bluuebunny/crossref_metadata_2025 huggingface dataset:
Jet characterization in the upper troposphere/lower stratosphere (UTLS): applications to climatology and transport studies
Authors: Manney G. L. , Hegglin M. I. , Daffer W. H. , Santee M. L. , Ray E. A. , Pawson S. , Schwartz M. J. , Boone C. D. , Froidevaux L. , Livesey N. J. , Read W. G. , Walker K. A.
Published: June 2011

Abstract. A method of classifying the upper tropospheric/lower stratospheric (UTLS) jets has been developed that allows satellite and aircraft trace gas data and meteorological fields to be efficiently mapped in a jet coordinate view. A detailed characterization of multiple tropopauses accompanies the jet characterization. Jet climatologies show the well-known high altitude subtropical and lower altitude polar jets in the upper troposphere, as well as a pattern of concentric polar and subtropical jets in the Southern Hemisphere, and shifts of the primary jet to high latitudes associated with blocking ridges in Northern Hemisphere winter. The jet-coordinate view segregates air masses differently than the commonly-used equivalent latitude (EqL) coordinate throughout the lowermost stratosphere and in the upper troposphere. Mapping O3 data from the Aura Microwave Limb Sounder (MLS) satellite and the Winter Storms aircraft datasets in jet coordinates thus emphasizes different aspects of the circulation compared to an EqL-coordinate framework: the jet coordinate reorders the data geometrically, thus highlighting the strong PV, tropopause height and trace gas gradients across the subtropical jet, whereas EqL is a dynamical coordinate that may blur these spatial relationships but provides information on irreversible transport. The jet coordinate view identifies the concentration of stratospheric ozone well below the tropopause in the region poleward of and below the jet core, as well as other transport features associated with the upper tropospheric jets. Using the jet information in EqL coordinates allows us to study trace gas distributions in regions of weak versus strong jets, and demonstrates weaker transport barriers in regions with less jet influence. MLS and Atmospheric Chemistry Experiment-Fourier Transform Spectrometer trace gas fields for spring 2008 in jet coordinates show very strong, closely correlated, PV, tropopause height and trace gas gradients across the jet, and evidence of intrusions of stratospheric air below the tropopause below and poleward of the subtropical jet; these features are consistent between instruments and among multiple trace gases. Our characterization of the jets is facilitating studies that will improve our understanding of upper tropospheric trace gas evolution.
Characteristics of atmospheric ammonia over Beijing, China
Authors: Meng Z. Y. , Lin W. L. , Jiang X. M. , Yan P. , Wang Y. , Zhang Y. M. , Jia X. F. , Yu X. L.
Published: June 2011

Abstract. Continuous measurements of atmospheric ammonia (NH3) were conducted using Ogawa passive samplers from February 2008 to July 2010 at an urban site and from January 2007 to July 2010 at a rural site in Beijing, China. NH4+ in fine particles was also collected at the rural site during 2008–2009. The field comparison between the Ogawa passive samplers and an active analyzer for NH3 conducted at the urban site assures the quality and accuracy of the measurements. The concentrations of NH3 at the urban site ranged from 0.7 to 85.1 ppb, with the annual average of 18.5 ± 13.8 and 23.5 ± 18.0 ppb in 2008 and 2009, respectively. The NH3 concentrations at the rural site were lower than those at urban site, and varied from 0.8 to 42.9 ppb, with the annual average of 4.5 ± 4.6, 6.6 ± 7.0 and 7.1 ± 3.5 ppb in 2007, 2008 and 2009, respectively. The data showed marked seasonal variations at both sites. The results emphasized traffic to be a significant source of NH3 concentrations in winter in urban areas of Beijing. This was illustrated by the strong correlations of NH3 with the traffic related pollutants (NOx and CO) and also by the bimodal diurnal cycle of NH3 concentrations that was synchronized with traffic. Similar patterns were not observed during the summer, suggesting other non-traffic sources became more important. At the rural site, the daily NH4+ concentrations ranged from 0.10 to 36.53 μg m−3, with an average of 7.03 μg m−3 from June 2008 to December 2009. Monthly NH3 were significantly correlated with NH4+ concentrations. Average monthly NH3/NH4+ ratios varied from 0.13 to 2.28, with an average of 0.73. NH4+ in PM2.5 was primarily associated with SO4−2 at the rural site.
Steady-frequency waves at intradiurnal periods from simultaneous co-located microbarometer and seismometer measurements: a case study
Authors: Shved G. M. , Karpova N. V. , Petrova L. N. , Orlov E. G. , Ermolenko S. I.
Published: June 2011

Abstract. Simultaneous co-located microbarometer and vertical-pendulum seismometer measurements at St. Petersburg (59.9° N, 29.8° E) with total duration of 4 months are used to study atmospheric oscillations at steady frequencies at periods shorter than 8 h. The temporal behavior of the phase shift between oscillations detected simultaneously by both instruments is analyzed for oscillations of periods up to as short as ~0.5 h. Some of oscillations last up to several days. For the 42–90 min and 2.5–5 h period ranges, the temporal behavior of the power spectra are considered and correlated with the atmospheric angular momentum of zonal wind, tropical cyclones and large earthquakes. Signatures of sequences of subharmonics of the solar tide are revealed with periods up to day/30. There are indications of effects of the 5-day planetary waves and tropical cyclones on wave activity in the ~1–5 h period range. A weak increase of wave activity is observed when large earthquakes occur.
Effects of flooding cycles in the Pantanal on the turnover of soil nitrogen pools and emission of N2O
Authors: Liengaard L. , Nielsen L. P. , Revsbech N. P. , Elberling B. , Priemé A. , Prast A. E. , Kühl M.
Published: June 2011

Abstract. The global nitrous oxide (N2O) budget remains unbalanced. Currently, ~25 % of the global N2O emission is ascribed to uncultivated tropical soils, but the exact locations and controlling mechanisms are not clear. In this study, we present the first detailed study of the dynamics of soil nitrogen pools and flux of N2O from the world's largest wetland Pantanal, South America. At three long-term measurement sites we measured porewater pH, NO3–, NH4+ , N2O and O2 as well as N2O dynamics in soil slurry, and in situ fluxes of N2O and CO2. The pool of inorganic nitrogen changed (7.1–92 μg NH4+-N g dw−1, and 0.1–201 μg NO3–-N g dw–1) with the seasonal flooding and drying cycles, indicating dynamic shifts between ammonification, nitrification and denitrification. In the field, O2 penetrated to a depth of 60 cm in dry soil, but O2 was rapidly depleted in response to precipitation. Soil pH fluctuated from pH 7–7.5 in flooded soil to pH 3.5–4.5 in the same drained soil. Microsensor measurements showed rapid N2O accumulation reaching >500–1000 Pa in soil slurries due to incomplete denitrification. In situ fluxes of N2O were comparable to heavily fertilized forest or agricultural soils. The dominating parameter affecting N2O emission rate was precipitation inducing peak emissions of >3 mmol N2O m−2 d−1, while the mean daily flux was 0.43 mmol N2O m−2 d−1. Single measurement based screening of in situ activity at 10 Pantanal sites during dry conditions averaged 0.39 mmol N2O m−2 d−1. The in situ N2O fluxes were only weakly correlated (r2 = 0.177) with NO3– and pH value, showing a tendency (p = 0.063) for NO3– concentration to be positively correlated with the in situ N2O flux and a weaker tendency (p = 0.138) for the pH value to be negatively correlated with the in situ N2O flux. Over 170 days of the drained period we estimated non-wetted drained soil to contribute 70.0 mmol N2O m−2, while rain induced peak events contributed 9.2 mmol N2O m−2, resulting in a total N2O emission of 79.2 mmol N2O m−2. The total nitrogen loss via emission of NO, N2O and N2 was estimated to be 206 mmol N m−2 over 170 days, representing 0.7–1.6 % of the total nitrogen in the top 6.5 cm soil layer.
LOSCAR: Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir Model
Authors: Zeebe R. E.
Published: June 2011

Abstract. The LOSCAR model is designed to efficiently compute the partitioning of carbon between ocean, atmosphere, and sediments on time scales ranging from centuries to millions of years. While a variety of computationally inexpensive carbon cycle models are already available, many are missing a critical sediment component, which is indispensable for long-term integrations. One of LOSCAR's strengths is the coupling of ocean-atmosphere routines to a computationally efficient sediment module. This allows, for instance, adequate computation of CaCO3 dissolution, calcite compensation, and long-term carbon cycle fluxes, including weathering of carbonate and silicate rocks. The ocean component includes various biogeochemical tracers such as total carbon, alkalinity, phosphate, oxygen, and stable carbon isotopes. We have previously published applications of the model tackling future projections of ocean chemistry and weathering, pCO2 sensitivity to carbon cycle perturbations throughout the Cenozoic, and carbon/calcium cycling during the Paleocene-Eocene Thermal Maximum. The focus of the present contribution is the detailed description of the model including numerical architecture, processes and parameterizations, tuning, and examples of input and output. Typical CPU integration times of LOSCAR are of order seconds for several thousand model years on current standard desktop machines. The LOSCAR source code in C can be obtained from the author by sending a request to loscar.model@gmail.com.
The relevance of glacier melt in the water cycle of the Alps: the example of Austria
Authors: Koboltschnig G. R. , Schöner W.
Published: June 2011

Abstract. This paper quantifies the contribution of glacier melt to river runoff from compilation and statistical interpretation of data from available studies based on observations or glacio- hydrological modelling for the region of Austria (Austrian Salzach and Inn river basin). A logarithmic fit between the glacier melt contribution and the relative glacierized area was found not only for the long-term mean glacier contributions but also for the glacier melt contribution during the extreme hot an dry summer of 2003. Interestingly, the mean contributions of glacier melt to river runoff do not exceed 15 % for both river catchments and are uncorrelated to glacierization for glacierization values >10 %. This finding, however, has to be seen in the light of the general precipitation increase with altitude for the study region which levels out the increase of absolute melt with glacierization thus resulting in the rather constant value of glacier melt contribution. In order to qualitatively proof this finding another approach has been applied by calculating the quotient qA03 of the mean monthly August runoff in 2003 and the long-term mean August runoff for 38 gauging stations in Austria. The extreme summer 2003 was worth to be analysed as from the meteorological and glaciological point of view an extraordinary situation was observed. During June and July nearly the entire snow-cover melted and during August mainly bare ice melt of glaciers contributed to runoff. The qA03 quotients were calculated between 0.32 for a non-glacierized and 2.0 for a highly glacierized catchment. Using the results of this study the mean and maximum possible glacier melt contribution of catchments can be estimated based on the relative glacierized area. It can also be shown that the found correlation of glacierized area and glacier melt contribution is applicable for the Drau basin where yet no results of modelled glacier melt contributions are available.
Estimating river discharge from earth observation measurements of river surface hydraulic variables
Authors: Negrel J. , Kosuth P. , Bercher N.
Published: June 2011

Abstract. River discharge is a key variable for quantifying the water cycle, its fluxes and stocks at different scales. These scales range from a local scale for the efficient management of water resources to a global scale for the monitoring of climate change. Therefore, developing Earth observation (EO) techniques for the measurement or estimation of river discharge poses a major challenge. A key question deals with the possibility of deriving river discharge values from EO surface variables (width, level, slope, and velocity are the only such variables accessible through EO) without any in situ measurement. Based on a literature study and original investigations, this study explores the possibilities of estimating river discharge from water surface variables. The proposed method relies on limiting assumptions to simplify river flow equations to obtain the values of the hydraulic parameters at a given river station without using ground measurements. Once the hydraulic parameters are identified, the method allows the estimation of the river discharge corresponding to a set of surface measurements of hydraulic variables.
Bivariate Poincaré Series for the Algebra of Covariants of a Binary Form
Authors: Bedratyuk Leonid
Published: June 2011

A formula for computation of the bivariate Poincaré series Pd(z,t) for the
algebra of covariants of binary d-form is found.
The calcineurin—nuclear factor of activated T cells signaling pathway mediates the effect of corticotropin releasing factor and urocortins on catecholamine synthesis
Authors: Dermitzaki Eirini , Tsatsanis Christos , Gravanis Achille , Margioris Andrew N.
Published: June 2011

The biological effects of the Corticotropin‐releasing factor (CRF) family of neuropeptides are mediated by mobilization of [Ca2+]. Aim of the current work was to examine if the calcineurin/NFAT (nuclear factor of activated T‐cells) signaling pathway is involved in the effect of CRF peptides in catecholamine synthesis and secretion from PC12 rat pheochromocytona cells, a model for the study of adrenal catecholamine production. PC12 cells express both types of CRF receptors. Our data are as follows: (a) The calcineurin inhibitor cyclosporine A (CsA) blocked norepinephrine secretion induced by ligands of either CRF type 1 (CRF1) or 2 (CRF2) receptors on PC12 cells. (b) Silencing NFAT2 expression using a selective NFAT2 siRNA blocked CRF1 and CRF2‐induced NE production. (c) CRF ligands induced NFAT transcriptional activity in cells transfected with a luciferase reporter construct controlled by NFAT binding elements (NFAT‐Luc). (d) CsA completely blocked the stimulatory effect of CRF1 and CRF2 ligands on NFAT activity in NFAT‐Luc transfected cells. (e) PKA, PKC, p38‐MAPK, Tpl2, Ha‐Ras, and AKT1 were crucial intermediates for both CRF1 and CRF2‐induced NFAT activation. Interestingly, MEK1/2 and ERK1/2 were crucial only for the CRF2‐induced NFAT activation. (f) p38‐MAPK and Tpl2 were crucial intermediates for both CRF1 and CRF2‐induced norepinephrine production, while AKT1 affected only CRF2‐induced norepinephrine production. In conclusion, our data suggest that CRF1 and CRF2 ligands activate the transcription factor NFAT and its activation is prerequisite for CRF‐induced catecholamine production from chromaffin cells. J. Cell. Physiol. 227: 1861–1872, 2012. © 2011 Wiley Periodicals, Inc.
Frequency and damping of non-axisymmetric surface oscillations of a viscous cylindrical liquid bridge
Authors: KIDAMBI RANGACHARI
Published: June 2011

We present a semi-analytic solution for the non-axisymmetric oscillations of a viscous cylindrical free-standing liquid bridge formed between two coaxial discs of radius R. Even though a streamfunction does not exist, a Helmholtz decomposition is used to obtain an analytic representation of the velocity field. An eigenvalue problem is formulated by projecting the free-surface boundary conditions onto a suitable space of test functions. This is then solved iteratively along with the dispersion relation obtained from the satisfaction of endwall boundary conditions. Extensive comparison with previous theoretical and numerical results, for a range of Reynolds number and bridge slenderness ratio, shows very good agreement in most cases. The present solution generalises that of Tsamopoulos, Chen & Borkar (J. Fluid Mech., vol. 235, 1992, p. 579), which employed a streamfunction formulation and was for the axisymmetric case.
From Indigenous Economies to Market-Based Self-Governance: A Feminist Political Economy Analysis
Authors: Kuokkanen Rauna
Published: June 2011

Abstract.This paper examines the apparent contradiction between the current tendency of many Indigenous groups and their political institutions to embrace the capitalist economic model as the one and only solution in establishing contemporary Indigenous self-governance, on the one hand, and on the other, the detrimental force of the market economy on Indigenous societies, past and present. The starting point is the following question. If the global market economy historically played a significant role in the loss of political and economic autonomy of Indigenous societies and women, how meaningful or sustainable is it to seek to (re)build contemporary Indigenous governance on the very economic model that was largely responsible for undermining it in the first place? Shouldn't this history be taken into consideration when discussing and shaping models and policies for contemporary Indigenous governance and hence be more critical of the standard economic development frameworks hailed as the path toward self-governance?

Résumé.Cet article examine l'apparente contradiction entre la tendance actuelle de nombreux groupes autochtones et de leurs institutions politiques à adopter le modèle économique capitaliste contemporain en tant que seule et unique solution pour constituer une autonomie gouvernementale autochtone d'une part, et de l'autre, les forces néfastes de l'économie de marché dans les sociétés autochtones, passées et présentes. Au départ, se pose la question suivante : si l'économie de marché mondiale a historiquement joué un rôle important dans la perte d'autonomie politique et économique des sociétés autochtones et des femmes, jusqu'à quel point est-il pertinent ou viable de chercher à bâtir ou à rebâtir l'autonomie gouvernementale contemporaine des peuples autochtones sur le même modèle économique qui a été largement responsable de la saper en premier lieu? Cette dimension historique ne devrait-elle pas être prise en considération lors de l'examen et de l'élaboration des modèles et des politiques de gouvernance autochtone contemporains et, par conséquent, inciter à une vision plus critique des cadres de développement économique convenus qui sont salués comme le chemin vers l'autogouvernance?
The Civil Partnership Act 2004, Same-Sex Marriage and the Church of England
Authors: Humphreys Jacqueline
Published: June 2011

The Civil Partnership Act 2004 enables same-sex couples to enter into a status that provides very many of the same rights and responsibilities that married couples have in respect to each other and the wider community. This paper first considers the extent of the legal similarities between civil partnerships and marriage; that is to what extent civil partnerships are 'same-sex marriage' in practical effect. Secondly it considers to what extent the conceptual understanding of civil partnerships within the Act reflects the current conception of marriage within English law; that is the extent to which civil partnerships are 'same-sex marriage' in theory. Thirdly, and finally, some of the specific dilemmas for the Church of England in the light of this are considered.
Perspectives on our cosmic habitat
Authors: Rees Martin J.
Published: June 2011

In this talk I shall try to highlight some themes that seem to promise specially interesting progress in the coming decades. I can't claim to be much of a prophet myself, but I'd like to recall someone who was: Arthur C. Clarke. He lived in Sri Lanka, and died in 2007, aged 90. I'd like to discuss three issues that he would have found interesting: space and alien life; galaxies and their origin; and (more speculatively) the size of our universe.
Cosmology between two wars. Einstein's revolution and alternative models of the Universe
Authors: Curir Anna
Published: June 2011

The personality of Edward Milne is examined, deepening the historical period in which his Cosmological theory was produced. Is suggested that Milne's kinematical Cosmology can be regarded as a kind of ‘resistance’ to the scientific revolution deriving from the new Einstein's theory of gravitation. Is investigated the deep philosophical meaning of the metrics on curved manifolds as far as the representation of the universe is concerned, and the importance of the cosmological theories in the epistemology and in the evolution of science is stressed.
The worldwide impact of Donati's comet on art and society in the mid-19th century
Authors: Gasperini Antonella , Galli Daniele , Nenzi Laura
Published: June 2011

Donati's comet was one of the most spectacular astronomical events of the nineteenth century. Its extended sword-like tail was a spectacular sight that inspired several literary and artistic representations. Traces of Donati's comet are found in popular magazines, children's books, collection cards, and household objects through the beginning of the twentieth century.
The decline of natural sciences in the culture of mass media
Authors: Elías Carlos
Published: June 2011

This study sets out to determine if the interest in and study of natural sciences is declining in western countries as scientists currently contend. Part one demonstrates how survey results reveal a decline of interest in scientific news in the EU. Part two explores the decline of interest further through examining data such as the number of students interested in scientific subjects and scientific careers. I explore the hypothesis that the lack of interest in scientific subjects is influenced by the culture of the mass media, and the manner in which the media covers scientific items. I examine a range of media outlets, from reality TV shows and TV series, to movies and the press. Many aspects of this paper have been discussed in depth in my book published in 2008:La razón estrangulada(Reason Strangled: the Crisis of Science in Contemporary Society).
From a closed world to the infinite Universe: Astronomy in prisons
Authors: Briot Danielle
Published: June 2011

For over a decade, some French astronomers visit prisons to talk and discuss about astronomy with prisoners. First we note the paradoxes which exist in the juxtaposition of the words “astronomy” and “prisons”. The importance and interests of these talks are reviewed, as well as the specificities of the audiences. Some material details about the organisation and a brief review of actions done in France today are given. As a conclusion, we emphasize the interest and the utility of these astronomy lectures and discussions.
MENSURA CAELI Territory, Town, Architectures, Tools
Authors: Incerti Manuela , Antonello Elio
Published: June 2011

A brief discussion is given on the possible contributions of the schools of architecture to the safeguard of important monuments of astronomical interest. Some highlights of a meeting dedicated to the italian astronomical cultural heritage are also reported.
No “explosion” in Big Bang cosmology: teaching kids the truth of what cosmologists really know
Authors: Gangui Alejandro
Published: June 2011

Common wisdom says that cosmologists are smart: they have developed a theory that can explain the “origin of the universe”. Every time an astro-related, heavily funded “big-science” project comes to the media, naturally the question arises: will science –through this or that experiment– explain the origin of the cosmos? Can this be done with the LHC, for example? Will this dream machine create other universes? Of course, the very words we employ in cosmology reinforce this misconception: so Big Bang must be associated with an “explosion”, even if a “peculiar” one, as it took place nowhere (there was presumably no space before the beginning) and happened virtually in no time (supposedly, space-time was created on this peculiar –singular– event). Right, the issue sounds confusing. Let us imagine what kids may get out of all this.

We have recently presented a series of brief astronomy and cosmology books aimed at helping both kids and their teachers in these and other arcane subjects, all introduced with carefully chosen words and images that young children can understand. In particular, Volume Four deals with the Big Bang and emphasizes the notion of “evolution” as opposed to the –wrong– notion of “origin” behind the scientific model. We then explain some of the pillars of Big Bang cosmology: the expansion of space that drags away distant galaxies, as seen in the redshift of their emitted light; the build-up of light elements in a cooling bath of radiation, as explained by primordial nucleosynthesis; and the existence and main features of the ubiquitous cosmic microwave background radiation, where theory and observations agree to a highly satisfactory degree.

Of course, one cannot attempt to answer the “origins” question when it is well known that all theories so far break down close to this origin (if there was actually an origin). It is through observations, analyses, lively discussions and recognition of the basic limitations of current theories and ideas, that we are led to try and reconstruct the past and predict the future evolution of our universe. Just that. Sound science turns out to be much more attractive when we tell the truth of what we really know.
Astronomy in additional education in Kazakhstan
Authors: Zagainova Vera
Published: June 2011

The merging of astronomy and physics into one subject in Kazakhstan's schools has hampered the knowledge of astronomy that had been established over tha past years. It is necessary to create a new system of aspace education for schoolchildren and the system of additional education should be leading this work. Additional education of astronomy in Kazakhstan began with astronomical clubs in the 1960s. In this paper a new system of additional education of astronomy in Kazakhstan is proposed.
The International Astronomy Olympiad
Authors: Gavrilov Michael G.
Published: June 2011

The International Astronomy Olympiad (IAO) is an annual scientific-educating event for students of the junior high-school classes, aged 14–18 years. The Euro-Asian Astronomical Society founded the IAO in 1996. The Olympiad includes an intellectual competition between these students. The style of the problems is aimed at developping the imagination, creativity and independent thinking.
Astronomy in basic level schools in Brasil
Authors: Saraiva M.F.O. , Kepler S.O.
Published: June 2011

We present the structure of the basic school curriculum in Brazil, that for a few years has included astronomy, and comment on the strategies that universities are adopting for preparing the teachers for the new curriculum.
Amateur observations of variable stars: The French Association of Variable Stars Observers
Authors: Verdenet Michel , Proust Dominique
Published: June 2011

We briefly present the history and activities of amateur and professionnal astronomers from the “Association Française des Observateurs d'Etoiles Variables” (AFOEV, the French society of variable star observers).
Maximum outreach. . . minimum budget
Authors: Laychak Mary Beth
Published: June 2011

Many astronomical institutions have budgetary constraints that prevent them from spending large amounts on public outreach. This is especially true for smaller organizations, such as the Canada-France-Hawaii Telescope (CFHT), where manpower and funding are at a premium. To maximize our impact, we employ unconventional and affordable outreach techniques that underscore our commitment to astronomy education and our local community. We participate in many unique community interactions, ranging from rodeo calf-dressing tournaments to art gallery exhibitions of CFHT images. Further, we have developed many creative methods to communicate complex astronomical concepts to both children and adults, including the use of a modified webcam to teach infrared astronomy and the production of online newsletter for parents, children, and educators. This presentation will discuss the outreach methods CFHT has found most effective in our local schools and our rural community.
Learning to discount transformations as the computational goal of visual cortex
Authors: Leibo Joel , Mutch Jim , Poggio Tomaso
Published: June 2011

It has been long recognized that a key obstacle to achieving human-level object recognition performance is the problem of invariance. The human visual system excels at factoring out the image transformations that distort object appearance under natural conditions. Models with a cortex-inspired architecture such as HMAX as well as nonbiological convolutional neural networks are invariant to translation (and in some cases scaling) by virtue of their wiring. The transformations to which this approach has been applied so far are generic; a single example image of any object contains all the information needed to synthesize a new image of the transformed object. In contrast, viewpoint and illumination transformations depend on the object's 3D structure and material properties. These are normally consistent within, but not between, classes.Class-specific modifications of the HMAX model achieve good viewpoint and illumination tolerant performance in a one-shot identification task. Performance suffers when a model that is specialized for transformations of one class is tested on identification within a different class. In fact, viewpoint-pooling models employing templates from the wrong class perform worse on viewpoint invariant identification tasks than models that have no particular mechanisms for dealing with viewpoint at all. The same situation arises for illumination invariance. This is in stark contrast to the generic case where the model is invariant to all classes undergoing the transformation no matter what templates are used.
Structure and activity of the Saccharomyces cerevisiae dUTP pyrophosphatase DUT1, an essential housekeeping enzyme
Authors: Tchigvintsev Anatoli , Singer Alexander U. , Flick Robert , Petit Pierre , Brown Greg , Evdokimova Elena , Savchenko Alexei , Yakunin Alexander F.
Published: June 2011

Genomes of all free-living organisms encode the enzyme dUTPase (dUTP pyrophosphatase), which plays a key role in preventing uracil incorporation into DNA. In the present paper, we describe the biochemical and structural characterization of DUT1 (Saccharomyces cerevisiae dUTPase). The hydrolysis of dUTP by DUT1 was strictly dependent on a bivalent metal cation with significant activity observed in the presence of Mg2+, Co2+, Mn2+, Ni2+ or Zn2+. In addition, DUT1 showed a significant activity against another potentially mutagenic nucleotide: dITP. With both substrates, DUT1 demonstrated a sigmoidal saturation curve, suggesting a positive co-operativity between the subunits. The crystal structure of DUT1 was solved at 2 Å resolution (1 Å=0.1 nm) in an apo state and in complex with the non-hydrolysable substrate α,β-imido dUTP or dUMP product. Alanine-replacement mutagenesis of the active-site residues revealed seven residues important for activity including the conserved triad Asp87/Arg137/Asp85. The Y88A mutant protein was equally active against both dUTP and UTP, indicating that this conserved tyrosine residue is responsible for discrimination against ribonucleotides. The structure of DUT1 and site-directed mutagenesis support a role of the conserved Phe142 in the interaction with the uracil base. Our work provides further insight into the molecular mechanisms of substrate selectivity and catalysis of dUTPases.
A plant proton-pumping inorganic pyrophosphatase functionally complements the vacuolar ATPase transport activity and confers bafilomycin resistance in yeast
Authors: Pérez-Castiñeira José R. , Hernández Agustín , Drake Rocío , Serrano Aurelio
Published: June 2011

V-ATPases (vacuolar H+-ATPases) are a specific class of multi-subunit pumps that play an essential role in the generation of proton gradients across eukaryotic endomembranes. Another simpler proton pump that co-localizes with the V-ATPase occurs in plants and many protists: the single-subunit H+-PPase [H+-translocating PPase (inorganic pyrophosphatase)]. Little is known about the relative contribution of these two proteins to the acidification of intracellular compartments. In the present study, we show that the expression of a chimaeric derivative of the Arabidopsis thaliana H+-PPase AVP1, which is preferentially targeted to internal membranes of yeast, alleviates the phenotypes associated with V-ATPase deficiency. Phenotypic complementation was achieved both with a yeast strain with its V-ATPase specifically inhibited by bafilomycin A1 and with a vma1-null mutant lacking a catalytic V-ATPase subunit. Cell staining with vital fluorescent dyes showed that AVP1 recovered vacuole acidification and normalized the endocytic pathway of the vma mutant. Biochemical and immunochemical studies further demonstrated that a significant fraction of heterologous H+-PPase is located at the vacuolar membrane. These results raise the question of the occurrence of distinct proton pumps in certain single-membrane organelles, such as plant vacuoles, by proving yeast V-ATPase activity dispensability and the capability of H+-PPase to generate, by itself, physiologically suitable internal pH gradients. Also, they suggest new ways of engineering macrolide drug tolerance and outline an experimental system for testing alternative roles for fungal and animal V-ATPases, other than the mere acidification of subcellular organelles.
Thin film contact resistance with dissimilar materials
Authors: Zhang Peng , Lau Y. Y. , Gilgenbach R. M.
Published: June 2011

This paper presents results of thin film contact resistance with dissimilar materials. The model assumes arbitrary resistivity ratios and aspect ratios between contact members, for both Cartesian and cylindrical geometries. It is found that the contact resistance is insensitive to the resistivity ratio for a/h < 1, but is rather sensitive to the resistivity ratio for a/h > 1 where a is the constriction size and h is film thickness. Various limiting cases are studied and validated with known results. Accurate analytical scaling laws are constructed for the contact resistance over a large range of aspect ratios and resistivity ratios. Typically the minimum contact resistance is realized with a/h ∼ 1, for both Cartesian and cylindrical cases. Electric field patterns are presented, showing the crowding of the field lines in the contact region.
Effects of patterning induced stress relaxation in strained SOI/SiGe layers and substrate
Authors: Hermann P. , Hecker M. , Renn F. , Rölke M. , Kolanek K. , Rinderknecht J. , Eng L. M.
Published: June 2011

Local stress fields in strained silicon structures important for CMOS technology are essentially related to size effects and properties of involved materials. In the present investigation, Raman spectroscopy was utilized to analyze the stress distribution within strained silicon (sSi) and silicon-germanium (SiGe) island structures. As a result of the structuring of initially unpatterned strained films, a size-dependent relaxation of the intrinsic film stresses was obtained in agreement with model calculations. This changed stress state in the features also results in the appearance of opposing stresses in the substrate underneath the islands. Even for strained island structures on top of silicon-on-insulator (SOI) wafers, corresponding stresses in the silicon substrate underneath the oxide were detected. Within structures, the stress relaxation is more pronounced for islands on SOI substrates as compared to those on bulk silicon substrates.
Hyper-Raman scattering: New prospects for the description of the local structure of complex perovskites
Authors: Al-Zein A. , Hlinka J. , Rouquette J. , Kania A. , Hehlen B.
Published: June 2011

Hyper-Raman scattering is used to investigate the vibrations in two prototypical relaxors, PbMg1/3Nb2/3O3 and PbMg1/3Ta2/3O3 (PMT). First-order scattering from polar modes is clearly observed. Most of the triply-degenerate cubic vibrations are split into doublets and their frequencies compare very well to that of PbTiO3 in its tetragonal phase. Their shape and scattering intensities are sensitive to the local chemical ordering and ferroelectric distortions. For example, the tendency toward 1:1 local ordering on the B-site in PMT is clearly evidenced. These results demonstrate the strong potentiality of hyper-Raman scattering as structural probe of complex perovskites.
Synthesis of amorphous alloys and amorphous-crystalline composites in the Cu-Nb-Hf system by ion beam mixing
Authors: Luo S. Y. , Cui Y. Y. , Wang T. L. , Ding N. , Li J. H. , Liu B. X.
Published: June 2011

Seven sets of Cu-Nb-Hf multilayered films were designed and prepared with the overall compositions of Cu21Nb65Hf14, Cu33Nb49Hf18, Cu34Nb34Hf32, Cu34Nb10Hf56, Cu50Nb23Hf27, Cu58Nb10Hf32, and Cu70Nb8Hf22, and an ion beam mixing experiment was then conducted using 200 keV xenon ions. It is found that the Cu-Nb-Hf system is a metallic glass forming one, and the single amorphous alloys could be synthesized in the Cu-Nb-based alloys with less than 18 at.% of Hf as a third addition. Also, when the Hf concentration is greater than 18 at.%, i.e., at the compositions of Cu34Nb34Hf32, Cu34Nb10Hf56, Cu50Nb23Hf27, Cu58Nb10Hf32, and Cu70Nb8Hf22, ion beam mixing resulted in the formation of amorphous-crystalline composites, which might have better mechanical properties than single-phase glassy alloys. In addition, a detailed discussion was presented for the formation mechanism of the amorphous alloys and amorphous-crystalline composites.
Happy orang-utans live longer lives
Authors: Weiss Alexander , Adams Mark J. , King James E.
Published: June 2011

Nonhuman primate ageing resembles its human counterpart. Moreover, ratings of subjective well-being traits in chimpanzees, orang-utans and rhesus macaques are similar to those of humans: they are intercorrelated, heritable, and phenotypically and genetically related to personality. We examined whether, as in humans, orang-utan subjective well-being was related to longer life. The sample included 184 zoo-housed orang-utans followed up for approximately 7 years. Age, sex, species and number of transfers were available for all subjects and 172 subjects were rated on at least one item of a subjective well-being scale. Of the 31 orang-utans that died, 25 died a mean of 3.4 years after being rated. Even in a model that included, and therefore, statistically adjusted for, sex, age, species and transfers, orang-utans rated as being “happier” lived longer. The risk differential between orang-utans that were one standard deviation above and one standard deviation below baseline in subjective well-being was comparable with approximately 11 years in age. This finding suggests that impressions of the subjective well-being of captive great apes are valid indicators of their welfare and longevity.
Sir Nicholas John Shackleton. 23 June 1937 — 24 January 2006
Authors: McCave Ian Nicholas , Elderfield Henry
Published: June 2011

Nick Shackleton was an international scientist of great renown who fundamentally changed our understanding of how Earth processes work. His research on ancient oceans and climates was both innovative and pioneering, and he clarified the precise role of carbon dioxide in warming and cooling the Earth's climate. His work contributed greatly to our present understanding of the mechanism and causes of global warming. When he began his research, the investigation of past climatic changes was an area of ‘academic’ interest only. Four decades later, his lifetime achievements define the emergence of our understanding of the operation of Earth's natural climate system. This understanding of the past is now central to efforts to predict the future climate we have begun to create. As well as his many scientific accomplishments, Nick Shackleton excelled in another area, that of music, which was almost as important to him as science, and he was a very accomplished clarinet player. In his work he was spirited and curiosity-driven. He let his students and an entire community share in his brilliance and vision.
Spreading of a dielectric droplet through an interfacial electric pressure
Authors: Mahmoudi Seyed Reza , Adamiak Kazimierz , Castle G. S. Peter
Published: June 2011

A corona discharge-assisted technique for spreading of a gently deposited dielectric droplet into a uniform thin film over a dry isothermal conductive substrate is proposed. The surface charge was built up over the droplet interface through ion bombardment using a sharp emitter electrode. Interaction of the surface charge density and intense electric field generates an interfacial electrical pressure and leads to a uniform axisymmetric spreading of the droplet in the radial direction. It was shown that the droplet expansion process can be controlled through variation of the ion injection current and/or discharge exposure time. It is also demonstrated that the proposed technique can be analogous to the classical Stefan's squeezing liquid flow between two separated parallel discs. The dynamics of the film spreading owing to the corona discharge can be predicted through a simplified analytical model based on this analogy.
Curve Density Estimates
Authors: Lampe O. Daae , Hauser H.
Published: June 2011

In this work, we present a technique based on kernel density estimation for rendering smooth curves. With this approach, we produce uncluttered and expressive pictures, revealing frequency information about one, or, multiple curves, independent of the level of detail in the data, the zoom level, and the screen resolution. With this technique the visual representation scales seamlessly from an exact line drawing, (for low‐frequency/low‐complexity curves) to a probability density estimate for more intricate situations. This scale‐independence facilitates displays based on non‐linear time, enabling high‐resolution accuracy of recent values, accompanied by long historical series for context. We demonstrate the functionality of this approach in the context of prediction scenarios and in the context of streaming data.
Progressive Splatting of Continuous Scatterplots and Parallel Coordinates
Authors: Heinrich J. , Bachthaler S. , Weiskopf D.
Published: June 2011

Continuous scatterplots and parallel coordinates are used to visualize multivariate data defined on a continuous domain. With the existing techniques, rendering such plots becomes prohibitively slow, especially for large scientific datasets. This paper presents a scalable and progressive rendering algorithm for continuous data plots that allows exploratory analysis of large datasets at interactive framerates. The algorithm employs splatting to produce a series of plots that are combined using alpha blending to achieve a progressively improving image. For each individual frame, splats are obtained by transforming Gaussian density kernels from the 3‐D domain of the input dataset to the respective data domain. A closed‐form analytic description of the resulting splat footprints is derived to allow pre‐computation of splat textures for efficient GPU rendering. The plotting method is versatile because it supports arbitrary reconstruction or interpolation schemes for the input data and the splatting technique is scalable because it chooses splat samples independently from the size of the input dataset. Finally, the effectiveness of the method is compared to existing techniques regarding rendering performance and quality.
Visualising Errors in Animal Pedigree Genotype Data
Authors: Graham Martin , Kennedy Jessie , Paterson Trevor , Law Andy
Published: June 2011

Genetic analysis of a breeding animal population involves determining the inheritance pattern of genotypes for multiple genetic markers across the individuals in the population pedigree structure. However, experimental pedigree genotype data invariably contains errors in both the pedigree structure and in the associated individual genotypes, introducing inconsistencies into the dataset, rendering them useless for further analysis. The resolution of these errors requires consideration of genotype inheritance patterns in the context of the pedigree structure. Existing pedigree visualisations are typically more suited to human pedigrees and are less suitable for large complex animal pedigrees which may exhibit cross generational inbreeding. Similarly, table‐based viewers of genotype marker data can highlight where errors become apparent but lack the functionality and interactive visual feedback to allow users to locate the origin of errors within the pedigree. In this paper, we detail a design study steered by biologists who work with pedigree data, and describe successive iterations through approaches and prototypes for viewing genotyping errors in the context of a displayed pedigree. We describe how each approach performs with real pedigree genotype data and why eventually we deemed them unsuitable. Finally, a novel prototype visualisation for pedigrees, which we term the ‘sandwich view’, is detailed and we demonstrate how the approach effectively communicates errors in the pedigree context, supporting the biologist in the error identification task.
Comics: A Medium in Transition
Authors: McCloud Scott
Published: June 2011

More than any other popular art form, comics are sensitive to the formats, platforms, and devices that connect them to readers. How can this unique medium communicate content effectively when all assumptions about its form are up for grabs? Author and comics artist Scott McCloud puts a blizzard of new trends into perspective in a fast‐moving visual presentation.
Epidemic curve and hazard function for occurrence of clinical equine influenza in a closed population of horses at a 3‐day event in southern Queensland, Australia, 2007
Authors: Morton JM , Dups JN , Anthony ND , Dwyer JF
Published: June 2011

The risk of individuals becoming infected during an epidemic of infectious disease can vary as the disease progresses. Monitoring this risk may provide information about the dynamics of transmission. This study describes the epidemic curve for an epidemic of equine influenza (EI) in a closed population of horses predominantly immunologically naïve to EI at a 3‐day event at Morgan Park in southern Queensland, Australia.

The hazard function suggested that a subset of horses were at reduced risk of becoming infected. This highlights the importance, when modelling infectious disease in populations, of considering possible differences in the risk of infection among subgroups in the population.
High‐level coordination and strategy in the 2007 equine influenza outbreak response
Authors: Glanville RJ , Christie B
Published: June 2011

The equine influenza (EI) outbreak presented many challenges that required high‐level coordination and decision making, as well as the development of new approaches for satisfactory and consistent resolution. This paper outlines the elements of the national coordination arrangements, preparatory arrangements in place prior to the outbreak that facilitated national coordination, and some of the issues faced and resolved in the response.
HCV Homolog in Dog: A Scientist’s Best Friend
Authors: Nyendak Melissa
Published: June 2011

A new HCV homolog in dog provides the first nonprimate animal model for HCV therapeutics discovery.