulting in a sensitivity of 93%, specificity of 66%, and an overall test accuracy of 76%. With a 38% prevalence of advanced fibrosis, the negative predictive value was 94% and positive predictive value was 63%. A biopsy length of ≥2 cm was associated with higher concordance between FS results and liver fibrosis scores (P = 0.01). FS was clinically useful in ruling out advanced fibrosis in hepatitis C by identifying patients with mild disease in whom treatment could be deferred. The limitation of this test is its decreased sensitivity and specificity in the middle of the test's reporting range between scores of 0.42 and 0.80.
Comment: Number of sample populations required to determine the effects of herbicide resistance on plant growth and fitness
Authors: COUSENS R. D. , GILL G. S. , SPEIJERS E JANE
Published: July 2006

Experiments to determine the relative growth and fitness of herbicide–resistant and susceptible weeds commonly include only a single population of each. It is argued that such limited experimental designs can be misleading and should be avoided. Guidelines are given to aid decisions on choice of number of populations.
Assessment of weed density at an early stage by use of image processing
Authors: ANDREASEN C. , RUDEMO M. , SEVESTRE S.
Published: July 2006

Identification of plants against a soil background using colour images is discussed, and a technique is presented for finding plant segments consisting of crop or weed plants, or both. The problems of overlapping plants and image border effects are explored using techniques developed in stereology. An automatic weed density estimation method is proposed, based on a non–linear regression model and features of the plant segments in an image. The method is applied to a set of images from five barley fields. At present two features of the segments are used: segment area and whether a segment cuts the image border or not. Further, a method is suggested for evaluating the automatic weed density estimation by comparison with an interactive weed density estimator including human judgement. Critical factors and ways of improving the automatic method by including additional features are discussed.
Evaluation of the bioefficacy and leaching of a controlled–release formulation of chlorsulfuron
Authors: Stork P. R.
Published: July 2006

A controlled–release formulation of chlorsulfuron (DT26B) and a conventional granular formulation were compared for their initial bioefficacy and leaching in laboratory and field experiments. Three alkaline soil types, representative of farm soils in SE Australia, were used for these experiments. Laboratory tests of initial bioefficacy using a Mallee sand (pH 7.2) were able to detect, within ED05–95 limits, that approximately 50% of active ingredient remained as a non–available reserve in DT26B immediately after spraying, when compared with the granular formation. There was also an indication that the bioavailable component of active ingredient in DT26B would be sufficient for weed control. This was confirmed at field sites on a Kattyoong sand (pH 7.9) and a Wimmera Grey clay (pH 8.4), after using recommended application rates of chlorsulfuron during the 1994 winter growing season. The formulations produced only marginal differences in control of Lolium rigidum Gaud. The field leaching trials at these sites showed that there can be rapid leaching of chlorsulfuron with only small amounts of rainfall. Under these conditions, there was an overall trend of reduced leaching by DT26B at both trial sites, although these reductions were not significant when compared with the granular formation, A laboratory system designed to measure the mobility of herbicides is described. It was used to impose upon each formulation a greater level of leaching than in the field trials, using Mallee sand columns irrigated with 50 mm day–1 under –50 kPa suction. This test revealed a negligible reduction in leaching of chlorsulfuron by DT26B as compared with the granular formulation. Therefore, although the controlled–release formulation DT26B demonstrated that it could provide a viable alternative for weed control under conventional spraying conditions in arable farming, the agricultural usage of DT26B for the purpose of reducing leaching could not be warranted at its current stage of development.
Rates of chlorsulfuron degradation in three Brazilian oxisols
Authors: RAVELLI A. , PANTANI O. , CALAMAI L. , FUSI P.
Published: July 2006

The degradation of chlorsulfuron was studied in laboratory experiments in three oxisols from south and south–east Brazil. Three soil profiles were sampled by horizon, and classified according to USDA soil taxonomy and the Brazilian system. Degradation assays were made to evaluate the influence of temperature, humidity and liming on chlorsulfuron decomposition. Further experiments were set up to study enhanced biodegradation. Abiotic degradation was also studied in sterile soils, to evaluate, by comparison with non–sterile soils, the role of microorganisms in degradation. The degradation always followed first–order kinetics and was generally faster in samples from A than B horizons. An increase in temperature (from 25 to 40°C) increased chlorsulfuron degradation. Further, an increase in moisture content increased chlorsulfuron degradation in samples from the A horizons of all soils, whereas for two out of three soils, degradation in samples from the B horizon was greater at lower water content. The biotic contribution to degradation was significant only for the soil with higher fertility. Soil liming significantly increased chlorsulfuron half–life in all samples. Significant enhancement of degradation (decrease in half–life on reapplication) was observed only in soil from A horizons, where a higher microbial activity was likely.
Changes of clotting factors (7, 9 and 10) and hepatocyte growth factor in patients with thrombotic microangiopathy after bone marrow transplantation
Authors: Takatsuka Hiroyuki , Nakajima Toshiyuki , Nomura Kaori , Okikawa Yoshiko , Wakae Takeshi , Toda Akinari , Itoi Hisayuki , Okada Masaya , Misawa Mahito , Hara Hiroshi , Ogawa Hiroyasu
Published: July 2006

Abstract: To investigate risk factors for thrombotic microangiopathy (TMA) after bone marrow transplantation (BMT), the levels of three clotting factors (7, 9 and 10) and hepatocyte growth factor (HGF) were measured. Among 46 consecutive patients who underwent BMT, six developed TMA and 40 did not. The levels of the clotting factors and HGF did not differ significantly between the six patients with TMA and the 40 patients without it. In two patients who developed TMA during the earlyperiod after BMT, however, the levels of the three clotting factors were significantly decreased even before BMT, along with a significant increase of HGF. These findings suggest that patients with severe hepatic dysfunction before BMT, especially those with impaired protein synthesis, had an increased risk of developing TMA soon after BMT. It was also suggested that measurement of clotting factors (7, 9 and 10) and HGF may be useful to predict the occurrence of TMA in the early period after BMT.
Chronic hepatitis C virus infection in renal transplant: treatment and outcome
Authors: Sharma R.K. , Bansal S.B. , Gupta A. , Gulati S. , Kumar A. , Prasad N.
Published: July 2006

Abstract:  Background:  Chronic hepatitis C virus (HCV) infection is a common cause of liver disease in post‐renal transplant period and causes poor patient and graft survival. We analyzed the effects of antiviral therapy using ribavirin monotherapy or ribavirin in combination with interferon (IFN)‐alpha in our kidney transplant recipients with chronic hepatitis C.

Methods:  Total of 14 patients received antiviral therapy, all of whom had stable graft function, raised aminotransferases and positive HCV viremia at the start of treatment. Eight patients received ribavirin alone for a period of six months to two yr, in doses of 400–800 mg daily. Five patients received IFN‐alpha therapy for a period of two months to 1.5 yr, in doses of 1.5 million units daily or three million units thrice weekly with ribavirin. One patient received pegylated IFN 50 μg once weekly in combination with ribavirin. The response was seen in terms of biochemical and virological improvement at the end of study period.

Results:  In patients treated with ribavirin alone (n = 8), mean alanine aminotransferase (ALT) levels before and after treatment were significantly different (198.4 ± 147.6 and 104.8 ± 66.5 IU/L respectively; p < 0.05). ALT levels normalized completely in three patients at the end of treatment, improved in three patients and deteriorated in two. Only in one of eight patients on ribavirin alone, HCV‐RNA became negative after six months of treatment while in the rest (n = 7) HCV‐RNA continued to be positive. In subjects on IFN plus ribavirin (n = 6), the mean ALT levels decreased significantly (from 280.2 ± 114.9 IU/L at baseline to 71 ± 49 IU/L at end of therapy; p < 0.05). Two patients had sustained remission (33.3%) on IFN plus ribavirin (persistently negative HCV‐RNA), two patients relapsed after initial remission and in two patients treatment was stopped after two months because of graft dysfunction. Totally four patients developed graft dysfunction at some time during the course of IFN therapy (66.6%), but it was discontinued in only two (33.3%). All patients regained normal creatinine levels after discontinuation of IFN, although one patient developed chronic allograft nephropathy as shown by kidney biopsy. Four patients in IFN group developed leucopenia. Two patients developed severe anemia one of whom required blood transfusion and one developed severe flu‐like syndrome requiring stoppage of therapy.

Conclusion:  Ribavirin monotherapy in renal transplant recipients with chronic hepatitis C infection results in good biochemical response but is not associated with virological clearance. IFN in combination with ribavirin is effective in two‐thirds of patients after a minimum therapy of six months, but it is poorly tolerated, results in graft dysfunction in significant number of patients, and relapse can occur after stopping treatment.
Investigating the in vivo calcium transport path to developing potato tuber using 45Ca: a new concept in potato tuber calcium nutrition
Authors: Busse James S. , Palta Jiwan P.
Published: July 2006

Calcium is believed to be transported with water in the xylem. Consistent with this proposal, low‐transpiring organs such as potato Solanum tuberosum tubers are known to suffer from calcium deficiency. Although roots on tubers and stolons have been shown to supply water to tubers, there is no direct evidence for the calcium transport pathway to tubers. Both a xylem and a phloem transport pathway have been suggested. We investigated in vivo calcium transport to developing potato, cv. Dark Red Norland and cv. Russet Burbank, tubers using 45Ca in a controlled environment facility. Whole plant split pot experiments allowed the placement of 45Ca either in the main (basal) root or the tuber and stolon areas of the pot. The results showed that 45Ca was transported to the shoot with the transpiration stream from both areas but was not re‐translocated to tubers or the main (basal) root system even 57 days after 45Ca application. Radioactivity could only be detected in the tuber when 45Ca was fed to the stolon and tuber area. When 45Ca was fed to specific tubers, radioactivity was detected in the aerial shoot; however, no activity was detected in other tubers or the main (basal) roots. In another set of experiments, roots on a stolon near a tuber were precisely fed 45Ca and Safranin O. The radioactive signal exactly overlapped the water transport pathway in the tuber marked with Safranin O dye, suggesting that water and calcium can be simultaneously transported from stolon roots to the tuber. No transport of 45Ca across the tuber periderm was detected 8 days after 45Ca was applied to the tuber periderm. This indicated that no significant transport of calcium occurs from the soil across the periderm. Our results provide evidence that: (1) calcium is not re‐translocated via the phloem from the aerial shoot tubers and main (basal) roots; (2) the main root system does not supply calcium to the tuber; (3) calcium is not transported across the periderm to the interior tuber tissue; (4) calcium is transported to the tuber via the xylem along with water, and the roots on the stolon associated with the tuber supply water and calcium to the developing tuber; and (5) transpirational demand is a significant determinant of calcium distribution within the plant.
Reproductive Behaviour of the Annona Fruit Borer, Cerconota anonella
Authors: Da Silva Edleide L. , De Carvalho Cenira M. , Do Nascimento Ruth R. , Mendonça Adriana L. , Da Silva Carlos E. , Gonçalves Gláucia B. , De Freitas Maria do Rosário T. , Sant'Ana Antônio E. G.
Published: July 2006

The Annona fruit borer, Cerconota anonella, causes significant damage to the fruits of Annona squamosa (custard apple) and A. muricata (soursop). The methods currently available for the control of this pest are costly and new techniques, possibly involving the use of pheromones for trapping or disrupting the mating cycle of the insect are required. In order to provide the basic information required for the development of new control systems, the reproductive behaviour of the moth was observed under laboratory conditions. The calling and courtship behaviours exhibited by virgin females and males of C. anonella commenced at the eighth hour of the scotophase and continued for a 3.5‐h period. Males were attracted by conspecific females as young as 1 d old, and showed a courtship behaviour composed of three steps: antennation, wing fanning and short flights. Mating mainly occurred when both males and females were between 2 and 5 d old, but maximum activity was observed on the third day after emergence. Receptive females elevated their wings, showing their abdomens where the abdominal hairpencils were already exposed. As part of the courtship repertoire and immediately prior to copula, males performed pronounced sideways movements of their abdomens, a behaviour that appears to be exclusive to C. anonella.