bluuebunny/crossref_metadata_2025 huggingface dataset:
Authors' Response
Authors: Newbury Dale E.
Published: July 2006

I am pleased to respond to the letter from Simon Burgess commenting on
my article, “Misidentification of Major Constituents by Automatic
Qualitative Energy Dispersive X-ray Microanalysis: A Problem That
Threatens the Credibility of the Analytical Community” (Newbury,
2005). First, I am grateful for the words of
support for my article, even if inevitably qualified, expressed in Mr.
Burgess's letter. In response to his specific comments (in boldface),
I offer the following:
Inconsistencies – The German Federal Constitutional Court on the European Arrest Warrant
Authors: Tomuschat Christian
Published: July 2006

Features European Arrest Warrant – Article 16(2) German Basic Law, which allows exceptionally for the extradition of German nationals, not read in the light of the European Union integration clause in Article 23(1) Basic Law – Complaint of violation of the democratic principle put in perspective – Preservation of the statehood of Germany – Lack of proportionality in and procedural defects of the implementing Act
European Court of Human Rights
Authors: Altiparmak Kerem , Karahanogullari Onur
Published: July 2006

On 10 November 2005 the Grand Chamber of the European Court of Human Rights (‘Court’) decided the long-running headscarf battle between Muslim students and Turkish universities in the Şahin judgment. On appeal, it held that the prohibition against wearing headscarves on university premises did not violate Article 9 of the European Convention on Human Rights (‘Convention’) on freedom of thought, conscience and religion. It thereby confirmed the decision of the Fourth Section of the Court of 29 June 2004.
Court of Justice of the European Communities
Authors: van der Wilt Harmen
Published: July 2006

The European Union has been tightening its grip on the criminal laws of the member states. Article 31 of the Treaty on European Union introduced the framework decision as the appropriate instrument to harmonize criminal law. In this way, member states may be required to adopt minimum levels of criminal definitions and sanctions. This is a matter of ‘third pillar’ law. The case under scrutiny, however, is a perfect illustration of the delicate relationship between EU first pillar law and domestic criminal law.
ENSO amplitude changes in climate change commitment to atmospheric CO2 doubling
Authors: Yeh Sang‐Wook , Park Young‐Gyu , Kirtman Ben P.
Published: July 2006

Simulations from six climate system models are analyzed to investigate the ENSO amplitude changes in response to a transient increase of the atmospheric CO2. It is found that the ENSO amplitude amplifies as the CO2 concentration increases, then weakens once the concentration is held fixed at 2xCO2 level in the Meteorological Research Institute (MRI) model simulation, but with no significant sensitivity in the other five models. By comparing the MRI and the Geophysical Fluid Dynamical Laboratory (GFDL) models, both of which simulate ENSO reasonably well for the unperturbed climate, we investigate the origin of the sensitivity or lack of sensitivity of the ENSO amplitude to changes in atmospheric CO2 concentration. It is found that in the MRI model the oceanic sensitivity to the equatorial zonal wind stress is significantly decreased in the doubled CO2 period compared to the transient period. Moreover, the vertical stratification at upper levels is weaker in the former period than in the latter period. However, these changes in the GFDL model are negligible.
Signatures of equatorial midnight temperature maximum as observed from in situ and ground‐based ionospheric measurements in the Indian sector
Authors: Niranjan K. , Brahmanandam P. S. , Srivani B.
Published: July 2006

Results of a preliminary study carried out on the features of midnight temperature maximum (MTM) over the Indian sector as observed from the first in situ electron temperature variations of Indian SROSS C2 RPA data, the thermospheric night airglow intensities at 630 nm recorded from a subtropical Indian station Waltair (17.7°N, 83.3°E) and a colocated Digital Ionosonde data are reported. The electron temperatures indicate that during the summer solstice months of low solar activity periods, there was a significant temperature gradient from the equator toward the latitudes of Waltair (14–18° N) from 2200 to 2400 hours IST even in the topside F region. In contrast, during the winter solstice months, temperature contours do not show significant gradient around midnight, though isolated peaks are seen between 0100 and 0300 hours IST, i.e., delayed in time by a couple of hours, suggesting that the MTM is weaker. The MTM induced F layer descent at subtropical latitudes due to a probable neutral wind modification and consequent increase in 630 nm night airglow zenith intensity are studied to characterize the MTM induced ionospheric changes in terms of the starting time, velocity of F layer descent indicative of the strength of MTM, and the time at minimum height indicative of the time of cessation of MTM induced perturbation. The results are discussed in the light of earlier work and the current understanding of the origin of equatorial MTM.
X‐ray emission from the outer planets: Albedo for scattering and fluorescence of solar X rays
Authors: Cravens T. E. , Clark J. , Bhardwaj A. , Elsner R. , Waite J. H. , Maurellis A. N. , Gladstone G. R. , Branduardi‐Raymont G.
Published: July 2006

Soft X‐ray emission has been observed from the low‐latitude “disk” of both Jupiter and Saturn as well as from the auroral regions of these planets. The disk emission as observed by ROSAT, the Chandra X‐Ray Observatory, and XMM‐Newton appears to be uniformly distributed across the disk and to be correlated with solar activity. These characteristics suggest that the disk X rays are produced by (1) the elastic scattering of solar X rays by atmospheric neutrals and (2) the absorption of solar X rays in the carbon K‐shell followed by fluorescent emission. The carbon atoms are found in methane molecules located below the homopause. In this paper we present the results of calculations of the scattering albedo for soft X rays. We also show the calculated X‐ray intensity for a range of atmospheric abundances for Jupiter and Saturn and for a number of solar irradiance spectra. The model calculations are compared with recent X‐ray observations of Jupiter and Saturn. We conclude that the emission of soft X rays from the disks of Jupiter and Saturn can be largely explained by the scattering and fluorescence of solar soft X rays. We suggest that measured X‐ray intensities from the disk regions of Jupiter and Saturn can be used to constrain both the absolute intensity and the spectrum of solar X rays.
Zonal winds in the equatorial upper thermosphere: Decomposing the solar flux, geomagnetic activity, and seasonal dependencies
Authors: Liu Huixin , Lühr Hermann , Watanabe Shigeto , Köhler Wolfgang , Henize Vance , Visser Pieter
Published: July 2006

Using 3 years (2002–2004), over 16,400 orbits of measurements from the accelerometer on board the CHAMP satellite, we have studied the climatology of the equatorial zonal wind in the upper thermosphere. Several main features are noticed. The most prominent one is that the solar flux significantly influences both the daytime and nighttime winds. It overrides the geomagnetic activity effect, which is found to be rather limited to the nightside. An elevation of the solar flux level from F10.7 ≈ 100 × 10−22 W m−2 Hz−1 to F10.7 ≈ 190 × 10−22 W m−2 Hz−1 produces an eastward disturbance wind up to ∼110 m s−1. This consequently enhances the nighttime eastward wind but suppresses the daytime westward wind. A seasonal variation with weaker wind (by over 50 m s−1 at night) around June solstice than in other seasons has been observed regardless of solar flux and geomagnetic activity levels. The zonal wind is eastward throughout the night except around June solstice, where it ebbs to almost zero or turns even westward in the postmidnight sector at low solar flux level. The daytime wind is found to be generally more stable than the nighttime wind, particularly unresponsive to geomagnetic activities. Predictions from the Horizontal Wind Model find good agreement with the CHAMP‐observed wind at high solar flux levels during nighttime. At low solar flux levels, however, the model strongly underestimates the westward wind during morning hours by 50–120 m s−1 depending on season. The major difference between the HWM‐predicted and the CHAMP‐observed wind is seen in the phase of its diurnal variation. The CHAMP‐observed wind turns eastward around 1200–1300 MLT instead of 1600–1700 MLT predicted by the model. Comparisons with ground FPI observations and the NCAR Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIEGCM) predictions show that the solar flux effect obtained from CHAMP is consistent with that modeled by TIEGCM. The solar flux dependence of zonal wind found here together with that of the zonal ion drift found in previous studies reflect the relative importance of the E‐ and F‐region wind dynamo in the thermosphere‐ionosphere coupling process. Furthermore, these wind measurements indicate that the Earth's atmosphere superrotates. The average superrotation speed amounts to about 22 m s−1 for a solar flux level of F10.7 ≈ 100 × 10−22 W m−2 Hz−1 but increases to 63 m s−1 for F10.7 ≈ 190 × 10−22 W m−2 Hz−1. Finally, the wind behavior presented in this study is longitudinally averaged and may differ from wind measurements at a certain longitude.
Reevaluating the relationship between the Martian ionospheric peak density and the solar radiation
Authors: Zou H. , Wang J.‐S. , Nielsen E.
Published: July 2006

Several sets of the electron density profiles measured by the radio occultation experiment on board Mars Global Surveyor have been analyzed to investigate the dependence of the peak electron density of the Martian ionosphere on the solar zenith angle (SZA), neutral gas scale height (Hn), and E10.7, which was used as a proxy of the solar EUV radiation. Corrections have been made for the E10.7 index at the Earth orbit to obtain the E10.7 index at the Mars orbit (denoted as E*10.7). The relationship between the peak electron density (npeak)(in northern hemisphere) of the Martian ionosphere and the E*10.7, SZA and Hn is that ɛ = ln(〈npeak〉)/ln[〈(E*10.7 · cos χ)/Hn(peak)0.33〉] ≈ 0.44, slightly departing from 0.5, the value for an ideal Chapman layer. For the data set measured in the strong crustal magnetic field region (southern hemisphere), ɛ is higher than that in the nonmagnetic field region (northern hemisphere), which could be caused by the higher electron temperature in the strong magnetic field.
Comparison of horizontal velocity spectra derived from chaff rockets with saturation models
Authors: Wu Y. F. , Xu Jiyao
Published: July 2006

We present vertical wave number spectra of wind fluctuations using data with a height resolution of 25 m observed near the mesopause by 64 chaff rockets. Direct measurement of Brunt‐Väisälä frequency allows accurate calculations of spectral amplitude and local Richardson number. Individual vertical wave number spectra reveal considerable variability in both slope and amplitude, which is not consistent with the predictions of various saturation models. Mean vertical wave number spectra observed at different locations and seasons show great similarities. While the spectral amplitude predicted by the linear saturation model or saturated‐cascade model is comparable to the spectral amplitude of the observed mean spectrum, those spectral amplitudes predicted by other saturation models are larger than the observed mean amplitude within a factor of 3. However, mean vertical wave number spectra observed at 69°N exhibit significant seasonal variation with a shallower slope of −2.40 and a larger spectral amplitude of 2.6 × 105 (m2/s2)/(cyc/m) at m = 1/(4 km) in winter compared to that spectrum observed in summer. Very large mean wind shears, as high as 42–77 m/s/km, are observed to be present at several heights near the mesopause. Such strong mean shear profiles, together with the Brunt‐Väisälä frequency squared N2 profiles, act collectively to produce dynamical instability regions of local Richardson number Ri smaller than 0.25. These regions are found to correlate well with the saturated gravity wave spectra. In contrast, the stable region of local Richardson number Ri larger than 0.4 observed at high latitude in winter is found to associate with an unsaturated gravity wave spectrum.
A synergetic approach for estimating the local direct aerosol forcing: Application to an urban zone during the Expérience sur Site pour Contraindre les Modèles de Pollution et de Transport d'Emission (ESCOMPTE) experiment
Authors: Roger J. C. , Mallet M. , Dubuisson P. , Cachier H. , Vermote E. , Dubovik O. , Despiau S.
Published: July 2006

A method dedicated to the investigation of direct radiative forcing of the main anthropogenic aerosol species (ammonium sulfate, black carbon, particulate organic matter) is presented. We computed the direct radiative aerosol forcing at the top of atmosphere (TOA), at the bottom of atmosphere (BOA), and into the atmospheric layer (ATM). The methodology is based on chemical, photometric, and satellite measurements. We first determined the optical properties of the main aerosol species and then computed their direct radiative impact at local scale. The method was applied to a periurban zone during the Expérience sur Site pour Contraindre les Modèles de Pollution et de Transport d'Emission experiment. Optical computations indicate that the single scattering albedo, for the total aerosol population in the external mixture, is equal to 0.83 ± 0.04 at 550 nm, indicative of a strong absorption of the solar radiation. At the same time the mean asymmetry parameter is equal to 0.59 ± 0.04, and the mean aerosol optical thickness is equal to 0.30 ± 0.02, at 550 nm. The anthropogenic urban aerosol layer reduces significantly the daily surface illumination (−24 W m−2 > ΔFBOA > −47.5 W m−2) by reflection to space (−6 W m−2 > ΔFTOA > −9 W m−2) and by absorption of the solar radiation into the atmosphere (17 W m−2 < ΔFATM < 39 W m−2). The available resulting energy in the atmospheric column heats the lowermost part of the atmosphere from 1.1°K d−1 to 2.8°K d−1. Our study shows that the black carbon particles have a large contribution to the BOA forcing (almost 50% of the total daily forcing), whereas the ammonium sulfate particles contribute only to about 10%. Conversely, the TOA daily forcing is mostly driven by the ammonium sulfate aerosol (around 50%).
Vertical and horizontal structure of winter precipitation systems over the western Pacific around Japan using TRMM data
Authors: Yamamoto Munehisa K. , Higuchi Atsushi , Nakamura Kenji
Published: July 2006

The characteristics of winter precipitation systems over the northwestern Pacific are analyzed using data from multiple sensors on board the Tropical Rainfall Measuring Mission (TRMM) satellite. Using the Precipitation Radar (PR) and the Visible Infrared Scanner (VIRS), vertical and horizontal distribution of precipitation is investigated and compared with microwave signatures measured by the TRMM Microwave Imager (TMI). Winter precipitation patterns are classified into four types by the cloud and pressure pattern and the region: the extratropical cyclone and front pattern (CF) and the cold outbreak pattern (CO) over the Sea of Japan (CO‐J), over the Yellow Sea (CO‐Y), and over the Pacific Ocean (CO‐P). For CO the height of precipitation is centered around 2 km and shallow, isolated, and weak (∼20 dBZ) precipitation dominates. Cloud top height reaches about 4 km. Compared with CO‐Y and CO‐J, CO‐P tends to develop larger systems and to have melting layers near the surface. For CF the height of precipitation is concentrated around 3 km and precipitation is relatively broad with a large variation of intensity. These characteristics explain the differences between the retrieved rain rate by PR and TMI. TMI frequently misses precipitation for CO because the systems are usually shallow but less frequently misses weak precipitation than PR for CF because of emission from 85 GHz channel. When both PR and TMI detect rain, the PR rain rate is larger than TMI for CO and smaller than TMI for weak precipitation for CF. From the microwave signature for each pattern it was suggested that the size of precipitation system is one of the possible cause of the differences of rain estimation and detection.
Polar stratospheric clouds observed by the ILAS‐II in the Antarctic region: Dual compositions and variation of compositions during June to August of 2003
Authors: Kim Y. , Choi W. , Lee K.‐M. , Park J. H. , Massie S. T. , Sasano Y. , Nakajima H. , Yokota T.
Published: July 2006

Compositions and effective radii of polar stratospheric clouds (PSCs) in the Antarctic region from 5 June to 28 August of 2003 are determined using transmittance data from the Improved Limb Atmospheric Spectrometer‐II (ILAS‐II). Dual compositions are derived for 83 Antarctic cases. The primary components are β‐NAT (β form of nitric acid trihydrate), NAW (nitric acid water, or SBS, supercooled binary solution), and ICE. Other minor composition components are LTA (liquid ternary aerosol, or STS, supercooled ternary solution), α‐NAT (α form of NAT), NAD (nitric acid dihydrate), and SAW (sulfuric acid water). Three single compositions are found; that is, β‐NAT particles were observed from 11 June to 12 August, NAW particles were observed from 28 June to 24 July, and ICE particles were observed from 28 July to 25 August. During this period, dual compositions are also found, i.e., NAW + β‐NAT, β‐NAT + ICE, NAW + ICE, β‐NAT + NAD, β‐NAT + LTA, and β‐NAT + SAW. For this observation period, temperatures varied from 195 K to 180 K while measurements were made progressively in time as latitude varied from 65°S to 80°S. This mixture of compositions is assumed to be either two separate patches of PSCs or a mixture of two different types along the line of sight. The feasibility of the coexistence of dual compositions in a PSC and importance of determination of the PSC particle type for the study of heterogeneous chemistry for ozone are briefly discussed.
Evaluation of fraction of absorbed photosynthetically active radiation products for different canopy radiation transfer regimes: Methodology and results using Joint Research Center products derived from SeaWiFS against ground‐based estimations
Authors: Gobron Nadine , Pinty Bernard , Aussedat Ophélie , Chen Jing M. , Cohen Warren B. , Fensholt Rasmus , Gond Valery , Huemmrich Karl Fred , Lavergne Thomas , Mélin Frédéric , Privette Jeffrey L. , Sandholt Inge , Taberner Malcolm , Turner David P. , Verstraete Michel M. , Widlowski Jean‐Luc
Published: July 2006

This paper discusses the quality and the accuracy of the Joint Research Center (JRC) fraction of absorbed photosynthetically active radiation (FAPAR) products generated from an analysis of Sea‐viewing Wide Field‐of‐view Sensor (SeaWiFS) data. The FAPAR value acts as an indicator of the presence and state of the vegetation and it can be estimated from remote sensing measurements using a physically based approach. The quality of the SeaWiFS FAPAR products assessed in this paper capitalizes on the availability of a 6‐year FAPAR time series over the full globe. This evaluation exercise is performed in two phases involving, first, an analysis of the verisimilitude of the FAPAR products under documented environmental conditions and, second, a direct comparison of the FAPAR values with ground‐based estimations where and when the latter are available. This second phase is conducted following a careful analysis of problems arising for performing such a comparison. This results in the grouping of available field information into broad categories representing different radiative transfer regimes. This strategy greatly helps the interpretation of the results since it recognizes the various levels of difficulty and sources of uncertainty associated with the radiative sampling of different types of vegetation canopies.
Comparison of satellite‐derived UV irradiances with ground‐based measurements at four European stations
Authors: Kazantzidis A. , Bais A. F. , Gröbner J. , Herman J. R. , Kazadzis S. , Krotkov N. , Kyrö E. , den Outer P. N. , Garane K. , Görts P. , Lakkala K. , Meleti C. , Slaper H. , Tax R. B. , Turunen T. , Zerefos C. S.
Published: July 2006

Satellite‐derived ultraviolet (UV) irradiances may form the basis for establishing a global UV climatology, provided that their accuracy is confirmed against ground‐based measurements of known quality. In this study, quality‐checked spectral UV irradiance measurements from four European stations (Sodankyla, Finland; Bilthoven, Netherlands; Ispra, Italy; and Thessaloniki, Greece) are compared with those derived from TOMS, based on the (version 8) data set. The aim of this study is to validate the TOMS UV irradiances and to investigate the origin of disagreements with ground‐based data. Comparisons showed that TOMS overestimates summertime noon CIE‐weighted irradiances from 6.6% at the high‐latitude site of Sodankyla up to 19% for the three other sites. The influence of clouds and aerosols on the observed differences was investigated. For the other three sites (Bilthoven, Ispra, and Thessaloniki), TOMS overestimates the irradiance at 324 nm by almost 15% even under conditions with cloud optical depth of less than 5. For cloud‐free days at Ispra and Thessaloniki, differences ranging between 3% and 20% are well correlated with aerosol optical depth.
High‐frequency climate linkages between the North Atlantic and the Mediterranean during marine oxygen isotope stage 100 (MIS100)
Authors: Becker Julia , Lourens Lucas J. , Raymo M. E.
Published: July 2006

High‐resolution records of Mediterranean and North Atlantic deep‐sea sediments indicate that rapid changes in hydrology and climate occurred during marine oxygen isotope stage 100 (MIS100) (at ∼2.52 Ma), which exhibits characteristics similar to late Pleistocene Dansgaard‐Oeschger, Bond cycles and Heinrich events. As in the late Pleistocene, North Atlantic oceanographic and atmospheric changes were probably transmitted into the Mediterranean by some combination of surface water inflow and Atlantic‐Mediterranean atmospheric pressure gradients. Our data suggest that the mechanism(s) responsible for sub‐Milankovitch and millennial‐scale climate oscillations were the same over at least the past 2.6 Ma, notwithstanding the transition from the 41‐kyr‐dominated glacial cycles of the late Pliocene to the 100‐kyr cycles of the late Pleistocene.
Recurrence of postseismic coastal uplift, Kuril subduction zone, Japan
Authors: Kelsey Harvey , Satake Kenji , Sawai Yuki , Sherrod Brian , Shimokawa Koichi , Shishikura Masanobu
Published: July 2006

Coastal stratigraphy of eastern Hokkaido indicates that decimeters of coastal uplift occurred repeatedly in the late Holocene. Employing radiocarbon dating and tephrochronology, we identify along a 100 km length of the Kuril subduction zone six uplift events since ∼2,800 years B.P. Uplift events occur at the same frequency as unusually high tsunamis. Each coastal uplift event, which occurs on average every 500 years, is the product of decade‐long post seismic deep slip on the down dip extension of the seismogenic plate boundary following an offshore multi‐segment earthquake that generates unusually high tsunamis.
Timescale dependency of spatial patterns in the variability of the Northern Hemisphere winter SLP field
Authors: Zhao Hongxu , Moore G. W. K.
Published: July 2006

The Arctic Oscillation (AO), the North Atlantic Oscillation (NAO) and the Cold Ocean‐Warm Land Pattern (COWL) have been identified as important modes of variability in the Northern Hemisphere winter sea‐level pressure field. However, which one is most fundamental in describing this variability and the relationship between them are still important open questions. A key uncertainty is our lack of knowledge of the linkages between the Arctic, North Atlantic and North Pacific Oceans that are manifest in these modes. In this study, the authors investigate these linkages through a frequency dependent decomposition of the variability in the Northern Hemisphere sea‐level pressure field. In particular, the authors show that the spatial expression of the variability in this field has a frequency dependence that results in a NAO‐like pattern on inter‐annual timescales, an AO‐like pattern on inter‐decadal timescales and a COWL‐like pattern on multi‐decadal timescales.
Bottom boundary layer flow and salt injection from the continental shelf to slope
Authors: Brink K. H. , Shearman R. Kipp
Published: July 2006

Austral winter oceanographic measurements from the northwest Australian continental shelf reveal salty water forming evaporatively inshore, moving across the wide shelf near the bottom and into the adjacent open ocean when the shelf edge alongshore flow is equatorward. The salt tongue is absent during more normal conditions, when the poleward Leeuwin Current is present. We hypothesize that the flow reversal enables shelf‐wide bottom boundary layer (Ekman) transport and thus creates the shelf‐edge convergence that accounts for the observed salt tongue. This flow is absent under sustained normal conditions because of buoyancy arrest in the bottom boundary layer.
Dayside convection aligned auroral arcs
Authors: Zhang Y. , Paxton L. J.
Published: July 2006

TIMED GUVI and IMAGE FUV observed a new phenomenon: Dayside Convection Aligned Auroral Arcs (DCAA) under conditions of high solar wind speed/dynamic pressure, and magnetic activity. The DCAA is observed near the dayside ionospheric convection throat and aligned with the convection direction. All the data suggest that DCAA is due to energetic proton/ions and/or electrons from the dayside ring current. The life time of the DCAA under northward IMF conditions is much longer than that of the DCAA under southward IMF conditions. The length of DCAA ranges from 5° to 8° in magnetic latitude.
Correlated increase in CO2 fumarolic content and diffuse emission from La Fossa crater (Vulcano, Italy): Evidence of volcanic unrest or increasing gas release from a stationary deep magma body?
Authors: Granieri D. , Carapezza M. L. , Chiodini G. , Avino R. , Caliro S. , Ranaldi M. , Ricci T. , Tarchini L.
Published: July 2006

The peculiarity of the quiescent La Fossa volcano is the occurrence of “crises” characterized by strong increases of fumarole T and output and by chemical changes indicative of an increasing input of magmatic fluids. Several surveys carried out during a new “crisis” began in November 2004 indicate that the total diffuse CO2 emission for the crater area increases by one order of magnitude during crises (up to 1600 ton·d−1 in December 2005). Concern exists on the possibility that these crises be related to an unrest process leading to eruption. The repetition along decades of the same gas compositional variations during crises, their temporal coincidence with increases of the local shallow seismicity, and the lack of any significant ground motion, rather suggest that they correspond to moments of increasing volatile release from a stationary magma system.
Temporal and spatial delineation of mouse Otx2 functions by conditional self‐knockout
Authors: Fossat Nicolas , Chatelain Gilles , Brun Gilbert , Lamonerie Thomas
Published: July 2006

To identify the independent spatial and temporal activities of the essential developmental gene the Otx2, the germline mutation of which is lethal at embryonic day 8.5, we floxed one allele and substituted the other with an inducible CreER recombinase gene. This makes ‘trans’ self‐knockout possible at any developmental stage. The transient action of tamoxifen pulses allows time‐course mutation. We demonstrate efficient temporal knockout and demarcate spatio‐temporal windows in which Otx2 controls the head, brain structures and body development.
The Yersinia enterocolitica effector YopP inhibits host cell signalling by inactivating the protein kinase TAK1 in the IL‐1 signalling pathway
Authors: Thiefes Axel , Wolf Alexander , Doerrie Anneke , A Grassl Guntram , Matsumoto Kunihiro , Autenrieth Ingo , Bohn Erwin , Sakurai Hiroaki , Niedenthal Rainer , Resch Klaus , Kracht Michael
Published: July 2006

The mechanism by which YopP simultaneously inhibits mitogen‐activated protein kinase (MAPK) and nuclear factor‐κB pathways has been elusive. Ectopic expression of YopP inhibits the activity and ubiquitination of a complex consisting of overexpressed TGF‐β‐activated kinase 1 (TAK1) and its subunit TAK1‐binding protein (TAB)1, but not of MEK kinase 1. YopP, but not the catalytically inactive mutant YopPC172A, also suppresses basal and interleukin‐1‐inducible activation of endogenous TAK1, TAB1 and TAB2. YopP does not affect the interaction of TAK1, TAB1 and TAB2 but inhibits autophosphorylation of TAK1 at Thr 187 and phosphorylation of TAB1 at Ser 438. Glutathione S‐transferase‐tagged YopP (GST–YopP) binds to MAPK kinase (MAPKK)4 and TAB1 but not to TAK1 or TAB2 in vitro. Furthermore, YopP in synergy with a previously described negative regulatory feedback loop inhibits TAK1 by MAPKK6–p38‐mediated TAB1 phosphorylation. Taken together, these data strongly suggest that YopP binds to TAB1 and directly inhibits TAK1 activity by affecting constitutive TAK1 and TAB1 ubiquitination that is required for autoactivation of TAK1.
Spot pattern of leopard Danio is caused by mutation in the zebrafish connexin41.8 gene
Authors: Watanabe Masakatsu , Iwashita Motoko , Ishii Masaru , Kurachi Yoshihisa , Kawakami Atsushi , Kondo Shigeru , Okada Norihiro
Published: July 2006

Leopard, a well‐known zebrafish mutant that has a spotted skin pattern instead of stripes, is a model for the study of pigment patterning. To understand the mechanisms underlying stripe formation, as well as the spot variation observed in leopard, we sought to identify the gene responsible for this phenotype. Using positional cloning, we identified the leopard gene as an orthologue of the mammalian connexin 40 gene. A variety of different leopard alleles, such as leot1, leotq270 and leotw28, show different skin‐pattern phenotypes. In this manuscript we show that the mutation in allele leot1 is a nonsense mutation, whereas alleles leotq270 and leotw28 contain the missense mutations I202F and I31F, respectively. Patch‐clamp experiments of connexin hemichannels demonstrated that the I202F substitution in allele leotq270 disrupted the channel function of connexin41.8. These results demonstrate that mutations in this gene lead to a variety of leopard spot patterns.
HoxB domain induction silences DNA replication origins in the locus and specifies a single origin at its boundary
Authors: Grégoire Damien , Brodolin Konstantin , Méchali Marcel
Published: July 2006

In multicellular organisms, changes in the DNA replication programme could act to integrate differentiation with cell division in various developmental and transcriptional contexts. Here, we have addressed the use of DNA replication origins during differentiation in the HoxB domain—a cluster of nine genes developmentally regulated in a collinear manner. In undifferentiated mouse P19 cells, we detected several DNA replication origins in the 100 kb HoxB locus, indicating a relaxed origin use when the locus is transcriptionally silent. By contrast, in retinoic‐acid‐induced differentiated cells, when HoxB transcription is activated, a general silencing of DNA replication origins occurs in the locus except one located downstream of Hoxb1, at the 3′ boundary of the HoxB domain. Silencing of the replication origins is associated with histone hyperacetylation, whereas the active Hoxb1 origin persists as a hypoacetylated island. These findings provide direct evidence for the differentiated use of origins in HoxB genes, and we suggest that this regulation might contribute to the regulated expression of HoxB genes during development.
Global phase diagram for the honeycomb potential
Authors: Hynninen Antti-Pekka , Panagiotopoulos Athanassios Z. , Rechtsman Mikael C. , Stillinger Frank H. , Torquato Salvatore
Published: July 2006

We calculate the global phase diagram using classical statistical mechanics for an isotropic pair potential that has been previously [Rechtsman et al., Phys. Rev. Lett. 95, 228301 (2005)] shown to produce the low-coordinated two-dimensional honeycomb crystal as the ground-state structure. Low-coordinated crystals are of practical interest because they have desirable photonic band-gap properties. The phase diagram is obtained from Helmholtz free energies calculated using thermodynamic integration and Monte Carlo simulations. Our results show that the honeycomb crystal remains stable in the global phase diagram even after temperature effects are taken fully into account. Other stable phases in the phase diagram are high and low density triangular phases and a fluid phase. We find no evidence of gas-liquid or liquid-liquid phase coexistence.
Thermal properties of THz quantum cascade lasers based on different optical waveguide configurations
Authors: Vitiello Miriam S. , Scamarcio Gaetano , Spagnolo Vincenzo , Alton Jesse , Barbieri Stefano , Worrall Chris , Beere Harvey E. , Ritchie David A. , Sirtori Carlo
Published: July 2006

We compare the thermal properties of THz quantum cascade lasers (QCLs) fabricated with metal-metal optical waveguides based on Au∕Au or In∕Au wafer bonding. This information was obtained from the analysis of microprobe band-to-band photoluminescence spectra measured on devices operating in continuous wave (cw). The experimental normalized thermal resistances (RL*), show that the use of Au∕Au wafer bonding optimizes the heat dissipation. Comparison with surface-plasmon based THz QCLs, demonstrates that the use of metal-metal wafer bonding can allow cw operation at progressively higher temperatures.
Effect of three-dimensional current and temperature distributions on void formation and propagation in flip-chip solder joints during electromigration
Authors: Liang S. W. , Chang Y. W. , Shao T. L. , Chen Chih , Tu K. N.
Published: July 2006

Effect of three-dimensional current distribution on void formation in flip-chip solder joints during electromigration was investigated using thermoelectrical coupled modeling, in which the current and temperature redistributions were coupled and simulated at different stages of void growth. Simulation results show that a thin underbump metallization of low resistance in the periphery of the solder joint can serve as a conducting path, leading to void propagation in the periphery of the low current density region. In addition, the temperature of the solder did not rise significantly until 95% of the contact opening was eclipsed by the propagating void.
An enzyme-linked immunosorbent assay for the detection of Rathayibacter toxicus, the bacterium involved in annual ryegrass toxicity, in hay
Authors: Masters A. M. , Gregory A. R. , Evans R. J. , Speijers J. E. , Sutherland S. S.
Published: July 2006

An enzyme-linked immunosorbent assay (ELISA) for Rathayibacter toxicus is described. The development of a monoclonal antibody for a specific antigen from R. toxicus and a polyclonal antibody raised against the same R. toxicus preparation enabled a capture assay format. The assay is specific for a soluble polysaccharide produced by the bacterium and was found to be sensitive enough to detect antigen equivalent to less than one gall per kilogram of hay. The applicability of the assay to samples of pasture or hay is demonstrated. Cost-effective testing of large numbers of samples for the presence of R. toxicus is possible with the ELISA. This will assist stockowners, hay producers, and hay exporters in the management of the risk of annual ryegrass toxicity.
Development of black pigmented skin spots and pigmented wool fibres in a Merino flock—causes, field observations, and wool measurement
Authors: Fleet M. R.
Published: July 2006

The development of black-grey pigmented skin spots and pigmented wool fibres on adult Merino sheep over a 3-year period was assessed. Effects of long-term grazing of oestrogenic pasture and multiple shearing were studied. The number of affected sheep and number of pigmented spots on affected sheep increased with age, with the greatest increase at 8.5 years age. Grazing of oestrogenic pastures had no effect but twice yearly shearing increased the development of pigmented spots after 2 years of treatment. Measurements on fleeces and top from sheep with no apparent pigmented spots showed that this wool was generally free of pigmented fibres. In contrast, wool from affected individuals generally had high concentrations of pigmented wool fibres, with substantial pigmented lengths (means 20–40 mm) and intensely darkened, which related to the field records of black-grey pigmented skin spots. The amounts of dark pigmented fibres found in the processed top from affected fleeces ranged between 262 and 1293/kg. Based on these findings, sheep age is an important factor for inclusion in decision systems alerting wool buyers to the risk of hidden dark fibres. However, if adequate inspection of sheep during shearing is practical to isolate fleeces from sheep with black-grey pigmented skin spots in the fleece areas, then the risk level applied could be lowered or removed for the wool from the unaffected sheep.
Limited ecoclinal variation found in Malva parviflora (small-flowered mallow) across the Mediterranean-climatic agricultural region of Western Australia
Authors: Michael Pippa J. , Steadman Kathryn J. , Plummer Julie A.
Published: July 2006

Malva parviflora L. populations were collected from 24 locations across the Mediterranean–climatic agricultural region of Western Australia and grown in Perth in a common garden experiment. Seventeen morphometric and taxonomic measurements were taken and genetic variation was investigated by performing principal components analysis (PCA). Taxonomic measurements confirmed that all plants used in the study were M. parviflora. Greater variation occurred within populations than between populations. Separation between populations was only evident between northern and southern populations along principal components 2 (PC2), which was due mainly to flowering time. Flowering time and consequently photoperiod were highly correlated with latitude and regression analysis revealed a close relationship (r2 = 0.6). Additionally, the pollination system of M. parviflora was examined. Plants were able to self-pollinate without the need for external vectors and the pollen–ovule ratio (31 ± 1.3) revealed that M. parviflora is most likely to be an obligate inbreeder with a slight potential for outcrossing. The limited variation of M. parviflora enhances the likelihood of suitable control strategies being effective across a broad area.
Prevalence, severity, and heritability of Stephanofilaria lesions on cattle in central and southern Queensland, Australia
Authors: Sutherst R. W. , Bourne A. S. , Maywald G. F. , Seifert G. W.
Published: July 2006

Observations of cattle in central and southern Queensland are collated to define the prevalence and area of Stephanofilaria lesions associated with infestations of the buffalo fly, Haematobia irritans exigua. The observations were made on herds that were being used for other purposes. In a survey of ~1500 animals at Belmont in central Queensland in 1982, 98% of cows and 70% of calves had lesions. Most lesions were on the neck and dewlap and 10% were raw and weeping at the time of sampling. The total area of lesions per animal was strongly related to cattle breed and age. Old Bos taurus animals had the greatest area of lesions, whereas young Bos indicus had the least. Heritability estimates were low, averaging 0.01 for calves and 0.18 for cows. A smaller survey of cows and steers at Craighoyle in central Queensland in 1986 showed a higher numbers of lesions and positive correlations between the total lesion area and animal size. The lesion area increased with tick survival, suggesting that tick-resistant animals are also resistant to Stephanofilaria infection. Steers had smaller areas of lesions than cows, as found previously with cattle ticks. Long-term monitoring observations in central and southern Queensland between 1981 and 1986 showed that the total area of lesions was seasonal with a peak in late summer, consistent with the seasonal incidence of buffalo fly. Animals segregated into Low and High lesion herds maintained their differences over time. The lesions penetrated the dermis of the cattle hides and rendered the affected area unusable, but few lesions occurred on valuable parts of the hide so such economic effects are likely to be insignificant. One animal nearly died of a haemorrhage from a lesion on the dewlap and had to be treated. The results can inform policy on buffalo fly control, and biosecurity preparations in relation to the potential establishment of the Old World screw-worm fly, Chrysomyia bezziana, in Australia, which will be facilitated by the lesions. The results emphasise the significant animal welfare and biosecurity risks posed by the lesions in northern Australia.
Small grain screenings in wheat—using the grain size distribution for predicting cultivar responses
Authors: Sharma D. L. , D'Antuono M. F. , Anderson W. K.
Published: July 2006

Small grain is a concern for wheat growers in water-limited environments worldwide. Following from our preliminary results that cultivars can differ for small grain screenings despite similarity of average grain weight in wheat, grain size distribution was investigated with the aim of identifying alternative parameters that could more reliably discriminate cultivars for their tendency to screenings without actually subjecting breeding material to harsh environments.
Pre-cleaned harvest samples (using screen with 1.5-mm-wide holes) of 5 cultivars from 2 field cultivar × time of sowing experiments were divided into 5 grain-width fractions using 4 sieves with holes from 2.5 to 3.4-mm wide. The experiments conducted in the Western Australian wheatbelt experienced a dry finish in 2000 and a relatively wetter year in 2003. The grain that was separated into each width fraction was weighed and the average weight of grains for each fraction (called the size-specific weight) was derived from a subsample.
The weight of grain (expressed as a percentage of the whole) collected between the 2.8 and 3.1-mm screens (fraction F3) was highly and negatively correlated with small grain screenings (r = –0.85; P < 0.001), thus strengthening the perception that screenings percentages may follow a certain form of grain size distribution. Among various grain size distributions, the skew-Laplace distribution fitted on grain weight was found to be the most suitable to characterise the cultivars. This provides a general approach in the examination of a grain size distribution, which is invariant to combinations of sieve sizes that different individuals may choose.
We conclude that: (i) parameters µ and 1/α of the skew-Laplace distribution based on grain weight separated into each fraction can be used as a selection tool in predicting propensity for small grain screenings in wheat without having to subject breeding material to harsh conditions; (ii) higher values for both µ and 1/α are desirable but if the cultivar has small µ, a high 1/α is required to reduce screenings; (iii) breeders could consider the grain size distribution in addition to grain weight as a breeding objective; and (iv) millers should be looking for higher average grain weight and higher weight per unit grain length especially at small width fractions, to maximise flour yield. Hence, we anticipate that future research into aspects of starch packaging such as grain shape and endosperm density will optimise grain size distribution, grain weight per unit grain length, and eventually the flour yield per unit land area.
Susceptibility of pigeonpea and some of its wild relatives to predation by Helicoverpa armigera: implications for breeding resistant cultivars
Authors: Green P. W. C. , Sharma H. C. , Stevenson P. C. , Simmonds M. S. J.
Published: July 2006

Helicoverpa armigera (Hübner), the podborer, is a pest of considerable economic importance to crop production across Asia and Australia. The larvae cause significant damage to many crops including the cultivated pigeonpea, Cajanus cajan. We have conducted oviposition and pod feeding-damage studies with H. armigera on 5 varieties of C. cajan, 6 other Cajanus species, and Rhynchosia bracteata. The species could be divided into podborer-resistant [C. scarabaeoides (ICPW 83), C. cajanifolius, C. sericeus, C. albicans, and C. platycarpus], moderately resistant [Rhynchosia bracteata and some varieties of C. cajan], or susceptible [C. cajan (ICPL 87)]. At 100 μg/g a methanol extract of the susceptible cultivar of Cajanus (ICPL 87) stimulated significantly more oviposition than a similar extract of the resistant species C. scarabaeoides, ICPW 83. Pod surface extracts of both ICPW 83 and ICPL 87 contained isoquercitrin, quercetin, and quercetin-3-methyl ether, although they were present at much lower concentrations in ICPW 83. A fourth compound, 3-hydroxy-4-prenyl-5-methoxystilbene-2-carboxylic acid (stilbene), was detected in a methanol extract of the pod surfaces of ICPL 87. A methanol extract of ICPL 87, from which the stilbene had been removed, stimulated oviposition when paired with the whole extract. These results are discussed in relation to the selection of varieties with morphological and chemical characters that can be used for developing cultivars less susceptible to podborer.
Detection of nitrogen deficiency in wheat from spectral reflectance indices and basic crop eco-physiological concepts
Authors: Rodriguez D. , Fitzgerald G. J. , Belford R. , Christensen L. K.
Published: July 2006

We tested the capacity of several published multispectral indices to estimate the nitrogen nutrition of wheat canopies grown under different levels of water supply and plant density and derived a simple canopy reflectance index that is greatly independent of those factors. Planar domain geometry was used to account for mixed signals from the canopy and soil when the ground cover was low. A nitrogen stress index was developed, which adjusts shoot %N for plant biomass and area, thereby accounting for environmental conditions that affect growth, such as crop water status. The canopy chlorophyll content index (CCCi) and the modified spectral ratio planar index (mSRPi) could explain 68 and 69% of the observed variability in the nitrogen nutrition of the crop as early as Zadoks 33, irrespective of water status or ground cover. The CCCi was derived from the combination of 3 wavebands 670, 720 and 790 nm, and the mSRPi from 445, 705 and 750 nm, together with broader bands in the NIR and RED. The potential for their spatial application over large fields/paddocks is discussed.