bluuebunny/crossref_metadata_2025 huggingface dataset:
Multidimensional Quantitative Structure–Activity Relationships of Diacylhydrazine Toxicity to Lepidopteran and Coleopteran Insect Pests
Authors: Hormann Robert E. , Smagghe Guy , Nakagawa Yoshiaki
Published: August 2008

Insecticidal activity indices, i.e., median lethal dose causing mortality in 50% of insects treated (pLD50) values, of 77 Diacylhydrazines (DAHs) were determined against larvae of the Beet Armyworm (Spodoptera exigua), the rice stem borer (Chilo suppressalis), and the Colorado Potato Beetle (Leptinotarsa decemlineata). A series of multidimensional Comparative Molecular Field Analysis (CoMFA) Quantitative Structure–Activity Relationship (QSAR) models was constructed for each type of insect toxicity, and these models were evaluated by q2 of 67‐member training sets and r2 of ten‐member test sets. Favored models yielded r2 values in the range of 0.77–0.88, q2 values in the range of 0.54–0.62 after consideration of outliers, test set r2 values in the range of 0.54–0.72, and external q2 values in the range of 0.31–0.58. The structure–activity relationships for each type of insect toxicity can be partially, but not entirely, rationalized in view of Ecdysone Receptor (EcR) LBD sequence alignments and putative contact residues relative to the known crystallized Heliothis virescens EcR LBD/BYI06830 holoreceptor. Alternate ligand poses or LBD remodeling may pertain across members of the DAH chemotype.
Computed effects of electric fields upon the CNO2 and NNO2 bonds of nitromethane and dimethylnitramine
Authors: Politzer Peter , Murray Jane S.
Published: August 2008

We report the results of a computational (B3PW91/6‐31G**) investigation of the effects of electric fields of different strengths and directions upon some properties related to the CNO2 and NNO2 bonds in nitromethane, H3CNO2, and dimethylnitramine, (H3C)2NNO2. We look at the interaction energies of the fields with the molecules, the dipole moments of the latter, the lengths of the CNO2 and NNO2 bonds, and we particularly focus upon their stretching vibration frequencies. The field‐induced frequency shifts are determined by means of a formula linking them to the dipole moment derivatives and the field strengths. This formula was derived originally for hydrogen‐bonded systems, but we show that it is applicable as well to these CNO2 and NNO2 bonds; their predicted relative frequency shifts correlate extremely well with directly computed Δω(ϵ) (R2 = 0.9992). It was found that the fields that reinforce the intrinsic H3CNO2 and (H3C)2NNO2 polarities also interact favorably energetically with the molecules and, particularly important, increase the CNO2 and NNO2 stretching frequencies. This presumably indicates the strengthening of these bonds. Fields in the opposite direction do the reverse. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Comparative population dynamics ofPeromyscus leucopusin North America: influences of climate, food, and density dependence
Authors: Wang Guiming , Wolff Jerry O. , Vessey Stephen H. , Slade Norman A. , Witham Jack W. , Merritt Joseph F. , Hunter Malcolm L. , Elias Susan P.
Published: August 2008

Temporal variation in population size is regulated by both exogenous forces and density‐dependent feedbacks. Furthermore, accumulating evidence indicates that temporal and spatial variation in climate and resources can modify the strength of density dependence in animal populations. We analyzed six long‐term time series estimates ofPeromyscus leucopus(white‐footed mouse) abundance from Kansas, Ohio, Pennsylvania, Virginia, Vermont, and Maine, USA, using the Kalman filter. Model‐averaged estimates of the strength of delayed density dependence increased from west to east and from south to north. The strength of direct and delayed density dependence was positively related to the annual number of days with minimum temperature below −17.8°C. Annual population growth rates ofP. leucopusat the Maine site were positively related to acorn abundance andP. leucopuspopulations tracked the changes in red‐oak acorn abundance. The populations ofP. leucopusliving in northern latitudes might be more dependent on northern red oak (Quercus rubra) acorns for winter food thanP. leucopusin southern latitudes. Furthermore, northern red oak trees mast every 4–5 years. Thus, longer, colder winters in northerly latitudes might result in stronger delayed density dependence in mouse populations with a shortage of winter food. Mice might simply track the acorn fluctuations in a delayed autocorrelated manner; however, delayed density dependence remained in our models for the Maine mouse populations after accounting for acorns, suggesting additional sources for delayed density dependence. Our results suggest that, in seed‐eatingPeromyscus, cyclicity may be regulated, in part, from low to high trophic levels.
Married women's occupations in eighteenth-century London
Authors: ERICKSON AMY LOUISE
Published: August 2008

The evidence of criminal court records suggests that almost all London wives were engaged in gainful occupations in the eighteenth century. The records of the City livery companies and of Christ's Hospital show that the wives of craft masters and professional men worked, as well as those in poorer families where their income was essential. At lower socio-economic levels it was unusual for couples to work in the same trade. At middling levels it was more common, especially in textiles and retail, but no more than half of couples worked together or in related occupations.
Couples cooperating? Dutch textile workers, family labour and the ‘industrious revolution’, c. 1600–1800
Authors: VAN NEDERVEEN MEERKERK ELISE
Published: August 2008

This article aims to provide an empirical test of Jan de Vries' theory of the ‘industrious revolution’, most notably his assumptions concerning the increased participation of married women in the labour force. The focus is on the pre-industrial textile industry in the Dutch Republic, within which a distinction is made between various ways in which family members cooperated in the work they undertook. This differentiation depended on the existing segmentation of the labour market, between social groups and between the sexes. It is shown that at least some groups within proletarian textile families were able to make a decent living, and that the earnings of wives played an important role in the increased industriousness of these families.
Millian Qualitative Superiorities and Utilitarianism, Part I
Authors: RILEY JONATHAN
Published: August 2008

Arrhenius and Rabinowicz (henceforth, AR) have argued that Millian qualitative superiorities are possible without assuming that any pleasure, or type of pleasure, is infinitely superior to another. But AR's analysis is fatally flawed in the context of ethical hedonism, where the assumption in question is necessary and sufficient for Millian qualitative superiorities. Marginalist analysis of the sort pressed by AR continues to have a valid role to play within any plausible version of hedonism, provided the fundamental incoherence that infects AR's use of such analysis is removed. But what AR call ‘Millian superiorities’ are never genuine qualitative superiorities in Mill's sense. Mill scholars need to appreciate this point and recognize that the interpretation of qualitative superiorities as infinite superiorities is the only interpretation which is compatible with the text of Mill's Utilitarianism. The continuing failure to appreciate the possibility of infinite superiorities has precluded any adequate understanding of the extraordinary structure of Mill's pluralistic hedonistic utilitarianism.
Intake of dairy products and risk of colorectal neoplasia
Authors: Pufulete Maria
Published: August 2008

Prospective cohort studies suggest that higher intakes of dairy products, in particular milk, are associated with a decreased risk of colorectal cancer (CRC). In Western populations, dairy products are major contributors to dietary Ca, which may have chemopreventive effects in the colon. The pooling of data from prospective studies suggests a significant protective effect of Ca on CRC risk. Randomised controlled trials with Ca supplements have been conducted with both colorectal adenoma and CRC as endpoints. Results suggest that Ca supplementation at a level of 1000–2000 mg/d reduces adenoma recurrence in individuals with a previous adenoma but has no effect on CRC incidence. There is evidence that the risk reduction from dairy foods may not be solely due to their high Ca content. Dairy products contain other potential chemopreventive components such as vitamin D, butyric acid, conjugated linoleic acid, sphingolipids, and probiotic bacteria in fermented products such as yoghurt. The present review will focus on the epidemiological evidence (and in particular prospective cohort studies) investigating the relationship between dairy product consumption and risk of CRC. An outline of the proposed mechanisms responsible for the protective effect of both Ca and other potential chemopreventive components in dairy products will also be presented.
THE ROLE OF ALGEBRAIC INFERENCES IN NA‘ĪM IBN MŪSĀ’S COLLECTION OF GEOMETRICAL PROPOSITIONS
Authors: PANZA MARCO
Published: August 2008

Na‘īm ibn Mūsā’s lived in Baghdad in the second half of the 9th century. He was probably not a major mathematician. Still his Collection of geometrical propositions – recently edited and translated in French by Roshdi Rashed and Christian Houzel – reflects quite well the mathematical practice that was common in Thābit ibn Qurra’s school. A relevant characteristic of Na‘īm’s treatise is its large use of a form of inferences that can be said ‘algebraic’ in a sense that will be explained. They occur both in proofs of theorems and in solutions of problems. In the latter case, they enter different sorts of problematic analyses that are mainly used to reduce the geometrical problems they are concerned with to al-Khwārizmī’s equations.
AL-FĀRĀBĪ ON INDEFINITE AND PRIVATIVE NAMES
Authors: THOM PAUL
Published: August 2008

In his Short Treatise and his Commentary on the Peri hermeneias, al-Fārābī offers two different but related accounts of indefinite terms and the propositions that contain them. In both works he presents a series of different senses that an indefinite term may have, commencing with a sense in which such a term would be equivalent to a privative term, and concluding with a sense in which it would determine the logical complement of the corresponding definite term. I offer an interpretation of this series according to which they reveal the workings of a fine analytical mind and a subtle teacher.
Resveratrol content in seeds of peanut germplasm quantified by HPLC
Authors: Wang M. L. , Pittman R. N.
Published: August 2008

trans-Resveratrol (trans-3,4′,5-trihydroxystilbene), a polyphenolic compound uniquely identified in plants, is believed to greatly contribute to human health. Peanut (Arachis hypogaea L.) seeds of 20 germplasm accessions were harvested from the same field and used for resveratrol analysis by high-performance liquid chromatography. trans-Resveratrol content in air-dried peanut seeds was on average about 0.5 μg/g and a statistically significant variation (from 0.125 to 1.626 μg/g, at least a ten-fold difference) was detected among the accessions analysed. The average weight for 100 seeds was 52.84 g. A statistically significant variation in seed weight (from 22.30 to 87.94 g, at least a four-fold difference) was observed. There was no significant correlation between trans-resveratrol content and seed weight. The information about the levels of trans-resveratrol in peanut seeds will be useful for peanut cultivar development and peanut product processing. Breeders could use germplasm accessions containing a high amount of resveratrol to develop new nutritionally improved peanut cultivars and food processors could use these new cultivars to manufacture high resveratrol peanut products.
Realization of the Terrestrial Reference System by a reprocessed global GPS network
Authors: Rülke A. , Dietrich R. , Fritsche M. , Rothacher M. , Steigenberger P.
Published: August 2008

We present a GPS‐only reference frame named PDR05 (Potsdam‐Dresden‐Reprocessing TRF 2005) based on the results of a homogeneous reprocessing of a global GPS network over the time span 1994.0–2006.0. The reference frame is realized in the center of mass (CM) system. This implies that a self‐consistent model considering the reference frame and loading dynamics has been applied. The determined set of coordinates at epoch 2000.0 and their linear changes with time are evaluated in terms of self‐consistency and are compared to other realizations of the Terrestrial Reference System (TRS), such as ITRF2000, ITRF2005, and the GPS‐only realizations IGb00 and IGS05. We demonstrate that GPS is able to realize a TRS with the origin in the center of mass and a scale which are both on an equivalent level of self‐consistency, stability, and precision as other space techniques. The results show the high potential of homogeneously reprocessed GPS networks for future International Terrestrial Reference System (ITRS) realizations and for the realization of the Global Geodetic Observing System (GGOS). Hence, PDR05 represents a stable metrological basis for global geodynamic investigations.
The mantle transition zone as seen by global Pds phases: No clear evidence for a thin transition zone beneath hotspots
Authors: Tauzin Benoit , Debayle Eric , Wittlinger Gérard
Published: August 2008

We present a new global study of the transition zone from Pds converted waves at the 410‐ and 660‐km discontinuities. Our observations extend previous global Pds studies with a larger data set, especially in oceanic regions where we have been able to measure Pds travel times, sampling the mantle transition zone (MTZ) beneath 26 hotspot locations. We find significant lateral variations of the MTZ thickness. Both the maximum variations (±35–40 km) and the long‐wavelength pattern are in overall agreement with previous SS precursors studies. The MTZ is generally thick beneath subduction zones, where the observed MTZ variations are consistent with thermal anomalies ranging between −100°K and −300°K. In Central and North America, we observe an NW–SE pattern of thick MTZ, which can be associated with the fossil Farallon subduction. We do not find clear evidence for a thin MTZ beneath hotspots. However, the 410‐km discontinuity remains generally deepened after correcting our Pds travel times for the 3D heterogeneities located above the MTZ, and its topography variations can be explained by thermal anomalies between +100°K and +300°K. The depth of the 660‐km discontinuity may be less temperature sensitive in hot regions of the mantle, which is consistent with the effect of a phase transition from majorite garnet to perovskite at a depth of 660 km.
Culture‐independent characterization of a novel microbial community at a hydrothermal vent at Brothers volcano, Kermadec arc, New Zealand
Authors: Stott M. B. , Saito J. A. , Crowe M. A. , Dunfield P. F. , Hou S. , Nakasone E. , Daughney C. J. , Smirnova A. V. , Mountain B. W. , Takai K. , Alam M.
Published: August 2008

The bacterial and archaeal diversity of a hydrothermal vent microbial community at Brothers volcano situated in the Kermadec arc, ∼400 km off the north coast of New Zealand, was examined using culture‐independent molecular analysis. An unusual microbial community was detected with only 1% and 40% of the bacterial phylotypes exhibiting >92% small subunit (SSU) rRNA gene sequence similarity with cultivated and noncultivated microbes, respectively. Of the 29 bacterial representative phylotypes, over one third of the SSU rRNA gene sequences retrieved belonged to uncultivated candidate divisions including OP1, OP3, OP5, OP8, OD1, and OP11. All archaeal phylotypes belonged to the phylum Euryarchaeota in the uncultivated groups deep hydrothermal vent euryarchaeotal (DHVE) I and II or to the phylum Korarchaeota. Like the bacterial clone library, only a small proportion of archaeal SSU rRNA gene sequences (∼2% and 20%) displayed >92% sequence identity with any archaeal isolates or noncultivated microbes, respectively. Although the bacterial phylotypes detected were phylogenetically most similar to microbial communities detected in methane, hydrocarbon, and carbon dioxide‐based hydrothermal and seep environments, no phylotypes directly associated with anaerobic methane oxidation and mcrA activity could be detected. The geochemical composition of the vent fluids at the Brothers‐lower cone sample site is unusual and we suggest that it may play a prominent role in the species selection of this microbial community.
Probabilistic predictions of climate change for Australia and southern Africa using the reliability ensemble average of IPCC CMIP3 model simulations
Authors: Moise A. F. , Hudson D. A.
Published: August 2008

“Reliability ensemble averaging” (REA) is applied to a multimodel ensemble of coupled atmosphere‐ocean general circulation models (AOGCMs) from the third phase of the Coupled Model Intercomparison Project (CMIP3) to produce mean and probabilistic climate change projections for Australia and southern Africa. CMIP3 was conducted in preparation for the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC). REA produces a weighted average of the ensemble of climate change results, based on a measure of each model's bias and each model's degree of convergence in the predicted climate change. The methodology allows an assessment of the reliability of the projected climate change, the quantification of model uncertainty range, and the production of climate change projections in probabilistic form. Temperature and precipitation changes for three emission scenarios (B1, A1B, and A2) are analyzed, with a special focus on the A2 scenario. Regional differences in temperature and rainfall changes are identified, and threshold probabilities and probability density functions (PDFs) for key subregions are produced. In summer for temperature the A2 scenario results show a narrow PDF over southwestern Australia, reflecting agreement between models, partially caused by down weighting of outlier models due to their large biases. In contrast, the PDF for southeastern Australia is much broader, and that for tropical Australia has a bimodal character. There are significant decreases in rainfall under the A2 scenario in winter in the southwest (25–30% decrease) (common in sign to all AOGCM simulations) and the southeast (15–25% decrease) of Australia. There are no changes above natural variability in summer, hence no significant changes in the magnitude of Australian monsoon rainfall. Over southern Africa the region of maximum warming is over the Kalahari Desert in summer and winter. Under the A2 scenario in summer, there is a significant increase in rainfall over Kenya and Tanzania and a significant drying (∼10–20%) over parts of Namibia and Botswana. In winter, most of southern Africa south of 15°S shows significant decreases in rainfall.
Metrics for solar wind prediction models: Comparison of empirical, hybrid, and physics‐based schemes with 8 years of L1 observations
Authors: Owens M. J. , Spence H. E. , McGregor S. , Hughes W. J. , Quinn J. M. , Arge C. N. , Riley P. , Linker J. , Odstrcil D.
Published: August 2008

Space weather effects on technological systems originate with energy carried from the Sun to the terrestrial environment by the solar wind. In this study, we present results of modeling of solar corona‐heliosphere processes to predict solar wind conditions at the L1 Lagrangian point upstream of Earth. In particular we calculate performance metrics for (1) empirical, (2) hybrid empirical/physics‐based, and (3) full physics‐based coupled corona‐heliosphere models over an 8‐year period (1995–2002). L1 measurements of the radial solar wind speed are the primary basis for validation of the coronal and heliosphere models studied, though other solar wind parameters are also considered. The models are from the Center for Integrated Space‐Weather Modeling (CISM) which has developed a coupled model of the whole Sun‐to‐Earth system, from the solar photosphere to the terrestrial thermosphere. Simple point‐by‐point analysis techniques, such as mean‐square‐error and correlation coefficients, indicate that the empirical coronal‐heliosphere model currently gives the best forecast of solar wind speed at 1 AU. A more detailed analysis shows that errors in the physics‐based models are predominately the result of small timing offsets to solar wind structures and that the large‐scale features of the solar wind are actually well modeled. We suggest that additional “tuning” of the coupling between the coronal and heliosphere models could lead to a significant improvement of their accuracy. Furthermore, we note that the physics‐based models accurately capture dynamic effects at solar wind stream interaction regions, such as magnetic field compression, flow deflection, and density buildup, which the empirical scheme cannot.
Imaging cold ions in the plasma sheet from the Equator‐S satellite
Authors: Ebihara Y. , Kistler L. M. , Eliasson L.
Published: August 2008

Energy‐dispersed H+ structures observed by Equator‐S in the sub‐keV range in the dawn sector of the ring current region were used to perform the remote sensing of cold ions in the near‐earth plasma sheet. A time history of the source distribution function in the nightside plasma sheet was reconstructed by using the phase space mapping method under a time‐dependent convection electric field model. We obtained the following major conclusions: (1) A cold H+ component (∼10 eV) exists in the near‐earth plasma sheet. (2) The cold component is readily distinguished from the main component of the plasma sheet (>∼a few keV). (3) The cold component is distributed over a relatively wide area in MLT. (4) Energy‐dispersed H+ structures in the inner magnetosphere results from temporal variation of the cold component. Our scheme will be applicable for investigating long‐term plasma processes acting on the cold component whose behavior is largely unknown.
Alfvén vortices in Saturn's magnetosheath: Cassini observations
Authors: Alexandrova O. , Saur J.
Published: August 2008

First signatures of Alfvén vortices in the Kronian magnetosheath are presented. An Alfvén vortex is a non‐linear bi‐dimensional magnetic structure associated with sheared magnetic field and velocity perturbations, propagating obliquely to the external magnetic field direction. Such structures have been recently discovered by Cluster in Earth's magnetosheath downstream of a quasi‐perpendicular bow‐shock at scales close to 10c/ωpi (where c is the speed of light and ωpi the ion plasma frequency). The presence of Alfvén vortices downstream of a quasi‐perpendicular bow‐shock of Saturn with comparable scales to the ones at Earth indicates the universality of this phenomenon. It suggests that such non‐linear structures are an inherent property of plasma flow downstream of collisionless shock waves, which can have broad astrophysical applications.
ICESat over Arctic sea ice: Estimation of snow depth and ice thickness
Authors: Kwok R. , Cunningham G. F.
Published: August 2008

Starting with retrieved freeboards from four ICESat campaigns (ON05, October/November 2005; FM06, February/March 2006; ON06, October/November 2006; and MA07, March/April 2007) we estimate their ice thicknesses using constructed fields of daily snow depth and compare them with ice drafts from moored upward‐looking sonars. The methodologies, considerations, and assumptions used in the conversion of freeboard to ice thickness are discussed. The thickness distributions of the Arctic multiyear and seasonal ice covers are contrasted. Broadly, the resulting fields seem seasonally and interannually consistent in terms of thickness, growth and ice production. We find mean thicknesses of 2.15/2.46 m in ON05/FM06 and an overall thinner ice cover of 1.96/2.37 m in ON06/MA07. This represents a growth of ∼0.3 m and ∼0.4 m during the ∼4‐month intervals of the ON05‐FM06 and ON06‐MA07 campaigns, respectively. After accounting for data gaps, we compute overall Arctic Ocean ice volumes of 11,318, 14,075, 10,626, and 13,891 km3 for the ON05, FM06, ON06, and MA07 campaigns, respectively. The higher total volume in ON05 (versus ON06) can be attributed to the higher multiyear ice coverage that fall: 37% versus 31%. However, the higher estimated ice production (less export) during the second year (3265 versus 2757 km3) is likely due to the higher growth rate over the larger expanse of seasonal sea ice during the fall and winter. Inside a 25‐km radius of two mooring locations in the Beaufort Sea, the estimated mean ICESat ice drafts from ON05 and FM06 are within 0.5 m of those measured at the moorings.
Controls on the heterogeneity of soil respiration in a tolerant hardwood forest
Authors: Webster K. L. , Creed I. F. , Bourbonnière R. A. , Beall F. D.
Published: August 2008

The spatial and temporal distribution of soil respiration (Rs) in forested landscapes and its control by environmental conditions and carbon pools has not been sufficiently investigated. A Rs monitoring strategy targeting different topographic features within a sugar maple forest on the Algoma Highlands on the Canadian Shield revealed that the critical transition zones (transiently wet areas adjacent to wetlands, streams, and lakes) yielded significantly larger Rs than adjacent upland or wetland portions of the catchment. Environmental conditions (soil temperature and soil moisture) explained the majority of variance in Rs. An exponential relationship in which the exponent is a polynomial expression that is linear with respect to temperature (°C) and quadratic with respect to moisture (% by volume) explained 57.0% of the variance in Rs (μmol CO2 m−2 s−1). However, inclusion of the quantity of carbon and substrate quality (carbon: nitrogen ratio) in the freshly fallen leaves, and the organic and/or mineral soils into the polynomial regression model explained an additional 15.3% of the variance in Rs (μmol CO2 m−2 s−1). This study highlighted the critical transition zone as major sites of Rs because of the synchronicity in optimal temperature and moisture conditions during the growing season and the large pool of high quality substrate that accumulates in topographic depositional areas.
The Brain in Business: The Case for Organisational Cognitive Neuroscience?
Authors: Lee Nick , Butler Michael , Senior Carl
Published: August 2008

The application of cognitive neuroscientific techniques to understanding social behaviour has resulted in many discoveries. Yet advocates of the ‘social cognitive neuroscience’ approach maintain that it suffers from a number of limitations. The most notable of these is its distance from any form of real-world applicability. One solution to this limitation is ‘Organisational Cognitive Neuroscience’ – the study of the cognitive neuroscience of human behaviour in, and in response to, organizations. Given that all of us will spend most of our lives in some sort of work related organisation, organisational cognitive neuroscience allows us to examine the cognitive underpinnings of social behaviour that occurs in what may be our most natural ecology. Here we provide a brief overview of this approach, a definition and also some possible questions that the new approach would be best suited to address.
Apoptotic sensitivity of murine IAP-deficient cells
Authors: Rumble Julie M. , Bertrand Mathieu J. M. , Csomos Rebecca A. , Wright Casey W. , Albert Lori , Mak Tak W. , Barker Philip A. , Duckett Colin S.
Published: August 2008

Although numerous studies have implicated the IAPs (inhibitor of apoptosis proteins) in the control of apoptotic cell death, analyses of murine Iap-targeted cells have not revealed significant differences in their susceptibility to apoptosis. In the present study, we show that, under defined conditions, murine cells lacking XIAP (X-linked inhibitor of apoptosis) and c-IAP (cellular IAP) 2, but not c-IAP1, exhibit heightened apoptotic sensitivity to both intrinsic and extrinsic apoptotic stimuli.
Phosphoregulation of human Mps1 kinase
Authors: Tyler Rebecca K. , Chu Matthew L. H. , Johnson Hannah , McKenzie Edward A. , Gaskell Simon J. , Eyers Patrick A.
Published: August 2008

The dual-specificity protein kinase Mps1 (monopolar spindle 1) is a phosphoprotein required for error-free mitotic progression in eukaryotes. In the present study, we have investigated human Mps1 phosphorylation using combined mass spectrometric, mutational and phosphospecific antibody approaches. We have identified 16 sites of Mps1 autophosphorylation in vitro, several of which are required for catalytic activity after expression in bacteria or in cultured human cells. Using novel phosphospecific antibodies, we show that endogenous Mps1 is phosphorylated on Thr686 and Ser821 during mitosis, and demonstrate that phosphorylated Mps1 localizes to the centrosomes of metaphase cells. Taken together, these results reveal the complexity of Mps1 regulation by multi-site phosphorylation, and demonstrate conclusively that phosphorylated Mps1 associates with centrosomes in mitotic human cells.
Do mammals make all their own inositol hexakisphosphate?
Authors: Letcher Andrew J. , Schell Michael J. , Irvine Robin F.
Published: August 2008

A highly specific and sensitive mass assay for inositol hexakisphosphate (InsP6) was characterized. This centres around phosphorylating InsP6 with [32P]ATP using a recombinant InsP6 kinase from Giardia lambia, followed by HPLC of the 32P-labelled products with an internal [3H]InsP7 standard. This assay was used to quantify InsP6 levels in a variety of biological samples. Concentrations of InsP6 in rat tissues varied from 10–20 μM (assuming 64% of wet weight of tissue is cytosol water), whereas using the same assumption axenic Dictyostelium discoideum cells contained 352±11 μM InsP6. HeLa cells were seeded at low density and grown to confluence, at which point they contained InsP6 levels per mg of protein similar to rat tissues. This amounted to 1.952±0.117 nmol InsP6 per culture dish, despite the cells being grown in serum shown to contain no detectable (less than 20 pmol per dish) InsP6. These results demonstrate that mammalian cells synthesize all their own InsP6. Human blood was analysed, and although the white cell fraction contained InsP6 at a concentration comparable with other tissues, in serum and platelet-free plasma no InsP6 was detected (<1 nM InsP6). Human urine was also examined, and also contained no detectable (<5 nM) InsP6. These results suggest that dietary studies purporting to measure InsP6 at micromolar concentrations in human plasma or urine may not have been quantifying this inositol phosphate. Therefore claims that administrating InsP6 in the diet or applying it topically can produce health benefits by increasing extracellular InsP6 levels may require reassessment.
Specific and dynamic detection of palytoxins byin vitromicroplate assay with human neuroblastoma cells
Authors: Espiña Begoña , Cagide Eva , Louzao M. Carmen , Fernandez Maria M. , Vieytes Mercedes R. , Katikou Panagiota , Villar Adriano , Jaen David , Maman Luz , Botana Luis M.
Published: August 2008

Palytoxin is one of the most complex and biggest molecules known to show extreme acute toxicity. The dinoflagellate Ostreopsis spp., the producer organism of palytoxin, has been shown to be distributed worldwide, thus making palytoxin an emerging toxin. Rat-derived hepatocytes (Clone 9) and BE (2)-M17 human neuroblastoma cells were used to test palytoxin or palytoxin-like compounds by measuring the cell metabolic rate with Alamar Blue. The dose-dependent decrease in viability was specifically inhibited by ouabain in the case of BE (2)-M17 neuroblastoma cells. This is a functional, dynamic and simple test for palytoxins with high sensitivity (as low as 0.2 ng/ml). This method was useful for toxin detection in Ostreopsis extracts and naturally contaminated mussel samples. A comparative study testing toxic mussel extracts by LC (liquid chromatography)-MS/MS (tandem MS), MBA (mouse bioassay), haemolysis neutralization assay and a cytotoxicity test indicated that our method is suitable for the routine determination and monitoring of palytoxins and palytoxin-like compounds.
ORF-C4 from the early branching eukaryoteGiardia lambliadisplays characteristics of α-crystallin small heat-shock proteins
Authors: Nores María J. , Prucca César G. , Quiroga Rodrigo , Elías Eliana V. , Cavallín Lucas , Price Argenta M. , Saura Alicia , Carranza Pedro G. , Gottig Natalia , Solari Alberto J. , Lujan Hugo D.
Published: August 2008

Giardia lamblia is a medically important protozoan parasite with a basal position in the eukaryotic lineage and is an interesting model to explain the evolution of biochemical events in eukaryotic cells. G. lamblia trophozoites undergo significant changes in order to survive outside the intestine of their host by differentiating into infective cysts. In the present study, we characterize the previously identified Orf-C4 (G. lamblia open reading frame C4) gene, which is considered to be specific to G. lamblia. It encodes a 22 kDa protein that assembles into high-molecular-mass complexes during the entire life cycle of the parasite. ORF-C4 localizes to the cytoplasm of trophozoites and cysts, and forms large spherical aggregates when overexpressed. ORF-C4 overexpression and down-regulation do not affect trophozoite viability; however, differentiation into cysts is slightly delayed when the expression of ORF-C4 is down-regulated. In addition, ORF-C4 protein expression is modified under specific stress-inducing conditions. Neither orthologous proteins nor conserved domains are found in databases by conventional sequence analysis of the predicted protein. However, ORF-C4 contains a region which is similar structurally to the α-crystallin domain of sHsps (small heat-shock proteins). In the present study, we show the potential role of ORF-C4 as a small chaperone which is involved in the response to stress (including encystation) in G. lamblia.
Switching of off-axis viewing quality in twisted nematic liquid crystal display by controlling phase retardation of additional liquid crystal layers
Authors: Jeong Eun , Chin Mi Hyung , Lim Young Jin , Srivastava Anoop Kumar , Lee Seung Hee , Park Kyung Ho , Choi Hyun Chul
Published: August 2008

This study examined the viewing angle control of twisted nematic liquid crystal displays (TN-LCDs). Conventional TN mode has intrinsic characteristics, such as a narrow viewing angle along the vertical direction and a relatively wide viewing angle along the horizontal and diagonal directions. Our study shows that the viewing angle of the TN-LCD can be made wider and smaller than that of a normal TN cell by adding one or two homogeneously aligned liquid crystal layers between the TN cell and polarizers, and controlling their retardation with an applied voltage.
Nanocrystalline Ba0.97Ca0.03SO4:Eu for ion beams dosimetry
Authors: Lochab S. P. , Kanjilal D. , Salah Numan , Habib Sami S. , Lochab Jyoti , Ranjan Ranju , Aleynikov V. E. , Rupasov A. A. , Pandey A.
Published: August 2008

Nanoparticles of Ba0.97Ca0.03SO4:Eu have been irradiated by 48 MeV Li3+, 75 MeV C6+, and 90 MeV O7+ ion beams with a fluence range of 1×109−1×1013 ion/cm2. The thermoluminescence (TL) glow curves along with the response curves of this nanophosphor have been investigated and compared with those of the corresponding microcrystalline samples. TL glow curve of the nanophosphor exposed to γ-rays has also been included in the letter with the aim of reporting some of the comparative measurements. The glow curves of the ion-beam irradiated nanomaterials are similar in their shapes to those induced by gamma rays, with a shift in the peak positions to the higher temperature side by around 30 K. The TL intensity of the ion-beam irradiated nanomaterials is found to decrease, while going from low to high atomic number (Z) ions (i.e., Li3+→O7+). Similar trend was also observed in the linearity of the TL response curves. The response curve of Li ion irradiated nanomaterials is sublinear in the whole range of studied fluences. C ion has also a more or less similar response, while the O ion has a sublinear response over a shorter range of 1×109−1×1012 ion/cm2, and above this range the response saturates. These results for the nanomaterials are much better than that of the corresponding microcrystalline sample irradiated by Li3+ ions. The curve was sublinear up to the fluence 1×1010 ion/cm2 and then saturates at higher fluences. The wider sublinear TL response of the nanocrystalline Ba0.97Ca0.03SO4:Eu makes it superior to its corresponding microform and thus makes it a suitable candidate as a dosimeter to be used for detecting the doses of ions, especially the Li and C ions for their application in cancer radiotherapy and radiation biology.
An experimental study on the molecular organization and exciton diffusion in a bilayer of a porphyrin and poly(3-hexylthiophene)
Authors: Huijser Annemarie , Savenije Tom J. , Shalav Avi , Siebbeles Laurens D. A.
Published: August 2008

The exciton root-mean-square displacement (ΛD) in regioregular poly(3-hexylthiophene) (P3HT) deposited onto meso-tetrakis (n-methyl-4-pyridyl) porphyrin tetrachloride (H2TMPyP) has been determined from the photovoltaic response of a device based on these materials in a bilayer configuration. Excitons formed on illumination that reach the interface between H2TMPyP and P3HT can undergo interfacial charge separation by electron injection into the H2TMPyP and hole injection into the P3HT. The incident photon to current efficiency (IPCE) exceeds 20% over a broad wavelength regime. The theoretical analysis of the IPCE values gives a value for ΛD in H2TMPyP that amounts to 14 nm, while for P3HT a value of 18 nm is obtained. The latter value exceeds literature values reported for P3HT by almost a factor of 3. X-ray diffraction analysis shows that in the studied bilayer the P3HT backbones are aligned parallel to the interface with H2TMPyP. In contrast, in the case of P3HT deposited onto TiO2, for which ΛD has been reported to equal only 7 nm, hardly any organization of the P3HT backbones is observed. The excitonic coupling between P3HT backbones deposited onto H2TMPyP is as high as 125 cm−1, a factor of 3 larger than the excitonic coupling between the disordered P3HT backbones that amounts to 47 cm−1. The difference illustrates the importance of controlling the molecular organization for the realization of efficient energy transfer in organic optoelectronics.
Tuning the wavelength of lasing emission in organic semiconducting laser by the orientation of liquid crystalline conjugated polymer
Authors: Song Myoung Hoon , Wenger Bernard , Friend Richard H.
Published: August 2008

We report the optical pumping of one-dimensional distributed feedback (DFB) conjugated polymer devices using a uniaxially aligned liquid crystalline polymer, poly(9,9-dioctylfluorene). We can independently select the alignment direction (via a rubbed polyimide layer) and the DFB structure (via nanoimprinting). In comparison with unaligned film, we show that lasing threshold is substantially reduced when absorption is parallel to the aligned direction (∼20.0 μJ cm−2 pulse−1). This is mainly due to the higher absorption coefficient estimated in the table by calculating the exciton densities at each threshold value. We also report the control of lasing wavelength through independent selection of alignment direction and DFB orientation, which is achieved through the control of the effective refractive index of waveguide (neff).
Orientation-dependent conductance study of pentacene nanocrystals by conductive atomic force microscopy
Authors: Hu Wei-Shan , Tao Yu-Tai , Chen Yen-Fu , Chang Chia-Seng
Published: August 2008

Oriented pentacene nanocrystals with long molecular axis either parallel or perpendicular to a Au substrate were prepared on a bare Au surface or a self-assembled monolayer (SAM)-modified Au surface, respectively. The conductance across the differently oriented pentacene crystals were measured by conductive atomic force microscopy in a similar device configuration of Au/SAM/pentacene/Au-tip and Au/pentacene/SAM-modified-Au-tip, respectively. Rectifying current was observed depending on the location of the SAM in the device. With an average thickness of 50nm, the conductance along the C–H⋯π stacking direction (a-b plane) was nearly five orders of magnitude larger than along the layer direction (c axis).
Electronic structure and bonding of ozone
Authors: Kalemos Apostolos , Mavridis Aristides
Published: August 2008

The ground and low-lying states of ozone (O3) have been studied by multireference variational methods and large basis sets. We have constructed potential energy curves along the bending coordinate for (1,2) A1′, (1,2) A1″, (1,2) A3′, and (1,2) A3″ symmetries, optimizing at the same time the symmetric stretching coordinate. Thirteen minima have been located whose geometrical and energetic characteristics are in very good agreement with existing experimental data. Special emphasis has been given to the interpretation of the chemical bond through valence-bond-Lewis diagrams; their appropriate use captures admirably the bonding nature of the O3 molecule. The biradical character of its ground state, adopted long ago by the scientific community, does not follow from a careful analysis of its wave function.
Raman study of self-assembled InAs/InP quantum wire stacks with varying spacer thickness
Authors: Angelova T. , Cros A. , Cantarero A. , Fuster D. , González Y. , González L.
Published: August 2008

Self-assembled InAs/InP (001) quantum wire stacks have been investigated by means of Raman scattering. The characteristics of the observed vibrational modes show clear evidence of confinement and atomic intermixing between As and P atoms from the wire and the spacer. The change in the intermixing with spacer layer thickness and growth temperature is investigated. Likewise, the effect of annealing on the exchange of As and P atoms is also studied. Resonance effects in confined and interface phonons are discussed for excitation in the vicinity of the InAs E1 critical point. Finally, the energy of the interface modes is related to the structural characteristics of the wires by comparing the experimental data with a lattice dynamic calculation based on the dielectric continuum model.
Room temperature epitaxial stabilization of a tetragonal phase in ARuO3 (A=Ca and Sr) thin films
Authors: Vailionis Arturas , Siemons Wolter , Koster Gertjan
Published: August 2008

We demonstrate that SrRuO3 and CaRuO3 thin films undergo a room temperature structural phase transition driven by the substrate imposed epitaxial biaxial strain. As tensile strain increases, ARuO3 (A=Ca and Sr) films transform from the orthorhombic phase which is usually observed in bulk SrRuO3 and CaRuO3 at room temperature into a tetragonal phase which in bulk samples is only stable at higher temperatures. More importantly, we show that the observed phenomenon strongly affects the electronic and magnetic properties of ARuO3 thin films that are grown on different single crystal substrates which, in turn, offers the possibility to tune these properties.
Investigation of two-branch boron diffusion from vapor phase in n-type 4H-SiC
Authors: Bolotnikov A. V. , Muzykov P. G. , Sudarshan T. S.
Published: August 2008

Boron diffusion from gas phase was implemented for p-type doping of 4H-SiC at temperatures in the range of 1800–2000°C. A two-branch diffusion associated with two different diffusion mechanisms was observed. The activation energy Ea and prefactor D0 were calculated for each diffusion branch, that are Ea=7.258eV∕D0=1.931×106cm2∕s and Ea=8.742eV∕D0=2.126×107cm2∕s for fast and slow diffusion, respectively. It has been confirmed that the surface layer of diffused boron mostly consists of shallow boron acceptors, while the tail of diffusion profile has mostly deep level D centers.
Genetic parameters for yearling wool production, wool quality and bodyweight traits in fine wool Merino sheep
Authors: Swan A. A. , Purvis I. W. , Piper L. R.
Published: August 2008

Genetic parameters were estimated for traits measured in the first year of production in a multi-bloodline flock of fine wool Merino sheep. Between 5025 and 9271 animals were measured, depending on the trait, and these animals were the progeny of up to 430 sires. Heritability estimates for fleece weight traits ranged from 0.37 to 0.49, while estimates for five wool quality traits ranged from 0.34 for staple strength to 0.66 for mean fibre diameter. For bodyweight, the heritability estimated at weaning was 0.20, and at the yearling age was 0.51. Maternal genetic effects were significant for fleece weight and bodyweight traits and were highly correlated between these trait groups, indicating that these effects are determined by similar groups of genes in both trait groups. While most genetic correlation estimates were either favourable or neutral, there were economically antagonistic correlations between fleece weight and mean fibre diameter, ranging from 0.15 to 0.30, and between mean fibre diameter and staple strength (0.26). Overall, the heritabilities and genetic correlations estimated in this fine wool population were similar to estimates from other strains, indicating that outcomes from selection programs will be similar across strains and that fine wool sheep can be included in across flock genetic evaluations with other strains.
Assessing the differenced Normalized Burn Ratio's ability to map burn severity in the boreal forest and tundra ecosystems of Alaska's national parks
Authors: Allen Jennifer L. , Sorbel Brian
Published: August 2008

Burn severity strongly influences post-fire vegetation succession, soil erosion, and wildlife populations in the fire-adapted boreal forest and tundra ecosystems of Alaska. Therefore, satellite-derived maps of burn severity in the remote Alaskan landscape are a useful tool in both fire and resource management practices. To assess satellite-derived measures of burn severity in Alaska we calculated the Normalized Burn Ratio (NBR) from pre- and post-fire Landsat TM/ETM+ data. We established 289 composite burn index (CBI) plots in or near four national park areas between 2001 and 2003 in order to compare ground-based measurements of burn severity with satellite-derived values of burn severity. Within the diverse vegetation types measured, a strong linear relationship between a differenced Normalized Burn Ratio (dNBR) and CBI for eight out of the nine fire assessments was found; R2 values ranged from 0.45 to 0.88. The variations in severity among four pre-fire vegetation types were examined and a significant difference in the average dNBR and average CBI values among the vegetation types was found. Black spruce forests overall had the strongest relationship with dNBR, while the high severity white spruce forests had the poorest fit with dNBR. Deciduous forests and tall shrub plots had the lowest average remotely sensed burn severity (dNBR), but not the lowest ground severity among the vegetation types sampled. The tundra vegetation sampled had the lowest ground severity. Finally, a significant difference was detected between initial and extended assessments of dNBR in tundra vegetation types. The results indicated that the dNBR can be used as an effective means to map burn severity in boreal forest and tundra ecosystems for the climatic conditions and fire types that occurred in our study sites.