bluuebunny/crossref_metadata_2025 huggingface dataset:
Idealized numerical experiments associated with the intensity and rapid intensification of stationary tropical‐cyclone‐like vortex and its relation to initial sea‐surface temperature and vortex‐induced sea‐surface cooling
Authors: Wada Akiyoshi
Published: September 2009

Idealized numerical experiments were performed using a nonhydrostatic atmospheric model coupled with a slab mixed‐layer ocean model with a horizontal grid spacing of 2 km in order to investigate the roles of initial sea‐surface temperature (SST) and vortex‐induced sea‐surface cooling (SSC) in the intensity and intensification of a stationary idealized tropical‐cyclone‐like vortex. Numerical experiment results indicate that the coupled model reproduces rapid intensification, transition, and mature phases in the SST‐central pressure (CP) relation. CP is better approximated by a power function of mixed‐layer heat potential (MLHP) accumulated every 3 hours. The evolution of the vortex and the impacts of initial SST and SSC on the vortex's structural evolution were investigated using potential vorticity (PV) and filamentation time (FT). Mesovortices are rapidly intensified wherein both a steep PV gradient and a positive FT exist. Mesovortices yield the acceleration of inward angular momentum transports, resulting in enhanced inertial forcing. SSC decelerates inward angular momentum transports by reducing PV around the mesovortices. This deceleration suppresses periodic variations of the average atmospheric boundary layer heights, reduces warm‐core temperature anomalies, and lowers their existing heights during the rapid intensification phase. The role of the initial SST in the vortex's evolution is that a high initial SST accelerates the rapid intensification process. Even if accumulated MLHP increases during the mature phase, the vortex Rossby number is reduced, indicating that enhanced vortex Rossby waves increase the radius of maximum wind speed due to high SST.
Reconstruction of solar UV irradiance since 1974
Authors: Krivova N. A. , Solanki S. K. , Wenzler T. , Podlipnik B.
Published: September 2009

Variations of the solar UV irradiance are an important driver of chemical and physical processes in the Earth's upper atmosphere and may also influence global climate. Here we reconstruct solar UV irradiance in the range 115–400 nm over the period 1974–2007 by making use of the recently developed empirical extension of the Spectral And Total Irradiance Reconstruction (SATIRE) models employing Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) data. The evolution of the solar photospheric magnetic flux, which is a central input to the model, is described by the magnetograms and continuum images recorded at the Kitt Peak National Solar Observatory between 1974 and 2003 and by the Michelson Doppler Imager instrument on SOHO since 1996. The reconstruction extends the available observational record by 1.5 solar cycles. The reconstructed Ly‐α irradiance agrees well with the composite time series by Woods et al. (2000). The amplitude of the irradiance variations grows with decreasing wavelength and in the wavelength regions of special interest for studies of the Earth's climate (Ly‐α and oxygen absorption continuum and bands between 130 and 350 nm) is 1–2 orders of magnitude stronger than in the visible or if integrated over all wavelengths (total solar irradiance).
A precise and rapid mapping protocol for correlative light and electron microscopy of small invertebrate organisms
Authors: Kolotuev Irina , Schwab Yannick , Labouesse Michel
Published: September 2009

Background information. CLEM (correlative live cell and electron microscopy) seeks to bridge the data acquired with different imaging strategies, typically between light microscopy and electron microscopy. It has been successfully applied in cell cultures, although its use in multicellular systems is hampered by difficulties in locating the ROI (region of interest).

Results. We developed a CLEM technique that enables easy processing of small model animals and is adequate both for morphology and immunoelectron‐microscopic specimen preparations. While this method has been initially developed for Caenorhabditis elegans samples, we found that it works equally well for Drosophila samples. It enables handling and observation of single animals of any complex genotype in real time, fixation by high‐pressure freezing and flat embedding. Our major improvement has been the development of a precise mapping system that considerably simplifies and speeds up the retrospective location of the ROI within 1 μm distance. This method can be successfully used when correlative microscopy is required, as well as to facilitate the treatment of non‐correlative TEM procedures. Our improvements open the possibility to treat statistically significant numbers of animals processed by electron microscopy and considerably simplifies electron‐microscopic protocols, making them more accessible to a wider range of researchers.

Conclusions. We believe that this technique will contribute to correlative studies in multicellular models and will facilitate the time‐demanding procedure of specimen preparation for any kind of TEM.
Accurate Atomic Transition Probabilities for Hydrogen, Helium, and Lithium
Authors: Wiese W. L. , Fuhr J. R.
Published: September 2009

We have carried out a comprehensive tabulation of the atomic transition probabilities for allowed and forbidden lines of hydrogen, helium and lithium, including LiII, as well as the hydrogen isotopes deuterium and tritium. Altogether, we tabulated about 3600 transitions and listed scaling relations for the hydrogenlike ions HeII and LiIII. The selected data are based on a critical evaluation of available literature sources and are all taken from recent advanced calculations. The tables are normally arranged in multiplets, and these are ordered in increasing excitation energies. For hydrogen, deuterium, and tritium, the energy levels are degenerate, i.e., all energy levels of the same principal quantum number essentially coincide. Thus, the principal tables for these species are for the average transition probabilities of lines between different principal quantum numbers.
Fundamental Equations of State for Parahydrogen, Normal Hydrogen, and Orthohydrogen
Authors: Leachman J. W. , Jacobsen R. T , Penoncello S. G. , Lemmon E. W.
Published: September 2009

If the potential for a boom in the global hydrogen economy is realized, there will be an increase in the need for accurate hydrogen thermodynamic property standards. Based on current and anticipated needs, new fundamental equations of state for parahydrogen, normal hydrogen, and orthohydrogen were developed to replace the existing property models. To accurately predict thermophysical properties near the critical region and in liquid states, the quantum law of corresponding states was applied to improve the normal hydrogen and orthohydrogen formulations in the absence of available experimental data. All three equations of state have the same maximum pressure of 2000MPa and upper temperature limit of 1000K. Uncertainty estimates in this paper can be considered to be estimates of a combined expanded uncertainty with a coverage factor of 2 for primary data sets. The uncertainty in density is 0.04% in the region between 250 and 450K and at pressures up to 300MPa. The uncertainties of vapor pressures and saturated liquid densities vary from 0.1% to 0.2%. Heat capacities are generally estimated to be accurate to within 1%, while speed-of-sound values are accurate to within 0.5% below 100MPa.
Tuning of threshold voltage in organic field-effect transistors with hydrophobic gate dielectric using monoenergetic low-energy electron beams and triode corona
Authors: Deshmukh K. D. , Reuter K. , Kempa H. , West J. E. , Katz H. E.
Published: September 2009

We report organic field-effect transistors (OFETs) with the hydrophobic gate dielectric exposed to an electron beam before semiconductor deposition, shifting the threshold voltage toward positive gate bias for a p-channel semiconductor. A 1 μm Cytop film was irradiated with defined doses of electron beams with different energies. The charges/polarizations embedded in the dielectric by the irradiation have effective charge densities of ∼10−8 C/cm2. OFETs were completed using 5,5′-bis(4-hexylphenyl)-2,2′-bithiophene as the semiconductor, and showed corresponding shifts in Vth. Other OFETs were made where the gate dielectric was treated with a corona discharge. Both types of devices showed similar shifts in Vth and transfer characteristics. There is no change in mobility of the charge carriers after either charging process. The charges do not contribute to the gate capacitance but induce changes in the onset of capacitance increase caused by accumulation of mobile channel charge during capacitance-voltage experiments in two-terminal metal-insulator-semiconductor-metal configurations.
Fabrication of nanometer-spaced superconducting Pb electrodes
Authors: Luo Kang , Yao Zhen
Published: September 2009

We report the fabrication of superconducting Pb electrodes with nanometer-sized separation by using the electromigration technique. Below the superconducting transition temperature, the electrodes show current-voltage characteristics consistent with the tunneling between two superconducting electrodes, which can be well understood within conventional theory of superconductivity. The electrodes can be reversibly switched between the normal and superconducting states by the application of an external magnetic field. These electrodes are suited for electron-transport studies of chemically synthesized nanostructures and the utility is demonstrated by making single-molecule transistors incorporating individual Co-porphyrin molecules.
Spectroscopic study of V doped Hg0.018Cd0.981Mn0.001Te bulk crystals as near-infrared materials for optical applications
Authors: Gnatenko Yu. P. , Bukivskij P. M. , Piryatinski Yu. P. , Faryna I. O. , Shigiltchoff O. A. , Gamernyk R. V.
Published: September 2009

It was shown that the photosensitivity region of the semi-insulating V doped Hg0.018Cd0.981Mn0.001Te crystals extends up to 1800 nm and is caused by the electron photogeneration resulting in the transitions from the main T41(F) state to the excited A42(F)- and T41(P) states of V2+ ions, which are in resonance with the conduction band. The electronic processes in the crystals are fast and correspond to the nanosecond region. Codoping by the Mn atoms leads to considerable improvement their optical quality and increase the resistivity. The obtained results indicate that such crystals can be considered as promising near-infrared materials for various optical applications.
Broadband optical amplification in silicate glass ceramics containing Li2ZnSiO4:Cr4+ nanocrystals
Authors: Zhuang Yixi , Teng Yu , Luo Jin , Zhu Bin , Chi Yingzhi , Wu E , Zeng Heping , Qiu Jianrong
Published: September 2009

Transparent glass ceramics containing Li2ZnSiO4:Cr4+ nanocrystals are prepared and their optical properties are investigated. The glass ceramics show intense broadband infrared luminescence and long fluorescence lifetime of about 90 μs. The single-pass optical amplification is demonstrated on a traditional two-wave mixing configuration. The optical gain efficiency is about 1.27 cm−1 when the excitation power is 0.80 W. The optical gain shows the similar wavelength dependence with luminescence properties. The transparent glass ceramics containing Li2ZnSiO4:Cr4+ nanocrystals have potential application as broadband gain media in optical communication system.
Three-dimensional fabrication of optically active microstructures containing an electroluminescent polymer
Authors: Mendonca C. R. , Correa D. S. , Marlow F. , Voss T. , Tayalia P. , Mazur E.
Published: September 2009

Microfabrication via two-photon absorption polymerization is a technique to design complex microstructures in a simple and fast way. The applications of such structures range from mechanics to photonics to biology, depending on the dopant material and its specific properties. In this paper, we use two-photon absorption polymerization to fabricate optically active microstructures containing the conductive and luminescent polymer poly(2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV). We verify that MEH-PPV retains its optical activity and is distributed throughout the microstructure after fabrication. The microstructures retain the emission characteristics of MEH-PPV and allow waveguiding of locally excited fluorescence when fabricated on top of low refractive index substrates.
The reason for the increased threshold switching voltage of SiO2 doped Ge2Sb2Te5 thin films for phase change random access memory
Authors: Ryu Seung Wook , Lee Jong Ho , Ahn Young Bae , Kim Choon Hwan , Yang Bong Seob , Kim Gun Hwan , Kim Soo Gil , Lee Se-Ho , Hwang Cheol Seong , Kim Hyeong Joon
Published: September 2009

This study examined the threshold switching voltage (VT) of 150 nm thick SiO2 doped Ge2Sb2Te5 (SGST) films for phase change random access memory applications. The VT of the SGST films increased from ∼0.9 V (for GST) to ∼1.5 V with increasing SiO2 content. The optical band gap and Urbach edge of the SGST films were similar regardless of the SiO2 concentration. The dielectric constant decreased by ∼37% and the electrical resistivity increased by ∼19%. The increase in VT of SGST films is associated with an effective increase in electric field and the decreased generation rate caused by impact ionization.
Selective liquid crystal molecule orientation on ion beam irradiated tantalum oxide ultrathin films
Authors: Lim Ji-Hun , Oh Byeong-Yun , Lee Won-Kyu , Lee Kang-Min , Na Hyun-Jae , Kim Byoung-Yong , Seo Dae-Shik , Han Jeong-Min , Hwang Jeong-Yeon
Published: September 2009

We recently achieved the homogeneous alignment of liquid crystal (LC) on amorphous Ta2O5 layers. This study demonstrates that LC layers could be aligned either homogeneously or vertically by increasing the growth temperature of rf magnetron sputtering device and the irradiation time of the DuoPIGatron type Ar ion beam device causing uniform and dense plasma. We attained two LC orientations by observing Ta 4f and O 1s peak shifts with x-ray photoelectron spectroscopy. Moreover, the decreased thickness of layers with high-k dielectric constants helped to decrease driving LC voltages and in turn to achieve low power consumption.
Semiconductor to metal transition characteristics of VO2 thin films grown epitaxially on Si (001)
Authors: Gupta A. , Aggarwal R. , Gupta P. , Dutta T. , Narayan Roger J. , Narayan J.
Published: September 2009

We report semiconductor to metal transition (SMT) characteristics of vanadium dioxide (VO2) grown epitaxially on Si (001) at 500 °C. The epitaxial integration with Si (001) was achieved by using epitaxial tetragonal yttria-stabilized zirconia (YSZ) as an intermediate buffer layer, which was grown in situ. From x-ray (θ-2θ and ϕ-scan) and electron diffraction studies, we established that VO2 and YSZ grow in (020) and (001) orientations, respectively, on Si (001) substrate and epitaxial relationship was established to be “VO2[001] or VO2[100]”//YSZ[110]//Si [100] and VO2(010)//YSZ(001)//Si(001). VO2/YSZ/Si(001) heterostructures showed approximately three orders of magnitude reversible change in resistivity and hysteresis of ∼6 K upon traversing the transition temperature. A 10 °C increase in the SMT temperature of these VO2 films, compared to the value reported for bulk VO2, has been explained on the basis of uniaxial stress along the c-axis, which can stabilize the covalent monoclinic phase up to higher temperatures. A correlation between in-plane orientations of the film and the transition width has also been suggested, which is consistent with our previously published thermodynamic model.
Left-handed behavior and low-loss passband in a ferromagnetic sandwich structure
Authors: Xu Fang , Bai Yang , Qiao Lijie , Zhao Hongjie , Zhou Ji
Published: September 2009

The electromagnetic properties of a ferromagnetic-dielectric-ferromagnetic sandwich structure were studied by experiment and simulation. In the transmission spectra, an obvious passband emerges in the broad forbidden band of ferromagnetic resonance because the strong coupling of two resonating ferrite slabs excites a propagating mode. The passband has ultralow loss (∼−1 dB) due to the feature of surface wave and the bias magnetic field pump. A negative phase evolution of propagating wave occurs in the second slab only based on the magnetic resonance. The ultralow insertion loss of passband and magnetotunability endow the sandwich structure a promising application future.
Inversion of magnetic field effects on electrical current and electroluminescence in tri-(8-hydroxyquinoline)-aluminum based light-emitting diodes
Authors: Xin Linyuan , Li Chuannan , Li Feng , Liu Shiyong , Hu Bin
Published: September 2009

The magnetic field effects on electrical current and electroluminescence have been investigated for tri-(8-hydroxyquinoline)-aluminum based organic light emitting diodes through the transient electroluminescence method. By applying rectangular pulse to drive the devices, the influence of the degradation is dramatically decreased; and a full-range evolvement for the magnetoconductance (MC) and magnetoelectroluminescence (MEL) with the driving voltage has been obtained. The transition voltages for MC (1.6 V) from the negative to positive value and MEL (7 V) from the positive to negative value are different, which suggests that the magnetic field effect on the MC and MEL may have different mechanisms.
Efficiency retention at high current injection levels in m-plane InGaN light emitting diodes
Authors: Li X. , Ni X. , Lee J. , Wu M. , Özgür Ü. , Morkoç H. , Paskova T. , Mulholland G. , Evans K. R.
Published: September 2009

We investigated the internal quantum efficiency (IQE) and the relative external quantum efficiency (EQE) of m-plane InGaN light emitting diodes (LEDs) grown on m-plane freestanding GaN emitting at ∼400 nm for current densities up to 2500 A/cm2. IQE values extracted from intensity and temperature dependent photoluminescence measurements were consistently higher, by some 30%, for the m-plane LEDs than for reference c-plane LEDs having the same structure, e.g., 80% versus 60% at an injected steady-state carrier concentration of 1.2×1018 cm−3. With increasing current injection up to 2500 A/cm2, the maximum EQE is nearly retained in m-plane LEDs, whereas c-plane LEDs exhibit approximately 25% droop. The negligible droop in m-plane LEDs is consistent with the reported enhanced hole carrier concentration and light holes in m-plane orientation, thereby enhanced hole transport throughout the active region, and lack of polarization induced field. A high quantum efficiency and in particular its retention at high injection levels bode well for m-plane LEDs as candidates for general lighting applications.
Voltage-tunable two-color quantum-dot infrared photodetectors
Authors: Lin Shih-Yen , Lin Wei-Hsun , Tseng Chi-Che , Chao Kuang-Ping , Mai Shu-Cheng
Published: September 2009

A two-terminal quantum-dot infrared photodetector with stacked five-period InAs/GaAs and InGaAs-capped InAs/GaAs quantum-dot (QD) structures is investigated. The device has exhibited distinct responses at mid-wavelength and long-wavelength infrared regions under positive and negative biases, respectively. The results suggest that the QD confinement states near the anode side are completely filled, such that selective responses at different wavelength ranges would be observed for the stacked structure under different voltage polarities. Also observed are the similar absorption ratios of the device under different incident light polarizations at the two response regions.
A model for incorporating novel alleles from the primary gene pool into elite crop breeding programs while reselecting major genes for domestication or adaptation
Authors: Cowling W. A. , Buirchell B. J. , Falk D. E.
Published: September 2009

Cost, time, linkage drag, and genetic drift work against the incorporation of potentially valuable alleles from exotic or non-adapted germplasm into elite crop plants, particularly for quantitative traits. We present a model, motivated by narrow-leafed lupin (Lupinus angustifolius), for efficient incorporation of new alleles from exotic or non-adapted donors into elite gene pools during two phases of breeding. In Phase 1, probability functions from the binomial distribution provide at least 95% confidence that a potentially valuable donor allele (A′) will survive two cycles of backcrossing to elite lines and is fixed in BC2-derived lines. During backcrossing, up to 6 major domestication or adaptation genes from the elite parents are reselected and made homozygous in BC2S0 : 1 family rows. Each plant in the BC2S0 : 1 contains on average 12.5% donor alleles, with >95% probability that a particular donor allele is homozygous in at least one fully domesticated plant in the BC2S0 : 1 population. Plants in these rows or subsequent field trials are selected for valuable quantitative traits, and crossed into elite germplasm to commence Phase 2. Phase 1 is rapid and relatively low cost, and provides a continuous flow of novel genetic diversity into the elite breeding pool.
Climate change effects on pasture systems in south-eastern Australia
Authors: Cullen B. R. , Johnson I. R. , Eckard R. J. , Lodge G. M. , Walker R. G. , Rawnsley R. P. , McCaskill M. R.
Published: September 2009

Climate change projections for Australia predict increasing temperatures, changes to rainfall patterns, and elevated atmospheric carbon dioxide (CO2) concentrations. The aims of this study were to predict plant production responses to elevated CO2 concentrations using the SGS Pasture Model and DairyMod, and then to quantify the effects of climate change scenarios for 2030 and 2070 on predicted pasture growth, species composition, and soil moisture conditions of 5 existing pasture systems in climates ranging from cool temperate to subtropical, relative to a historical baseline. Three future climate scenarios were created for each site by adjusting historical climate data according to temperature and rainfall change projections for 2030, 2070 mid- and 2070 high-emission scenarios, using output from the CSIRO Mark 3 global climate model. In the absence of other climate changes, mean annual pasture production at an elevated CO2 concentration of 550 ppm was predicted to be 24–29% higher than at 380 ppm CO2 in temperate (C3) species-dominant pastures in southern Australia, with lower mean responses in a mixed C3/C4 pasture at Barraba in northern New South Wales (17%) and in a C4 pasture at Mutdapilly in south-eastern Queensland (9%). In the future climate scenarios at the Barraba and Mutdapilly sites in subtropical and subhumid climates, respectively, where climate projections indicated warming of up to 4.4°C, with little change in annual rainfall, modelling predicted increased pasture production and a shift towards C4 species dominance. In Mediterranean, temperate, and cool temperate climates, climate change projections indicated warming of up to 3.3°C, with annual rainfall reduced by up to 28%. Under future climate scenarios at Wagga Wagga, NSW, and Ellinbank, Victoria, our study predicted increased winter and early spring pasture growth rates, but this was counteracted by a predicted shorter spring growing season, with annual pasture production higher than the baseline under the 2030 climate scenario, but reduced by up to 19% under the 2070 high scenario. In a cool temperate environment at Elliott, Tasmania, annual production was higher than the baseline in all 3 future climate scenarios, but highest in the 2070 mid scenario. At the Wagga Wagga, Ellinbank, and Elliott sites the effect of rainfall declines on pasture production was moderated by a predicted reduction in drainage below the root zone and, at Ellinbank, the use of deeper rooted plant systems was shown to be an effective adaptation to mitigate some of the effect of lower rainfall.
Short-term management and stocking rate effects of grazing sheep on herbage quality and productivity of Inner Mongolia steppe
Authors: Schönbach P. , Wan H. , Schiborra A. , Gierus M. , Bai Y. , Müller K. , Glindemann T. , Wang C. , Susenbeth A. , Taube F.
Published: September 2009

Degradation and decreasing productivity increasingly demand sustainable grazing management practices within Inner Mongolian steppe ecosystems. This study focuses on grazing-induced degradation processes over a wide range of stocking rates and aims to identify short-term sensitive indicators and alternative management practices. Short-term effects of 2 grazing management systems (Mixed System and Traditional System) and 7 stocking rates (SR0, SR1.5, SR3, SR4.5, SR6, SR7.5, and SR9 for 0,1.5, 3, 4.5, 6, 7.5, and 9 sheep/ha, respectively) on yielding performance and herbage quality were measured on experimental plots in which moveable exclosures were used on areas chronically grazed by sheep. The experiment was conducted in a typical steppe ecosystem in Inner Mongolia, P. R. China. Results are presented for 2005 and 2006.
Sampling time was the main factor affecting yield and quality. Stocking rate also showed considerable effects on yield. Herbage mass decreased linearly from SR0 to SR9, by 85% and 82% in 2005 and 2006, respectively. Herbage accumulation was also affected by stocking rate, and was highest at SR1.5 and clearly reduced at SR9. Grazing effects on relative growth rate indicated grazing tolerance of plants in the short-term, since up to high stocking rates, relative growth rates remained stable. Precipitation also determined plant responses to increasing levels of grazing. The year of higher rainfall generated higher grazing tolerance of plants and higher herbage growth than the drought year. Despite considerable reduction of herbage mass, consistent short-term responses of herbage quality to grazing in 2005 and 2006 were reflected only in terms of crude protein and acid detergent lignin. Herbage crude protein content was highest at SR7.5 and SR9, while lignin was lowest at SR7.5 and SR9. Neither productivity nor herbage quality was affected by the management system, suggesting that both systems may be applicable on typical steppe in the short-term.
Effects of depth and time of sowing and over-wintering on tropical perennial grass seedling emergence in northern New South Wales
Authors: Lodge G. M. , Harden S.
Published: September 2009

Two studies were conducted in northern NSW to examine some of the factors affecting the successful emergence of seedlings of five species of tropical perennial grasses [Panicum coloratum var. makarikariense cv. Bambatsi (panic), Digitaria eriantha ssp. eriantha cv. Premier (digit), Chloris gayana cv. Katambora (Rhodes grass), Dichanthium aristatum cv. Floren (bluegrass), and Bothriochloa bladhii ssp. glabra cv. Swann (forest bluegrass)]. The first experiment investigated the effects of depth and time (month) of sowing on tropical perennial grass seedling emergence, while a second series of studies examined the effects of contact of dispersal/sowing units with the soil, particularly over winter, on subsequent seed germination and seedling emergence.
No seedling emergence of any species occurred in September 2006 and June–August 2007. From October 2006 to May 2007 there were significant effects (P < 0.001) of species, sowing time, depth, and their interaction on predicted emergence. From December to March, predicted emergence was always lower for surface-sown caryopses compared with those sown at 10 and 25 mm depth, and Bambatsi was the only species that had >50% emergence from a depth of 50 mm. Recovery of intact caryopses from 300 μm nylon mesh bags stored in the soil for 6 and 12 months was low for all species. Similarly, predicted germination of caryopses from field soil surface and buried locations (2007 and 2008) and those from florets and coated seeds (2008) was low, indicating that these species had a poor ability to over-winter in moist soil.
Relationship between growth rate and the development of hollow stem in broccoli
Authors: Boersma M. , Gracie A. J. , Brown P. H.
Published: September 2009

Boron deficiency is widely accepted as the dominant cause of hollow stem in broccoli (Brassica oleracea L. var. italica Plenck), although high growth rate has also been mentioned in the literature as a possible cause of the disorder. In this study, we investigated the role of growth rate and boron in the development of hollow stem. Two experiments were conducted with broccoli cv. Marathon, using planting density to manipulate growth rate. In the first experiment, plants were grown at 3 planting densities (19 512, 32 520, and 69 686 plants/ha) and either supplemented or not supplemented with foliar boron applications (0.35 kg B/ha) on two occasions. In the second experiment, broccoli plants at 2 planting densities (32 520 and 100 000 plants/ha) were treated in factorial combination from inflorescence initiation onwards with complete trace element fertiliser (1.5% B), 57% light interception, and paclobutrazol (480 g a.i./ha). The incidence and severity of hollow stem were assessed using digital image analysis and were found to increase with plant spacing but were not affected by boron application. The probability of hollow stem occurring increased with absolute growth rate in the first trial, but not the second. Absolute growth rate, measured as dry weight accumulation, was suppressed independently of planting density by the shading treatment, but did not influence the incidence or severity of hollow stem. The application of paclobutrazol did not influence absolute growth rate but reduced the severity of hollow stem at the lowest planting density. Our data support the hypothesis that the rate and pattern of growth are involved in the development of hollow stem, and that a boron deficiency is not the major causal factor.
Clonality of mouse and human cardiomyogenesis in vivo
Authors: Hosoda Toru , D'Amario Domenico , Cabral-Da-Silva Mauricio Castro , Zheng Hanqiao , Padin-Iruegas M. Elena , Ogorek Barbara , Ferreira-Martins João , Yasuzawa-Amano Saori , Amano Katsuya , Ide-Iwata Noriko , Cheng Wei , Rota Marcello , Urbanek Konrad , Kajstura Jan , Anversa Piero , Leri Annarosa
Published: September 2009

An analysis of the clonality of cardiac progenitor cells (CPCs) and myocyte turnover in vivo requires genetic tagging of the undifferentiated cells so that the clonal marker of individual mother cells is traced in the specialized progeny. CPC niches in the atria and apex of the mouse heart were infected with a lentivirus carrying EGFP, and the destiny of the tagged cells was determined 1–5 months later. A common integration site was identified in isolated CPCs, cardiomyocytes, endothelial cells (ECs), and fibroblasts, documenting CPC self-renewal and multipotentiality and the clonal origin of the differentiated cell populations. Subsequently, the degree of EGFP-lentiviral infection of CPCs was evaluated 2–4 days after injection, and the number of myocytes expressing the reporter gene was measured 6 months later. A BrdU pulse-chasing protocol was also introduced as an additional assay for the analysis of myocyte turnover. Over a period of 6 months, each EGFP-positive CPC divided approximately eight times generating 230 cardiomyocytes; this value was consistent with the number of newly formed cells labeled by BrdU. To determine whether, human CPCs (hCPCs) are self-renewing and multipotent, these cells were transduced with the EGFP-lentivirus and injected after acute myocardial infarction in immunosuppressed rats. hCPCs, myocytes, ECs, and fibroblasts collected from the regenerated myocardium showed common viral integration sites in the human genome. Thus, our results indicate that the adult heart contains a pool of resident stem cells that regulate cardiac homeostasis and repair.
TRAF5 is a critical mediator of in vitro signals and in vivo functions of LMP1, the viral oncogenic mimic of CD40
Authors: Kraus Zachary J. , Nakano Hiroyasu , Bishop Gail A.
Published: September 2009

The cytoplasmic signaling protein TNF receptor-associated factor 5 (TRAF5) has been implicated in several biological roles in Tlymphocyte responses. However, a clear connection between in vivo TRAF5 immune cell functions and specific signaling pathways has not been made. This study shows that TRAF5 associated strongly with the viral oncogenic CD40 mimic latent membrane protein 1 (LMP1), in contrast to weaker association with CD40, for which it has been shown to play a modest role. LMP1 uses specific TRAFs differently than CD40, resulting in amplified and dysregulated CD40-like activation of B lymphocytes. When the cytoplasmic domain of LMP1 is expressed as a transgenic replacement for CD40 in mouse B cells, the resulting mouse exhibits measures of B-cell hyperactivity such as splenomegaly, lymphadenopathy, elevated serum IL-6, elevated serum autoantibodies, and abnormal splenic architecture. Thus, in contrast to CD40, TRAF5 may have an important nonredundant role as a positive mediator of LMP1 signaling and functions in B cells. To test this hypothesis, mice were created that express mCD40LMP1 in place of CD40, and are either sufficient or deficient in TRAF5. Results revealed that TRAF5 plays a critical role in LMP1-mediated c-Jun kinase signaling and is required for much of the abnormal phenotype observed in mCD40LMP1 transgenic mice. This is the first report showing a major requirement for TRAF5 in signaling by a specific receptor both in vitro and in vivo, as well as playing an important role in biological function in B lymphocytes.
Human gut microbiome adopts an alternative state following small bowel transplantation
Authors: Hartman Amber L. , Lough Denver M. , Barupal Dinesh K. , Fiehn Oliver , Fishbein Thomas , Zasloff Michael , Eisen Jonathan A.
Published: September 2009

Small bowel transplants provide an exceptional opportunity for long-term study of the microbial ecology of the human small bowel. The ileostomy created at time of transplant for ongoing monitoring of the allograft provides access to samples of ileal effluent and mucosal biopsies. In this study, we used qPCR to assay the bacterial population of the small bowel lumen of 17 small bowel transplant patients over time. Surprisingly, the posttransplant microbial community was found to be dominated by Lactobacilli and Enterobacteria, both typically facultative anaerobes. This represents an inversion of the normal community that is dominated instead by the strictly anaerobic Bacteroides and Clostridia. We found this inverted community also in patients with ileostomies who did not receive a transplant, suggesting that the ileostomy itself is the primary ecological determinant shaping the microbiota. After surgical closure of the ileostomy, the community reverted to the normal structure. Therefore, we hypothesized that the ileostomy allows oxygen into the otherwise anaerobic distal ileum, thus driving the transition from one microbial community structure to another. Supporting this hypothesis, metabolomic profiling of both communities demonstrated an enrichment for metabolites associated with aerobic respiration in samples from patients with open ileostomies. Viewed from an ecological perspective, the two communities constitute alternative stable states of the human ileum. That the small bowel appears to function normally despite these dramatic shifts suggests that its ecological resilience is greater than previously realized.
MEIG1 is essential for spermiogenesis in mice
Authors: Zhang Zhibing , Shen Xuening , Gude David R. , Wilkinson Bonney M. , Justice Monica J. , Flickinger Charles J. , Herr John C. , Eddy Edward M. , Strauss Jerome F.
Published: September 2009

Spermatogenesis can be divided into three stages: spermatogonial mitosis, meiosis of spermatocytes, and spermiogenesis. During spermiogenesis, spermatids undergo dramatic morphological changes including formation of a flagellum and chromosomal packaging and condensation of the nucleus into the sperm head. The genes regulating the latter processes are largely unknown. We previously discovered that a bi-functional gene,Spag16, is essential for spermatogenesis. SPAG16S, the 35 kDa, testis-specific isoform derived from theSpag16gene, was found to bind to meiosis expressed gene 1 product (MEIG1), a protein originally thought to play a role in meiosis. We inactivated theMeig1gene and, unexpectedly, found thatMeig1mutant male mice had no obvious defect in meiosis, but were sterile as a result of impaired spermatogenesis at the stage of elongation and condensation. Transmission electron microscopy revealed that the manchette, a microtubular organelle essential for sperm head and flagellar formation was disrupted in spermatids of MEIG1-deficient mice. We also found that MEIG1 associates with the Parkin co-regulated gene (PACRG) protein, and that testicular PACRG protein is reduced in MEIG1-deficient mice. PACRG is thought to play a key role in assembly of the axonemes/flagella and the reproductive phenotype ofPacrg-deficient mice mirrors that of theMeig1mutant mice. Our findings reveal a critical role for the MEIG1/PARCG partnership in manchette structure and function and the control of spermiogenesis.
C-type natriuretic peptide (CNP) is a bifurcation factor for sensory neurons
Authors: Schmidt Hannes , Stonkute Agne , Jüttner René , Koesling Doris , Friebe Andreas , Rathjen Fritz G.
Published: September 2009

Neuronal circuits are shaped during development by the coordinated action of guidance factors and signals that regulate axonal branching. Unlike guidance cues, the molecules and signaling cascades that underlie axonal branching remain to be resolved. Here we show that the secreted molecule C-type natriuretic peptide (CNP) induces a cGMP signaling cascade via its receptor particulate guanylyl cyclase Npr2 which is essential for sensory axon bifurcation at the dorsal root entry zone (DREZ) of the spinal cord. In contrast, another form of sensory axon branching—collateral formation—is not affected by this pathway. We also demonstrate that cGMP signaling via the nitric oxide-stimulated soluble guanylyl cyclase system (NO-GC) is dispensable for sensory axon branching. Functionally, the bifurcation error in CNP mutant mice is maintained at mature stages and results in a reduced input on secondary neurons as detected by patch-clamp recordings.
Comparative genomic analysis of
Lactobacillus rhamnosus
GG reveals pili containing a human- mucus binding protein
Authors: Kankainen Matti , Paulin Lars , Tynkkynen Soile , von Ossowski Ingemar , Reunanen Justus , Partanen Pasi , Satokari Reetta , Vesterlund Satu , Hendrickx Antoni P. A. , Lebeer Sarah , De Keersmaecker Sigrid C. J. , Vanderleyden Jos , Hämäläinen Tuula , Laukkanen Suvi , Salovuori Noora , Ritari Jarmo , Alatalo Edward , Korpela Riitta , Mattila-Sandholm Tiina , Lassig Anna , Hatakka Katja , Kinnunen Katri T. , Karjalainen Heli , Saxelin Maija , Laakso Kati , Surakka Anu , Palva Airi , Salusjärvi Tuomas , Auvinen Petri , de Vos Willem M.
Published: September 2009

To unravel the biological function of the widely used probiotic bacterium
Lactobacillus rhamnosus
GG, we compared its 3.0-Mbp genome sequence with the similarly sized genome of
L. rhamnosus
LC705, an adjunct starter culture exhibiting reduced binding to mucus. Both genomes demonstrated high sequence identity and synteny. However, for both strains, genomic islands, 5 in GG and 4 in LC705, punctuated the colinearity. A significant number of strain-specific genes were predicted in these islands (80 in GG and 72 in LC705). The GG-specific islands included genes coding for bacteriophage components, sugar metabolism and transport, and exopolysaccharide biosynthesis. One island only found in
L. rhamnosus
GG contained genes for 3 secreted LPXTG-like pilins (
spaCBA
) and a pilin-dedicated sortase. Using anti-SpaC antibodies, the physical presence of cell wall-bound pili was confirmed by immunoblotting. Immunogold electron microscopy showed that the SpaC pilin is located at the pilus tip but also sporadically throughout the structure. Moreover, the adherence of strain GG to human intestinal mucus was blocked by SpaC antiserum and abolished in a mutant carrying an inactivated
spaC
gene. Similarly, binding to mucus was demonstrated for the purified SpaC protein. We conclude that the presence of SpaC is essential for the mucus interaction of
L. rhamnosus
GG and likely explains its ability to persist in the human intestinal tract longer than LC705 during an intervention trial. The presence of mucus-binding pili on the surface of a nonpathogenic Gram-positive bacterial strain reveals a previously undescribed mechanism for the interaction of selected probiotic lactobacilli with host tissues.
E3 ubiquitin ligase GRAIL controls primary T cell activation and oral tolerance
Authors: Kriegel Martin A. , Rathinam Chozhavendan , Flavell Richard A.
Published: September 2009

T cell unresponsiveness or anergy is one of the mechanisms that maintain inactivity of self-reactive lymphocytes. E3 ubiquitin ligases are important mediators of the anergic state. The RING finger E3 ligase GRAIL is thought to selectively function in anergic T cells but its mechanism of action and its role in vivo are largely unknown. We show here that genetic deletion of
Grail
in mice leads not only to loss of an anergic phenotype in various models but also to hyperactivation of primary CD4
+
T cells.
Grail
−/−
CD4
+
T cells hyperproliferate in vitro to TCR stimulation alone or with concomitant anti-CD28 costimulation, with transient increased survival. In vitro differentiated T helper 1 cells show slight but significant hypersecretion of IFN-γ in
Grail
−/−
mice whereas Th2 and Th17 cytokine secretions are unchanged. Consistent with defective in vitro anergy, oral tolerance is abolished in vivo in OT-II TCR transgenic
Grail
−/−
mice fed with ovalbumin. In experimental allergic encephalitis, a model of organ-specific autoimmunity, oral tolerization with myelin basic protein was abrogated as well in
Grail
−/−
mice. On the protein level,
Grail
−/−
naïve T cells show no significant differences of total and phosphorylated levels of ZAP70, phospholipase Cγ1, and MAP kinases p38 and JNK but elevated baseline levels of MAP kinase ERK1/2. In summary, we define a role for GRAIL in primary T cell activation, survival, and differentiation. In addition, we formally prove an indispensable role for GRAIL in T cell anergy and oral tolerance—a promising, antigen-specific strategy to treat autoimmune diseases.
Mice with the
CHEK2
*1100delC SNP are predisposed to cancer with a strong gender bias
Authors: Bahassi El Mustapha , Robbins Susan B. , Yin Moying , Boivin Gregory P. , Kuiper Raoul , van Steeg Harry , Stambrook Peter J.
Published: September 2009

The CHEK2 kinase (Chk2 in mouse) is a member of a DNA damage response pathway that regulates cell cycle arrest at cell cycle checkpoints and facilitates the repair of dsDNA breaks by a recombination-mediated mechanism. There are numerous variants of the
CHEK2
gene, at least one of which,
CHEK2
*1100delC (SNP), associates with breast cancer. A mouse model in which the wild-type
Chk2
has been replaced by a
Chk2
*1100delC allele was tested for elevated risk of spontaneous cancer and increased sensitivity to challenge by a carcinogenic compound. Mice homozygous for
Chk2
*1100delC produced more tumors than wild-type mice, whereas heterozygous mice were not statistically different. When fractionated by gender, however, homozygous and heterozygous mice developed spontaneous tumors more rapidly and to a far greater extent than wild-type mice, indicative of a marked gender bias in mice harboring the variant allele. Consistent with our previous data showing elevated genomic instability in mouse embryonic fibroblasts (MEFs) derived from mice homozygous for
Chk2
*1100delC, the level of Cdc25A was elevated in heterozygous and homozygous MEFs and tumors. When challenged with the carcinogen 7,12-dimethylbenz[
a
]anthracene, all mice, regardless of genotype, had a reduced lifespan. Latency for mammary tumorigenesis was reduced significantly in mice homozygous for
Chk2
*1100delC but unexpectedly increased for the development of lymphomas. An implication from this study is that individuals who harbor the variant
CHEK2
*1100delC allele not only are at an elevated risk for the development of cancer but also that this risk can be further increased as a result of environmental exposure.
The Social Effects of Travel to Learn Patterns - A Case Study of 16-19 Year Olds in London
Authors: Watson Judith , Church Andrew
Published: September 2009

Previous research into education and student geographies has usually focussed on either compulsory schooling or university education. This paper, using London as a case study, is an innovative attempt to understand the geographies of non-compulsory, non-university education (‘further education’, FE) which plays a crucial role in a world city labour market that requires a wide range of skills. Original analysis is provided using findings from a questionnaire, interviews with students and senior college managers and the analysis of individual student records, the Individualised Student Record (ISR) and Pupil-Level School Census (PLASC). The education geography of 16-19 year olds in FE involves selection by institutions alongside choice by learners resulting in complex patterns of social segregation and travel to learn. The division between post 16 colleges and sixth forms attached to schools is crucial with the latter, wherever they are located, taking a less deprived section of the cohort.
PoreLogo: a new tool to analyse, visualize and compare channels in transmembrane proteins
Authors: Oliva Romina , Thornton Janet M. , Pellegrini-Calace Marialuisa
Published: September 2009

Summary: The increasing number of available atomic 3D structures of transmembrane channel proteins represents a valuable resource for better understanding their structure–function relationships and to eventually predict their selectivity. Herein, we present PoreLogo, an automatic tool for analysing, visualizing and comparing the amino acid composition of transmembrane channels and its conservation across the corresponding protein family.

Availability: PoreLogo is accessible as a public web server at http://www.ebi.ac.uk/thornton-srv/software/PoreLogo/.

Contacts:  marial@ebi.ac.uk; romina.oliva@uniparthenope.it.
Introduction: The Study of Religion and Emotion
Authors: Corrigan John
Published: September 2009

This book is about religion and emotion. It explores the emotional component in religion within the framework of a certain tradition, focusing on emotion in new religious movements. There are essays on Judaism, Christianity, Hinduism, Japanese religions, Buddhism, and Islam. The book remarks on ways that emotion has been overlooked in the study of religious traditions, and how a focus on the emotional can lead to fresh understandings about how persons create, through religion, relationships with nature, deities, and each other. It also includes essays that address the emotion component in various areas of religious life, including ritual, gender, sexuality, music, and material culture. The book shows that emotional life is profoundly shaped by religion, and that religion, in turn, directs and reinforces the construction of emotional ideologies having to do with a wide array of behaviors. In addition, it addresses specific emotions such as ecstasy, love, terror, hate, melancholy, and hope.
Realism
Authors: Harrison Bernard
Published: September 2009

This article considers the relation between literature and philosophy during the period of realism. It explains that the notion of realism, in its development as a term of literary criticism, is in origin a genre concept and that discussions of realism in nineteenth- and twentieth-century literary criticism and polemic rapidly acquire a moral, political, and philosophical dimensions. It suggests that all questions of literary form and technique fall to the will of the writer to determine. However, the article states, it does not follow that literature is a free field for play in the sense of frivolity because the connection between literature and reality does not run by way of the truth or falsity of statements, but by way of deeper linkages, internal to language, between the meanings of words and the practices that constitute human worlds and form the outlook and personalities of their inhabitants.