bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of sputum smear-positive tuberculosis in a rural area in Bangladesh
Authors: ZAMAN K. , YUNUS M. , ARIFEEN S. E. , BAQUI A. H. , SACK D. A. , HOSSAIN S. , RAHIM Z. , ALI M. , BANU S. , ISLAM M. A. , BEGUM N. , BEGUM V. , BREIMAN R. F. , BLACK R. E.
Published: March 2006

The objective of the study was to determine the prevalence of smear-positive tuberculosis (TB) in a rural area in Bangladesh at Matlab. A TB surveillance system was established among 106000 people in rural Bangladesh at Matlab. Trained field workers interviewed all persons aged [ges ]15 years to detect suspected cases of TB (cough>21 days) and sputum specimens of suspected cases were examined for acid-fast bacilli (AFB). Of 59395 persons interviewed, 4235 (7·1%) had a cough for >21 days. Sputum specimens were examined for AFB from 3834 persons, 52 (1·4%) of them were positive for AFB. The prevalence of chronic cough and sputum positivity were significantly higher among males compared to females (P<0·001). The population-based prevalence rate of smear-positive TB cases was 95/100000 among persons aged [ges ]15 years. Cases of TB clustered geographically (relative risk 5·53, 95% CI 3·19–9·59). The high burden of TB among rural population warrants appropriate measures to control TB in Bangladesh. The higher prevalence of persistent cough and AFB-positive sputum among males need further exploration. Factors responsible for higher prevalence of TB in clusters should be investigated.
XOO-PHASE CERAMICS FROM OAXACA FOUND AT CALIXTLAHUACA IN CENTRAL MEXICO
Authors: Smith Michael E. , Lind Michael D.
Published: March 2006

We describe tombs and ceramic collections in Zapotec style excavated in central Mexico, outside Oaxaca. The most notable are 13 ceramic vessels and objects from the Xoo complex (a.d.500–800) excavated by José García Payón in Calixtlahuaca (near the city of Toluca), and three Zapotec-style tombs excavated in Los Teteles (near the city of Puebla). We also mention Zapotec remains excavated near Tula, Hidalgo, and tombs in other parts of central Mexico. We briefly explore the implications of these data for our understanding of central Mexico after the fall of Teotihuacan.
The transition to a monetary union in the United States, 1787–1795
Authors: SYLLA RICHARD
Published: March 2006

A convertible US-dollar monetary union was the least controversial component of the US financial revolution of the early 1790s. Although the fiat paper currencies of the colonies before 1776 sometimes worked reasonably well, the founders had good reasons for the constitutional ban on their continuance by US states. The ban, a surrender of states' sovereignty over money, at the time proved to be relatively uncontroversial for two reasons. One is that the financial revolution lightened the fiscal burdens of states by assuming their debts and making them part of the national debt. The other is that states quickly learned that chartering banks could accomplish virtually all of the legitimate purposes of state fiat money issues, and possessed additional economic and political advantages.
Social Modernization and the End of Ideology Debate: Patterns of Ideological Polarization
Authors: DALTON RUSSELL J.
Published: March 2006

Over 40 years ago, Daniel Bell made the provocative claim that ideological polarization was diminishing in Western democracies, but new ideologies were emerging and driving politics in developing nations. This article tests the End of Ideology thesis with a new wave of public opinion data from the World Values Survey (WVS) that covers over 70 nations representing more than 80 per cent of the world's population. We find that polarization along the Left/Right dimension is substantially greater in the less affluent and less democratic societies than in advanced industrial democracies. The correlates of Left/Right orientations also vary systematically across regions. The twin pillars of economic and religious cleavages remain important in European states; cultural values and nationalism provide stronger bases of ideology in Asia and the Middle East. As Bell suggested, social modernization does seem to transform the extent and bases of ideological polarization within contemporary societies.
Japan's Top-Down Policy Process to Dispatch the SDF to Iraq
Authors: SHINODA TOMOHITO
Published: March 2006

In July 2003, Prime Minister Koizumi successfully passed the legislation to dispatch ground SDF units to Iraq in the Diet. His top-down policy process was completely different from Japan's traditional bottom-up system, which Aurelia George Mulgan calls the ‘Un-Westminster System’ in which the bureaucrats in the ministries play a central role with the LDP being the only political power to negotiate with them. Mulgan also argues that the system has not changed despite recent institutional changes. On the contrary, this paper illustrates how Koizumi and his Cabinet took advantage of the strengthened authority of the Cabinet Secretariat to initiate policies, and successfully pushed the controversial national security legislation through LDP decision-making organs and the Diet by gaining support first from the coalition partners, presenting a new style of Westminster system.
Democracy and Modernity – When the Twain Shall Meet? Reflections on the Asian Conundrum
Authors: SARAVANAMUTTU JOHAN
Published: March 2006

This article examines the trajectory of Asian politics in terms of modernization and democratization. Going beyond broad generalizations about democracy's Third Wave, empirical evidence is adduced to show an affective orientation and lively appetite for democracy among Asian citizens and even states. However, in many instances, while the citizens are willing to democratize, the state is institutionally weak. Conversely, strong, high performance states ofen block the path of democratization. Historically speaking, modernity and its social and economic concomitants have been coterminous with the emergence and arrival of democracy, but, owing to socio-economic and historical disjunctures in Asian social fromations, such an emergence or arrival of democracy has remained tortuous and problematic. The institutionalization of middle-class driven ‘bourgeois’ democracy is clearly evident in many cases. However, civil society and political culture in some instances remain mired by a lack of political maturity and sophistication and a superficial attachment to economic performance. Many Asian politics have remained starkly authoritarian or simply undemocratic, even as modernization has advanced rapidly. Ultimately, the agency for democratization rests with a vibrant civil society. Again no necessary automatic correspondence obtains between modernization and the development of a vibrant civil society. The agency for such a social transformation has to be contestualized for different social formations. Finally, an important distinction has to be made between procedural and substantive democracy. For the latter to be sustained, it necessitates the engagement of citizens and civil forces on a multiplicity of social and political terrains outside of electoral politics.
Review of: c-Myc suppresses p21WAF1/CIP1expression during oestrogen signalling and antioestrogen resistance in human breast cancer cells
Authors: McNeil C. M. , Musgrove E. A.
Published: March 2006

Citation of original article:

S. Mukherjee, S. E. Conrad.Journal of Biological Chemistry2005;280: 17616–17625.

Abstract of the original article:

Oestrogen rapidly induces expression of the proto-oncogene c-Myc. c-Myc is required for oestrogen-stimulated proliferation of breast cancer cells, and deregulated c-Myc expression has been implicated in antioestrogen resistance. In this report, we investigate the mechanism(s) by which c-Myc mediates oestrogen-stimulated proliferation and contributes to cell cycle progression in the presence of antioestrogen. The MCF-7 cell line is a model of oestrogen-dependent, antioestrogen-sensitive human breast cancer. Using stable MCF-7 derivatives with inducible c-Myc expression, we demonstrated that in antioestrogen-treated cells, the elevated mRNA and protein levels of p21WAF1/CIP1, a cell cycle inhibitor, decreased upon either c-Myc induction or oestrogen treatment. Expression of p21 blocked c-Myc-mediated cell cycle progression in the presence of antioestrogen, suggesting that the decrease in p21WAF1/CIP1is necessary for this process. Using RNA interference to suppress c-Myc expression, we further established that c-Myc is required for oestrogen-mediated decreases in p21WAF1/CIP1. Finally, we observed that neither c-Myc nor p21WAF1/CIP1is regulated by oestrogen or antioestrogen in an antioestrogen-resistant MCF-7 derivative. The p21 levels in the antioestrogen-resistant cells increased when c-Myc expression was suppressed, suggesting that loss of p21 regulation was a consequence of constitutive c-Myc expression. Together, these studies implicate p21WAF1/CIP1as an important target of c-Myc in breast cancer cells and provide a link between oestrogen, c-Myc, and the cell cycle machinery. They further suggest that aberrant c-Myc expression, which is frequently observed in human breast cancers, can contribute to antioestrogen resistance by altering p21WAF1/CIP1regulation.
Neurostatin: cellular sources and cellular targets of the inhibitor
Authors: VALLEJO-CREMADES MAYTE , NIETO-SAMPEDRO MANUEL
Published: March 2006

Neurostatin, a modified ganglioside in mammalian brain, is highly immunogenic. Fusion of spleen cells of Balb/C mice immunized with bovine neurostatin with SP2O myeloma cells, led to hybridoma producers of anti-neurostatin antibodies. Two, monoclonal, IgG secreters were selected that recognized the inhibitor in blots and tissue of cow, rat and pig. The lack of species specificity indicated that the molecular structure of the inhibitory epitope is similar in these mammals. That epitope was also present in other gangliosides of the b series, defining a new regulatory system of glial-cell proliferation and apoptosis. The antibodies further revealed the neuronal origin of neurostatin.
Krebs-Immuntherapie – wo stehen wir?
Authors: Kündig  , Renner  , Knuth
Published: March 2006

Bei der Immuntherapie von Krebserkrankungen wird zwischen passiven und aktiven Strategien unterschieden. Die passive Immuntherapie, z.B. der therapeutische Einsatz von monoklonalen Antikörpern, oder im weitesten Sinn auch von anderen immunologischen Effektormolekülen, wie z.B. Interferon-alpha, ist längst klinisch etabliert. Der zunehmende Erfolg der passiven Immuntherapie belegt, dass das Immunsystem erfolgreich gegen Krebserkrankungen eingesetzt werden kann. Der logische nächste Schritt ist es deshalb eine Weiterentwicklung zur aktiven Immuntherapie, also zur «Impfung gegen Krebs». Diese Übersichtsarbeit konzentriert sich auf die aktive Immuntherapie gegen Krebsleiden und versucht den heutigen Stand der Forschung und des klinischen Fortschrittes darzustellen. Obwohl heute noch keine aktive Immuntherapie außerhalb von klinischen Studien empfohlen werden kann, sind die Daten vielversprechend und es ist zu erwarten, dass einige Impfstoffe demnächst zur Verfügung stehen werden.
Translokationsnachweis bei Lymphomen in der Pathologie
Authors: Tinguely  , Frigerio
Published: March 2006

Der Nachweis von Translokationen ist heute integrativer Bestandteil der hämatopathologischen Diagnostik. Ihr Nachweis in Non-Hodgkin Lymphomen nahm in den letzten Jahren stark an Bedeutung zu, da neben ihrer diagnostischen Wertigkeit zunehmend auch ihre prognostische und prädiktive Voraussagekraft erkannt wurde. Der Nachweis dieser Translokationen kann dank verfeinerten Aufarbeitungsprozessen der Gewebe nicht mehr nur an Frischmaterial, sondern auch an Formalin fixierten und Paraffin eingebetteten, selbst entkalkten Biopsien nachgewiesen werden. Zum Einsatz kommen zwei molekulare Untersuchungs-Techniken: Hybridisierungs- (Southern blot, FISH) und Genamplifikationsmethoden (PCR, RT-PCR). Trotz der zahlreichen bekannten Translokationen fand bis jetzt nur ein kleiner Anteil den Eingang in die Routine-Diagnostik. Gemäß der Häufigkeit der entsprechenden Lymphome sind Translokationen besonders in B-Zell Lymphomen gut untersucht, während in T-Zell Lymphomen nur einige wenige charakterisiert wurden. Der nachfolgende Beitrag gibt einen Einblick in die Entstehungsmechanismen von Translokationen, Vor- und Nachteile von deren Nachweismethoden sowie ihre klinisch-pathologische Bedeutung.
Testing the effect of carbonate saturation on the Sr/Ca of biogenic aragonite: A case study from the River Ehen, Cumbria, UK
Authors: Bailey Trevor R. , Lear Caroline H.
Published: March 2006

It has been suggested that the incorporation of strontium into biogenic aragonite may be influenced by the degree of carbonate saturation in aquatic environments. We measured the Sr/Ca ratios of river water and the aragonitic shells of freshwater bivalves (Margaritifera margaritifera) from two sites with different carbonate saturation states in the River Ehen, Cumbria, UK. Shell Sr/Ca and river water Sr/Ca are 0.1 mmol/mol and 0.42 mmol/mol lower, respectively, at the high carbonate saturation site. However, the distribution coefficients of strontium into aragonite (KD) are the same (∼0.28) at both sites. These analyses show that Sr uptake into aragonite bivalve shells is not affected by the degree of carbonate saturation of the water, perhaps reflecting a strong biological control on trace element incorporation.
How accurate are 234Th measurements in seawater based on the MnO2‐impregnated cartridge technique?
Authors: Cai Pinghe , Dai Minhan , Lv Dongwei , Chen Weifang
Published: March 2006

In the past decade, a MnO2‐impregnated cartridge technique has been widely used to extract 234Th from seawater. One of the inherent assumptions associated with this technique is that all Th species in the dissolved phase are subject to extraction by the MnO2 cartridges. In this study, an intercalibration between the cartridge technique and a small‐volume MnO2 coprecipitation technique was carried out to test this assumption. We demonstrated that the collection efficiency for 234Th could be substantially overestimated by the MnO2 cartridge technique. This may be the result of organic complexation of a significant portion of 234Th in seawater, causing this fraction of Th to pass through the MnO2 cartridges. The overestimate in collection efficiency may explain the deep‐water 234Th deficit observed in some oceanographic settings (e.g., the Gulf of Mexico, the Middle Atlantic Bight, and the Gulf of Maine). Sensitivity tests show that using the cartridge technique can yield 234Th‐based particulate organic carbon export rates that are overestimated by factors of up to 10. Furthermore, the frequent observed disagreements between Th fluxes recorded by shallow sediment traps and estimated using the cartridge method may be ascribed, at least partially, to this methodological issue.
Seismic structure beneath the Tonga arc and Lau back‐arc basin determined from joint Vp, Vp/Vs tomography
Authors: Conder James A. , Wiens Douglas A.
Published: March 2006

The Tonga arc and associated Lau basin exhibit many geologically important processes that link subduction and mantle flow with plate separation and crustal production. We create seismic tomograms of the Tonga‐Lau region by jointly inverting for Vp and Vp/Vs structure using data from the LABATTS ocean bottom seismograph experiment and several island deployments to better constrain dynamic processes in the mantle wedge. Jointly using P and S data can help distinguish between the various mechanisms responsible for seismic velocity anomalies such as temperature and the presence of melt and/or volatiles. Because high attenuation in the wedge limits the S wave data set, we focus on 2‐D inversions beneath the linear OBS array where resolution is best and also parameterize the solution in terms of the Vp/Vs ratio. As expected, the subducting slab has fast Vp and Vs and a low Vp/Vs ratio, consistent with the cold downgoing plate. The Central Lau Spreading Center (CLSC) exhibits stronger anomalies in Vp/Vs than in Vp, with the anomalies larger than would be predicted purely by temperature variations. The CLSC anomaly extends >100 km to the west of the axis, suggesting a broad region of melt production driven by passive upwelling from plate separation rather than active upwelling mechanisms. The anomaly is asymmetric about the axis, suggesting that slab‐induced corner flow possibly influences mantle dynamics several hundred kilometers away from the arc. There is a strong anomaly beneath the volcanic arc that gradually deepens as it trends toward the back arc, likely outlining a hydrated region of melt production that feeds the volcanic front. Hydration possibly continues throughout the wedge to at least 400 km depth. The Lau ridge exhibits a thicker lithosphere relative to the rest of the Basin, while the Fiji platform likely has a thinner lithosphere than the Lau Ridge from more recent extension. There is also a reasonable likelihood of a small degree of partial melt in the uppermost mantle beneath the platform.
Variations of absolute gravity accompanying earthquake‐induced changes in subsurface pore water pressure at the Mizunami Underground Research Institute construction site, central Japan
Authors: Tanaka T. , Salden W. , Martin A. J. , Saegusa H. , Asai Y. , Fujita Y. , Aoki H.
Published: March 2006

The Tono Research Institute of Earthquake Science has been measuring gravity using an FG5 absolute gravimeter located at the Mizunami Geoscience Academy (MGA) in central Japan since January 2004. Measured gravity decreased immediately following the 2004 earthquake off the Kii peninsula (MJMA 7.4) by about 6 μGal. Here, we investigate the empirical relationship between pore water pressure change in a borehole near the MGA and gravity change measured at the MGA. We reveal that (1) gravity change correlates inversely with pore water pressure change at 81 m below the surface at a particular borehole and (2) several different sets of conversion coefficients from pressure head to gravity can be used to explain 60–70% of gravity variations with less than 2 μGal uncertainty. These newly identified relationships may suggest that an absolute gravimeter alone could be used to observe the change of groundwater quantity.
Ocean loading deformations caused by storm surges on the northwest European shelf
Authors: Fratepietro F. , Baker T. F. , Williams S. D. P. , Van Camp M.
Published: March 2006

A model of the non‐tidal ocean loading deformations caused by storm surges on the northwest European shelf has been developed using the output from a 12 km grid storm surge model. The spatial distributions of displacements and gravity variations caused by a typical storm surge event are computed in order to show the magnitudes of the effects that can be expected in space geodetic or gravity measurements. A storm surge of just over 2 m in the southern North Sea produces vertical displacements of −20 to −30 mm and increases of gravity of 6 to 8 μgal in the coastal areas of Denmark, Germany, the Netherlands and the east coast of England. It is shown that the loading deformations due to surges affect a wide area of northwest Europe and that high resolution non‐tidal loading models are required for correcting geodetic measurements made in areas near shallow continental shelves.
Influence of carbon dioxide on the large‐scale dynamics of magmatic eruptions at Phlegrean Fields (Italy)
Authors: Esposti Ongaro Tomaso , Papale Paolo , Neri Augusto , Del Seppia Dario
Published: March 2006

Carbon dioxide is the second most abundant volatile species in magmas after water (Johnson et al., 1994) but its role on eruption dynamics is still largely unknown. The effects of the presence of CO2 in the Agnano Monte Spina eruption (4100 BP, Phlegrean Fields, Italy) are here evaluated by simulating the eruption dynamics from the base of the volcanic conduit up into the atmosphere. The numerical simulations consider multiphase flow dynamics and couple the steady‐state, one‐dimensional magma ascent model of Papale (2001) and the transient, axisymmetric pyroclast dispersal model of Neri et al. (2003). The main input parameters of the models were based on eruptive conditions estimated from the deposits. A parametric study has been performed on H2O and CO2 concentrations in the erupted magma. The addition of CO2 results in increased volatile saturation pressure and complex non‐linear changes in the conduit flow. Nonetheless, within the range of conditions explored, this volatile scarcely affects the eruption style and dynamics in the atmosphere, which are principally controlled by the H2O content. The different roles of the two volatiles in the large‐scale eruption dynamics are mostly the result of the competing changes induced by CO2 on vent conditions.
Extended surface exposures of granitoid compositions in Syrtis Major, Mars
Authors: Bandfield Joshua L.
Published: March 2006

The number of quartz and feldspar rich surfaces identified in northwestern Syrtis Major has been extended beyond previously reported results to a region of about 230 by 125 km. Thermal Emission Imaging System infrared data were used to locate surfaces spectrally identical to previously reported central peak units in Syrtis Major. These surfaces are indicative of the production of highly differentiated magmas. Though it is possible that the granitoid exposures add to the variety of igneous compositions associated with the Syrtis Major volcanic construct, the geologic context of these exposures suggests a formation that predates Syrtis Major.
Relationship of the quasi‐biennial oscillation to the stratospheric signature of the solar cycle
Authors: Salby Murry L. , Callaghan Patrick F.
Published: March 2006

Records of analyzed dynamical structure indicate a correlation with the 11‐year variation of solar flux Fs. In the monthly record, anomalous temperature maximizes in the stratosphere, with symmetry about the equator. However, even there, the signature is weak and scarcely significant. Sampling the same record around solstice and during extremal phases of the QBO sharply enhances the strength, significance, and symmetry of the solar signature. In the tropics the solar signature follows from a decadal modulation in the frequency of the quasi‐biennial oscillation (QBO). In instantaneous power spectra the modulation is manifested to either side of the QBO's mean frequency, in two spectral peaks where the QBO dwells: one at (24 months)−1, reflecting a biennial oscillation (BO), and another at (36 months)−1. Intrinsic to the QBO, those peaks are separated from its mean frequency by ∼11 yr−1. The decadal modulation produces a strong correlation to Fs and, through the residual circulation of the QBO, symmetry about the equator. Augmenting this high‐frequency contribution is a low‐frequency contribution to the solar signature, one that simply tracks the 11‐year variation of Fs. Characterized by broad symmetry about the equator, it reflects the involvement of the Brewer‐Dobson circulation. Accompanying anomalous temperature in the subtropics is a stronger signature over the winter pole, where interannual variance is large. Discovered by Labitzke and van Loon (1988), that solar signature reflects anomalous downwelling of the Brewer‐Dobson circulation. As strong as the RMS interannual variation, it is accounted for entirely by the high‐frequency contribution associated with the QBO. The extratropical signature is shown to follow through the BO, which is transmitted poleward by planetary waves. Salient features of the observed behavior are reproduced by a simple model of the QBO's modulation and its interaction with the extratropical circulation.
Radiometric and spectral validation of Atmospheric Infrared Sounder observations with the aircraft‐based Scanning High‐Resolution Interferometer Sounder
Authors: Tobin David C. , Revercomb Henry E. , Knuteson Robert O. , Best Fred A. , Smith William L. , Ciganovich Nick N. , Dedecker Ralph G. , Dutcher Steven , Ellington Scott D. , Garcia Raymond K. , Howell H. Benjamin , LaPorte Daniel D. , Mango Stephen A. , Pagano Thomas S. , Taylor Joe K. , van Delst Paul , Vinson Kenneth H. , Werner Mark W.
Published: March 2006

The ability to accurately validate high–spectral resolution infrared radiance measurements from space using comparisons with a high‐altitude aircraft spectrometer has been successfully demonstrated. The demonstration is based on a 21 November 2002 underflight of the AIRS on the NASA Aqua spacecraft by the Scanning‐HIS on the NASA ER‐2 high‐altitude aircraft. A comparison technique which accounts for the different viewing geometries and spectral characteristics of the two sensors is introduced, and accurate comparisons are made for AIRS channels throughout the infrared spectrum. Resulting brightness temperature differences are found to be 0.2 K or less for most channels. Both the AIRS and the Scanning‐HIS calibrations are expected to be very accurate (formal 3‐sigma estimates are better than 1 K absolute brightness temperature for a wide range of scene temperatures), because high spectral resolution offers inherent advantages for absolute calibration and because they make use of high‐emissivity cavity blackbodies as onboard radiometric references. AIRS also has the added advantage of a cold space view, and the Scanning‐HIS calibration has recently benefited from the availability of a zenith view from high‐altitude flights. Aircraft comparisons of this type provide a mechanism for periodically testing the absolute calibration of spacecraft instruments with instrumentation for which the calibration can be carefully maintained on the ground. This capability is especially valuable for assuring the long‐term consistency and accuracy of climate observations, including those from the NASA EOS spacecraft (Terra, Aqua and Aura) and the new complement of NPOESS operational instruments. The validation role for accurately calibrated aircraft spectrometers also includes application to broadband instruments and linking the calibrations of similar instruments on different spacecraft. It is expected that aircraft flights of the Scanning‐HIS and its close cousin the NPOESS Airborne Sounder Test Bed (NAST) will be used to check the long‐term stability of AIRS and the NPOESS operational follow‐on sounder, the Cross‐track Infrared Sounder (CrIS), over the life of the missions.
Use of Atmospheric Infrared Sounder high–spectral resolution spectra to assess the calibration of Moderate resolution Imaging Spectroradiometer on EOS Aqua
Authors: Tobin David C. , Revercomb Henry E. , Moeller Christopher C. , Pagano Thomas S.
Published: March 2006

AIRS and MODIS on the EOS Aqua spacecraft collect global observations of the Earth's upwelling infrared radiance for numerous remote sensing and climate related applications. This paper presents comparisons of the AIRS and MODIS radiance observations and illustrates the utility of using high–spectral resolution observations to create a highly accurate assessment of broadband sensor calibration. In the analysis, the high–spectral resolution AIRS spectra are reduced to MODIS spectral resolution, and the high–spatial resolution MODIS data are reduced to AIRS spatial resolution for global data collected on 6 September 2002 and 18 February 2004. Spatially uniform scenes are selected, and the observed differences are characterized as a function of several parameters including scene temperature, sensor scan (view) angle, and solar zenith angle. The comparisons are in general very good with respect to the expected radiometric accuracies of the sensors, with mean brightness temperature differences of 0.1 K or less for many of the MODIS bands. Uncertainties of these determinations range from near 0 K for window region bands to as large as 0.2 K for other bands. For MODIS water vapor bands 27 (6.8 μm) and 28 (7.3 μm) and temperature sounding bands 34 (13.7 μm), 35 (13.9 μm), and 36 (14.2 μm), the differences exhibit a dependence on scene temperature, with peak differences exceeding 1 K for bands 27 and 36. Differences as a function of scan angle are 0.4 K or less for all bands, and scan angles but clear trends are defined. Results for the 2 days demonstrate good reproducibility with changes in mean differences of 0.1 K or less for most bands.
On the vertical structure of the stratosphere at midlatitudes during the first stage of the polar vortex formation and in the polar region in the presence of a large mesospheric descent
Authors: Huret N. , Pirre M. , Hauchecorne A. , Robert C. , Catoire V.
Published: March 2006

CH4 and N2O measured by the balloon‐borne Spectromètre Infra Rouge pour l'Étude de l'Atmosphère par Diodes Laser Embarquées (SPIRALE) instrument at midlatitude on 2 October 2002 and in the polar region on 21 January 2003 are used to study the vertical structure of the stratosphere. SPIRALE utilizes a direct absorption technique using tunable diodes laser in the midinfrared. For the two flights, detailed structures with vertical extents less than 1 km and nonmonotonic profiles are observed. Measured N2O and CH4 have been compared with correlation curves deduced from ATMOS space shuttle measurements. The high vertical resolution (5 m) and high precision of the measurements allow us to discuss the air mass origin in detail. To help with the interpretation, the potential vorticity maps have been used. At midlatitude we have identified a tropospheric tropical air mass intrusion. The layer located just above has been identified as the “tropically controlled transition region.” For this layer a specific correlation line has been deduced from our measurements. The nonmonotonic part of the profile in the 23–29 km altitude range corresponds to a transition layer where mixing is still occurring. For the polar flight the instrument has sampled air masses outside the polar vortex at the lower levels and inside the polar vortex above. An intense mesospheric descent is observed. We provide new CH4:N2O correlation values that can be encountered in cases of large mesospheric descent. Our measurements show also a nontypical CH4:N2O correlation line in a thin layer corresponding to a midlatitude filament crossing the balloon trajectory.
Determination of the contribution of northern Africa dust source areas to PM10 concentrations over the central Iberian Peninsula using the Hybrid Single‐Particle Lagrangian Integrated Trajectory model (HYSPLIT) model
Authors: Escudero M. , Stein A. , Draxler R. R. , Querol X. , Alastuey A. , Castillo S. , Avila A.
Published: March 2006

A source apportionment methodology has been implemented to estimate the contribution from different arid geographical areas to the levels of measured atmospheric particulate matter with diameters less than 10 μm (PM10). Toward that end, the Hybrid Single‐Particle Lagrangian Integrated Trajectory model (HYSPLIT) has been used to quantify the proportions of mineral dust originated from specific geographical areas in northern Africa. HYSPLIT simulates the transport, dispersion, and deposition of dust plumes as they travel from the source areas to the receptors. This model has been configured to reproduce high daily ambient PM10 levels recorded at three Spanish EMEP (Cooperative Programme for Monitoring and Evaluation of the Long‐Range Transmission of Air pollutants in Europe) regional background monitoring stations, located over the central Iberian Peninsula, during a North African dust outbreak from 12 to 15 March 2003. Different model setups have been utilized to determine the best suite of parameters needed to better represent the observed concentrations. Once the simulation has been configured, the model has been run for individual scenarios which include eight specific source areas over northern Africa considered as possible contributors to the PM10 levels measured at the monitoring stations. One additional run has been carried out to account for the rest of the dust sources in northern Africa. Furthermore, the fractional contribution to the PM10 air concentrations at the receptors from each run has been used to estimate the source apportionment. According to these calculations, the contribution from each area to the PM10 recorded over central Iberia for the March 2003 episode can be detailed as follows: 20–30% of the PM10 dust originated in Mauritania and the western Sahara, 15–20% from Mali, Mauritania and the western flanks of the Ahaggar Mountains, and 55–60% from other northwestern African sources within the rest of the desert source area.
Unsolved problems in the lowermost mantle
Authors: Hirose Kei , Karato Shun‐ichiro , Cormier Vernon F. , Brodholt John P. , Yuen David A.
Published: March 2006

Many characteristics of D″ layer may be attributed to the recently discovered MgSiO3 post‐perovskite phase without chemical heterogeneities. They include a sharp discontinuity at the top of D″, regional variation in seismic anisotropy, and a steep Clapeyron slope. However, some features remain unexplained. The seismically inferred velocity jump is too large in comparison to first principles calculations, and the sharpness of the discontinuity may require a chemical boundary. Chemical heterogeneity may play an important role in addition to the phase transformation from perovskite to post‐perovskite. Phase transformation and chemical heterogeneity and the attendant changes in physical properties, such as rheology and thermal conductivity, are likely to play competing roles in defining the dynamical stability of the D″ layer. Revealing the relative roles between phase transition and chemical anomalies is an outstanding challenge in the study of the role of D″ in thermal‐chemical evolution of the Earth.
Comparison of SeaWiFS, MODIS and MERIS radiometric products at a coastal site
Authors: Zibordi G. , Mélin F. , Berthon J.‐F.
Published: March 2006

SeaWiFS, MODIS and MERIS remote sensing radiometric products were assessed using in situ data collected at a coastal site in the northern Adriatic Sea from May 2002 to September 2005. The analysis was restricted to satellite and in situ data taken within one hour interval to minimize the effects of temporal variability of atmosphere and seawater around the measurement site. The comparison of SeaWiFS and MODIS normalized water‐leaving radiances with in situ values showed averages of relative percent difference varying from 0% to −9% in the 443–555 nm spectral range. Higher values ranging from +15 to +42% were observed for the MERIS data in the equivalent spectral range (i.e., 443–560 nm).
Interaction with Grb14 results in site‐specific regulation of tyrosine phosphorylation of the insulin receptor
Authors: Nouaille Sébastien , Blanquart Christophe , Zilberfarb Vladimir , Boute Nicolas , Perdereau Dominique , Roix Johan , Burnol Anne‐Françoise , Issad Tarik
Published: March 2006

The dynamics of interaction of the insulin receptor (IR) with Grb14 was monitored, in real time, in living human embryonic kidney cells, using bioluminescence resonance energy transfer (BRET). We observed that insulin rapidly and dose‐dependently stimulated this interaction. We also observed that insulin‐induced BRET between the IR and protein tyrosine phosphatase 1B (PTP1B) was markedly reduced by Grb14, suggesting that Grb14 regulated this interaction in living cells. Using site‐specific antibodies against phosphorylated tyrosines of the IR, we showed that Grb14 protected the three tyrosines of the kinase loop from dephosphorylation by PTP1B, while favouring dephosphorylation of tyrosine 972. This resulted in decreased IRS‐1 binding to the IR and decreased activation of the extracellular signal‐regulated kinase pathway. Increased Grb14 expression in human liver‐derived HuH7 cells also seemed to specifically decrease the phosphorylation of Y972. Our work therefore suggests that Grb14 may regulate signalling through the IR by controlling its tyrosine dephosphorylation in a site‐specific manner.
Two-dimensional numerical model of electron cyclotron resonance discharge with pointwise mappings
Authors: Eruhimov V. , Semenov V.
Published: March 2006

We suggest a new approach to numerical modeling of electron distribution function in an electron cyclotron resonance (ECR) discharge. The method is based on a pointwise mapping of electron velocity over a single bounce oscillation. We limit our consideration to ECR heating, collisions, ionization, and ambipolar losses from the trap although other processes can be accounted for as well. The method gives a solution close to the brute-force particle-in-cell integration but is incomparably faster. Initial results of experiments are presented.
Production of high intensity primary beams at GANIL
Authors: Barué C. , Canet C. , Cornell J. , Dubois M. , Dupuis M. , Eléon C. , Flambard J. L. , Gaubert G. , Huet-Equilbec C. , Jardin P. , Lecesne N. , Lehérissier P. , Lemagnen F. , Leroy R. , Pacquet J. Y.
Published: March 2006

The 100kV platform used for the production of primary beams has been modified in order to increase the beam intensity. The configuration of the new platform is described and preliminary results are reported. A gain intensity of a factor of 2 has already been obtained for sulfur: S36 (65% enriched) 3.2kW at 77.5MeV∕u, i.e., 1.14pμA, as well as for nickel: Ni58 (68%) 1.5kW at 74.5MeV∕uA, i.e., 0.35pμA.
High current vacuum-arc ion source for ion implantation and coating deposition technologies
Authors: Ryabchikov Alexander I. , Ryabchikov Igor A. , Stepanov Igor B. , Dektyarev Sergey V.
Published: March 2006

This work is devoted to the development and investigation of a high current ion source based on dc vacuum-arc plasma generation. Extraction and acceleration of ion beams are realized in a repetitively pulsed mode with the pulse repetition rate up to 200 pps, the pulse duration up to 400μs, the accelerating voltage up to 40 kV, and the pulsed ion-beam current up to 2 A. To remove microparticles from the vacuum-arc plasma a straight-line plasma filter is used. Examples of the source use for realization of high-intensity and high-concentration ion implantation regimes including those with formation of doped layers at depths that exceed ion projective range for more than an order of magnitude are presented. At the expense of change in order and intensity of ion and plasma material treatment, the advantage of application of one source for execution of material surface pretreatment and activation regimes, formation of wide transition layers between the substrate and coating, coating deposition, and high-intensity ion mixing using ions of the same type was shown.
Close-packed structures and phase diagram of soft spheres in cylindrical pores
Authors: Koga Kenichiro , Tanaka Hideki
Published: March 2006

It is shown for a model system consisting of spherical particles confined in cylindrical pores that the first ten close-packed phases are in one-to-one correspondence with the first ten ways of folding a triangular lattice, each being characterized by a roll-up vector like the single-walled carbon nanotube. Phase diagrams in pressure-diameter and temperature-diameter planes are obtained by inherent-structure calculation and molecular dynamics simulation. The phase boundaries dividing two adjacent phases are infinitely sharp in the low-temperature limit but are blurred as temperature is increased. Existence of such phase boundaries explains rich, diameter-sensitive phase behavior unique for cylindrically confined systems.
Defects in Cu2O studied by deep level transient spectroscopy
Authors: Paul G. K. , Nawa Y. , Sato H. , Sakurai T. , Akimoto K.
Published: March 2006

Hole traps in p-type Cu2O were studied by means of deep level transient spectroscopy in the heterostructure of p-Cu2O∕i-ZnO∕n-ZnO. In addition to the trap level at about 0.45eV from the valance band edge, which is already reported as being due to Cu vacancy, we found a new trap level at about 0.25eV. The new trap is tentatively assigned as Cu-di-vacancy from the trap concentration dependence on oxygen flow rate and substrate temperature.
Forces between chemically structured substrates mediated by critical fluids
Authors: Sprenger Monika , Schlesener Frank , Dietrich S.
Published: March 2006

We consider binary liquid mixtures close to their critical points confined by two parallel, geometrically flat, and chemically structured substrates. Universal order parameter profiles are calculated within mean field theory for periodic patterns of stripes with alternating preferences for the two species of the mixture and with different relative positions of the two substrates. From the order parameter profiles the effective forces between the two plates are derived. The tuning of Casimir amplitudes is discussed.
Rabi oscillations in systems with small anharmonicity
Authors: Amin M. H. S.
Published: March 2006

When a two-level quantum system is irradiated with a microwave signal in resonance with the energy difference between the levels, it starts Rabi oscillations between those states. If there are other states close, in energy, to the first two, the microwave signal will also induce transitions to those. Here we study the probability of transition to the third state, in a three-level system, while Rabi oscillations between the first two states are performed. We investigate the effect of pulse shaping on the probability and suggest methods for optimizing the pulse shapes to reduce the transition probability.
Quantitative determination of the single-molecule detection regime in fluorescence fluctuation microscopy by means of photon counting histogram analysis
Authors: Niesner Raluca , Gericke Karl-Heinz
Published: March 2006

Fluorescence fluctuation experiments are performed in single-molecule detection regime if the fluorescence of at most one molecule is registered at a time. Although the significance of such experiments for investigations of complex nonergodic systems like those met in the biosciences has been stressed out by many scientists, the quantitative and accurate determination of the single-molecule detection regime received rather little attention. In this work we present a method based on the photon counting histogram (PCH) analysis, which enables the determination of the average number N¯ of molecules within the observation volume, for which only the fluorescence of individual molecules is detected at a time. Thus, the accurate design of fluorescence fluctuation experiments performed in single-molecule detection regime is possible. Demonstrative fluorescence fluctuation experiments based on two-photon excitation are performed on diluted solutions of coumarin 153, in order to verify the potential of the PCH analysis in experiments on the single-molecule detection level. If the mean number N¯ of molecules within the excitation volume is larger than 0.048, the probability to simultaneously detect the fluorescence of two or more molecules is no longer negligible, i.e., no single-molecule detection regime. If the mean number N¯ of molecules is lower than 0.0057, the detection limit of the method is reached, i.e., the fluorescence signal cannot be distinguished from the background. Consequently, the concentration of coumarin 153 characteristic for the single-molecule detection regime lies in the range 13–110pmol∕l for the given experimental conditions. We also investigate the influence of the molecular brightness, i.e., detected photons per fluorophore molecule and sampling time, on the single-molecule detection regime.
Reflection symmetries for multiqubit density operators
Authors: Altafini Claudio , Havel Timothy F.
Published: March 2006

For multiqubit density operators in a suitable tensorial basis, we show that a number of nonunitary operations used in the detection and synthesis of entanglement are classifiable as reflection symmetries, i.e., orientation changing rotations. While one-qubit reflections correspond to antiunitary symmetries, as is known, for example, from the partial transposition criterion, reflections on the joint density of two or more qubits are not accounted for by the Wigner theorem and are well-posed only for sufficiently mixed states. One example of such nonlocal reflections is the unconditional NOT operation on a multiparty density, i.e., an operation yeilding another density and such that the sum of the two is the identity operator. This nonphysical operation is admissible only for sufficiently mixed states.
Computing the density of paths in complex systems
Authors: Passerone Daniele
Published: March 2006

Trajectories of duration τ joining two points q0 and q1 in the configuration space of a classical system satisfy Hamilton’s principle: they are stationary points of the classical action. The second variation (fluctuations) of the action around the stationary point signals whether the latter is or not a minimum and delivers the density in trajectory space around the points q0 and q1. This concept of density of paths is of great importance in semiclassical quantum theory, where it weights the contribution to the propagator from the single classical trajectories. In this paper, two algorithms based on the concepts of molecular dynamics simulation are introduced for computing the density of paths, also called van Vleck [Proc. Natl. Acad. Sci. U.S.A. 14, 178 (1928)] determinant. Examples for realistic systems are presented, together with a suggestion about possible applications in the field of rare events in physics and chemistry.
Proposal for an electrical spin cell with single barrier
Authors: Wu B. H. , Ahn Kang-Hun
Published: March 2006

We propose a spin cell based on photon-assisted tunneling through a conventional semiconductor barrier. The Dresselhaus spin-orbit interaction is included to break the spin rotation symmetry. Due to the in-plane electric field induced asymmetric momentum distribution in one lead, continuous flows of spin currents are driven through a barrier by an ac field. The net charge current remains zero. The spin current via photon-assisted tunneling can be readily adjusted via tuning the ac frequency or the in-plane electric field. This device may function as an ideal spin cell to supply spin currents in the spintronics circuit.
A coherent state approach to semiclassical nonadiabatic dynamics
Authors: Song XiaoGeng , Van Voorhis Troy
Published: March 2006

A semiclassical (SC) approximation to the quantum mechanical propagator for nonadiabatic systems is derived. Our derivation starts with an exact path integral expression that uses canonical coherent states for the nuclear degrees of freedom and spin coherent states for the electronic degrees of freedom. A stationary path approximation (SPA) is then applied to the path integral to obtain the SC approximation. The SPA results in complex classical trajectories of both nuclear and electronic degrees of freedom and a double ended boundary condition. The root search problem is solved using the previously proposed “real trajectory local search” algorithm. The SC approximation is tested on three simple one dimensional two-state systems proposed by Tully [J. Chem. Phys. 93, 1061 (1990)], and the SC results are compared to Ehrenfest and surface hopping predictions. Excellent agreement with quantum results is reached when the SC trajectory is far away from caustics. We discuss the origin of caustics in this SC formalism and the strengths and weaknesses of this approach.
Thermodynamics of symmetric dimers: Lattice density functional theory predictions and simulations
Authors: Chen Y. , Aranovich G. L. , Donohue M. D.
Published: March 2006

A new lattice density functional theory (DFT) approach is proposed for symmetric dimers taking into account all possible configurations for molecules adjacent to a central dimer. Comparison with Monte Carlo simulations shows significant improvement of the proposed model compared to previously developed version of lattice DFT for dimers. It is shown that the new model gives accurate analytical solutions over a wide range of densities and temperatures. Phase transitions in dimers are analyzed and fundamental differences between dimers and monomers are discussed.