bluuebunny/crossref_metadata_2025_split huggingface dataset:
Order of arrival structures arbuscular mycorrhizal colonization of plants
Authors: Werner Gijsbert D. A. , Kiers E. Toby 
Published: October 2014

Summary

Priority effects – the impact of a species' arrival on subsequent community development – have been shown to influence species composition in many organisms. Whether priority effects among arbuscular mycorrhizal fungi (AMF) structure fungal root communities is not well understood. Here, we investigated whether priority effects influence the success of two closely related AMF species (Rhizophagus irregularis and Glomus aggregatum), hypothesizing that a resident AMF suppresses invader success, this effect is time‐dependent and a resident will experience reduced growth when invaded.

We performed two glasshouse experiments using modified pots, which permitted direct inoculation of resident and invading AMF on the roots. We quantified intraradical AMF abundances using quantitative PCR and visual colonization percentages.

We found that both fungi suppressed the invading species and that this effect was strongly dependent on the time lag between inoculations. In contrast to our expectations, neither resident AMF was negatively affected by invasion.

We show that order of arrival can influence the abundance of AMF species colonizing a host. These priority effects can have important implications for AMF ecology and the use of fungal inocula in sustainable agriculture.
Synthesis, Structure and Photophysical Properties of Ferrocenyl or Mixed Sandwich Cobaltocenyl Ester Linked meso‐Tetratolylporphyrin Dyads
Authors: Gokulnath Sabapathi , Achary Balahoju Shivaprasad , Kumar Chakka Kiran , Trivedi Rajiv , Sridhar Balasubramanian , Giribabu Lingamallu 
Published: October 2014

AbstractWe report here the design and synthesis of porphyrin–metallocene dyads consisting of a metallocene [either ferrocene or mixed sandwich η5‐[C5H4(COOH)]Co(η4‐C4Ph4) connected via an ester linkage at meso phenyl position of either free‐base or zinc porphyrin. All these dyad systems were characterized by various spectroscopic and electrochemical methods. A dimeric form of this molecule was observed in the X‐ray crystal structure of Zn‐TTPCo. The absorption spectra of all four dyads indicated the absence of electronic interactions between porphyrin macrocycle and metallocene in the ground state. However, interestingly, in all four dyads, fluorescence emission of the porphyrin was quenched (19–55%) as compared to their monomeric units. The quenching was more pronounced in ferrocene derivatives rather than cobaltocenyl derivatives. The emission quenching can be attributed to the excited‐state intramolecular photoinduced electron transfer from metallocene to singlet excited state of porphyrin and the electron‐transfer rates (kET) were established in the range 1.51 × 108 to 1.11 × 109 s−1. They were found to be solvent dependent.
In Situ FTIR Spectroscopy Study of the Photodegradation of Acetaldehyde and azo Dye Photobleaching on Bismuth‐Modified TiO2
Authors: Henych Jiří , Štengl Václav , Mattsson Andreas , Österlund Lars 
Published: October 2014

AbstractThe photocatalytic properties of bismuth‐modified titania were studied by photobleaching of two aqueous azo dyes solutions (Reactive Black 5 and Acid Orange 7), and by photoinduced decomposition (PID) of acetaldehyde using in situ FTIR spectroscopy. Low bismuth doping concentrations up to 3 at.% is shown to lead to an increased photobleaching rate of both azo dyes solutions. Too high Bi dopant concentrations lead to less developed crystallite nanoparticles and exhibit weaker adsorption capacity. Bismuth doping altered the adsorption kinetics of acetaldehyde resulting in different surface products, and a modified photocatalytic reaction pathway was inferred.
Can we use photography to estimate radiation interception by a crop canopy?
Authors: Chakwizira E. , Meenken E.D. , George M.J. , Fletcher A. L. 
Published: October 2014

AbstractAccuracy of determining radiation interception, and hence radiation use efficiency, depends on the method of measuring photosynthetically active radiation intercepted. Methods vary, from expensive instruments such as Sunfleck ceptometers to simple methods such as digital photography. However, before universal use of digital photography there is need to determine its reliability and compare it with conventional, but expensive, methods. In a series of experiments at Lincoln, New Zealand, canopy development for barley, wheat, white clover and four forage brassica species was determined using both digital photographs and Sunfleck ceptometer. Values obtained were used to calculate conversion coefficient (Kf/Ki) ratios between the two methods. Digital photographs were taken at 45° and 90° for barley, wheat and white clover and at only 90° for brassicas. There was an interaction of effects of crop and cultivar for the cereal crops. Barley closed canopies earlier than wheat, and ‘Emir’ barley and ‘Stettler’ wheat had consistently higher canopy cover than ‘Golden Promise’ and ‘HY459′, respectively. Canopy cover was consistently larger at 45° than 90° for cereals. However, for white clover, the angle of digital photography was not important. There was also an interaction between effects of species and method of determining canopy cover for brassicas. Photographs gave higher cover values than ceptometer for forage rape and turnip, but the relationship was variable for forage kale and swede. Kf/Ki ratios of 1.0–1.10 for cereals, white clover and forage rape and turnip show that digital photographs can be used to estimated radiation interception, in place of Sunfleck ceptometer, for these crops.
Does the Network Centrality of Government Actors Matter? Examining the Role of Government Organizations in Aquaculture Partnerships
Authors: Resh William , Siddiki Saba , McConnell Will R. 
Published: October 2014

AbstractThe growth in the use of collaborative governance arrangements has been accompanied by burgeoning scholarship in the field of public affairs that seeks to understand the benefits of engaging diverse stakeholders in common venues. However, few scholars have formally assessed the role of government actors in facilitating outcomes for individual participants in such efforts. Moreover, little work on collaborative governance examines how individual incentives and barriers to collective action are formed within the nested nature of these contexts. We contribute to the study of collaborative governance by formally investigating how the relative centrality of government actors in collaborative policy‐making venues affects individual relationship building and learning for participants therein. We find that government actor centrality is positively associated with relationship building and learning. However, in testing two different conceptualizations of “centrality,” we find that the definition of this construct clearly matters.
The Challenges of Consulting the Public on Science Policy: Examining the Development of European Risk Assessment Policy for Genetically Modified Animals
Authors: Hartley Sarah , Millar Kate M. 
Published: October 2014

AbstractWith the growing importance of public engagement in science policy making and declining levels of public trust in food production, the European Food Safety Authority (EFSA) has attempted to embed “good governance” approaches to strengthen scientific independence and open up risk decision making, which include the use of public consultations. However, “opening up” of risk assessment policies reveals some tensions; namely, balancing the goals of scientific excellence and transparency, protecting science from interests, addressing value judgments, and limited opportunities to debate ethical and social issues. EFSA's development of risk assessment policy for genetically modified animals is used as a case study to analyze these tensions. This analysis suggests that in order to fulfill good governance commitments and maintain trust in risk governance, closer cooperation between EFSA and the European Commission is required to provide “space” for debating the broader risk management issues. This publically accessible space may be needed alongside rather than instead of EFSA's consultation.
Public Support for Climate Change Policy: Consistency in the Influence of Values and Attitudes Over Time and Across Specific Policy Alternatives
Authors: Stoutenborough James W. , Bromley‐Trujillo Rebecca , Vedlitz Arnold 
Published: October 2014

AbstractThis study examines the factors that explain public preferences for a set of climate change policy alternatives. While scholarly work indicates a relationship between attitudes and values on views toward specific issues, the literature often examines general support for issues rather than specific policy proposals. Consequently, it is unclear the extent to which these attitudes and values affect specific policy considerations. This project examines public support for five climate change policy options in two national surveys taken three years apart. The empirical analysis reveals that time is a factor and that those who are liberal, have strong ecological values, report greater concern for climate change, and trust experts are consistently more supportive of the climate policy options considered here. The results shed new light on the nuanced views of the American public toward climate change.
Stratigraphic architecture of a tide‐influenced shelf‐edge delta, Upper Cretaceous Dorotea Formation, Magallanes‐Austral Basin, Patagonia
Authors: Schwartz Theresa M. , Graham Stephan A. 
Published: October 2014

ABSTRACTThe Magallanes‐Austral Basin of Patagonian Chile and Argentina is a retroforeland basin associated with Late Cretaceous–Neogene uplift of the southern Andes. The Upper Cretaceous Dorotea Formation records the final phase of deposition in the Late Cretaceous foredeep, marked by southward progradation of a shelf‐edge delta and slope. In the Ultima Esperanza district of Chile, laterally extensive, depositional dip‐oriented exposures of the Dorotea Formation contain upper slope, delta‐front and delta plain facies. Marginal and shallow marine deposits include abundant indicators of tidal activity including inclined heterolithic stratification, heterolithic to sandy tidal bundles, bidirectional palaeocurrent indicators, flaser/wavy/lenticular bedding, heterolithic tidal flat deposits and a relatively low‐diversity Skolithos ichnofacies assemblage in delta plain facies. This work documents the stratigraphic architecture and evolution of the shelf‐edge delta that was significantly influenced by strong tidal activity. Sediment was delivered to a large slump scar on the shelf‐edge by a basin‐axial fluvial system, where it was significantly reworked and redistributed by tides. A network of tidally modified mouth bars and tidal channels comprised the outermost reaches of the delta complex, which constituted the staging area and initiation point for gravity flows that dominated the slope and deeper basin. The extent of tidal influence on the Dorotea delta also has important implications for Magallanes‐Austral Basin palaeogeography. Prior studies establish axial foreland palaeodrainage, long‐term southward palaeotransport directions and large‐scale topographic confinement within the foredeep throughout Late Cretaceous time. Abundant tidal features in Dorotea Formation strata further suggest that the Magallanes‐Austral Basin was significantly embayed. This ‘Magallanes embayment’ was formed by an impinging fold–thrust belt to the west and a broad forebulge region to the east.
Sex differences in nutritional status of HIV‐exposed children in Rwanda: a longitudinal study
Authors: Condo Jeanine U. , Gage Anastasia , Mock Nancy , Rice Janet , Greiner Ted 
Published: October 2014

AbstractObjectiveTo examine sex differences in nutritional status in relation to feeding practices over time in a cohort of HIV‐exposed children participating in a complementary feeding programme in Rwanda.MethodsWe applied a longitudinal design with three measurements 2–3 months apart among infants participating in a complementary feeding programme who were 6–12 months old at baseline. Using early feeding practices and a composite infant and child feeding index (ICFI) as indicators of dietary patterns, we conducted a multivariate analysis using a cross‐sectional time series to assess sex differences in nutritional status and to determine whether there was a link to discrepancies in dietary patterns.ResultsAmong 222 boys and 258 girls, the mean (±SD) Z‐score of stunting, wasting and underweight was −2.01 (±1.59), −0.15 (±1.46), −1.19 (±1.29) for boys; for girls they were −1.46 (±1.56), 0.22 (±1.29), −0.63 (±1.19); all sex differences in all three indicators were statistically significant (P < 0.001). However, there were only minor differences in early feeding practices and none in the ICFI by sex.ConclusionsHIV‐exposed male children may be at higher risk of malnutrition in low‐resource setting countries than their female counterparts. However, at least in a setting where complementary foods are being provided, explanations may lie outside the sphere of dietary patterns.
Incidence and molecular basis of CD36 deficiency in Shanghai population
Authors: Li Ruishu , Qiao Zhenglei , Ling Bing , Lu Ping , Zhu Ziyan 
Published: October 2014

BackgroundCD36 is a multifunctional membrane receptor and is expressed in several cell lines. Individuals who lack platelet (PLT) CD36 are at risk for immunization against this antigen, leading to several clinical syndromes. This study aimed to investigate the frequency and molecular basis of CD36 deficiency in Shanghai.Study Design and MethodsWhole blood samples were collected from healthy blood donors, and the PLTs and monocytes were analyzed using flow cytometry to determine CD36 deficiency type. After genomic DNA was extracted, Exons 3 to 14 of CD36 gene including a part of relevant flanking introns were amplified. Direct nucleotide sequencing and sequence alignment were performed. The samples that showed mutations were confirmed by clonal sequencing.ResultsOf the 1022 healthy blood donors analyzed, 22 individuals failed to express CD36 on PLTs; two of them expressed no CD36 on their monocytes either. These results demonstrated that the frequencies of Type I (lacking CD36 expression on PLTs and monocytes) and Type II (lacking CD36 expression on PLTs only) CD36 deficiency among the study population were 0.2 and 2.0%, respectively. Nucleotide sequencing analysis revealed nine different mutations including six mutations that were not yet reported. The most frequent mutations among the study population were 329‐330delAC and 1228‐1239delATTGTGCCTATT.ConclusionThe study findings have confirmed the fact that the frequency of CD36 deficiency in the Chinese population is slightly lower than that in other Asian countries. The identification of several new mutation types indicated the polymorphism of CD36 gene in the Shanghai population.
Liberalisation and Protection under Overlapping Free Trade Agreements: Dynamic Interplay between Free Trade Agreements and Investment
Authors: Postigo Antonio 
Published: October 2014

AbstractTwo decades into the most recent wave of regionalism many of its implications remain to be fully understood. A vast literature has explored the impacts of free trade agreements (FTAs) on investment flows, but less attention has been given to how existing patterns of investment alter FTA liberalisation. It is contended here that the dynamic interplay between overlapping FTA areas and the investment sunk in them shapes governments' and firms' positions regarding further FTA liberalisation. During trade negotiations, a country may decide to exclude a sector from FTA liberalisation to prevent (concession prevention) future FTA partners from making similar demands. Concession prevention could also occur when a foreign firm, holding a dominant market position in a host country, relinquishes liberalisation demands in an FTA between host and home countries to prevent its current position being eroded if the host country grants similar (or better) concessions to competing firms from other countries in future FTAs. Conversely, investment sunk into a country's sensitive sector in the territory of partners from previous FTAs could pre‐empt (concession pre‐emption) the protectionist position of that country when it subsequently negotiates FTAs with the investment‐source countries. These arguments were tested in the negotiations around the liberalisation of the automotive industry that Thailand and Malaysia had with Japan in their respective bilateral FTAs. The distinct interaction between investment and the FTAs in which these countries participate resulted either in entrenchment of protectionism in the sector or its liberalisation across subsequent FTAs.
Estimating the residual risk for HIV, HCV and HBV in different types of platelet concentrates in Germany
Authors: an der Heiden M. , Ritter S. , Hamouda O. , Offergeld R. 
Published: October 2014

Background and ObjectivesWe estimated and compared the residual risks due to window‐period donations for pooled and apheresis platelets in Germany using a modification of a previously described statistical model. This model directly utilizes the reported interdonation intervals before a positive donation and reflects in this aspect the look‐back procedures used in haemovigilance.Materials and MethodsData from the German National Blood Donor Surveillance System for the years 2006–2012, including reports about donations from repeat donors with confirmed positive test results for HIV, HCV and HBV, were used to estimate the risk of undetected infectious units for both pooled and apheresis platelets.ResultsDemographics of whole‐blood and apheresis donors differed in age, gender, catchment area and interdonation interval. These differences impact on the prevalence and incidence of transfusion relevant infections and consequently the residual risk. The estimates for the residual risks for pooled and apheresis platelets were comparable. For HIV, there was no significant difference, for HCV apheresis platelets had a lower residual risk, whereas pooled platelets had a lower risk for undetected HBV infections.ConclusionThese findings do not support calls for a shift to an apheresis platelets‐only policy in Germany.
Servers Powered by a 10kW In-Rack Proton Exchange Membrane Fuel Cell System
Authors: Zhao Li , Brouwer Jacob , James Sean , Siegler John , Peterson Eric , Kansal Aman , Liu Jie 
Published: October 2014

To improve the reliability and the energy efficiency of datacenters, as well as to reduce infrastructure costs and environmental impacts, we demonstrated and evaluated the use of a 10 kW Proton Exchange Membrane Fuel Cell (PEMFC) stack and system for powering the servers in a data center.
In this study, we designed, tested and demonstrated a PEMFC system as a Distributed Generation (DG) prime mover that has high reliability and efficiency for both steady state and dynamic operations. The 10kW PEMFC stack and system was designed to power a server rack and eliminate the power distribution system in the datacenter. The steady state electrical properties such as efficiency and polarization curves were evaluated. The ramp rate and dynamic response of the PEMFC system to server and system dynamics was also characterized and can be used to determine energy storage requirements and develop optimal control strategies to enable the dynamic load following capability.
Crack Propagation Resistance in Thickness Direction of Proton Exchange Membrane (PEM)
Authors: Sasaki Yusuke , Kai Yusuke , Omiya Masaki , Uchiyama Tomoaki , Kumei Hideyuki 
Published: October 2014

Mechanical reliabilities of membrane electrode assemblies (MEA) in polymer electrolyte fuel cells (PEFCs) are a major concern to fuel cell vehicles. Especially, MEAs are designed to be thinner for obtaining higher generating performance and reducing cost. Proton exchange membranes (PEM) in MEA are especially important parts. When PEFCs generate power, MEAs are in high temperature and water is generated. Hygro-thermal cyclic conditions induce the mechanical stress in MEA and cracks are formed on catalyst layers. Once cracks form on catalyst layers, cracks may propagate into PEM or on the interface between the catalyst layer and PEM. The failures of PEM induce the leak of fuel gases and result in the shortage of output power. Therefore, in order to ensure the durability of thin MEAs, it is important to know the fracture resistance of PEM.
The deformation of PEM is constrained by coated catalyst layers and crack propagates into thickness direction of PEM under the constrained condition. However, there are no available data for the fracture resistance of cracks propagating into thickness direction in MEA, because of the difficulty of measurements. Therefore, in this paper, we try to measure the fracture resistance of cracks propagating into thickness direction in PEM under several environmental conditions. Elastic-plastic fracture toughness tests for PEM were carried out in temperature and humidity controlled chamber. The results showed that the fracture resistances of crack propagation into thickness direction of PEM were strongly affected by temperature and humidity conditions.
Control Impacts of Cold-Air Bypass on Pressurized Fuel Cell Turbine Hybrids
Authors: Pezzini Paolo , Celestin Sue , Tucker David 
Published: October 2014

A pressure drop analysis for a direct-fired fuel cell turbine hybrid power system was evaluated using a hardware-based simulation of an integrated gasifier/fuel cell/turbine hybrid cycle (IGFC), implemented through the Hybrid Performance (Hyper) project at the National Energy Technology Laboratory, U.S. Department of Energy (NETL). The Hyper facility is designed to explore dynamic operation of hybrid systems and quantitatively characterize such transient behavior. It is possible to model, test and evaluate the effects of different parameters on the design and operation of a gasifier/fuel cell/gas turbine hybrid system and provide means of evaluating risk mitigation strategies.
The cold air bypass in the Hyper facility directs compressor discharge flow to the turbine inlet duct, bypassing the fuel cell and exhaust gas recuperators in the system. This valve reduces turbine inlet temperature while reducing cathode airflow, but significantly improves compressor surge margin. Regardless of the reduced turbine inlet temperature as the valve opens, a peak in turbine efficiency is observed during characterization of the valve at the middle of the operating range. A detailed experimental analysis shows the unusual behavior during steady state and transient operation, which is considered a key point for future control strategies in terms of turbine efficiency optimization and cathode airflow control.
Improved Passive Water Management Design for Use in Unitized Regenerative Fuel Cells
Authors: Lele Sandeep S. , Sizemore Michael A. , Fabris Drazen 
Published: October 2014

Proton Exchange Membrane (PEM) fuel cells require effective water transport away from the cathode to ensure stable operation. Many existing water management strategies involve active methods, reducing system efficiency by introducing parasitic losses. In the present work, we report on the improved design and fabrication of a passive water management scheme involving UV-catalyzed porous polymer wicks. The design features two connected porous domains consisting of a methacrylate-based transport layer and polyvinyl alcohol storage layer.
In our previous prototype, large water transport lengths (∼12 mm) prevented adequate removal of generated water. The capillary pressure drop across the two porous domains was insufficient to drive a flow rate matched to the rate of generation. Thus, the current design produces a shorter transport distance (∼3 mm) by developing a new vertical design. An independently produced SU-8 photolithographic mold is incorporated to improve the fabrication process.