bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid hydrogen hydrate growth from non-stoichiometric tuning mixtures during liquid nitrogen quenching
Authors: Grim R. Gary , Kerkar Prasad B. , Sloan E. Dendy , Koh Carolyn A. , Sum Amadeu K.
Published: June 2012

In this study the rapid growth of sII H2 hydrate within 20 min of post formation quenching towards liquid nitrogen (LN2) temperature is presented. Initially at 72 MPa and 258 K, hydrate samples would cool to the conditions of ∼60 MPa and ∼90 K after quenching. Although within the stability region for H2 hydrate, new hydrate growth only occurred under LN2 quenching of the samples when preformed hydrate “seeds” of THF + H2 were in the presence of unconverted ice. The characterization of hydrate seeds and the post-quenched samples was performed with confocal Raman spectroscopy. These results suggest that quenching to LN2 temperature, a common preservation technique for ex situ hydrate analysis, can lead to rapid unintended hydrate growth. Specifically, guest such as H2 that may otherwise need sufficiently long induction periods to nucleate, may still experience rapid growth through an increased kinetic effect from a preformed hydrate template.
Numeric kinetic energy operators for molecules in polyspherical coordinates
Authors: Sadri Keyvan , Lauvergnat David , Gatti Fabien , Meyer Hans-Dieter
Published: June 2012

Generalized curvilinear coordinates, as, e.g., polyspherical coordinates, are in general better adapted to the resolution of the nuclear Schrödinger equation than rectilinear ones like the normal mode coordinates. However, analytical expressions of the kinetic energy operators (KEOs) for molecular systems in polyspherical coordinates may be prohibitively complicated for large systems. In this paper we propose a method to generate a KEO numerically and bring it to a form practicable for dynamical calculations. To examine the new method we calculated vibrational spectra and eigenenergies for nitrous acid (HONO) and compare it with results obtained with an exact analytical KEO derived previously [F. Richter, P. Rosmus, F. Gatti, and H.-D. Meyer, J. Chem. Phys. 120, 6072 (2004)]10.1063/1.1651051. In a second example we calculated π → π* photoabsorption spectrum and eigenenergies of ethene (C2H4) and compared it with previous work [M. R. Brill, F. Gatti, D. Lauvergnat, and H.-D. Meyer, Chem. Phys. 338, 186 (2007)]10.1016/j.chemphys.2007.04.002. In this ethene study the dimensionality was reduced from 12 to 6 by freezing six internal coordinates. Results for both molecules show that the proposed method for obtaining an approximate KEO is reliable for dynamical calculations. The error in eigenenergies was found to be below 1 cm−1 for most states calculated.
Proton nuclear magnetic resonance studies of hydrogen diffusion and electron tunneling in Ni-Nb-Zr-H glassy alloys
Authors: Niki Haruo , Okuda Hiroyuki , Oshiro Morihito , Yogi Mamoru , Seki Ichiro , Fukuhara Mikio
Published: June 2012

Using the Fourier transform of the echo envelope, the proton line shapes, spin-lattice relaxation time, and spin-spin relaxation time have been measured in a (Ni0.36Nb0.24Zr0.40)90H10 glassy alloy at 1.83 T (∼78 MHz) and at temperatures between 1.8 and 300 K. First, the spectral line width decreases abruptly between 1.8 and 2.1 K. Next, it remains almost constant at 13 kHz up to ∼150 K. Finally, the line width decreases as the temperature increases from ∼150 to 300 K. The initial decrease in the spectral line width is ascribed to the distribution of the external field, which is caused by the penetration of vortices in the superconducting state. The subsequent leveling off in the spectral line width is ascribed to the dipole-dipole interaction between protons when hydrogen atoms are trapped into vacancies among the Zr-centered icosahedral Zr5Ni5Nb3 clusters. The final decrease in the spectral line width is ascribed to the motional narrowing of the width that is caused by the movement of hydrogen atoms. The temperature dependences of the spin-lattice and spin-spin relaxation time showed that at temperature above 150 K and the activation energy of 8.7 kJ/mol allowed the hydrogen atoms to migrate among the clusters. The distance between the hydrogen atoms is estimated to be 2.75 Å. Hydrogen occupancies among clusters in the (Ni0.36Nb0.24Zr0.40)90H10 glassy alloy play an important role in the diffusion behavior and in the electronic properties of this alloy.
Polymer induced changes of the crystallization scenario in suspensions of hard sphere like microgel particles
Authors: Beyer Richard , Iacopini Sara , Palberg Thomas , Schöpe Hans Joachim
Published: June 2012

We investigated the crystallization scenario of highly cross linked polystyrene particles dispersed in the good solvent 2-ethylnaphtalene and their mixtures with non-adsorbing low molecular weight polysterene polymer using time resolved static light scattering. The samples were prepared slightly below the melting volume fraction of the polymer free system. For the polymer free samples, we obtained polycrystalline solids via crystallization scenario known from hard sphere suspensions with little competition of wall crystal formation. Addition of non-adsorbing low molecular weight polystyrene polymer leads to a considerably slowing down of the bulk crystallization kinetics. We observed a delay of the precursor to crystal conversion for the bulk crystallization while the induction times for the wall nucleation are reduced. The increased polymer concentration thus shifts the balance between the two competing crystallization pathways giving the possibility to tune the relative amount of wall based crystals.
Deflection gating for time-resolved x-ray magnetic circular dichroism–photoemission electron microscopy using synchrotron radiation
Authors: Wiemann C. , Kaiser A. M. , Cramm S. , Schneider C. M.
Published: June 2012

In this paper, we present a newly developed gating technique for a time-resolving photoemission microscope. The technique makes use of an electrostatic deflector within the microscope's electron optical system for fast switching between two electron-optical paths, one of which is used for imaging, while the other is blocked by an aperture stop. The system can be operated with a switching time of 20 ns and shows superior dark current rejection. We report on the application of this new gating technique to exploit the time structure in the injection bunch pattern of the synchrotron radiation source BESSY II at Helmholtz-Zentrum Berlin for time-resolved measurements in the picosecond regime.
Development of the prototype pneumatic transfer system for ITER neutron activation system
Authors: Cheon M. S. , Seon C. R. , Pak S. , Lee H. G. , Bertalot L.
Published: June 2012

The neutron activation system (NAS) measures neutron fluence at the first wall and the total neutron flux from the ITER plasma, providing evaluation of the fusion power for all operational phases. The pneumatic transfer system (PTS) is one of the key components of the NAS for the proper operation of the system, playing a role of transferring encapsulated samples between the capsule loading machine, irradiation stations, counting stations, and disposal bin. For the validation and the optimization of the design, a prototype of the PTS was developed and capsule transfer tests were performed with the developed system.
Resonant charge-exchange involving excited helium atoms and reactive transport of local thermodynamic equilibrium helium plasma
Authors: Kosarim A. V. , Smirnov B. M. , Laricchiuta A. , Capitelli M.
Published: June 2012

The cross sections for charge-exchange and charge-transfer processes are evaluated for collisions of helium ions with parent-atoms in ground and excited states, with the principal quantum number n = 1–5, in the collision energy range from thermal up to 10 eV. Corresponding diffusion-type collision integrals are derived, and the role of “abnormal” transport of electronically excited states on the reactive thermal conductivity of equilibrium helium plasma, at atmospheric pressure, estimated in the frame of a simplified approach.
Memory-like behavior as a feature of electrical signal transmission in melanin-like bio-polymers
Authors: Ambrico M. , Ambrico P. F. , Ligonzo T. , Cardone A. , Cicco S. R. , Lavizzera A. , Augelli V. , Farinola G. M.
Published: June 2012

The memory-like behavior of melanin biopolymer under electrical stimuli is shown through electrical transport characterization performed on melanin based metal insulator semiconductor structures on silicon. The presence of a memory window and retention behavior is verified by capacitance-voltage read outs before and after the application of voltage pulses. Interestingly, these phenomena occur without the presence of metallic nanoclusters enclosed in the melanin matrix. Charge trapping is considered the main mechanism responsible for the melanin memory-like character. The inability to erase the memory window has been ascribed to the permanent polarization effect during the application of the voltage pulse.
Sidewall passivation layer thickness and composition profiles of etched silicon patterns from angle resolved x-ray photoelectron spectroscopy analysis
Authors: Haass Moritz , Darnon Maxime , Joubert Olivier
Published: June 2012

In this study, we present a technique to analyze side wall passivation layers formed on silicon sidewalls after plasma processing. The thickness and chemical composition are derived from angle resolved x-ray photoelectron spectroscopy analyses. It is a non-destructive, quasi in situ method to determine profiles of the thickness and the chemical composition of passivation layers in trenches up to an aspect ratio of about 3. The performance of this technique to quantify the passivation layer thickness is compared to a standard technique using secondary electron microscopy images with respect to two different samples and is found to be at least equivalent. The possible uncertainties and limitations of this technique are discussed as well.
Tailoring non-linear dielectric properties by local field engineering in anisotropic porous ferroelectric structures
Authors: Padurariu Leontin , Curecheriu Lavinia , Galassi Carmen , Mitoseriu Liliana
Published: June 2012

A method to control the nonlinear dielectric properties in porous anisotropic ceramics is proposed. The local field distributions in anisotropic porous ceramic structures were determined and the field-induced permittivity was estimated in parallel and perpendicular configurations (with respect to the pore orientation vs. the applied field direction). The predicted tunability behavior agrees well with the measured values obtained for Pb(Zr0.52Ti0.48)Nb0.024O3 ceramics with different anisotropic porosity levels. The paper demonstrates the concept of engineered local fields in porous microstructures for tailoring the permittivity and tunability values and the possibility to increase tunability with reducing permittivity for small porosity levels.
History dependence of directly observed magnetocaloric effects in (Mn, Fe)As
Authors: Bratko Milan , Morrison Kelly , de Campos Ariana , Gama Sergio , Cohen Lesley F. , Sandeman Karl G.
Published: June 2012

We use a calorimetric technique operating in sweeping magnetic field to study the thermomagnetic history-dependence of the magnetocaloric effect (MCE) in Mn0.985Fe0.015As. We study the magnetization history for which a “colossal” MCE has been reported when inferred indirectly via a Maxwell relation. We observe no colossal effect in the direct calorimetric measurement. We further examine the impact of mixed-phase state on the MCE and show that the first order contribution scales linearly with the phase fraction. This validates various phase-fraction based methods developed to remove the colossal peak anomaly from Maxwell-based estimates.
Absence of long-range chemical ordering in equimolar FeCoCrNi
Authors: Lucas M. S. , Wilks G. B. , Mauger L. , Muñoz J. A. , Senkov O. N. , Michel E. , Horwath J. , Semiatin S. L. , Stone M. B. , Abernathy D. L. , Karapetrova E.
Published: June 2012

Equimolar FeCoCrNi alloys have been the topic of recent research as “high-entropy alloys,” where the name is derived from the high configurational entropy of mixing for a random solid solution. Despite their name, no systematic study of ordering in this alloy system has been performed to date. Here, we present results from anomalous x-ray scattering and neutron scattering on quenched and annealed samples. An alloy of FeNi3 was prepared in the same manner to act as a control. Evidence of long-range chemical ordering is clearly observed in the annealed FeNi3 sample from both experimental techniques. The FeCoCrNi sample given the same heat treatment lacks long-range chemical order.
An empirical study on seasonal fluctuations in electricity demand in China
Authors: Yu Yihong , Zhang Lei
Published: June 2012

Seasonal fluctuations in electricity demand have resulted in power cuts in peak periods in China. This paper finds that the main component of fluctuations in electricity demand of secondary industry consists of four high energy consumption industries. The fluctuations in electricity demand of steel are relevant to the fluctuations in automobile sales. The energy consumption of tertiary industry is highly consistent with the seasonal fluctuations in residential electricity consumption, which is mainly affected by extreme weather conditions. In view of the transmission mechanism of the seasonal fluctuations in electricity demand from the demand side, to improve energy efficiency, electricity companies can adopt the strategy of price discrimination to smooth the seasonal fluctuations in demand.
Network Capital, Social Networks, and Travel: An Empirical Illustration from Concepción, Chile
Authors: Carrasco Juan Antonio , Cid-Aguayo Beatriz
Published: June 2012

The recent interest in the role of transport in social interactions has been partly motivated by the hope of achieving a better understanding of the role that transport plays in network capital, or the resources that people can gather from their social networks. Despite the relevancy of this question for policy, little empirical work has been done to elucidate this relationship. This paper illustrates a method of data collection and analysis, using the social networks approach to assess the role of transport in social support, both emotional and material. The personal networks of two neighbourhoods in Concepción, Chile, with different income levels, are compared, focusing on the role of car ownership in network capital, and the relevance of the time and space characteristics of social contacts. The results suggest that having a car at home does not lead to homogeneous access to network capital, which depends heavily on the kind of social resource studied and the income context (neighbourhood) in which the individuals are embedded. The findings also underscore the need to treat social capital as a truly multidimensional concept and the usefulness of the personal networks approach for assessing these complex relationships.
Investigating the Effects of Social Influence on the Choice to Telework
Authors: Scott Darren M , Dam Ivy , Páez Antonio , Wilton Robert D
Published: June 2012

This paper contributes to the telework literature by investigating empirically the impact of social influence on the decision to telework. An innovative web-based telework survey was developed and used to obtain data from a sample of employees of a large postsecondary institution in Ontario, Canada, between January and March 2009. A unique feature of the survey instrument is that it allowed employees to easily construct their workplace social networks. Using a univariate (binary) probit model, we identify three mutually exclusive sources of social influence on the decision to telework: friends who telework, neighbors who telework, and colleagues at the workplace. With respect to colleagues, we find that the net impact of social influence is governed by both the composition and the size of an employee's workplace social network. Composition is captured by interacting telework status with relationship strength.
Focusing on Connected Personal Leisure Networks: Selected Results from a Snowball Sample
Authors: Kowald Matthias , Axhausen Kay W
Published: June 2012

Explanations of leisure travel must take the influence of participants' social contacts into account. To analyze this influence, transport planning uses social network analysis methods. While most past projects have focused on isolated network components, this paper presents a study collecting data on connected personal networks by taking a snowball sample. The paper explains difficulties for transport planning in approaching and explaining leisure travel and then introduces both the survey methodology and the instrument in detail. Advantages and disadvantages of snowball sampling are addressed, and the question why this strategy is important for approaching leisure travel, followed by experiences from the field about response rate, the fit between survey and target population, and sources of bias are given. Descriptive analyses highlight the potential of the data to produce new empirical insights.
Pensions or Property?
Authors: Clark Gordon L
Published: June 2012

Saving for retirement is fraught with risk and uncertainty. For those not privileged by participation in a defined benefit pension plan, the issue is made complex by problematic decision rules: the options available are variable in terms of their costs and possible consequences, there is considerable uncertainty surrounding the anticipated outcomes of different options, and it is quite unclear whether conventional savings instruments are better or worse than simply relying upon housing and property. In this paper the problem of saving for the future is conceptualised and interrogated against respondents' views and opinions as reported in the Money section of The Sunday Times. Those interviewed are representative of a distinctive segment of the UK working population and face, more than most, the prospect of being largely responsible for their retirement income. Due regard is paid to the age and reported incomes of respondents in relation to their professed intentions just as consideration is given to their apparent risk predispositions. It is noted that many respondents preferred property over pensions across the four years considered—from the peak of the bubble through to the onset of the age of austerity. An interpretation of this preference is offered, emphasising the control of risk apparent in many people's perceptions of the value of property.
Separating Contextual from Endogenous Effects in Automobile Ownership Models
Authors: Goetzke Frank , Weinberger Rachel
Published: June 2012

Using the 1997/98 New York Metropolitan Transportation Council household survey and United States Census, we estimate an instrumental variable probit model to test the impact of contextual and endogenous social interaction effects on auto ownership and determine that the probability of car ownership is affected by both types of social interaction effects. Previous research focused only either on contextual effects, or, increasingly, on endogenous effects using contextual effects variables as instruments. Therefore we were unable to find studies looking at both social interaction effects simultaneously. Consistent with earlier results, we find that households have a higher probability of possessing a vehicle if they are surrounded by other automobile-owning households (endogenous effect). However, we find that contextual effects are correctly measured only when the endogenous effect is included. In our case, everything else being equal, households in poorer neighborhoods are more likely to own vehicles, and households in neighborhoods with higher proportions of people with graduate degrees are less likely to own vehicles. This suggests that car ownership in New York City is a status symbol for poorer households and that non-car-ownership is a status symbol for people with post baccalaureate education. The results are important in two policy contexts: as auto ownership is a precursor to trip generation and mode choice, auto ownership estimation is important to effective travel forecasting; as vehicle miles traveled (VMT) is tied to auto ownership, VMT reduction strategies, as a way to improve air quality, reduce congestion, and reduce greenhouse gas emissions, may depend on strategies to reduce auto ownership. In either case, correct modeling of auto ownership will lead to more effective policy outcomes.
A Boundary Organization and its Changing Environment: The Netherlands Environmental Assessment Agency, the MNP
Authors: Pesch Udo , Huitema Dave , Hisschemöller Matthijs
Published: June 2012

In this paper we address the way boundary organizations can accommodate tensions in the science – politics interface. Literature on boundary organizations suggests that this type of organization can provide stability in science – politics interaction, but how these organizations function over a longer period of time is not a point of theoretical or empirical attention. We study a boundary organization, the Netherlands Environmental Assessment Agency (MNP), by analyzing the ideas that guided the foundation of the MNP and by analyzing two cases in which the MNP advised Dutch policy makers. In both cases the MNP had to adjust its boundary orientation because of changes in its institutional context. These findings show that the dynamics involved in boundary organizations should be included in academic research. We conclude by discussing two conceptual frameworks that may help to capture these dynamics: the notion of ‘learning organizations’ and a typology of roles of experts in politics.
Growing Grassroots Innovations: Exploring the Role of Community-Based Initiatives in Governing Sustainable Energy Transitions
Authors: Seyfang Gill , Haxeltine Alex
Published: June 2012

The challenges of sustainable development (and climate change and peak oil, in particular) demand system-wide transformations in sociotechnical systems of provision. An academic literature around coevolutionary innovation for sustainability has recently emerged as an attempt to understand the dynamics and directions of such sociotechnical transformations, which are termed ‘sustainability transitions’. This literature has previously focused on market-based technological innovations. Here we apply it to a new context of civil-society-based social innovation and examine the role of community-based initiatives in a transition to a low-carbon sustainable economy in the UK. We present new empirical research from a study of the UK's Transition Towns movement (a ‘grassroots innovation’) and assess its attempts to grow and influence wider societal sociotechnical systems. By applying strategic niche management theory to this civil society context, we deliver theoretically informed practical recommendations for this movement to diffuse beyond its niche: to foster deeper engagement with resourceful regime actors; to manage expectations more realistically by delivering tangible opportunities for action and participation; and to embrace a community-based, action-oriented model of social change (in preference to a cognitive theory of behaviour change). Furthermore, our study indicates areas where theory can be refined to better explain the growth and broader impacts of grassroots innovations—namely, through a fuller appreciation of the importance of internal niche processes, by understanding the important role of identity and group formation, and by resolving how social practices change in grassroots innovations.
Proceeding in Parallel or Drifting Apart? A Systematic Review of Policy Appraisal Research and Practices
Authors: Adelle Camilla , Jordan Andrew , Turnpenny John
Published: June 2012

Policy appraisal has spread rapidly throughout the OECD and beyond, as has the associated academic literature. In this paper we present the findings of a systematic review of this literature. We assess the extent to which developments in academic research and in everyday appraisal practices have informed one other. While there are signs that policy appraisal research is moving away from the ‘technical–rational model’ of appraisal, both research and practice remain heavily informed by it. The review reveals that research and practice are interacting in subtle ways, but these fall well short of what is sought by advocates of more reflexive approaches. We systematically examine the exact pattern of research–practice interaction depicted in the literature and explore how this may change in the future.
Creating ‘a Generation of NIMBYs’? Interpreting the Role of the State in Managing the Politics of Urban Development
Authors: Inch Andy
Published: June 2012

The traditional relationship between politics and policy making has been challenged in recent years, highlighting how policy itself can generate political action. This raises questions about how conflict produced or mediated through the policy process is managed, particularly within what has been described as a ‘postpolitical settlement’ where fundamental politicoideological issues are liable to be ‘displaced’ rather than opened up for debate. I argue that such displacement generates its own distinctive politicomanagerial logic. Drawing on the discourses and practices of planning reform in England, I suggest that ongoing systemic reform might be understood as a product of a politics of displacement that seeks to cover over the causes of the antagonism generated by the logic of urban development. Tracing this logic through the policy process, I further suggest that displacement has a range of underexamined effects on local democracy and the legitimacy of local government.
Ethnic Minority Business Support in the West Midlands: Challenges and Developments
Authors: Ram Monder , Trehan Kiran , Rouse John , Woldesenbet Kassa , Jones Trevor
Published: June 2012

We examine the challenges and developments relating to the support of ethnic minority businesses (EMBs). The challenges pertain to the distinctiveness of business support needs, the ‘mainstreaming’ of EMB support, and the dynamics of delivery. An ‘engaged scholarship’ approach is adopted, on the basis of an examination of business support providers in the West Midlands. We find considerable evidence of ‘policy learning’ in respect of these challenges. Hence, a nuanced approach to EMB support needs is in evidence, and ‘good practice’ principles are adhered to in respect of mainstreaming and EMB engagement. However, the new era of austerity imperils many of these gains.
Bisiminopropadienes R-N=C=C=C=N-R from Pyridopyrimidines
Authors: Andersen Heidi Gade , Kvaskoff David , Wentrup Curt
Published: June 2012

Chlorination of the N,N′-di(2-pyridyl)malonamide 13a affords 2-chloro-8-methyl-4-(2-(4-picolinyl)imino-4H-pyrido[1,2-a]pyrimidine 17a. Flash vacuum thermolysis of 17a causes efficient ring opening to the valence-tautomeric ketenimine 18a/19a, elimination of HCl, and formation of the bis(4-methyl-2-pyridyl)iminopropadiene, R-N=C=C=C=N-R 20a.
The Chemical Problem of Energy Change: Multi-Electron Processes
Authors: Hughes Joseph L. , Krausz Elmars
Published: June 2012

This special issue is focussed on arguably the most important fundamental question in contemporary chemical research: how to efficiently and economically convert abundant and thermodynamically stable molecules, such as H2O, CO2, and N2 into useable fuel and food sources. The 3 billion year evolutionary experiment of nature has provided a blueprint for the answer: multi-electron catalysis. However, unlike one-electron transfer, we have no refined theories for multi-electron processes. This is despite its centrality to much of chemistry, particularly in catalysis and biology. In this article we highlight recent research developments relevant to this theme with emphasis on the key physical concepts and premises: (i) multi-electron processes as stepwise single-electron transfer events; (ii) proton-coupled electron transfer; (iii) stimulated, concerted, and co-operative phenomena; (iv) feedback mechanisms that may enhance electron transfer rates by minimizing activation barriers; and (v) non-linearity and far-from-equilibrium considerations. The aim of our discussion is to provide inspiration for new directions in chemical research, in the context of an urgent contemporary issue.
Molecular Chemistry for Solar Fuels: From Natural to Artificial Photosynthesis
Authors: Magnuson Ann , Styring Stenbjörn
Published: June 2012

The world needs new, environmentally friendly, and renewable fuels to exchange for fossil fuels. The fuel must be made from cheap, abundant, and renewable resources. The research area of solar fuels aims to meet this demand. This paper discusses why we need a solar fuel, and proposes solar energy as the major renewable energy source to feed from. The scientific field concerning artificial photosynthesis is expanding rapidly and most of the different scientific visions for solar fuels are briefly reviewed. Research strategies for the development of artificial photosynthesis to produce solar fuels are overviewed, with some critical concepts discussed in closer detail.
The Synthesis of a Cubane-Substituted Dipeptide
Authors: Churches Quentin I. , Mulder Roger J. , White Jonathan M. , Tsanaktsidis John , Duggan Peter J.
Published: June 2012

Amino acids and peptides bearing cyclic hydrocarbon side-chains are of interest in the development of a wide range of bioactive molecules. The preparation of an amino acid and a dipeptide derivative bearing an unfunctionalised cubane substituent is described. Attempts to prepare a cubylalanine derivative via the corresponding dehydroalanine were unsuccessful due to the high sensitivity of this vinyl cubane compound. Conversely, the addition of cubyllithium to a (RS)-glyoxylate sulfinimine led to an effective synthesis of a cubylglycine derivative and a cubane-substituted dipeptide in diastereomerically pure form.
Genetic diversity among a founder parent and widely grown wheat cultivars derived from the same origin based on morphological traits and microsatellite markers
Authors: Li X. J. , Xu X. , Yang X. M. , Li X. Q. , Liu W. H. , Gao A. N. , Li L. H.
Published: June 2012

Founder parents have contributed significantly to the improvement of wheat. Beijing 8 has been used as a founder parent in developing many outstanding improved cultivars in China. The widely grown cultivars Beijing 8 and 6 additional derivatives both derived from the cross ‘Bima 4 × Early Premium’ in China, were characterised using seven morphological traits and 537 microsatellite markers. Phenotypic comparisons revealed that Beijing 8 was similar for certain characteristics to the widely grown cultivars Shijiazhuang 54 and Jinan 2, hinting that acceptable performance for yield components may be the basis for Beijing 8 serving as a founder parent. Simple sequence repeat analysis indicated that Bima 4 contributed more genome information to the derivatives than Early Premium. Fifty-nine unique simple sequence repeat alleles, present in Beijing 8 and absent in other cultivars, were observed. Nearly all loci were in close proximity to the positions of known genes conferring important traits. Furthermore, pedigree tracking found that the frequencies of alleles unique to Beijing 8 varied from 0 to 0.96 in its 51 descendants, suggesting that some of them underwent rigorous selection during breeding.
Agronomic value and morphophysiological diversity of non-Ladino Italian white clover wild populations compared with variety germplasm
Authors: Annicchiarico P.
Published: June 2012

Non-Ladino Italian white clover wild populations are widespread in hill and mountain areas of the Alps and northern Apennines. The agronomic value of these populations is unknown. This study was based on results of four experiments and had the following objectives: (i) comparing 11 small-leaved or medium-leaved wild populations from these areas with eight medium-leaved or large-leaved varieties of different origin and one wild population from Sardinia, for forage yield in a mown association with cocksfoot, forage yield under sheep grazing, seed yield, forage quality, and 14 vegetative or reproductive traits; (ii) investigating the relationships among traits; (iii) assessing the association of individual trait expression with the environments of origin of the wild populations. Clover competitive ability was greater in large-leaved material, tended to imply higher total yield of the association, and was unrelated to clover yield under grazing. Most wild populations from northern Italy were acyanogenic, several exhibited high yield under grazing and high seed yield, and one medium-leaved wild population outperformed any medium-leaved variety for forage and seed yield traits. Higher altitude of collecting site of these populations was related to lower forage yield and smaller size of some traits. Pasture collecting habitat implied greater adaptation to grazing than woodland, greater competitive ability than wasteland, and several morphophysiological differences relative to populations collected from wasteland or meadow. The Sardinian wild population displayed low seed yield and high cyanogenic potential, whereas the Ladino variety Giga was top-performing for forage yield in association and seed yield. Several vegetative and reproductive traits showed covariation. The generated results can drive the exploitation of non-Ladino genetic resources from northern Italy.
Oil yield components and oil quality of high stearic-high oleic sunflower genotypes as affected by intercepted solar radiation during grain filling
Authors: Martínez Roberto D. , Izquierdo Natalia G. , Belo Raúl González , Aguirrezábal Luis A. N. , Andrade Fernando , Reid Roberto
Published: June 2012

High stearic-high oleic sunflower oil presents high thermal stability. This oil is an alternative to the hydrogenation process which produces trans fatty acids. The effect of intercepted solar radiation (ISR) per plant during grain filling on oil yield components and oil fatty acid composition was investigated in three sunflower high stearic-high oleic genotypes. Three field experiments were conducted and treatments to modify ISR per plant were applied during grain filling: shading, defoliating and thinning plants. Increasing ISR per plant linearly increased grain number per capitulum, weight per grain and in some cases palmitic and stearic acid percentages. In the hybrid, grain oil percentage and oleic acid concentration increased with a decreasing rate, reaching a maximum value at high levels of ISR per plant. Linoleic acid percentage decreased with a decreasing rate, reaching a minimum value at high levels of ISR per plant. Oil yield components presented heterosis. This information contributes to explain the effects of environment on yield and oil quality in high stearic-high oleic genotypes and could be used to design management practices that optimise these traits.
Climatic conditions for seedling recruitment within perennial grass swards in south-eastern Australia
Authors: Thapa R. , Kemp D. R. , Mitchell M. L.
Published: June 2012

Recruitment of new perennial grass plants within existing grassland ecosystems is determined by seed availability, suitable microsites, nutrients and climatic conditions, water and temperatures. This paper reports on the development of criteria to predict recruitment events using modelled soil moisture conditions associated with recruitment of species in five field experiments at Orange (Phalaris aquatica), Trunkey Creek (Austrodanthonia spp.), and Wellington (Bothriochloa macra) in central New South Wales, Australia, and the frequency of those conditions during the past 30 years. Recruitment events were recorded when a rainfall event (median 68 mm across the three sites) kept the surface volumetric soil moisture (0–50 mm) above the permanent wilting point for at least 15 continuous days, allowing for, at most, two ‘dry days’ in between. A key finding from our study is that rainfall events creating favourable soil moisture conditions for seedling emergence typically occurred in the second half of February, sometimes extending to early March. Previously it was thought that recruitment would more likely occur through autumn, winter, and spring when rainfall in southern Australia is more reliable. The 30 years’ data (1975–2004) showed that the P. aquatica site had a median of 20 continuous moist days each year in February–March, whereas, there were 16 and 10 days for the Austrodanthonia and B. macra sites, respectively. The probabilities of exceeding seven or 15 continuous days of moist surface soil were 98% and 78% at the P. aquatica site, 91% and 49% at the Austrodanthonia site, and 73% and 30% at the B. macra site, and indicated that some recruitment is possible in most years. These analyses were extended to several sites across New South Wales, Victoria, and Tasmania to estimate the frequency with which recruitment could occur within natural swards. Across these sites, the probabilities of exceeding seven continuous days of soil moisture were >55% and of exceeding 15 continuous days were lower, which showed that suitable climatic conditions exist during late summer–early autumn across south-eastern Australia for a recruitment event to occur. Future research may show that the criteria developed in this paper could have wider regional application.
A scaling law derived from optimal dendritic wiring
Authors: Cuntz Hermann , Mathy Alexandre , Häusser Michael
Published: June 2012

The wide diversity of dendritic trees is one of the most striking features of neural circuits. Here we develop a general quantitative theory relating the total length of dendritic wiring to the number of branch points and synapses. We show that optimal wiring predicts a 2/3 power law between these measures. We demonstrate that the theory is consistent with data from a wide variety of neurons across many different species and helps define the computational compartments in dendritic trees. Our results imply fundamentally distinct design principles for dendritic arbors compared with vascular, bronchial, and botanical trees.
Expansion, folding, and abnormal lamination of the chick optic tectum after intraventricular injections of FGF2
Authors: McGowan Luke D. , Alaama Roula A. , Freise Amanda C. , Huang Johnny C. , Charvet Christine J. , Striedter Georg F.
Published: June 2012

Comparative research has shown that evolutionary increases in brain region volumes often involve delays in neurogenesis. However, little is known about the influence of such changes on subsequent development. To get at this question, we injected FGF2—which delays cell cycle exit in mammalian neocortex—into the cerebral ventricles of chicks at embryonic day (ED) 4. This manipulation alters the development of the optic tectum dramatically. By ED7, the tectum of FGF2-treated birds is abnormally thin and has a reduced postmitotic layer, consistent with a delay in neurogenesis. FGF2 treatment also increases tectal volume and ventricular surface area, disturbs tectal lamination, and creates small discontinuities in the pia mater overlying the tectum. On ED12, the tectum is still larger in FGF2-treated embryos than in controls. However, lateral portions of the FGF2-treated tectum now exhibit volcano-like laminar disturbances that coincide with holes in the pia, and the caudomedial tectum exhibits prominent folds. To explain these observations, we propose that the tangential expansion of the ventricular surface in FGF2-treated tecta outpaces the expansion of the pial surface, creating abnormal mechanical stresses. Two alternative means of alleviating these stresses are tectal foliation and the formation of pial holes. The latter probably alter signaling gradients required for normal cell migration and may generate abnormal patterns of cerebrospinal fluid flow; both abnormalities would generate disturbances in tectal lamination. Overall, our findings suggest that evolutionary expansion of sheet-like, laminated brain regions requires a concomitant expansion of the pia mater.
Next-generation Digital Earth
Authors: Goodchild Michael F. , Guo Huadong , Annoni Alessandro , Bian Ling , de Bie Kees , Campbell Frederick , Craglia Max , Ehlers Manfred , van Genderen John , Jackson Davina , Lewis Anthony J. , Pesaresi Martino , Remetey-Fülöpp Gábor , Simpson Richard , Skidmore Andrew , Wang Changlin , Woodgate Peter
Published: June 2012

A speech of then-Vice President Al Gore in 1998 created a vision for a Digital Earth, and played a role in stimulating the development of a first generation of virtual globes, typified by Google Earth, that achieved many but not all the elements of this vision. The technical achievements of Google Earth, and the functionality of this first generation of virtual globes, are reviewed against the Gore vision. Meanwhile, developments in technology continue, the era of “big data” has arrived, the general public is more and more engaged with technology through citizen science and crowd-sourcing, and advances have been made in our scientific understanding of the Earth system. However, although Google Earth stimulated progress in communicating the results of science, there continue to be substantial barriers in the public’s access to science. All these factors prompt a reexamination of the initial vision of Digital Earth, and a discussion of the major elements that should be part of a next generation.
Atg16L1 deficiency confers protection from uropathogenic
Escherichia coli
infection in vivo
Authors: Wang Caihong , Mendonsa Graziella R. , Symington Jane W. , Zhang Qunyuan , Cadwell Ken , Virgin Herbert W. , Mysorekar Indira U.
Published: June 2012

Urinary tract infection (UTI), a frequent and important disease in humans, is primarily caused by uropathogenic
Escherichia coli
(UPEC). UPEC forms acute cytoplasmic biofilms within superficial urothelial cells and can persist by establishing membrane-enclosed latent reservoirs to seed recurrent UTI. The host responds with an influx of innate immune cells and shedding of infected epithelial cells. The autophagy gene
ATG16L1
has a commonly occurring mutation that is associated with inflammatory disease and intestinal cell abnormalities in mice and humans. Here, we show that Atg16L1-deficient mice (Atg16L1
HM
) cleared bacteriuria more rapidly and thoroughly than controls and showed rapid epithelial recovery. Atg16L1 deficiency was associated with a potent proinflammatory cytokine response with increased recruitment of monocytes and neutrophils to infected bladders. Chimeric and genetic studies showed that Atg16L1
HM
hematopoietic cells alone could increase clearance and that Atg16L1-deficient innate immune cells were required and sufficient for enhanced bacteriuric clearance. We also show that Atg16L1-deficient mice exhibit cell-autonomous architectural aberrations of superficial urothelial cells, including increases in multivesicular bodies, lysosomes, and expression of the UPEC receptor Up1a. Finally, we show that Atg16L1
HM
epithelial cells contained a significantly reduced number of latent reservoirs. Together, our results show that Atg16L1 deficiency confers protection in vivo to the host against both acute and latent UPEC infection, suggest that deficiency in a key autophagy protein can be protective against infection in an animal model of one of the most common diseases of women worldwide, and may have significant clinical implications for understanding the etiology of recurrent UTIs.
Apoptotic and antitumor activity of death receptor antibodies require inhibitory Fcγ receptor engagement
Authors: Li Fubin , Ravetch Jeffrey V.
Published: June 2012

By virtue of their ability to induce apoptosis and regulate growth, differentiation, and cytokine responses, the tumor necrosis factor receptor (TNFR) superfamily members have emerged as attractive targets for anticancer therapeutics. Agonistic antibodies to apoptosis-inducing TNFRs, such as death receptor 5 (DR5), although displaying impressive activities against a variety of tumors in preclinical models, appear to be less active in clinical trials. We report that the in vivo apoptotic and antitumor activities of these antibodies have an absolute requirement for the coengagement of an inhibitory Fcγ receptor, FcγRIIB. Anti-DR5 antibodies of the type currently in clinical trials have weak FcγRIIB binding and thus are compromised in their proapoptotic and antitumor activities in both colon and breast carcinoma models. Enhancing FcγRIIB engagement increases apoptotic and antitumor potency. Our results demonstrate that Fc domain interactions are critical to the therapeutic activity of anti-DR5 antibodies and, together with previous reports on agonistic anti-CD40 antibodies, establish a common requirement for FcγRIIB coengagement for optimal biological effects of agonistic anti-TNFR antibodies.
Environmental enrichment and practical applications for welfare in production agriculture.
Authors: Dixon L. M.
Published: June 2012

Environmental enrichment refers to stimuli that are added to an animal's environment in an attempt to improve biological functioning and animal welfare by increasing the complexity of the environment and providing opportunities for the animal to perform species-appropriate activities. Enrichments are often provided to help decrease or alleviate performance of abnormal behaviour patterns that are often found in barren and static environments. Enrichments can be divided into four categories: foraging opportunities, structural complexity, sensory stimulation/novelty and social stimulation from conspecifics or humans. However, different species have different behavioural requirements and therefore may benefit from different types of enrichment. To summarize the research that has been conducted on environmental enrichment, tables have been created for some of the more common production species, which give examples of enrichments that can be used and the potential benefits and costs found from implementing them. In general, most species seem to benefit from the provision of a foraging substrate/bedding, places to hide/dividers/platforms and access to conspecifics. However, most enrichment studies are performed on a much smaller scale than normally found in production environments; therefore the full benefits and costs of the enrichment may not yet be known. Practically, enrichments should improve animal welfare and satisfy behavioural needs while being inexpensive, available and easy to maintain for the producer. The development of improved welfare brands that require certain enrichment items should help improve the lives of production animals and help guide producers on the environmental enrichments to provide for their animals.
Olives and olive oil: diet and health impacts.
Authors: Lopez S. , Bermudez B. , Varela L. M. , Ortega A. , Jaramillo S. , Abia R. , Muriana F. J. G.
Published: June 2012

The Mediterranean diet is a compilation of the nutritional and dietary habits of the countries of the Mediterranean Basin. The principal product of the Mediterranean Basin is virgin olive oil, which is obtained from different varieties of olives that confer their individual nutritional and organoleptic properties. Virgin olive oil is rich in monounsaturated fatty acids (MUFAs; mainly oleic acid), but contains other minor compounds (mainly polyphenols), both of which have been demonstrated to have benefits on human health. Epidemiological studies, long- and short-term intervention studies, and postprandial studies have found associations between a virgin-olive-oil-rich diet and decreased cardiovascular risk factors, stroke incidence and type-2 diabetes. Lowered plasma low-density lipoprotein (LDL)-cholesterol levels, haemostatic factors and inflammation markers, as well as improved endothelial function and insulin sensitivity, are common outcomes of such studies. Furthermore, these studies showed additional protection against oxidative stress, LDL oxidation and thrombosis, which were attributed to minor compounds in virgin olive oil.